# Scientists on Reddit, explaining things to strangers Researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-07. Interactive version: https://www.autumn.ai/resources/scientists-on-reddit We read through 36,776 posts and comments from 84 scientists' Reddit accounts. Most came for one AMA, answered a few hundred questions and left. Some never left, and still turn up in AskReddit threads explaining radio astronomy to strangers. 230 real Reddit posts and replies from 84 scientists, from Buzz Aldrin to Geoffrey Hinton, quoted exactly and linked. ## What we noticed ### Explaining things to strangers Someone asks a simple question, and one of the people who knows the answer best just answers it. These are the ones we would screenshot. - Max Tegmark (u/MaxTegmark) in r/IAmA: https://www.reddit.com/r/IAmA/comments/6x0s6p/comment/dmc7qoy/ - Craig DeForest (u/Craig_DeForest) in r/science: https://www.reddit.com/r/science/comments/6tlt2e/comment/dlm4pa7/ ### Asked about their own famous work Where dropout, the name of the Web and the Dunning-Kruger label came from, told by the people involved. - Geoffrey Hinton (u/geoffhinton) in r/MachineLearning: https://www.reddit.com/r/MachineLearning/comments/4w6tsv/comment/d6dgyse/ - Tim Berners-Lee (u/timbl) in r/IAmA: https://www.reddit.com/r/IAmA/comments/2091d4/comment/cg0y0bp/ ### Stories from orbit Astronauts get asked the same things in every AMA. Some of the answers are still surprising. - Buzz Aldrin (u/BuzzAldrinHere) in r/IAmA: https://www.reddit.com/r/IAmA/comments/2a5vg8/comment/cirucq5/ - Jeffrey Hoffman (u/jhoffma1) in r/IAmA: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9pkvi/ ### Regular redditors, mostly 30 of the 84 people here posted across five years or more, in AskReddit, r/math and Kerbal Space Program threads like everyone else. - Michael Stevens (u/Michael_Stevens) in r/neutralmilkhotel: https://www.reddit.com/r/neutralmilkhotel/comments/1evko0l/comment/lis2r8j/ - Matt Parker (u/standupmaths) in r/badmathematics: https://www.reddit.com/r/badmathematics/comments/7ukjzy/comment/dtl3b7c/ ## Best moments ### **Geoffrey Hinton** (u/geoffhinton) in r/MachineLearning, Aug 11, 2016 · Behind the scenes Replying to a redditor: > How was '[Dropout](https://en.wikipedia.org/wiki/Convolutional_neural_network#Dropout)' conceived? Was there an 'aha' moment? > There were actually three aha moments. One was in about 2004 when Radford Neal suggested to me that the brain might be big because it was learning a large ensemble of models. I thought this would be a very inefficient use of hardware since the same features would need to be invented separately by different models. Then I realized that the "models" could just be the subset of active neurons. This would allow combinatorially many models and might explain why randomness in spiking was helpful. > > Soon after that I went to my bank. The tellers kept changing and I asked one of them why. He said he didn't know but they got moved around a lot. I figured it must be because it would require cooperation between employees to successfully defraud the bank. This made me realize that randomly removing a different subset of neurons on each example would prevent conspiracies and thus reduce overfitting. > > I tried this out rather sloppily (I didn't have an adviser) in 2004 and it didn't seem to work any better than keeping the squared weights small so I forgot about it. > > Then in 2011, Christos Papadimitriou gave a talk at Toronto in which he said that the whole point of sexual reproduction was to break up complex co-adaptations. He may not have said it quite like that, but that's what I heard. It was clearly the same abstract idea as randomly removing subsets of the neurons. So I went back and tried harder and in collaboration with my grad students we showed that it worked really well. Full thread: https://www.reddit.com/r/MachineLearning/comments/4w6tsv/comment/d6dgyse/ · 81 points as of Nov 7, 2026 ### **Geoffrey Hinton** (u/geoffhinton) in r/MachineLearning, Aug 11, 2016 · Personal story Replying to a redditor: > Oh wow I have an MA in experimental psychology and am super interested in hearing from him about the path he took to get to where he is now. I feel a bit stuck as I try to head into data science as a career. > I did not like experimental psychology. The kinds of theories they were willing to entertain were hopelessly simple. So I became a carpenter for a year. I wasn't very good at that so I did a PhD in AI. Unfortunately, my idea of AI was a great big neural network that learned everything from data. This was not the received wisdom at the time even though, so far as I can tell, it was what Turing believed in. Full thread: https://www.reddit.com/r/MachineLearning/comments/4w6tsv/comment/d6dlbsg/ · 109 points as of Nov 7, 2026 ### **John Mather** (u/johnmather) in r/IAmA, Nov 26, 2012 · Behind the scenes Replying to a redditor: > Of all the different scientific fields, why did you choose physics? Did your Nobel Prize-winning work come about by accident, or did you set out to find exactly what you found? Along those same lines, what was the moment like when you realized, "Wow, I may actually win a Nobel… > 2. The Nobel work came by a roundabout path. My thesis project at Berkeley was chosen because it was exciting and I liked the professors. Then it failed to function and I thought I would give up on the cosmic microwave background radiation. Then, I was a postdoc doing radio astronomy and NASA asked for satellite proposals; that was 1974. i said, my thesis project failed, but it should have been done in outer space. So we wrote a proposal and it was chosen. > > 3. About the Nobel, a lot of people thought the COBE was Nobel-quality work, but I thought, the competition is fierce, and only people like Einstein get on the list. So it was a lovely surprise! (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/13tjrx/comment/c771yyl/ · 104 points as of Nov 7, 2026 ### **Brian Schmidt** (u/Schmidt_and_Francis) in r/askscience, Nov 24, 2015 · Behind the scenes Replying to a redditor: > Hi, Thanks for doing this AMA.. Brain, What led you and your team to discover Dark Energy? And how has that helped understanding what's happening in the universe? > We were trying to measure how the Universe was slowing down (its expansion - where everything in the Universe moves away from everything else) over time - Predicted by General Relativity - instead we found the Universe was speeding up - that is - things were moving apart more and more quickly over time. Einstein, in 1917 realised that if there was energy that was spread through out space - it could cause the Universe to accelerate. It is still our best (and only viable) explanation of the Universe's acceleration. Full thread: https://www.reddit.com/r/askscience/comments/3u3ijv/comment/cxbut5l/ · 13 points as of Nov 7, 2026 ### **Randy Schekman** (u/schekman) in r/IAmA, Dec 12, 2013 · Normal redditor Replying to a redditor: > Are you in VLSB? How much competition will you have for the nearest parking spot? Congrats!!! Go Bears!!!! > No, I am n the Li Ka Shing building. Fortunately, there are usually enough spaces in the garage in which I park that the addition of my NL spot will have little to no effect on the freedom of others to park in this garage. Full thread: https://www.reddit.com/r/IAmA/comments/1sq4vd/comment/ce04zms/ · 48 points as of Nov 7, 2026 ### **Carolyn Bertozzi** (u/Carolyn_Bertozzi) in r/science, Jun 19, 2015 · Behind the scenes Replying to a redditor: > Hi Professor Bertozzi, I am a cardiologist and used to always value practice over academia. However, I recently gained a thirst for something more. I attained an additional degree in healthcare management and co-authored a paper in the NEJM. Do you have any advice for someone… > From a practical perspective, teaching can be a muse for new research ideas. Indeed, we developed a reaction called "copper-free click chemistry" that exploits the ring strain of a cyclooctyne reagent to activate its reaction with azides. That idea came when I was writing my lecture on ring strain for sophomore organic chemistry students. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3ae7uw/comment/csc18mu/ · 21 points as of Nov 7, 2026 ### **Paul Greengard** (u/DrGreengard) in r/IAmA, Mar 16, 2016 · Personal story Replying to a redditor: > Out of curiosity: did you rent or buy your tux for the Nobel ceremony? > The Nobel Foundation requires that one wear tails. Tuxedos are not acceptable. I rented my tails! Full thread: https://www.reddit.com/r/IAmA/comments/4ap29a/comment/d12c9yr/ · 5 points as of Nov 7, 2026 ### **Buzz Aldrin** (u/BuzzAldrinHere) in r/IAmA, Jul 8, 2014 · Personal story Replying to a redditor: > What's the most frightening moment that you have ever experienced in space? > I believe it was after leaving the surface of the moon and completing a successful rendezvous with Mike Collins in the command module, as we approached connecting / docking, the procedures in the checklist said one thing, and I thought maybe doing it a slightly different way, rolling and pitching instead of something else, and I thought that was better on the spur of the moment! It turns out that it was not a good thing to do, because it caused the platform to become locked, and we were not able to use the primary thrusters, the primary guidance, to control the spacecraft, to its final few feet to dock and join the other spacecraft. That was my mistake. I suggested to my commander that we do it differently, and it was his mistake to assume that i knew what I was talking about. So we both made mistakes - brought about by me! We recovered successfully on the "abort guidance" system. > > (I don't admit that to many people) > > (but I'm sure the mission controllers in Houston, while it was happening or certainly afterwards, they certainly knew what had happened, but fortunately they didn't squeal on us) Full thread: https://www.reddit.com/r/IAmA/comments/2a5vg8/comment/cirucq5/ · 1,138 points as of Nov 7, 2026 ### **Buzz Aldrin** (u/BuzzAldrinHere) in r/IAmA, Oct 30, 2014 · Personal story Replying to a redditor: > Hi Buzz. I read that there was no plan B to get you off the moon in case of equipment failure, and you'd be simply left to die. What was your personal plan if this would of happend? > To continue trying to fix the problem until the lack of oxygen caused us go to sleep. Full thread: https://www.reddit.com/r/IAmA/comments/2ks6kj/comment/clo7ym1/ · 3,008 points as of Nov 7, 2026 ### **Buzz Aldrin** (u/BuzzAldrinHere) in r/IAmA, Jul 8, 2014 · Personal story Replying to a redditor: > Col Aldrin, what went through your head when you first looked back and saw the Earth from space? > *"Where are the billions and billions and billions of people, on what I'm looking at? We're the only 3 that are not back there."* > > And we didn't get to celebrate. Because we were out of town. Full thread: https://www.reddit.com/r/IAmA/comments/2a5vg8/comment/cirusn1/ · 2,841 points as of Nov 7, 2026 ### **Scott Kelly** (u/StationCDRKelly) in r/IAmA, Jan 23, 2016 · Personal story Replying to a redditor: > Hi Scott, thanks for doing this AMA. Could you tell us something unusual about being in space that many people don't think about? > The calluses on your feet in space will eventually fall off. So, the bottoms of your feet become very soft like newborn baby feet. But the top of my feet develop rough alligator skin because I use the top of my feet to get around here on space station when using foot rails. Full thread: https://www.reddit.com/r/IAmA/comments/42cllg/comment/cz9bhzt/ · 3,329 points as of Nov 7, 2026 ### **Terry Virts** (u/Astro-Terry) in r/IAmA, Apr 15, 2019 · Normal redditor Replying to a redditor: > What do you think about SpaceX? > I'm a big fan of SpaceX. They sent up two cargo ships of food and clean underwear for me while I was up there, so I'm 100% supportive of commercial space flights! Full thread: https://www.reddit.com/r/IAmA/comments/bdia22/comment/ekydfyo/ · 1,068 points as of Nov 7, 2026 ### **Ron Garan** (u/RonGaran) in r/IAmA, Mar 21, 2012 · Personal story Replying to a redditor: > Huh, I was expecting something more like "I was looking forward to seeing my family again" but yeah, that would logically be going through my mind to. Was it a bumpy ride back? > it was like going over Niagara Falls in a barrel (that's on fire) followed by a high speed crash Full thread: https://www.reddit.com/r/IAmA/comments/r62jp/comment/c437m6o/ · 2,471 points as of Nov 7, 2026 ### **Ed Lu** (u/edluB612) in r/IAmA, Aug 13, 2012 · Personal story Replying to a redditor: > I think we need to hear this full story, please! > We were actually just getting suited up on ISS for a spacesuit test. Yuri and I were in the airlock, and all buttoned up in our EVA suits. Then the cooling failed in my suit. But the suit generates a lot of heat due to the electronics and also the fact that the CO2 removal system uses an exothermic reaction to remove CO2. So within a few minutes the airflow into my suit got really really hot (think of a parking lot in Houston on a summer day but while wearing a snowmobile suit_) Full thread: https://www.reddit.com/r/IAmA/comments/y5vn0/comment/c5snmzf/ · 60 points as of Nov 7, 2026 ### **Mike Massimino** (u/MikeMassimino) in r/IAmA, Oct 4, 2016 · AMA answer Replying to a redditor: > Do you have to pay tax when you are off planet? And do you still get wages every month or is it a bonus when you get home - always wondered how that works > Income taxes yes, sales tax no - there is nothing to buy up there...unless you sop online > They still pay us while in space, but we dont get any overtime or even harzardous duty pay Full thread: https://www.reddit.com/r/IAmA/comments/55ukwc/comment/d8dt4wd/ · 11 points as of Nov 7, 2026 ### **Jeffrey Hoffman** (u/jhoffma1) in r/IAmA, Sep 20, 2017 · Personal story Replying to a redditor: > I imagine that lots of stuff gets loose and travels around the cabin in zero-g, so my question is what's the most surprising thing you found floating in front of your face? > The most surprising thing that anyone found floating in front of his face was, I think, his own hand! When you are weightless, you can lose track of your arms and legs if you are totally relaxed. A sleeping astronaut awoke to see a "mysterious hand" floating in front of his face. It took quite some time for him to realize that it was his own hand! Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9pkvi/ · 6 points as of Nov 7, 2026 ### **Chris Hadfield** (u/ColChrisHadfield) in r/IAmA, Feb 17, 2013 · Personal story Replying to a redditor: > And the most embarrassing? > During my 2nd spaceflight, while doing a live National TV News broadcast, I forgot the name of the Space Shuttle Commander. He always went by his nickname of Rommel, and to come up with Kent Rominger somehow escaped me. Instead, I said Ken Cameron, the CDR of my 1st flight. Oops. Full thread: https://www.reddit.com/r/IAmA/comments/18pik4/comment/c8gu0dj/ · 2,307 points as of Nov 7, 2026 ### **Mae Jemison** (u/Dr_Mae_Jemison) in r/science, Feb 24, 2015 · Personal story Replying to a redditor: > Hi Dr. Jemison! You're an incredible inspiration for women (and me too, as a chemistry student!). You've cited Lt. Uhura as your first inspiration to pursue a career in science and space. Do you have any advice you'd like to pass on for female scientists? > Hello, actually I was interested in science very early on. Lt Uhura was an image of the possible. My best role models were my parents. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/2x0i75/comment/covzx0w/ · 126 points as of Nov 7, 2026 ### **Mike Melvill** (u/Mike_Melvill) in r/science, Sep 21, 2016 · Personal story Replying to a redditor: > Hey Mike, I'm 22 with an aerospace engineering degree and a private pilot's license. I would love to do what you do, but I have no idea how to get there. Any advice? Thanks in advance > Sad to say you just have to be lucky! I happened to buy a set of plans to build a homebuilt plane. The designer happened to be Burt Rutan! I had never heard of Burt. When It was flying My wife and I flew it to Mojave to show it to Burt, he flew it and hired both of us during lunch that day! We both worked for Burt for 29 years! Full thread: https://www.reddit.com/r/science/comments/53sl88/comment/d7wjke6/ · 26 points as of Nov 7, 2026 ### **Anousheh Ansari** (u/Anousheh_Ansari) in r/science, Sep 27, 2016 · Personal story Replying to a redditor: > Would you say that you've always had a passion for space flight? Or was this more of an adventure you were able to fulfill like a check off of a bucket list? What was the training before your flight like and how long before the flight date did you have to train? I desperately… > I wanted to go to space since I was 6 years old. I never knew how because I was living in Iran but I just knew I would find a way. I even prayed for aliens to abduct me :) (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/54pzmg/comment/d84kpy9/ · 13 points as of Nov 7, 2026 ### **Emily Lakdawalla** (u/elakdawalla) in r/space, Nov 18, 2014 · Personal story Replying to a redditor: > In all your time covering space news, what was the most exciting moment for you? And the most stressful? Thank you > Man, that's tough. Landings like Philae's are always really stressful. I remember all of them quite clearly. But then they're followed by the euphoria of seeing that first photo from the surface. I was with the science teams for both Spirit and Opportunity landings -- Opportunity was absolutely tremendous because the first photo showed intact bedrock, and all the geologists around me realized instantly what an awesome mission it was going to be. The Curiosity landing, I honestly didn't believe it was going to work, so when I heard "Tango Delta Nominal!" I jumped out of my chair in the press center, and then I had to sit down because I was hyperventilating :) Landings are thrilling, in both positive and negative ways! Full thread: https://www.reddit.com/r/space/comments/2mofoz/comment/cm63lz9/ · 74 points as of Nov 7, 2026 ### **Alex Filippenko** (u/AlexFilippenko) in r/IAmA, Mar 14, 2013 · Personal story Replying to a redditor: > What made you decide astrophysics as a career? > I've always been fascinated by science. From ages 10 through 17, my main interest > was chemistry, but as a freshman in high school I was given a small telescope. > With it, I "discovered" Saturn -- the third "star" at which I pointed the telescope! > This really jazzed me, and astronomy became a growing interest. In my freshman > year of college, at the University of California at Santa Barbara, I took an introductory > astronomy course from Professor Stanton J. Peale, and it was truly wonderful. I realized > that the physics of the very large is governed by the physics of the very small (atoms > and subatomic particles), so by switching to astrophysics I could "have it all." So I > changed majors with the intention of becoming an astrophysicist, and I've never > regretted the choice. > > One final factor in my decision: As a budding young chemist, I played with explosives > and had a couple of pretty bad accidents. I realized that I don't have the self-discipline > to stay away from dangerous chemicals, so I should switch fields as an act of > self-preservation, if nothing else! Full thread: https://www.reddit.com/r/IAmA/comments/1aaaug/comment/c8vnpku/ · 111 points as of Nov 7, 2026 ### **Janna Levin** (u/Janna_Levin) in r/science, Jan 12, 2018 · Explains things Replying to a redditor: > Science AMAs are posted early to give readers a chance to ask questions and vote on the questions of others before the AMA starts. Guests of r/science have volunteered to answer questions; please treat them with due respect. Comment rules will be strictly enforced, and uncivil… > All black holes, rotating or not, allow you to see behind them because even light travels along the curved spacetime. If you were to shine a flashlight directly “behind” (can’t say which is the front or the back) a black hole, some of the light will fall in, some will spray out and its path will curve around the black hole so that those standing on the other side will see your flashlight. The lesson: Don’t hide behind a black hole. They can still see you. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/7pwibg/comment/dsktlmt/ · 6 points as of Nov 7, 2026 ### **Mike Brown** (u/Dr_Mike_Brown) in r/science, Apr 25, 2015 · Behind the scenes Replying to a redditor: > Dr. Brown, if you weren't a planetary scientist, what do you imagine you'd be doing? Also, can you give us an example of a theory you tested and how you tested it? > When we first discovered the dwarf planet Haumea we knew it was weird. Almost as dense as pure rock, but covered in pure ice, spinning faster than ANY large body in the solar system (~4 hrs!), and shaped like a stepped on American football. Why hypothesized: maybe it used to be bigger, but got smashed by another dwarf planet, knocking most of the ice off, spinning it up, stretching it out. > > Crazy idea, we were told by most of our colleagues. > > We found a pair of moons around Haumea, which looked like they might have been formed in an impact. > > Nuts, they said. > > Finally, we found a cloud of icy bodies associated with Haumea that was the ejecta from the giant impact. > > Of course, said everyone. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/33tlbq/comment/cqofkak/ · 172 points as of Nov 7, 2026 ### **Mike Brown** (u/Dr_Mike_Brown) in r/science, Apr 25, 2015 · Behind the scenes Replying to a redditor: > So, first off I'd like to say I love all the work scientists do progressing humanity and life in general. You guys are awesome. Questions; in the line of work that you are involved in, how many new things are you discovering? Have you put a name yourself on any, and if so, what… > I have had the privilege of naming Eris, Dysnomia, Haumea, Namaka, Hi'iaka, Makemake, Orcus, Vanth, Quaoar, Weywoot, Sedna.... I think that's it. There's also an asteroid named for me: Mikebrown. As I like to say, it's oddly inclined, and not very bright. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/33tlbq/comment/cqogud8/ · 43 points as of Nov 7, 2026 ### **Seth Shostak** (u/sshostak) in r/science, Aug 28, 2014 · Explains things Replying to a redditor: > Considering that human beings have been around for 200,000 years or so and we have been communicating through radio waves for about 100 years, isn't it kind of naive to think that aliens that could have 1 million years on us would still be using radio communication? What else… > I still use the wheel every day. It's old, but it never ceases to be useful. Full thread: https://www.reddit.com/r/science/comments/2eta6t/comment/ck2y279/ · 106 points as of Nov 7, 2026 ### **Yvette Cendes** (u/Andromeda321) in r/AskReddit, Nov 30, 2015 · Explains things Replying to the post "What fact or statistic seems like obvious exaggeration, but isn't?". > Radio astronomer here! You exert more energy when you unfold a single piece of paper than we have collected in *all* the radio waves we have *ever* collected from outer space. (Excerpt.) Full thread: https://www.reddit.com/r/AskReddit/comments/3uudrc/comment/cxhvnfh/ · 5,807 points as of Nov 7, 2026 ### **Craig DeForest** (u/Craig_DeForest) in r/science, Aug 14, 2017 · Explains things Replying to a redditor: > Dr. DeForest, thanks for doing the AMA. We're driving down from NY to South Carolina for a family science road trip, and I was wondering if you had any thoughts on how I can explain the sun's corona to my kids (3 and 7)? > The corona is the largest, brightest object in the sky -- other than the Sun. The problem is that you can never really see it, because the Sun is so bright. An eclipse is a great chance to see it. > > The corona is the Sun's atmosphere. It is very, very hot, and many times larger than the Sun itself. The Sun may *seem* hot, but the surface is only about as hot as the inside of the projector at a movie theater. The corona is about a thousand times hotter than that. Nobody knows why. You can see the corona mostly because it scatters sunlight. Sort of like the air does, so you see blue sky when the Sun is up, but the corona is wrapped around the Sun instead of around the Earth. There isn't much material in the corona. It's many, many times larger than the Sun, which itself is about a million times larger than Earth -- but the whole thing weighs about as much as the water in Lake Michigan. > > Around the corona you'll see planets come out. You will be able to see four planets, all lined up across the sky. That is the shape of our solar system. All the planets orbit the Sun in a flat plane, like the surface of a table. An ant on a picnic table would see all the other ants on the table lining up in a straight line (the horizon). Since the planets are all in a flat plane (the "plane of the ecliptic") and we're standing on one, they all line up in the sky. Full thread: https://www.reddit.com/r/science/comments/6tlt2e/comment/dlm4pa7/ · 6 points as of Nov 7, 2026 ### **Katie Mack** (u/astro_katie) in r/science, Apr 27, 2014 · Personal story Replying to a redditor: > What is the most exciting thing that's happened in your job that you've directly been involved in? > This is a really tough question. As a theorist, I don't often get to see new data come in that I've been involved with, and I haven't yet seen any of my ideas totally confirmed or falsified. There've been a LOT of exciting developments in cosmology in the last few years as new experiments have given us new data about the Universe, but as a theorist I can't say I've been directly involved in any of it. > > I was pretty excited about the [BICEP2](http://www.planetary.org/blogs/guest-blogs/2014/0324-detecting-spacetime-distortions.html) result, though, and although I certainly wasn't involved in it, the result *does* suggest that a dark matter model I wrote some papers about, the [high-scale string theoretic axion](http://adsabs.harvard.edu/abs/2011JCAP...07..021M), probably can't account for dark matter. So that was pretty cool. :-) > > One time, back in the day, when I did experimental work in particle physics, I got to spend a few weeks going around in the [Super Kamiokande neutrino detector](http://www-sk.icrr.u-tokyo.ac.jp/sk/gallery/index-e.html) in a boat, repairing photomultiplier tubes. That was pretty sweet. > > Oh also I once gave a talk that Stephen Hawking attended. Though I'd call that more [terrifying](http://thelaborastory.com/stories/stephen-hawking/) than exciting. Full thread: https://www.reddit.com/r/science/comments/244m55/comment/ch3p053/ · 73 points as of Nov 7, 2026 ### **Neil deGrasse Tyson** (u/neiltyson) in r/IAmA, Nov 13, 2011 · Explains things Replying to a redditor: > Since time slows relative to the speed of light, does this mean that photons are essentially not moving through time at all? > yes. Precisely. Which means ----- are you seated? > > Photons have no ticking time at all, which means, as far as they are concerned, they are absorbed the instant they are emitted, even if the distance traveled is across the universe itself. Full thread: https://www.reddit.com/r/IAmA/comments/mateq/comment/c2zg8gi/ · 3,444 points as of Nov 7, 2026 ### **Brian Cox** (u/ProfessorBrianCox) in r/space, Mar 3, 2022 · Explains things Replying to a redditor: > If you could eat anything forever, what meal would you take on a trip to the inside of a black hole? > It depends on the mass of the black hole. For a small black hole you have less time before you meet the end of time at the singularity and so maybe a quick curry, whereas for a supermassive black hole you'd have plenty of time for a full tasting menu with wine pairing. Full thread: https://www.reddit.com/r/space/comments/t5ur10/comment/hz7h51u/ · 149 points as of Nov 7, 2026 ### **Sean Carroll** (u/seanmcarroll) in r/askscience, May 25, 2016 · AMA answer Replying to a redditor: > Hello Sean. Given your similarity in name to Sean B Carroll, and both of your strong science outreach activities, do you have any fun stories to share about sharing the same name? If you challenged him to a duel to the death, what weapons would you choose? Also, have you ever… > There is photographic evidence that we can exist in the same spatial vicinity without mutual destruction. But he is clearly the evil twin, given the evidence of the beard. (Excerpt.) Full thread: https://www.reddit.com/r/askscience/comments/4kza3d/comment/d3jdf6s/ · 19 points as of Nov 7, 2026 ### **Max Tegmark** (u/MaxTegmark) in r/IAmA, Aug 30, 2017 · Explains things Replying to a redditor: > Why are we living in a three-dimensional universe? Is there something special about having three spatial dimensions? > As described in https://arxiv.org/pdf/gr-qc/9702052.pdf and in my 1st book (http://mathematicaluniverse.org), you can't have stable atoms or solar systems if there are more than 3 spatial dimensions, you don't have gravitational attraction in less than 3, and you can't predict anything if there's more than 1 time dimension, making it pointless to have a brain. So if there's a multiverse where different parts have different dimensionality (as in many models with stringtheory + inflation, say), then you'd probably only have observers in parts with 3 space dimensions and one 1 time dimension - and here we are! :-) Full thread: https://www.reddit.com/r/IAmA/comments/6x0s6p/comment/dmc7qoy/ · 54 points as of Nov 7, 2026 ### **Michio Kaku** (u/michiokakuauthor) in r/IAmA, Feb 21, 2018 · Explains things Replying to a redditor: > Dr. You study string theory. For someone who is scientific illiterate can you explain this study? > Briefly, each sub atomic particle we see (and there are hundreds of them) are nothing but tiny vibrations of a string, a rubble band. > So each particle is just a musical note. That explains why we have so many particles. Then physics is the laws of harmony of these strings. Chemistry is the melodies we can play on > these strings. The universe is a symphony of strings. > And the Mind of God, that Einstein searched for for the last 30 years of his life, is Cosmic Music resonating through 11 dimensional hyperspace. Full thread: https://www.reddit.com/r/IAmA/comments/7z9531/comment/dumbl04/ · 615 points as of Nov 7, 2026 ### **Brian Greene** (u/briangreeneauthor) in r/IAmA, Feb 24, 2020 · Explains things Replying to a redditor: > What do you think are the biggest questions about the universe right now? Are there any limitations to what humans are capable of knowing? > From my perspective, the biggest questions are (a) the nature of spacetime and (b) the nature of consciousness. Regarding limits to human knowledge--there could well be things we are unable to understand. Take dogs. They're smart creatures but they seemingly don't know much about quantum mechanics. They, seemingly, don't have the brain power. Perhaps, then, we humans too don't have the brain power to grasp certain deep truths about reality. Full thread: https://www.reddit.com/r/IAmA/comments/f8vvdo/comment/finv6my/ · 462 points as of Nov 7, 2026 ### **Stephen Hawking** (u/Prof-Stephen-Hawking) in r/science, Oct 8, 2015 · Explains things Replying to the post "Science AMA Series: Stephen Hawking AMA Answers!". > You’re right: media often misrepresent what is actually said. The real risk with AI isn’t malice but competence. A superintelligent AI will be extremely good at accomplishing its goals, and if those goals aren’t aligned with ours, we’re in trouble. You’re probably not an evil ant-hater who steps on ants out of malice, but if you’re in charge of a hydroelectric green energy project and there’s an anthill in the region to be flooded, too bad for the ants. Let’s not place humanity in the position of those ants. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3nyn5i/comment/cvsdlnr/ · 3,881 points as of Nov 7, 2026 ### **Anthony Aguirre** (u/Anthony_Aguirre) in r/science, Mar 11, 2016 · Explains things Replying to a redditor: > reddit had a recent thread regarding the Universe not having a center - I've been racking my brain for two days about it and it still doesn't make sense. Maybe you could help with another or more detailed explanation? The explanation came out on top in our thread was that the… > The balloon metaphor is good but suffers from the flaw that people always ask about the inside and outside of the balloon, when you're supposed to imagine being a flatlander stuck on its surface. > > Here's another way to think about a related version of a center-less universe. Consider the ancient game Asteroids, or anything more modern where the screen wraps around in both horizontal and vertical directions. That is, as you pass off the right edge of the screen you reappear on the left. Now imagine that screen filled with little tiny galaxies placed randomly. Where is the *center* of the distribution of galaxies? You might say the center of the screen, but in terms of what each galaxy 'sees' nearby, there is no difference between the center and any other place -- the galaxies don't see the edge of the screen, since photons just go from one 'edge' to another. In other words if you translate the entire thing to the right (or left or top or bottom) you don't change anything. > > Now imagine a 3-dimensional space that wraps around in just the same way -- maybe in minecraft-world instead of asteroids. > > This is a model of a flat universe with a toroidal topology. A finite closed universe is technically different, but this might help conceptualize things a bit better. Full thread: https://www.reddit.com/r/science/comments/49yiy8/comment/d0w9gnz/ · 32 points as of Nov 7, 2026 ### **Stephen Wolfram** (u/StephenWolfram-Real) in r/IAmA, Mar 5, 2012 · Personal story Replying to a redditor: > What is the most interesting use of Mathematica and/or Wolfram Alpha you've ever seen? > There are so many; very hard to pick just one. > > An old one for Mathematica: Mike Foale was using it on the Mir space station; there was an accident; the computer it was on got sucked into space; Mike had a backup disk, but needed a password for a different computer; all-time favorite call to customer service ... and finally an in-action solving of equations of motion for a spinning space station. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/qisot/comment/c3xyqf7/ · 1,054 points as of Nov 7, 2026 ### **Stephen Wolfram** (u/StephenWolfram-Real) in r/IAmA, Feb 23, 2016 · Personal story Replying to a redditor: > Hi, Thanks for taking time to do this AMA. I have a few questions: 1) What was it like working with Richard Feynman? 2) How did you manage to start legitimate research on quantum field theory when you were only 15? 3) What are your plans and goals for the future? > Richard Feynman and I had rather different styles of solving problems ... so there was often a certain amount of "I don't understand what you're talking about" on both sides. We worked on quantum computing back around 1982 or so. He did hand calculation which I could never believe got the right answer, and I did computer calculations which he could never believe got the right answer... (In retrospect, I think we actually both got the right answers.) (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/478njk/comment/d0b42om/ · 178 points as of Nov 7, 2026 ### **Robert Sapolsky** (u/RobertSapolsky) in r/IAmA, Nov 10, 2023 · Personal story Replying to a redditor: > What was the most powerful personal moment you can recall during your in depth studies of primates? > There was this young adult male who I really liked in one of my troops (name was Benjamin). He was a little on the dozy side, and one day I was doing a lengthy observational sample on him and it consisted entirely of him sitting underneath a bush and falling asleep. End of the riveting sample was right around when he woke up, and we both discovered that the entire troop had moved on to someplace else during the stretch, and neither of us had a clue where the troop was. He ran around being agitated, I got on top of my jeep to try to get a view of things, finally spotted them, and I started driving in that direction -- and I paused and looked back at him, and we had this second of shared eye contact where I felt absolutely certain that he knew I had found the troop, and there was something almost resembling relief on his baboon face. I drove slowly, he trotted along beside me, we found the rest of the troop. Of course, the rest of the time, he'd look at me as if I was a tree, but for that moment at least we were just two primates being clueless together. Full thread: https://www.reddit.com/r/IAmA/comments/17rms04/comment/k8li58j/ · 212 points as of Nov 7, 2026 ### **Robert Sapolsky** (u/RobertSapolsky) in r/IAmA, Nov 10, 2023 · Personal story Replying to a redditor: > Hey Dr. Sapolsky, What's the most unusual conclusion that came up from one of your researches? And how did you interpret it? > Well, there was one that struck me as hugely unusual coming out of my baboon research (which is to say that it sure struck me as unexpected, but all sorts of sensible people would not have been at all surprised). When I started my research, I was out there thinking I was proving that if you want to be a healthy baboon, protected from stress-related disease, try to be high-ranking. This wouldn't be surprising, given that high rank gives you all sorts of psychological privileges that protect against stress. And it took me merely twenty years to start to figure out that if you get a choice in the matter, don't go for being a high-ranking baboon -- go for being a socially affiliated one. In retrospect, that long delayed insight may have something to do with the fact that I was all impressed with social dominance when starting out as a puerile twenty-year old, and it took some time for the world, even including baboon social behavior, to look different to me. Full thread: https://www.reddit.com/r/IAmA/comments/17rms04/comment/k8llzhj/ · 68 points as of Nov 7, 2026 ### **George Church** (u/George-Church) in r/science, Apr 19, 2016 · Explains things Replying to a redditor: > Hi Dr. Church! My question is about using DNA as an archival medium. What is the long-term fidelity of storage like? Will information be lost due to mutation or just chemical degradation over time? > The record for DNA persistence is 700,000 years (stored under less than ideal circumstances in a yukon horse). Stored in a dry, anoxic state this could be longer. As with other archival systems, redundancy is key. No energy is required during storage, the physical format doesn't change, and the size/density is a million times better than other current methods. Although the cost of copying is low (70 billion copies of a book was nothing), the cost of the original copy still needs to come down. Full thread: https://www.reddit.com/r/science/comments/4fbcyv/comment/d28p8vp/ · 2 points as of Nov 7, 2026 ### **Eric Lander** (u/Eric_Lander) in r/IAmA, Feb 21, 2013 · Explains things Replying to a redditor: > Would you rather map the genome of 1 horse sized duck or 100 duck sized horses? > No contest: I'd rather map the genome of 100 duck-sized horses than 1 horse-sized duck! With 100, you get information about the population genetics. So you can learn cool things about why some of the duck-sized horses can fly better and others can run better. Can anyone online get us the DNA for this project? Full thread: https://www.reddit.com/r/IAmA/comments/18ymad/comment/c8j5kms/ · 1,856 points as of Nov 7, 2026 ### **Brian Fisher** (u/Brian_Fisher) in r/science, Aug 21, 2015 · Explains things Replying to a redditor: > Why'd they call the ants in Ant-Man male pronouns. Aren't most ants female? > You are right, the Ant-Man film got it wrong. The ants in the film are all female and thus Anthony should have been Antoinette. They got so many aspects of ant society right, it is amazing they missed this obvious point - There is an important movement in Science to promote and encourage women in science, but seeing this obvious blind spot in this film makes me wonder if there is equal need for a Women in Film movement. Full thread: https://www.reddit.com/r/science/comments/3hu8oe/comment/cuayo72/ · 9 points as of Nov 7, 2026 ### **Carl Safina** (u/Carl_Safina) in r/science, Aug 29, 2016 · Personal story Replying to a redditor: > I've been very curious about Orcas recently, could you elaborate on their cognitive abilities? Particularly their emotional attachment and self-awareness? > During the era of captures in the Northwest, when they'd learned that the helicopters would bring the catch boats, one family split with the mothers and little babies going one way and staying underwater a long time and the others staying on the surface to decoy the helicopter. Astonishing but that's them. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/504pou/comment/d71hwkl/ · 21 points as of Nov 7, 2026 ### **Temple Grandin** (u/Prof_Temple_Grandin) in r/science, Nov 17, 2014 · Personal story Replying to a redditor: > I want to ask you the same thing I ask every scientist: what's an interesting time you were completely wrong? > A project I managed in 1980 is an example of something I did completely wrong. I installed a ramp with a conveyor floor to get pigs from stockyards to the third floor of a packing plant, because the pigs were not structurally sound enough to easily walk up the existing ramp on their own. I thought that installing a conveyor ramp would solve the problem. It was a failure. I learned not all problems can be fixed with engineering. For a fraction of the cost, we could have given the farm new breeding boars that could produce offspring that were structurally sound and would have been able to walk up the ramp. I learned that in solving problems, we must fix the root cause of the problem, and not just its symptoms. Full thread: https://www.reddit.com/r/science/comments/2mk0qz/comment/cm55bcf/ · 1,443 points as of Nov 7, 2026 ### **Jerry Coyne** (u/Jerry_Coyne) in r/science, May 22, 2015 · Explains things Replying to a redditor: > Hi Dr. Coyne, What is one of the most amazing thing you know as a evolutionary biologist that normal people might not? > When I look at a squirrel, for instance, I see it through the eyes of natural selection, and to me that makes the experience immensely richer. Think of all that morphology and behavior that has evolved: the teeth, the fur, the tendency to run around the other side of the tree when they see you, their remarkable agility. And all the fantastic metabolism and biochemistry going on inside! All that results from replicating molecules sorting themselves out, with the better-replicating ones being the ones that survive. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/36v7vp/comment/crhohez/ · 96 points as of Nov 7, 2026 ### **Heather Hendrickson** (u/Heather_Hendrickson) in r/science, Nov 7, 2016 · Explains things Replying to a redditor: > Furthermore, what are some of the options that are not currently being explored that may prove to hold some interesting results in the near future? > One of the ideas that I really like in this arena is actually an old one that has been in use in Russia and Georgia for decades. They still use viruses. These are called bacteriophages, the viruses that specifically attack particular bacterial strains. Bacteriophages are highly targeted in the bacteria that they destroy so I like to compare them to ninjas or trained assassins. Once in a complex system like a microbiome (the trillions of bacteria that live inside us and support our health) a bacteriophage army would only destroy that bacteria that are making us ill. This is very different from broad spectrum antibiotics that can be more like a nuclear bomb going off in our internal ecosystem: many casualties! Full thread: https://www.reddit.com/r/science/comments/5blwfu/comment/d9q34pa/ · 5 points as of Nov 7, 2026 ### **Cassandra Quave** (u/Cassandra_Quave) in r/science, May 5, 2017 · Explains things Replying to a redditor: > I just read about you for my botany class at Penn State University! What is the most interesting plant you've come across? Why do you find it so interesting? > Hmmm... this is a tough one. There are so many interesting plants that I've worked with over the years. I'm most interested in understanding human uses of wild plants. One really neat one that has multiple uses is Arundo donax - or the giant reed - in Poaceae (grass) family. In southern Italy, this plant is used as a tool (as a fork and wine barrel tap), in construction (to build grain bins, fencing for gardens, vineyard support), as a bartering stick (items that are traded are tracked by carved notches on the reed), as bedding (the leaves once were used to stuff mattresses), and as a medicine (the white internode membranes are used to stuff bleeding lacerations as a hemostatic). So many amazing uses from what some would just see as a weedy grass! Full thread: https://www.reddit.com/r/science/comments/69e7ni/comment/dh686s7/ · 14 points as of Nov 7, 2026 ### **David Eagleman** (u/Dr_David_Eagleman) in r/IAmA, Aug 26, 2020 · Explains things Replying to a redditor: > What are some myths about the brain you are tired of debunking? > One of the stickiest myths is that we use only 3% (or 5%, or 10%) of our brains. In fact, we use all of the brain, all of the time (even when we're asleep). I suspect the myth sticks around because of its inherent hopefulness: it makes us feel as though we could be a lot smarter if we just could just unlock some secret. :-) Full thread: https://www.reddit.com/r/IAmA/comments/ih4x52/comment/g2xvaap/ · 4 points as of Nov 7, 2026 ### **Julia Shaw** (u/Dr_Julia_Shaw) in r/askscience, Feb 10, 2016 · Explains things Replying to a redditor: > What is an area outside your direct expertise where you secretly suspect people routinely form false memories? > Everything! The question isn't whether our memories are false, it's how false are our memories. COMPLEX and full false memories (of entire events) are probably less common than PARTIAL false memories (where we misremember parts of events that happened), but we already naturally fill in so many gaps between pieces of memories and make so many assumptions, that our personal past is essentially just a piece of fiction. Full thread: https://www.reddit.com/r/askscience/comments/452fm7/comment/czuy9rh/ · 139 points as of Nov 7, 2026 ### **David Dunning** (u/Dr_David_Dunning) in r/science, Nov 13, 2014 · Behind the scenes Replying to a redditor: > Hey David, I'm a professional video game player in a game called Dota 2 and I am trying to start teaching people about the game. To give a little bit of background about the game if you've never heard of it, Dota 2 is a 5v5 game where mistakes from your team mates--as well as… > Oh, and how did I get top billing in the naming of the effect? Dunno. It does show that Justin Kruger and I did not provide the name. We don’t know how it happened, we just know that our good family names will be associated with ignorance, incompetence, foolishness, and the like far after we leave this mortal coil. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/2m6d68/comment/cm1jvp9/ · 1,053 points as of Nov 7, 2026 ### **David Dunning** (u/Dr_David_Dunning) in r/science, Nov 13, 2014 · Explains things Replying to a redditor: > What are some of the misconceptions of the Dunning-Kruger effect? > But the other big misconception is that the DKE is a story about other people: that other people suffer from it but not I. I believe this has caused the idea to become a second Godwin's Law, an epithet to throw at another person who doesn't agree with your point of view. People using the effect in this way are, ironically, not getting it. The DKE isn't about them, it is about us. We are the ones suffering from it, and should perhaps be the object of our doubt. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/2m6d68/comment/cm1obtd/ · 27 points as of Nov 7, 2026 ### **Chris French** (u/Prof_Chris_French) in r/science, Jun 29, 2015 · Personal story In the thread "Science AMA Series: I'm Professor Chris French, Director of the Anomalistic Psychology Research Unit at Goldsmiths, University of London. I research paranormal belief and paranormal experiences including hauntings, belief in conspiracy theories, false memories, demonic possession and UFOs. AMA!". > I've spent more nights in supposedly haunted houses than I care to remember. As a kid, I was terrified of the dark. These days, I find sitting in the dark in "haunted houses" about as exciting as watching paint dry. If I'm doing it for a TV show, I sometimes find myself thinking, "Why am I doing this? I used to have a proper job." Then I remember - they pay me! ;-) > > Nothing has ever happened during these programmes that scared me one little bit - and I am not a brave man! (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3bi3d7/comment/csmjeu5/ · 239 points as of Nov 7, 2026 ### **Jane Goodall** (u/janegoodall_official) in r/IAmA, Sep 13, 2017 · Normal redditor Replying to a redditor: > Hi Dr. Goodall, My four year old loves reading. She asks what is your favorite book? > When I was growing up, what I read where the Doctor Dolittle books. I learned a great deal from those books. When I was ten years old I read "Tarzan." I was sad when he married the wrong Jane. It was those books that directed me to grow up, go to Africa. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/6zvwqe/comment/dmyht0b/ · 802 points as of Nov 7, 2026 ### **Ed Boyden** (u/Ed_Boyden) in r/askscience, Mar 15, 2016 · Behind the scenes Replying to a redditor: > What are the advantages of your "Expansion Microscopy" technique over more conventional super-resolution imaging techniques? I assume it requires more up-front preparation of the specimen but results in much faster image acquisition? Can an optical clearing strategy such as… > Expansion microscopy (http://expansionmicroscopy.org/) physically makes biological specimens bigger. It does require up front preparation, to form the polymers and make the specimens swell. But then, you can image on inexpensive, conventional microscopy hardware. So the latter parts of the imaging are fast. Indeed, you could imagine that someday expanding a specimen and then taking pictures on cheap optics (e.g., like the kind on cell phones) might be possible. As for clearing: one nice side effect of expansion microscopy is that the tissue becomes quite clear, because we are moving the molecules away from each other and that reduces their scattering of light. (Excerpt.) Full thread: https://www.reddit.com/r/askscience/comments/4ak060/comment/d111df1/ · 10 points as of Nov 7, 2026 ### **Francis Collins** (u/NIHDirector) in r/science, Apr 20, 2018 · Behind the scenes Replying to a redditor: > In hindsight, do people associated with program have any regret about the coining of the term "junk DNA" to describe regions that weren't immediately related to protein coding genes? > Yes! That was an unfortunate term, and I hope I was not one of the ones who used it . . . at least not very often. We are learning more every day about the 98 percent of the genome that does not code for protein but determines how genes turn on and off in specific tissues during development and after environmental exposures. That’s incredibly important information. It certainly is not junk. Full thread: https://www.reddit.com/r/science/comments/8dn0jo/comment/dxp2bwa/ · 24 points as of Nov 7, 2026 ### **Adrian Owen** (u/ProfAdrianOwen) in r/science, May 2, 2014 · Behind the scenes Replying to a redditor: > Is the communication limited to simple yes/no responses or can you get more specific with it? That is mind-blowing. > It is not limited to yes/no responses at all. In principle, we can associate the mental imagery tasks with anything (e.g." Playing tennis if you want me to stop asking you questions"). But using a hierarchical series of Yes/No questions we are able to discern a lot of information about the patient relatively efficiently e.g "are you in pain? Is the pain in your body? Is the pain in the lower half of your body? etc" Full thread: https://www.reddit.com/r/science/comments/24jcz5/comment/ch7w4id/ · 7 points as of Nov 7, 2026 ### **Eric Green** (u/Eric_Green) in r/science, Apr 21, 2016 · Personal story Replying to a redditor: > What are the biggest challenges you have faced on your line of work, and how did you overcome them? > The word ‘genomics’ was not coined until around 1987-- and the field of genomics did not exist until then. Meanwhile, I graduated medical school and graduate school in 1987, which means that I never once heard the word ‘genomics’ at any time during my formal education. Yet here I am leading the largest organization in the world dedicated to genomics research! This means that I had to learn everything I know today about genomics AFTER all my formal education was over. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/4fskty/comment/d2bxnnw/ · 14 points as of Nov 7, 2026 ### **Matt Parker** (u/standupmaths) in r/badmathematics, Feb 1, 2018 · Normal redditor Replying to the post "Do you have any mathematical beliefs that border on being crank-y?". > My crank belief would be that 2 and 3 are not prime. They’re too small to really have factors and so only meet the criteria for prime-ness by default. 5 is the smallest prime which is bigger than a composite number, so it has earned being prime. > > This would solve all the prime proofs that need to exclude p=2 and/or p=3. > > Crank version of me would reclassify 2 and 3 as being sub-prime numbers. Full thread: https://www.reddit.com/r/badmathematics/comments/7ukjzy/comment/dtl3b7c/ · 109 points as of Nov 7, 2026 ### **James Grime** (u/JamesGrime) in r/IAmA, Oct 28, 2014 · Personal story Replying to a redditor: > Why are you a mathematician? I'm always interested in how people became one or another thing in life :) > The real answer to that is because I am lazy. And maths is the perfect subject for the lazy student. If you go to lectures you can do the coursework, if you can do the coursework you can do the exam. There are no books to read and no essays to write. Perfect! And for me it was all games and puzzles, and that's not a bad life. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/2klw5q/comment/clml4ug/ · 101 points as of Nov 7, 2026 ### **Hannah Fry** (u/HannahFry) in r/science, Mar 10, 2015 · Explains things Replying to a redditor: > One of the fascinating bits in your talk was that strong couples are those that express their petty irritations early, rather than "getting over it" and letting these irritants build up. You said that these early complainers are essentially in continuous improvement mode, always… > One thing I really like from Gottman's study is the distinction between the language used by couples who are in a 'good' or 'bad' relationship. > > Couples who are doing well have a deep-seated positive view of each other & dismiss bad behaviour as being out of the ordinary. So "She's just tired" or "He's having a stressful time at work" etc. > > But couples whose relationships are having difficulties are the opposite. Instead, they view their partner in a negative way & use anything bad as evidence to confirm their opinion: "You're always like this! You never bother about anyone else!" (Always and Never are key words here of course). (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/2yjntv/comment/cpad0uf/ · 26 points as of Nov 7, 2026 ### **Jordan Ellenberg** (u/Jordan-Ellenberg) in r/science, Mar 2, 2018 · Explains things Replying to a redditor: > How do you improve your math skills where subjects such as calc becomes easy to understand. Im just tired of everyone around me telling me how easy derivatives are and how stupid i look when i tell them its hard for ms > Math isn't easy to understand. It's hard to understand. There's a reason it took thousands of years of mathematical progress to get to calculus! > > The worst thing a teacher can say is "This is simple." It isn't simple! But it's *doable*, with work. > > The problem isn't you, it's the people around you. Full thread: https://www.reddit.com/r/science/comments/81dvbs/comment/dv2z7en/ · 8 points as of Nov 7, 2026 ### **Edward Frenkel** (u/EdwardFrenkel) in r/IAmA, Jul 16, 2015 · Explains things Replying to a redditor: > My whole life I have heard that math is an inter-national/galactic language. So much so that there is some sort of mathematical message on our space probe. In laymen's terms - can you provide me with an example of this? The math 'problem' and the answer and how it translates?… > If Leo Tolstoy had not lived, we would have never known "Anna Karenina". There is no reason to believe that another author would have written that same novel. But if Pythagoras had not lived, someone else would have discovered exactly the same Pythagoras theorem (in fact, it was discovered before he did it :) Moreover, this theorem means the same to us today as it meant to Pythagoras 2,500 years ago, and it will mean the same to anyone anywhere in the world a thousand years from now. If you think about, you see that there is something "strange" about mathematical knowledge. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/3diour/comment/ct5qgq1/ · 4 points as of Nov 7, 2026 ### **Yann LeCun** (u/ylecun) in r/MachineLearning, May 16, 2014 · Normal redditor Replying to a redditor: > Do you have a favorite sandwich? > I don't often eat sandwiches, but when I do, I make what my family calls "awesome sandwiches". They are a kind of spicy Reuben: pastrami with a mixture of Dijon mustard, Russian dressing and curry powder. I also like panini. Also, savory buckwheat crêpes, Breton style (not technically sandwiches, but best thing ever). > > This was our culinary interlude. Full thread: https://www.reddit.com/r/MachineLearning/comments/25lnbt/comment/chj9aib/ · 13 points as of Nov 7, 2026 ### **Yoshua Bengio** (u/yoshua_bengio) in r/MachineLearning, Feb 26, 2014 · Behind the scenes Replying to a redditor: > We have seen deep learning work really well for image/video/sound. Do you foresee it working for text classification as well? Most papers that have tried text/document classification using deep learning have not done better than the conventional SVM/Bayes. What are your thoughts… > I predict that deep learning will have a big impact in natural language processing. It has already had an impact, in part due to an old idea of mine (from NIPS'2000 and a 2003 paper in JMLR): represent words by a learned vector of attributes, learned so as to model the probability distribution of sequences of words in natural language text. The current challenge is to learn distributed representations for sequences of words, phrases and sentences. Look at the work of Richard Socher, which is pretty impressive. Look at the work of Tomas Mikolov, who beat the state of the art in language models using recurrent networks and who found that these distributed representations magically capture some form of analogical relationships between words. For example, if you take the representation for Italy minus the representation for Rome, plus the representation for Paris, you get something close to the representation for France: Italy - Rome + Paris = France. Similarly, you get that King - Man + Woman = Queen, and so on. Since the model was not trained explicitly to do these things, this is really amazing. Full thread: https://www.reddit.com/r/MachineLearning/comments/1ysry1/comment/cfpje92/ · 10 points as of Nov 7, 2026 ### **Andrew Ng** (u/andrewyng) in r/MachineLearning, Apr 14, 2015 · Behind the scenes Replying to a redditor: > Jürgen Schmidhuber QUOTE: *"Since BP was 3-5 decades old by then, and pattern deformations 2 decades, these results seemed to suggest that advances in exploiting modern computing hardware were more important than advances in algorithms."* [1] Yann LeCun QUOTE: *"Basically we… > For example, in 2008, we built I think the first CUDA/GPU deep learning implementation, and helped lead the field to use GPUs. In 2011, I (Andrew) founded and led the Google Deep Learning team (then called Google Brain) to use Google's cloud to scale up deep learning; and this helped put it on industry's radar. In 2013, Adam, Bryan Catanzaro and others built the first HPC-style deep learning system, and this helped drive scaling another 1-2 orders of magnitude. (Excerpt.) Full thread: https://www.reddit.com/r/MachineLearning/comments/32ihpe/comment/cqc4vfm/ · 10 points as of Nov 7, 2026 ### **Jürgen Schmidhuber** (u/JuergenSchmidhuber) in r/MachineLearning, Mar 4, 2015 · Personal story Replying to a redditor: > Kennen sie (was halten sie von) Herrn Prof Weizenbaum? https://en.wikipedia.org/wiki/Joseph_Weizenbaum > IMO, Joseph Weizenbaum was by far the coolest of the invited speakers. > The rest of us pulled out their slides and tried to make their point. > When it was his turn, he sat down, noticed that the projector was > still on, and said: switch that off, I don’t need this. Then he very > eloquently argued against “digital physics”, saying things such as “To > a man with a hammer, everything looks like a nail. To a man with a > computer, everything looks like a computation.” The audience loved it. > > In private conversation about both computable universes and Artificial > Intelligence he made fun of me and my “Schmidhubris” (I am an easy > target). In many ways, I found him very impressive and admirable. (He > did not convince me though.) (Excerpt.) Full thread: https://www.reddit.com/r/MachineLearning/comments/2xcyrl/comment/cp46onq/ · 9 points as of Nov 7, 2026 ### **Jeff Dean** (u/jeffatgoogle) in r/MachineLearning, Sep 13, 2017 · Personal story Replying to a redditor: > How old is the cutoff for an intern? I'm in my late 40's. :) > In 2012, I hosted [Geoffrey Hinton](https://scholar.google.com/citations?user=JicYPdAAAAAJ) as a visiting researcher in our group for the summer, but due to a snafu in how it was set up, he was classified as my intern. We don’t have any age cutoffs for interns. All we ask is that they be talented and eager to learn, like Geoffrey :). Full thread: https://www.reddit.com/r/MachineLearning/comments/6z51xb/comment/dmybky4/ · 39 points as of Nov 7, 2026 ### **Ian Goodfellow** (u/goodfellow_ian) in r/MachineLearning, Jan 15, 2016 · Behind the scenes Replying to the post "Generative Adversarial Networks for Text". > Hi there, this is Ian Goodfellow, inventor of GANs (verification: http://imgur.com/WDnukgP). > > GANs have not been applied to NLP because GANs are only defined for real-valued data. > > GANs work by training a generator network that outputs synthetic data, then running a discriminator network on the synthetic data. The gradient of the output of the discriminator network with respect to the synthetic data tells you how to slightly change the synthetic data to make it more realistic. > > You can make slight changes to the synthetic data only if it is based on continuous numbers. If it is based on discrete numbers, there is no way to make a slight change. > > For example, if you output an image with a pixel value of 1.0, you can change that pixel value to 1.0001 on the next step. > > If you output the word "penguin", you can't change that to "penguin + .001" on the next step, because there is no such word as "penguin + .001". You have to go all the way from "penguin" to "ostrich". (Excerpt.) Full thread: https://www.reddit.com/r/MachineLearning/comments/40ldq6/comment/cyyp0nl/ · 24 points as of Nov 7, 2026 ### **Luis von Ahn** (u/vonahn) in r/AskReddit, Aug 2, 2015 · Personal story Replying to the post "Has anyone here completed a language in Duolingo? How well versed in the language were you, by the end?". > When I had done about half the course, I went to Brazil to give a talk about Duolingo (in English), and the first question I got afterwards was what language I was learning myself. I made the mistake of saying Portuguese, and they proceded to ask me all other questions in Portuguese. This was the first time I ever spoke it with a real human, and it was in front of an audience of more than 1k people! I was terrified. But in the end it worked out pretty well. I was able to understand 100% of what they asked, and answer most things in Portuguese (though I sounded very broken). (Excerpt.) Full thread: https://www.reddit.com/r/AskReddit/comments/3fgxoz/comment/ctojpbr/ · 1,683 points as of Nov 7, 2026 ### **Tim Berners-Lee** (u/timbl) in r/IAmA, Mar 12, 2014 · Behind the scenes Replying to a redditor: > Tim, What other names did you consider other than the world wide web? > Mine of Information, > The Information Mine, > The Mesh > > None had quite the right ring. > I liked WWW partly because I could start global variable names with a W and not have them clash with other peoples' (in a C world) ...in fact I used HT for them) Full thread: https://www.reddit.com/r/IAmA/comments/2091d4/comment/cg0y0bp/ · 2,751 points as of Nov 7, 2026 ### **Tim Berners-Lee** (u/timbl) in r/IAmA, Mar 12, 2014 · Personal story Replying to a redditor: > what was your first computer? > I got a M6800 evaluation kit > > in 1976, and built a bunch of 3U high cards, put them in a rack with a car battery in the bottom of the crate as UPS. All hand-soldered on veroboard > > , and programmed in hex. 7E XX XX was a long jump, and 20 XX a relative jump IIRC. The display was an old TV and some logic and a bunch of discarded calculator buttons lovingly relabeled with transfer letters. Those were the days.... Full thread: https://www.reddit.com/r/IAmA/comments/2091d4/comment/cg0xpno/ · 1,945 points as of Nov 7, 2026 ### **Radia Perlman** (u/rjp2022Redmond) in r/IAmA, Sep 22, 2022 · Personal story Replying to a redditor: > firstly, thank you. then.. what was the biggest challenge in developing the STP successfully? > There actually were no challenges. My manager thought it was going to be a really hard thing, but it turned out to be really simple, once I realized the "obvious" solution. He proposed the problem to me late on a Friday, before disappearing on vacation for a week. This was before cellphones, or people reading email on vacation. That Friday night I realized just how to do it. Monday and Tuesday I wrote the spec, in enough details that the implementers got it working quickly without asking me a single question. But I couldn't concentrate on anything else because I had to show off to my manager, and he was going to be gone until Monday. So Wednesday-Friday I worked on the poem, which is the abstract of the paper in which I published the algorithm. The poem is called Algorhyme (easily found on the Internet). So, given how much time I spent on various aspects, I'd have to say the hardest thing was the poem, since I spent more time on that than on inventing the algorithms or writing the spec. Full thread: https://www.reddit.com/r/IAmA/comments/xl6cc4/comment/ipiehr2/ · 54 points as of Nov 7, 2026 ### **Bjarne Stroustrup** (u/bstroustrup) in r/learnprogramming, Jul 15, 2018 · Explains things Replying to the post "Why did Bjarne Stroustrup not get into copyright trouble with Dennis Ritchie, for basically copying C and adding his new features?". > Why should Dennis have complained? He helped me. The "const" design is partly his and he gave me the troff source of the C manual to use as a starting point for the C with Classes manual. Bell Labs Computer Science Research Lab was quite a friendly environment. Full thread: https://www.reddit.com/r/learnprogramming/comments/8yz57q/comment/e2f9i8t/ · 24 points as of Nov 7, 2026 ### **Tom Crowther** (u/Tom_Crowther) in r/science, Feb 3, 2017 · Explains things Replying to a redditor: > Hi Tom! My university environmental science professor believes that we can't prove climate change is human-caused, due to the fact that the earth's temperature has always fluctuated for thousands of years-- way before humans even existed. How would you argue against this stance?… > Ignoring climate change because we will be plunged into an ice age in 20,000 years is like ignoring a bus because we are all going to die when we are 90 anyway. > > The Earth is always going through massive glaciation cycles that take place over tens of thousands of years. We came out of the last glacial period 12 thousand years ago. We would normally be expecting to re-enter an ice age in tens of thousands of years. These fluctuations would also impact humans, but we don't even know what human society will look like in tens of thousands of years. > > The problem is that we are undoubtedly causing a MASSIVE fluctuation that is taking place within 100 years. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/5rtksv/comment/dda65oz/ · 194 points as of Nov 7, 2026 ### **Kerry Emanuel** (u/kerryemanuel) in r/science, Feb 13, 2014 · Explains things Replying to a redditor: > Is there a limit on how large hurricanes can get on earth? Is it different on other planets? What is the general idea by which you calculate speed limits? > Yes. There is a theoretical limit which is around 1000 km for the storms outer dimension. There is also a limit on wind speed which in the present climate, in the hottest parts of the tropical oceans, is about 190 MPH. This limit comes from equating dissipation of wind energy to its thermodynamic generation in hurricanes. Full thread: https://www.reddit.com/r/science/comments/1xsqyn/comment/cfej3dp/ · 114 points as of Nov 7, 2026 ### **Josh Willis** (u/ClimateElvis) in r/askscience, Oct 17, 2012 · Personal story Replying to a redditor: > To your knowledge, is it possible to make the switch from a non-engineering undergraduate degree to an engineering masters or PhD? I know it would take extra time if done but I'm wondering how common this is. > I actually set out to get a PhD in Physics, but ran aground when I didn't pass the Physics departmental exam. > > It was then that I switched to Oceanography, which has made me much happier in the long run, I think. (Excerpt.) Full thread: https://www.reddit.com/r/askscience/comments/11njvs/comment/c6o0hjx/ · 5 points as of Nov 7, 2026 ### **Forrest M. Mims III** (u/Forrest_Mims) in r/science, Nov 4, 2016 · Personal story Replying to a redditor: > Hi Forrest! Thank you for writing those little Engineer's Mini Notebooks . For young people excited about electronics, as I was, these are terrific bite sized introductions to the field. My question: How did these books come about? Did Radio Shack approach you to write them, or… > Radio Shack editor Dave Gunzel was familiar with my hand-lettered lab notebooks, and at he asked if I could do an entire book the same way I prepared the notebooks. This became the first "Engineer's Notebook," which sold 650,000 copies. The first few pages were prepared with a Selectric typewriter. I then inserted a signature to ease the reader into the hand lettered concept Dave wanted. After several pages, the book shifted to entirely hand-lettering and illustrating. The book was written/drawn with India ink on toothed Mylar, which meant a single error required redoing an entire page. This was a very tedious project, which drew blood from the middle finger of my right hand. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/5b3a09/comment/d9liqcj/ · 20 points as of Nov 7, 2026 ### **Hugh Herr** (u/Hugh_Herr) in r/science, Aug 22, 2016 · Personal story Replying to a redditor: > I heard your story on the radio. How tall have made yourself with the fake legs? Is it hard to balance when the legs get extended that much? > Years ago, when I was climbing actively, I on occasion made my height very very excessive. There was one occasion where I was 3m high! And yes indeed, it is very hard to balance (and a large distance to fall!). Full thread: https://www.reddit.com/r/science/comments/4z0a06/comment/d6s2jgp/ · 36 points as of Nov 7, 2026 ### **Burt Rutan** (u/Burt_Rutan) in r/science, Sep 20, 2016 · Personal story Replying to a redditor: > Mr Rutan: R/C sailplane flier here...There's a story in the radio control sailplane community about you listening with some scepticism to a presentation about the speeds being attained through R/C dynamic soaring. The story goes that when you were given an actual demonstration… > True story. A world class RC DS guy came to scaled and gave a presentation. I stood up and called him a lier, with fake videos (a bit tongue-in-cheek for my employees :-) ). > I then followed him to a special ridge line hill near palm springs, with a 45-knot wind blowing over the top. The experience was the most impressive thing I has seen in aviation (even thou I have flown at Mach 2.15 in the Phantom at 35kft and 820 Kt on the deck). Full thread: https://www.reddit.com/r/science/comments/53mucs/comment/d7uzmav/ · 38 points as of Nov 7, 2026 ### **Robert Zubrin** (u/RobertMZubrin) in r/spacex, Sep 9, 2023 · Normal redditor Replying to a redditor: > If the Mars colony isn't ready in time for you to live there, do you want to be buried there? In general, do Mars burials make sense as a quick, easy way to monetize a Mars colony? Do they make sense as a contribution to fertilizing Martian soil? > I would want the Mars colonists to send back enough Mars soil so I can be buried in it here. Full thread: https://www.reddit.com/r/spacex/comments/16ee7id/comment/jzusqqk/ · 88 points as of Nov 7, 2026 ### **Scott Manley** (u/illectro) in r/EliteDangerous, Jun 21, 2017 · Normal redditor Replying to the post ""Hello" is a banned word because it contains "Hell", which is banned for no apparent reason either. The word filter is a ridiculous idea.". > That's why I say 'Hullo!' > Because nobody would ever ban Hull Full thread: https://www.reddit.com/r/EliteDangerous/comments/6iourr/comment/dj7yy1j/ · 346 points as of Nov 7, 2026 ### **Bill Nye** (u/sundialbill) in r/IAmA, Nov 5, 2014 · AMA answer In the thread "Bill Nye, UNDENIABLY back. AMA.". > Earth. Earth is my favorite planet. > > All my friends are here, and I stay here for the air. Full thread: https://www.reddit.com/r/IAmA/comments/2le34s/comment/cltxyuj/ · 3,084 points as of Nov 7, 2026 ### **Emily Calandrelli** (u/emilycal) in r/askscience, Sep 14, 2020 · AMA answer Replying to a redditor: > Real talk, though? Are you shooting for being Bill Nye's successor, for today's generation of kids? Bill is getting up there in years, Emily. Someone's going to have to step up to the plate soon. Food for thought I guess. On a more serious note, just wanted to say well done. The… > haha I definitely appreciate the sentiment :) > > Though I will also say I don't think we need the next Bill Nye...I think we need 1000 Bill Nyes. We need people who look like the audience we're trying to reach and can speak to a different area of science. The world is advancing so quickly when it comes to STEM that no single person can be an expert on all the fields. We need a Bill Nye of climate change, of immunology and pandemics, of wildlife preservation, disaster science, space exploration, etc! There are so many wonderful SciCommer's out here SciComm'in that I think we're well prepared for this :) Full thread: https://www.reddit.com/r/askscience/comments/isiqk1/comment/g5a2zy1/ · 10 points as of Nov 7, 2026 ### **Karl Kruszelnicki** (u/DrKarlKruszelnicki) in r/IAmA, Nov 19, 2013 · Personal story Replying to a redditor: > Does it ever irritate you to have people call up asking the same question time after time? What is your most disliked question you regularly receive? You're a hero, someone to aspire to be like, and I'm an immense fan :-) > > Does it ever irritate you to have people call up asking the same question time after time? > > Never. One thing I learnt being a roadie for Bo Diddley, after hearing him sing the same songs, night after night. For the audience, it's their first time. Full thread: https://www.reddit.com/r/IAmA/comments/1qxh6p/comment/cdhmfv9/ · 83 points as of Nov 7, 2026 ### **Karl Kruszelnicki** (u/DrKarlKruszelnicki) in r/IAmA, Nov 19, 2013 · Explains things Replying to a redditor: > Hey Dr Karl! What is the most astounding fact you can tell us about the universe/life in general? > > What is the most astounding fact you can tell us about the universe/life in general? > > 1)all the gold you will ever touch was made inside an exploding star > 2)Kilogram for kilogram, your compost pile generates 33,000 times more power than our Sun Full thread: https://www.reddit.com/r/IAmA/comments/1qxh6p/comment/cdhjv7z/ · 398 points as of Nov 7, 2026 ### **Derek Muller** (u/veritasium) in r/IAmA, Jun 4, 2015 · Personal story Replying to a redditor: > By whom did derek got star struck the most? > I think of all my inspirations, the one I enjoyed meeting most was Bill Nye because he's a very down-to-Earth, unpretentious guy. And he taught me how to tie a bowtie, very patiently. He was an excellent teacher (as you might guess) and made me tie the bowtie again and again until I had it down. Repetition is the most important thing in learning how to tie a bowtie. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/38gekk/comment/cruua3q/ · 114 points as of Nov 7, 2026 ### **Randall Munroe** (u/xkcd) in r/pics, Aug 5, 2008 · Personal story Replying to a redditor: > What an awesome party trick for someone running for the Senate. > When I was a kid, I got tracing paper and an atlas for the same birthday. So it just seemed logical to me to trace everything in the atlas. This meant I knew tons about geography but nothing about demographics. I was winning the local geography bee until they asked "Which has more Spanish speakers -- Illinois or California?" I figured, well, Illinois is closer to Spain, so ... (Excerpt.) Full thread: https://www.reddit.com/r/pics/comments/6uw12/comment/c04xjle/ · 261 points as of Nov 7, 2026 ### **Carl Zimmer** (u/CarlZimmer) in r/IAmA, Dec 10, 2012 · Explains things Replying to a redditor: > Would it be possible to use a controlled application of tapeworms to control weight? I imagine a pill of tapeworm eggs, and another pill that would kill them once specific results were achieved. > Tapeworms don't make you lose weight! Common misperception. It would be an awful thing for a tapeworm to starve its host. Instead, people just carry them around for many years, with a normal appetite, pooping out millions of their eggs. (Fun fact: the egg packages people poop out have nerves and muscles and--yes!--CAN CRAWL ALONG THE GROUND!) Full thread: https://www.reddit.com/r/IAmA/comments/14mcvq/comment/c7edwsc/ · 21 points as of Nov 7, 2026 ### **Ed Yong** (u/edyong209) in r/IAmA, Mar 14, 2013 · Explains things Replying to a redditor: > Just wanted to say 'Thank You' for your wonderful writing. And for linking to other writers on twitter. Just one question to all of you: What organism do you find most fascinating? > THE MANTIS SHRIMP! It's a type of crustacean and not a mantis or a shrimp. It has some of the most sophisticated eyes in the animal kingdom--sensitive to 12 colours instead of our 3 and capable of seeing bits of the spectrum we can't. They attack their prey with arms tucked under their head that end in hammers or spears. The hammer species can strike with the force of a rifle bullet, and they create a pressure wave that sort of boils the water ahead of them. They're basically like Thor with really good eyes. Full thread: https://www.reddit.com/r/IAmA/comments/1aaji5/comment/c8vlvu7/ · 7 points as of Nov 7, 2026 ### **Alie Ward** (u/AlieWard) in r/OlogiesPodcast, Apr 21, 2023 · Explains things Replying to a redditor: > ~~Chickenology is a pretty lame term compared to some of the others ologies that use root words. Wish it sounded more professional and not so made up.~~ > Hi! Just your weird dad chiming in way late to say, YES. This is not the coolest term. I thought maybe Gallusology would have been used in the literature at least once, but nope. Nowhere. Rather, I found one of the world's leading poultry pathology researchers from the University of Bristol proudly identifying as a Chickenologist. So I defer to the academics and ... Chickenology it is: https://www.researchgate.net/lab/Chickenology-Paul-Wigley Full thread: https://www.reddit.com/r/OlogiesPodcast/comments/125w5ws/comment/jh71ojy/ · 3 points as of Nov 7, 2026 ### **Michael Stevens** (u/Michael_Stevens) in r/neutralmilkhotel, Aug 18, 2024 · Normal redditor Replying to the post "I Found Another Original Postcard With The Image That Was Adapted For "In the Aeroplane Over the Sea"!". > When I saw that u/tom-dooley had found an original, I set up my own eBay alert for "bathing beauties postcard 1900." I checked it every time there were new matches (which was a few times a week on average), and after FOUR YEARS, a collection of old postcards was listed and in the background of one of the pics I saw THIS ONE! It arrived just a few days ago. These images are scans I took of it. > > The dirt and wear on it do not match the dirt/wear on the actual ITAOTS cover art, so this is almost certainly not the actual card Mangum and Bilheimer used, but it's one of just a few that I think have ever been found. > > It's postmarked July 1 8AM 1907. I know there are unanswered questions about who the original artist was and where the postcard was printed; all I can add is that this one has a stamp on the back that says, "PUB. BY PHILA. POST-CARD CO." Full thread: https://www.reddit.com/r/neutralmilkhotel/comments/1evko0l/comment/lis2r8j/ · 189 points as of Nov 7, 2026 ## More moments ### **Geoffrey Hinton** (u/geoffhinton) in r/MachineLearning, Nov 10, 2014 · Behind the scenes Replying to a redditor: > How did you get the idea for the Boltzmann machine? > Terry Sejnowski had the idea of combining simulated annealing with Hopfield nets. We then figured out that the neurons would have to use the logistic function to make this work. Initially we thought of these stochastic Hopfield nets as just a way of doing search, but about six months later we started working on unsupervised learning for these nets. I had to give my first research seminar at CMU and I was terrified that I wouldn't have anything good to say. So I worked very hard. Terry always works very hard anyway. I guessed that we should be minimizing the KL divergence between the distribution we wanted to model and the distribution exhibited by the network when it was at thermal equilibrium at a temperature of 1. Terry did the math. This led to such nice derivatives that we knew we were onto something. Also it justified Crick and Mitchison's theory of sleep as unlearning. > > A few years later, Peter Brown pointed out that our learning algorithm was actually doing maximum likelihood and I said "What's maximum likelihood?". Full thread: https://www.reddit.com/r/MachineLearning/comments/2lmo0l/comment/clypbhc/ · 31 points as of Nov 7, 2026 ### **John Mather** (u/johnmather) in r/IAmA, Nov 26, 2012 · Explains things Replying to a redditor: > What is, in your opinion, the most commonly-held misconception people have about planets, stars and outer space? > I think people have a really hard time grasping how empty outer space is, in the sense of immense distances between objects, and immense time spent going from one to another. There's a lot of talk about space aliens as though it were physically possible for them to get here from somewhere else, and (sorry to say this) talk about human travel out of the solar system. We just don't live long enough to do that. Full thread: https://www.reddit.com/r/IAmA/comments/13tjrx/comment/c772eca/ · 401 points as of Nov 7, 2026 ### **Brian Schmidt** (u/Schmidt_and_Francis) in r/askscience, Nov 24, 2015 · Behind the scenes Replying to a redditor: > Which supernovas are cooler, type Ia or type II? edit: I don't mean temperature-wise > I love both - Ia's gave me Nobel Prize, and Type II's gave me my PhD thesis. > Ia's are the more spectacular explosions - but type IIs make the Carbon and Oxygen that allow us to exist... Full thread: https://www.reddit.com/r/askscience/comments/3u3ijv/comment/cxbxj63/ · 5 points as of Nov 7, 2026 ### **Brian Schmidt** (u/Schmidt_and_Francis) in r/askscience, Nov 24, 2015 · Personal story Replying to a redditor: > How far back, if at all, did the bush fire which gutted the telescopes at Mt. Stromlow Observatory set back your work? > So we burned to the ground on 18 January 2003 - See for example http://www.naturalhistorymag.com/htmlsite/0405/images/0405feature4.jpg > Paul and I were part of a project to map the southern sky - (we started on 1 January 2013) - We would have completed the survey in 2008 - > We are starting the survey again (started last year) - and while it will be better than what we were going to do back then - we are 10 years behind. > So I think I lost several years equivalent of my scientific career - but that which does not destroy you makes you stronger! Full thread: https://www.reddit.com/r/askscience/comments/3u3ijv/comment/cxbvy1x/ · 5 points as of Nov 7, 2026 ### **Randy Schekman** (u/schekman) in r/IAmA, Dec 12, 2013 · Behind the scenes Replying to a redditor: > Thanks, Dr. Schenkman. What applications do you foresee from your research? > My work has already yielded practical applications. When we found that yeast cells use a pathway of secretion similar to animal cells, the biotech industry engineered yeast to express and secrete useful quantities of human proteins such as insulin. Full thread: https://www.reddit.com/r/IAmA/comments/1sq4vd/comment/ce04ryl/ · 115 points as of Nov 7, 2026 ### **Carolyn Bertozzi** (u/Carolyn_Bertozzi) in r/science, Jun 19, 2015 · Personal story Replying to a redditor: > Dr Bertozzi, I was fortunate enough to have lunch with you wen you visited Iowa last year. During the lunch with a group of grad students and post docs you talked at length how you never "planned out" your career but, instead, kept following your genuine interests and… > I started as a biology major, maybe premed, but then fell in love with organic chemistry - synthesis and mechanism, really - when I took the intro organic chemistry course my sophomore year. After that year, I tried to get a summer job in an organic synthesis lab but the doors were not open to women at that time (there is another discussion that can be had here, of course, that even involves Title IX, but I digress...). So after many unsuccessful attempts, I finally conceded that my destiny would like squarely in biology and found a lab that would take me for the summer. > > Then, out of nowhere, the professor teaching my advanced physical organic chemistry course came up to me after class and offered me a summer research job. I didn't know what he did - turned out to be a physical chemist - but accepted on the spot simply because someone in chemistry wanted to hire me. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3ae7uw/comment/csc2t2z/ · 17 points as of Nov 7, 2026 ### **Carolyn Bertozzi** (u/Carolyn_Bertozzi) in r/science, Jun 19, 2015 · Personal story Replying to a redditor: > As a new graduate student I'm struggling to develop networking skills along with finishing my experiments. I'm passionate about science but I also want to complete work in a timely manner and be pragmatic about my career. As an extremely successful scientist what are those… > One thing I did learn in grad school which has been immensely helpful in all areas of life is how to be a "closer". That is, how to bring a project to a stage of completion where you have a product to show for it (in grad school, that product being a publication of some substance). When projects did not look like they had a path to closure, I learned how to redirect them toward such a path. The lesson was learned the hard way. My PhD advisor, a new assistant professor when I joined his lab, left the profession after my third year of grad school. For the last two years, I and two lab mates had to figure out how to finish our PhD work, get published and get jobs, with little "grown up supervision". (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3ae7uw/comment/csc28j7/ · 22 points as of Nov 7, 2026 ### **Buzz Aldrin** (u/BuzzAldrinHere) in r/IAmA, Jul 8, 2014 · Personal story Replying to a redditor: > Is there any experience on Earth that even compares slightly to having been on the Moon? > My first words of my impression of being on the surface of the Moon that just came to my mind was *"Magnificent desolation.*" The magnificence of human beings, humanity, Planet Earth, maturing the technologies, imagination and courage to expand our capabilities beyond the next ocean, to dream about being on the Moon, and then taking advantage of increases in technology and carrying out that dream - achieving that is magnificent testimony to humanity. But it is also desolate - there is no place on earth as desolate as what I was viewing in those first moments on the Lunar Surface. > > Because I realized what I was looking at, towards the horizon and in every direction, had not changed in *hundreds, thousands* of years. Beyond me I could see the moon curving away - no atmosphere, black sky. Cold. Colder than anyone could experience on Earth when the sun is up- but when the sun is up for 14 days, it gets very, very hot. No sign of life whatsoever. > > That is desolate. More desolate than any place on Earth. Full thread: https://www.reddit.com/r/IAmA/comments/2a5vg8/comment/cirsu5z/ · 4,020 points as of Nov 7, 2026 ### **Scott Kelly** (u/StationCDRKelly) in r/IAmA, Jan 23, 2016 · Explains things Replying to a redditor: > Why do you always have your arms folded? > Your arms don't hang by your side in space like they do on Earth because there is no gravity. It feels awkward to have them floating in front of me. It is just more comfortable to have them folded. I don't even have them floating in my sleep, I put them in my sleeping bag. Full thread: https://www.reddit.com/r/IAmA/comments/42cllg/comment/cz9agy8/ · 4,722 points as of Nov 7, 2026 ### **Scott Kelly** (u/StationCDRKelly) in r/IAmA, Apr 26, 2018 · Personal story Replying to a redditor: > Do you ever try to put objects down mid air forgetting there's gravity? > After my first flight, I had a tendency to want to that. I definitely tried to float out of bed to go to the bathroom. Full thread: https://www.reddit.com/r/IAmA/comments/8f4hjj/comment/dy0lkyx/ · 1,643 points as of Nov 7, 2026 ### **Scott Kelly** (u/StationCDRKelly) in r/IAmA, Oct 16, 2017 · Explains things Replying to a redditor: > What do you think is the biggest misconception that people have about astronauts? > That they were always the smartest kid in the class, and I was not. Full thread: https://www.reddit.com/r/IAmA/comments/76rrh0/comment/dog7v1b/ · 4,262 points as of Nov 7, 2026 ### **Terry Virts** (u/Astro-Terry) in r/IAmA, Apr 15, 2019 · Explains things Replying to a redditor: > Did you get taller during the trip? > I gained about 5 cm while in space. I was finally six foot tall! > Sadly, as soon as our feet hit the plant we go back to our original height :( Full thread: https://www.reddit.com/r/IAmA/comments/bdia22/comment/ekycy1c/ · 284 points as of Nov 7, 2026 ### **Terry Virts** (u/Astro-Terry) in r/IAmA, Apr 15, 2019 · Personal story Replying to a redditor: > What was your biggest "oh shit!" moment while in space? > There were a few- but a small piece of equipment came loose during my first launch and it banged against the back wall and made a loud noise- we were all 😳😳😳. Luckily it was OK! we found it floating a few minutes later once we were in space) Full thread: https://www.reddit.com/r/IAmA/comments/bdia22/comment/ekycgiz/ · 560 points as of Nov 7, 2026 ### **Terry Virts** (u/Astro-Terry) in r/IAmA, Apr 15, 2019 · Explains things Replying to a redditor: > What's it like trying to fall asleep in microgravity? Is it easy or difficult to adjust to mentally? > I was worried about that at first, but it was actually the easiest and best sleep I've ever had in my life! Full thread: https://www.reddit.com/r/IAmA/comments/bdia22/comment/ekydhb8/ · 892 points as of Nov 7, 2026 ### **Ron Garan** (u/RonGaran) in r/IAmA, Mar 21, 2012 · Explains things Replying to a redditor: > did you do a spacewalk at all? if you did what did it sound like? I think on earth we very rarely experience true complete silence, did you experience it? what was it like, was it different from the "silence" we experience on earth? I'm super interested in this. > I have done 4 spacewalks (in total I have been "outside over 27 hours) It's actually not that quiet since your spacesuit has fans running (you're basically in your own self-contained spaceship) Full thread: https://www.reddit.com/r/IAmA/comments/r62jp/comment/c437foi/ · 1,220 points as of Nov 7, 2026 ### **Ron Garan** (u/RonGaran) in r/IAmA, Dec 7, 2012 · Personal story Replying to a redditor: > This is off topic, but could you describe what it was like going out on your first spacewalk? > Part of my brain said, "This is an amazingly beautiful experience" - another part said, "Yeah, it's beautiful but it's not real" since on my 1st spacewalk I had no experience base to compare it to, part of me couldn't accept it was real Full thread: https://www.reddit.com/r/IAmA/comments/14f7gt/comment/c7ciqyi/ · 1,411 points as of Nov 7, 2026 ### **Ron Garan** (u/RonGaran) in r/IAmA, Mar 21, 2012 · Personal story Replying to a redditor: > How do you sleep in space? > While sleeping I free floated (interesting that I usually woke up up-side-down - in relation to my stuff) Full thread: https://www.reddit.com/r/IAmA/comments/r62jp/comment/c4379td/ · 859 points as of Nov 7, 2026 ### **Ed Lu** (u/edluB612) in r/IAmA, Jan 23, 2014 · Personal story Replying to a redditor: > What do you think Carl Sagan would have to say about the B612 Foundation and your work? > BTW, the only time I actually spoke to Carl Sagan was when I was an undergrad at Cornell. I was late for something and running down a hall in the physics building. I came around a corner and nearly ran over Dr. Sagan! The only words I ever said to him were "excuse me!". So I've got that going for me...... (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/1vycym/comment/cewzll0/ · 37 points as of Nov 7, 2026 ### **Ed Lu** (u/edluB612) in r/IAmA, Jan 23, 2014 · Personal story Replying to u/edluB612: > Apollo 13! and of course Galaxy Quest. > BTW, my crewmates and I on Shuttle mission STS-106 all watched Galaxy Quest in crew quarters just before our launch! "Never Give Up!" Full thread: https://www.reddit.com/r/IAmA/comments/1vycym/comment/cewz2fu/ · 197 points as of Nov 7, 2026 ### **Mike Massimino** (u/MikeMassimino) in r/IAmA, Oct 4, 2016 · Personal story Replying to a redditor: > When you went to space did you think "Wow we are actually on quite a small planet and we are way more vulnerable then we think we are" ? because i have heard that some other astronauts said this also umh what do you eat/drink in outer space ^^ ? > I love the food in space, I was one of the few astronauts who gained weight in space - some of my favorites: shrimp cocktail, macaroni and cheese, lasagna, and chocolate fudge cake..... no wonder I gained weight. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/55ukwc/comment/d8duuvu/ · 4 points as of Nov 7, 2026 ### **Jeffrey Hoffman** (u/jhoffma1) in r/IAmA, Sep 20, 2017 · Personal story Replying to a redditor: > What was the greatest adversity you faced during your time in space? How did you address it? > The most critical mission was the rescue/repair of the Hubble Space Telescope. On the first day, after replacing the gyroscopes, the main door would not close, which would have doomed the telescope. It took us an hour to figure out what the problem was and how to solve it, which involved using a standard tool in an unconventional way. But that's what astronauts are supposed to do - solve problems. Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9n3ll/ · 6 points as of Nov 7, 2026 ### **Jeffrey Hoffman** (u/jhoffma1) in r/IAmA, Sep 20, 2017 · Explains things Replying to a redditor: > What do you do when something dusty or anything like that starts floating around? How do you stop it prom hurting people or damaging stuff? Thanks! > Dust in space is a real problem, because it doesn't fall to the ground. The air is constantly circulated through filters to remove dust and lint, but we need to be careful to minimize the amount of dust created - for example no woolen clothes (lint) and no cashew nuts (too many crumbs). Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9mqfq/ · 4 points as of Nov 7, 2026 ### **Jeffrey Hoffman** (u/jhoffma1) in r/IAmA, Sep 20, 2017 · Behind the scenes Replying to a redditor: > What's the most interesting experiment that you were a part of aboard the space shuttle? > On my last flight (STS-75 in 1996) we deployed the tethered satellite, a 1.5 m diameter sphere that remained attached to the shuttle by a 20 km long wire. Looking up at the wire disappearing into space, I felt like Jack looking up at the beanstalk! Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9lu8f/ · 22 points as of Nov 7, 2026 ### **Chris Hadfield** (u/ColChrisHadfield) in r/pics, Jan 16, 2014 · Normal redditor Replying to a redditor: > [Photoshop fix.](http://i.imgur.com/kETHygY) > I'm not sure what you photoshopped. This is what I remember having happened. Full thread: https://www.reddit.com/r/pics/comments/1vasxs/comment/ceqn3lw/ · 3,595 points as of Nov 7, 2026 ### **Mike Melvill** (u/Mike_Melvill) in r/science, Sep 21, 2016 · Behind the scenes In the thread "XPrize AMA: Hi I’m Mike Melvill, the world’s first commercial (non-governmental) astronaut. Self-taught engineer, I took up piloting mid-life and went on to fly the first private spacecraft into space at 63. AMA!". > We got permission from the base commander of Edwards Air Force Base to take off in the mother ship, Whiteknight with me hanging under its belly in SpaceShipOne, climb to around 50,000 feet, and then drop the SS1 off the two hooks. I started the rocket motor, and pulled the nose up until I was near vertical, the accelerated to Mach 3 and at 170,000 feet I shut down the rocket motor, and coasted up to 328,000 feet, 62 miles. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/53sl88/comment/d7wj48d/ · 134 points as of Nov 7, 2026 ### **Mike Melvill** (u/Mike_Melvill) in r/science, Sep 21, 2016 · Personal story Replying to a redditor: > What was the scariest moment you've had when flying? > Good question Swag_train! I have had several scary moments, including a few engine out forced landings, but the one that sticks in my mind was a flight test involving spins in a small two place aircraft designed by my Boss. I ended up in a flat spin starting at 14,000 feet, and I finally managed to recover at less than 1,000 feet after making 17 disorienting spinning turns. It was caught on video, so I was able to count the turns! Full thread: https://www.reddit.com/r/science/comments/53sl88/comment/d7wivtw/ · 54 points as of Nov 7, 2026 ### **Anousheh Ansari** (u/Anousheh_Ansari) in r/science, Sep 27, 2016 · Normal redditor Replying to a redditor: > What did you wanted to become when you were a child? > are you kidding? an Astronaut :) > Specifically I wanted to be Ms. Spock. I wanted to be the Science Officer on board space ship Enterprise! Full thread: https://www.reddit.com/r/science/comments/54pzmg/comment/d84jqcy/ · 84 points as of Nov 7, 2026 ### **Emily Lakdawalla** (u/elakdawalla) in r/space, Nov 18, 2014 · Explains things Replying to a redditor: > Hey, I am really happy about the results philae already has delivered, but there is one thing I was curious about when I heard about the bounces. Did Philae have stability systems to keep its orientation after the bounces or was it pure luck that it kind of remained head up?… > It had an internal flywheel that spun up before it was released from Rosetta to give it stability. The moment it touched down the first time, the flywheel began to spin down. That turns out to have been *insanely* fortunate, because as a direct result of the flywheel spinning down, the lander started rotating. That gave the lander stability so it didn't flip over as it was bounding back up from the surface. Full thread: https://www.reddit.com/r/space/comments/2mofoz/comment/cm6blc6/ · 54 points as of Nov 7, 2026 ### **Emily Lakdawalla** (u/elakdawalla) in r/space, Jul 15, 2015 · Explains things Replying to a redditor: > New Horizons carried a RTG for energy requirements. Thus the light of the sun reaching would be very low. How did the probes camera capture such a vivid image? > First of all, it's not really that dim; it's like twilight on Earth. Do a Google search on "Pluto time" for explainers on that. Second of all, just as in photography on Earth, you choose a camera detector and an exposure setting that exposes the scene well and you get a nice picture. LORRI is a very sensitive camera; it actually had a difficult time photographing the moons of Jupiter because they were too bright, they saturated the detector. It did its best imaging of Jupiter moons on the *night* sides of the moons, where they were illuminated by Jupitershine. Full thread: https://www.reddit.com/r/space/comments/3de75i/comment/ct4a4s4/ · 56 points as of Nov 7, 2026 ### **Emily Lakdawalla** (u/elakdawalla) in r/Damnthatsinteresting, Dec 8, 2017 · Normal redditor Replying to the post "Cosmic Dress". > Hey, that's me, in a skirt I designed using photos from Cassini, and printed at Spoonflower, and stitched myself. The woman behind me is National Geographic reporter Nadia Drake in a dress from Belle Neptune that also uses Cassini photos. The animation comes from The Planetary Society's Instagram: https://www.instagram.com/p/BZC8YTTA9-M/?hl=en Full thread: https://www.reddit.com/r/Damnthatsinteresting/comments/7iddvr/comment/dqyxty1/ · 39 points as of Nov 7, 2026 ### **Alex Filippenko** (u/AlexFilippenko) in r/space, Sep 19, 2015 · Explains things Replying to a redditor: > Sorry if this is a stupid question, but if space is a vacuum and air naturally gets sucked into a vacuum what keeps our atmosphere from being sucked into outer space? EDIT: added 1 word > It's actually a misconception that a vacuum exerts a force that "sucks" air into it. Air can spread out from where it is located, into a vacuum if there's one nearby. But Earth's *gravity* keeps the air in our atmosphere from spreading out into space. Full thread: https://www.reddit.com/r/space/comments/3lkoul/comment/cv777dy/ · 12 points as of Nov 7, 2026 ### **Alex Filippenko** (u/AlexFilippenko) in r/IAmA, May 10, 2014 · Explains things Replying to a redditor: > Does the fact that the universe is "flat" suggest that we can put a minimum size on the entire universe that's at least as big as a hypothetical closed universe in which or local curvature is too small to detect with current techniques? > Yes, that's right. I think current estimates place the volume of the entire Universe to be *at least* 80 times the volume of the observable part of our Universe. > > But in fact, the entire Universe may well be far, far larger than that, according to inflation models. It could easily be the case that the ratio of the diameter of the entire Universe (all that there is) to the diameter of our observable Universe is as large as the ratio of the diameter of the observable Universe to the diameter of a proton: something like 10^41 for the ratio. In other words, our observable Universe is like a proton relative to the entire Universe. Whoa! Full thread: https://www.reddit.com/r/IAmA/comments/25830r/comment/chenf7f/ · 56 points as of Nov 7, 2026 ### **Alex Filippenko** (u/AlexFilippenko) in r/IAmA, May 10, 2014 · AMA answer Replying to a redditor: > Some of my friends have taken your Introduction to Astronomy course at UC Berkeley and loved it. They say that your last lecture is especially inspirational. What do you tell them in that lecture? > Well, one of the things I tell them is that each of them > is special in a cosmic sense, not just an insignificant speck > of dust in the Universe, because they have the intellectual > capacity to understand what scientists are learning about the > Universe. In a sense, it's as though the Universe has developed a > way to know itself, through us. We are the observers of the Universe, > the explorers of the Universe, the brains and conscience of the > Universe. And it needn't have been like this! Alter the laws of > physics ever so slightly, and our Universe may have been stillborn, > devoid of such complexity. We were dealt a darn good poker hand, > so to speak. Full thread: https://www.reddit.com/r/IAmA/comments/25830r/comment/chemd4j/ · 63 points as of Nov 7, 2026 ### **Janna Levin** (u/Janna_Levin) in r/science, Jan 12, 2018 · Explains things Replying to a redditor: > How would you explain expansion inside that gigantic black hole? > There is no expansion inside a gigantic black hole. The expansion of the universe has a domain of domination, the largest scales. The black hole overpowers that expansion locally, on the scale of the interior of the black hole. As do we. We are bound so well by atomic forces that we are not expanding with the expansion of the universe. We expand mostly by eating too much. Full thread: https://www.reddit.com/r/science/comments/7pwibg/comment/dsku2xu/ · 113 points as of Nov 7, 2026 ### **Janna Levin** (u/Janna_Levin) in r/science, Jan 12, 2018 · Explains things Replying to a redditor: > If Black Holes are “rips” in space time, at the Planck length, what is on the other side of space time? > If only we knew. Here the predictions of general relativity become unreliable. Like a dying man scrawling in the dirt, relativity is telling us something as it breaks down. The singularity is a clue not a genuine prediction, a clue that some other law of physics takes over at these Planck scales. That theory will predict for us what is on the other side. For now, we can conjecture. Maybe a big bang? The birth of a new universe? Full thread: https://www.reddit.com/r/science/comments/7pwibg/comment/dskufgn/ · 27 points as of Nov 7, 2026 ### **Janna Levin** (u/Janna_Levin) in r/science, Jan 12, 2018 · Explains things Replying to a redditor: > It has been said that the directions of space and time “reverse” within the event horizon of a black hole - the singularity effectively becomes your unavoidable “future”. Does this mean that there is some degree of freedom to move through time or receive information from the… > Yes, I love this. Think of a black hole as inducing a rotation of space into time and time into space for an infalling astronaut relative to a space traveller at a safe distance. At the event horizon the rotation is complete. All of the infalling astronaut's time has been rotated away and they appear to freeze at the horizon, time effectively stopped. However, from the astronaut's point of view, time ticks completely normally and she falls across the horizon in short order. Inside the black hole, the rotation overshoots. What the distant space traveller called a spatial direction has become a time direction and the infaller sees the singularity not in the center of a sphere, but in her future as inevitable as the next second is for us. There is no more freedom afforded. The singularity can no more be avoided than the conclusion of this hour. Full thread: https://www.reddit.com/r/science/comments/7pwibg/comment/dskuok6/ · 61 points as of Nov 7, 2026 ### **Seth Shostak** (u/sshostak) in r/askscience, Jan 5, 2017 · Personal story Replying to a redditor: > If we're pinged, what will be your personal reaction? Where will you go, and what will you do? > In the case of the 1997 false alarm we had, I just got very nervous, and worried about canceling all the meetings on my calendar for the next two weeks. And then realized that this was going to change my job for a lot longer than that! Full thread: https://www.reddit.com/r/askscience/comments/5m68zo/comment/dc1ekxm/ · 46 points as of Nov 7, 2026 ### **Seth Shostak** (u/sshostak) in r/IAmA, Mar 14, 2012 · Explains things In the thread "I'm Seth Shostak, Senior Astronomer at the SETI Institute AMA.". > Our galaxy has roughly a trillion planets. Hard to imagine that they're ALL sterile. > > Traveling between galaxies is hard ... typical distances are millions of light-years. That's a trip that, even with our fastest rockets, would take longer than the current age of the universe. That's a long time to be sitting in the middle seat ... Full thread: https://www.reddit.com/r/IAmA/comments/qwv9g/comment/c413k9o/ · 159 points as of Nov 7, 2026 ### **Seth Shostak** (u/sshostak) in r/askscience, Jan 5, 2017 · AMA answer Replying to a redditor: > Hi Seth, Do people work at SETI who lack the faith that you have regarding aliens? Thanks > Actually, I've never asked them this! But I don't think any of the scientists would work here if they didn't think that biology is more of an infection than a miracle. Heck, this is the Silicon Valley. There are better-paying jobs across the street ... Full thread: https://www.reddit.com/r/askscience/comments/5m68zo/comment/dc1f8b8/ · 39 points as of Nov 7, 2026 ### **Yvette Cendes** (u/Andromeda321) in r/AskReddit, Dec 28, 2016 · Explains things Replying to the post "What is surprisingly NOT scientifically proven?". > Astronomer here! Many of you have likely heard about [pulsars](https://en.wikipedia.org/wiki/Pulsar), which are neutron stars the size of a city that rotate as fast as thousands of times a second (and, at slowest, a few seconds per spin). We know this because pulsars emit a beam of radiation in the radio spectrum, which we can see each time the pulsar spins (like a lighthouse beam). We also can predict these beams so precisely they are more accurate than atomic clocks for timekeeping, and were used for [the first indirect proof of gravitational waves](https://en.wikipedia.org/wiki/PSR_B1257%2B12). > > So it sounds like we know a lot about pulsars, right? Well get this- *no one has a clue what creates the emitted beam in the first place*. We have known about these things since the 60s, and can do all these amazing experiments using them for timing, but what actually causes the emission? No friggin' clue. Neutron stars are just made of very exotic, very dense fundamental particles in ways that are impossible to recreate on Earth (a teaspoonful of the stuff would weigh about 10 million tons on Earth), so while there's been a lot of theoretical work on this problem no one knows as yet what causes the radio emission after half a century plus of research. (Excerpt.) Full thread: https://www.reddit.com/r/AskReddit/comments/5kq1p8/comment/dbpvi8p/ · 8,856 points as of Nov 7, 2026 ### **Yvette Cendes** (u/Andromeda321) in r/AskReddit, Sep 18, 2015 · Explains things Replying to the post "What false facts are thought as real ones because of film industry?". > Astronomer here! There are a *lot* of bad things people think are true about astronomy because of movies, but to just highlight one: asteroid fields are completely different than what most people think they're like. People tend to think of this crazy cramped field like in *Star Wars: The Empire Strikes Back* as the norm, but in actuality there is, on average, millions of kilometers between asteroids! > > Think of it this way: there are ~100,000 asteroids that are larger than a kilometer or so. If we think of the asteroid belt between Mars and Jupiter, that still leaves you an average spacing of 5 million kilometers between asteroids. In fact, there are so few that rather than having to worry about sending spacecraft through it due to too many, NASA had serious issues when *Galileo* was flying through on its way to Jupiter to ensure it passed close enough to asteroids to photograph them! (Excerpt.) Full thread: https://www.reddit.com/r/AskReddit/comments/3lf4rg/comment/cv5sku5/ · 4,773 points as of Nov 7, 2026 ### **Yvette Cendes** (u/Andromeda321) in r/AskReddit, Nov 7, 2016 · Personal story Replying to the post "What's the smallest decision you made that had the biggest impact on your life?". > From 6-12th grade (or age 11-18 for those not from the USA), I had a school bus ride home that lasted about an hour. It sucked, and I spent the morning going in doing homework and the afternoon home reading. One day, when I was in 8th grade, I ran through the library in panicked "class is out and I have just a few minutes to pick out a book else I'll be bored for an hour" mode, and happened to choose one on astronomy. Still remember it exactly, it was called *From the Big Bang to Planet X* by Terence Dickinson and had the Andromeda Galaxy on the cover- a galaxy I've had an affinity for since now that I think about it. :) > > Anyway, by the end of that school bus ride I was already thinking about what kind of telescope I wanted to buy, and realizing with a shock that *any* 13 year old could technically grow up to be an astronomer, even if they lived in Pittsburgh. And I wanted to be an astronomer ever since, and I am one now! All because of that one book I happened to grab for my school bus ride home. (Excerpt.) Full thread: https://www.reddit.com/r/AskReddit/comments/5blita/comment/d9pgf1p/ · 22,339 points as of Nov 7, 2026 ### **Craig DeForest** (u/Craig_DeForest) in r/science, Aug 14, 2017 · Explains things Replying to a redditor: > I live about 4 hours from the direct eclipse, how different will it be for me? > If you're a 4 hour freeway drive away from totality, you'll see about a 90% partial eclipse (90% of the Sun occulted). If there are no clouds, you will see some optical effects -- like "gloomy sunlight" that feels a little odd. (The day will appear normal, but without the strong heat and glare of the Sun.) You'll notice that shadows appear sharper. Near maximum eclipse for you, you *might* be able to pick out four planets lying along a straight line across the Sky -- the plane of the ecliptic, which forms the main shape of our solar system. It's best to be above 95% totality to catch the full view, though. > > This is one of the few chances you'll ever get to see the whole inner solar system lain out across the sky like that, and it is quite spectacular. > > On the other hand, from the standpoint of the visceral wonder of a total eclipse, 90% is very small potatoes. The difference has been compared to the difference between kissing someone and marrying that person. Full thread: https://www.reddit.com/r/science/comments/6tlt2e/comment/dlm2hyo/ · 10 points as of Nov 7, 2026 ### **Katie Mack** (u/astro_katie) in r/science, Apr 27, 2014 · Explains things Replying to a redditor: > How do you explain dark matter to kids? > I usually like to start with something like the intro to [this piece](http://www.slate.com/articles/health_and_science/mysteries_of_the_universe/2014/02/what_is_dark_matter_searching_with_gravity_lensing_wimps_and_antiparticles.html) -- I tell them that when they touch the table, what they're feeling is the electromagnetic repulsion (or, you know, I use some less jargony way of saying that) between that surface and their hand, and that's what makes it feel solid and what keeps you from passing right through it. Dark matter doesn't seem to have that force. It has gravity, but it doesn't do electromagnetic repulsion as far as we can tell. So if dark matter were in the room (which it probably is), it would pass through you unnoticed. And we know dark matter is out there because of the way it moves things around in galaxies and clusters of galaxies, and how its gravity bends light. And then I show them lots of pictures. :-) Full thread: https://www.reddit.com/r/science/comments/244m55/comment/ch3oes0/ · 249 points as of Nov 7, 2026 ### **Katie Mack** (u/astro_katie) in r/askscience, May 28, 2021 · Normal redditor Replying to a redditor: > Congrats on getting your private pilot license! What was the skill you found the most difficult to master before doing your checkride? > Thank you! The things I struggled with most were landings (which are always the hardest part, I suppose) -- especially short-field and soft-field landings -- and soft-field take-offs. And I still get super nervous whenever I have to talk to Air Traffic Control or really even just give radio calls at all, even just on the common frequency around an uncontrolled airport. You would think that someone who has given radio interviews for the BBC World Service would find ATC easy but no! It is terrifying!! Full thread: https://www.reddit.com/r/askscience/comments/nmvafn/comment/gzsdqs2/ · 10 points as of Nov 7, 2026 ### **Neil deGrasse Tyson** (u/neiltyson) in r/IAmA, Nov 13, 2011 · Explains things Replying to a redditor: > What never fails to blow your mind in physics? > 1) The fact that an electron has no known size -- it's smaller than the smallest measurement we have ever made of anything. > > 2) That Quarks come only in pairs: If you try to separate two of them, the energy you sink into the system to accomplish this feat is exactly the energy to spontaneously create two more quarks - one to partner with each of those you pulled apart. > > 3) That the space-time structure inside a rotating black hole does not preclude the existence of an entire other universe. > > MindBlown x 3 Full thread: https://www.reddit.com/r/IAmA/comments/mateq/comment/c2zg74j/ · 3,457 points as of Nov 7, 2026 ### **Brian Cox** (u/ProfessorBrianCox) in r/space, Mar 3, 2022 · Explains things Replying to a redditor: > If photons have no mass, why can they not escape the gravity of a black hole 🕳? > A black hole is essentially pure spacetime geometry, and the paths of photons 'follow' the geometry as it were. There are lots of ways of thinking about this. One is to use the equivalent principle, If you fire a laser beam horizontally in your room now, it actually 'falls' to the ground at the same rate as anything else you drop (neglecting air resistance). Einstein would say that a way to think about this is that the ground is accelerating upwards to meet the light beam. You don't see it curve of course from your perspective because it's travelling very fast. The basic point is that gravity is only associated with mass alone in Newton's theory, which isn't right! Einstein tells us that gravity is the curvature of spacetime, and everything responds to that. Full thread: https://www.reddit.com/r/space/comments/t5ur10/comment/hz7izei/ · 33 points as of Nov 7, 2026 ### **Brian Cox** (u/ProfessorBrianCox) in r/space, Mar 3, 2022 · Explains things Replying to a redditor: > If the most efficient shape is a sphere, is the center of a singularity a spherical mass or a spherical absence of matter? > The singularity inside a Schwarzschild black hole (not spinning) is actually a moment in time - the end of time in fact. it's not a place in space. Inside an eternal Kerr (spinning) black hole it's a ring. Full thread: https://www.reddit.com/r/space/comments/t5ur10/comment/hz7hezc/ · 50 points as of Nov 7, 2026 ### **Sean Carroll** (u/seanmcarroll) in r/askscience, May 25, 2016 · AMA answer Replying to a redditor: > Hi Sean! I've had your arrow of time book on my shelf for years, and I'd like to personally apologize for not picking it up yet. No good reason, really. Sorry. My question: So-called hidden variable theories of QM have been getting a lot more play in the popular press recently… > As an author, as long as you've purchased the book, your work here is done. (Excerpt.) Full thread: https://www.reddit.com/r/askscience/comments/4kza3d/comment/d3jc9hh/ · 35 points as of Nov 7, 2026 ### **Sean Carroll** (u/seanmcarroll) in r/seancarroll, Apr 1, 2019 · Behind the scenes Replying to the post "Sean Carroll's new book - acknowledgements". > Spoiler alert: the last paragraph of the acknowledgements reads as follows. "Thanks also to Jennifer for bringing into our lives Ariel and Caliban, the best writing-partner cats an author could ask for. No actual cats were subjected to thought experiments during the composition of this book." Full thread: https://www.reddit.com/r/seancarroll/comments/b827ap/comment/ejvhtdk/ · 18 points as of Nov 7, 2026 ### **Max Tegmark** (u/MaxTegmark) in r/IAmA, Aug 20, 2014 · Normal redditor Replying to a redditor: > What has been the weirdest/most interesting thing you've seen/heard of happening on MIT's campus? > The undergrad pranks are mindblowing. One morning, I looked out my office window to see a life-size replica of the Apollo 11 Lunar Lander atop the great dome. Full thread: https://www.reddit.com/r/IAmA/comments/2e3t77/comment/cjvtzu0/ · 7 points as of Nov 7, 2026 ### **Max Tegmark** (u/MaxTegmark) in r/IAmA, Aug 20, 2014 · Explains things Replying to a redditor: > Mr. Tegmark, do you believe that there will be a "bypass" of the theory of relativity that would enable us to reach remote destinations at apparent superluminal speeds? Maybe via such hypothetical technologies such as Alcubierre Drive or something similar? > I'm betting against it. I used to think that this was a pity, but I've changed my mind: it's actually very convenient for us if malevolent extraterrestrials are unable to reach us for billions of years even if their technology is way ahead of ours, simply because the laws of physics ban bypasses. > :) Full thread: https://www.reddit.com/r/IAmA/comments/2e3t77/comment/cjvwehs/ · 11 points as of Nov 7, 2026 ### **Max Tegmark** (u/MaxTegmark) in r/IAmA, Aug 30, 2017 · Explains things Replying to a redditor: > If you were allowed to say crazy things without anybody judging you, what would you say consciousness "actually is?" Do you have any far-out ideas about consciousness that you haven't subjected to any scientific scrutiny yet? > I think that consciousness is the way information feels when being processed in certain complex ways. To me, the exciting remaining challenge is to clarify what precisely those "certain complex ways" are, so that we can predict which entities are conscious. :-) Full thread: https://www.reddit.com/r/IAmA/comments/6x0s6p/comment/dmc8lif/ · 51 points as of Nov 7, 2026 ### **Michio Kaku** (u/michiokakuauthor) in r/IAmA, Apr 23, 2019 · Explains things Replying to a redditor: > What is your opinion on the simulation hypothesis? > I do not think we live in a computer simulation. No digital computer can compute all the motions of molecules in a simple object, e.g. the weather. The smallest object which can simulate the weather is the weather itself. When you add quantum corrections, then no digital computer on earth can simulate the quantum effects in the weather. So no digital computer can possibly simulate reality as we know it. Full thread: https://www.reddit.com/r/IAmA/comments/bghqn9/comment/elkxs66/ · 1,269 points as of Nov 7, 2026 ### **Michio Kaku** (u/michiokakuauthor) in r/IAmA, Feb 21, 2018 · Explains things Replying to a redditor: > Hi Michio, if I were to travel to the boundary of our universe right now, what do you think will be there? Is it possible to "fall off" this universe the same way we fall out of our bed? Thanks in advance! > No one knows. But one possibility is that the universe is a bubble of some sort. We live on the skin of the bubble. If you travel in one direction far enough, you come back to where you started. So the farthest object is the back of your head. In this way, this bubble universe is infinite in two dimensions, since you never hit the end, but finite in three dimensions, since its just a bubble. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/7z9531/comment/dumbef0/ · 1,490 points as of Nov 7, 2026 ### **Michio Kaku** (u/michiokakuauthor) in r/IAmA, Apr 23, 2019 · AMA answer Replying to a redditor: > Hey I just wanna say thanks for making me fall in love with something I don't really understand. I read one of your books in high school and it set me on a really great path of curiosity. The fact that you made these groundbreaking topics like string theory somewhat available… > Thank you. We are all born scientists. We are born wondering where we came from, why the sun shines, why the stars twinkle, etc. But eventually we hit one of the greatest destroyers of science known to science, high school. In high school, science is made boring and irrelevant to people's lives. In my books, I try to make young people cherish science once again. Full thread: https://www.reddit.com/r/IAmA/comments/bghqn9/comment/elkyd9k/ · 2,099 points as of Nov 7, 2026 ### **Brian Greene** (u/briangreeneauthor) in r/IAmA, Feb 24, 2020 · Explains things Replying to a redditor: > Do you think that the question of "consciousness" is ever possible to be explained via physics in the same way we describe other phenomenon? What other kind of reasoning or understanding could there be? > I do. I hold to a so-called physicalist perspective that imagines consciousness/mind not requiring any "spark" or "force" or "substance" that stands outside the very same types of ingredients that make up my desk or coffee cup. Some recoil at this possibility, thinking it diminishes mind. I have a different view. I consider it WONDROUS that ordinary particles governed by the usual forces of nature, when configured appropriately, can think and feel and explore. To me, that is the point--matter and laws accomplish spectacular things. Full thread: https://www.reddit.com/r/IAmA/comments/f8vvdo/comment/finwzg1/ · 370 points as of Nov 7, 2026 ### **Stephen Wolfram** (u/StephenWolfram-Real) in r/IAmA, Feb 23, 2016 · Behind the scenes Replying to a redditor: > What's the craziest thing you've seen your Wolfram Alpha engine respond with, and what was the query you used? Are there any easter eggs you'd care to share with us? > I sometimes think the problem is not the creation of artificial intelligence, but the avoidance of artificial stupidity... I put some of my favorites from the history of Wolfram|Alpha in http://blog.stephenwolfram.com/2012/04/overcoming-artificial-stupidity/ > > E.g. "all the king's horses" used to be interpreted as the total horse livestock population of the world, on Elvis's birthday... Full thread: https://www.reddit.com/r/IAmA/comments/478njk/comment/d0b2e9y/ · 352 points as of Nov 7, 2026 ### **Stephen Wolfram** (u/StephenWolfram-Real) in r/IAmA, Feb 24, 2016 · Normal redditor Replying to a redditor: > Hello Stephen, I have a very important question that many of my colleagues wish to have answered: Would you rather fight 100 duck sized horses, or 1 horse sized duck? How might you use Mathematica to answer this intelligently? > I'm certainly no expert on fighting ... but here's how I might approach the problem. Basically I would want to make models of these creatures---their mechanics, and if possible their behaviors. I know Mathematica has been used a bunch to model quadruped mechanics (e.g. for dinosaurs in movies, and real things). I'd probably start from models of the biomechanics of ducks and horses. We recently added detailed human anatomy data to the Wolfram Language and Wolfram|Alpha (see e.g. http://www.wolframalpha.com/examples/HumanAnatomy.html ), and I know from that project (which took a long time) that there isn't readily available comparable data for other species. So one would have to wing it a bit (and, yes, I have no idea about models for the wings...) (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/478njk/comment/d0bb9u9/ · 365 points as of Nov 7, 2026 ### **Robert Sapolsky** (u/RobertSapolsky) in r/IAmA, Nov 10, 2023 · Behind the scenes Replying to a redditor: > Dear Dr Sapolsky, I´ve been a great fan of your work after since watching your course on behavioural evolution, I especially enjoyed your stories about the baboons you studied. You once talked about a radical change in the behaviour of these baboons after the more agressive… > The social culture of that troop continued for about 15 more years, and it was a bit lucky -- male baboons change troops at puberty, so there'd be a new adolescent male show up now and then. Invariably, having grown up off the commune, he'd be this aggressive, displacing jerk; fortunately, the troop could handle one or two of these at a time, slowly assimilating the newcomer into this style -- "we don't do stuff like that here." (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/17rms04/comment/k8lfjwm/ · 85 points as of Nov 7, 2026 ### **Robert Sapolsky** (u/RobertSapolsky) in r/IAmA, Nov 10, 2023 · Explains things Replying to a redditor: > Considering the varying effects of stress on health and behavior, is there evidence to suggest that certain types of stress can be beneficial for the development of young individuals? By the way, I truly value and respect your work. > Nonetheless, there are types of stress that are not damaging. In fact, there are types that are so great that you pay to experience it -- eg., a roller coaster, a good scary movie. This sort of good stress has typical features -- it doesn't go on for a long time, it's not too severe, and it's within what is overall a benevolent setting. Roller coaster rides are 3 minutes, not 3 weeks long, and you know there's the danger that you're going to feel queasy afterward, not that there's a decent chance that you'll be decapitated. What do we call the right kind of stress? Stimulation. And too little of it (i.e., boredom) is just as damaging as too much of it (i.e., our everyday sense of stress as adverse). So that expains everyrthing...until you have to deal with that issue of individual differences -- optimal stimulation for one person might be, say, a tiring but fun morning spent bird-watching, while for someone else, it might be signing up to be a mercenary in Mali. How people wind up with these different setpoints is hugely important. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/17rms04/comment/k8lghq5/ · 119 points as of Nov 7, 2026 ### **Eric Lander** (u/Eric_Lander) in r/IAmA, Feb 21, 2013 · Behind the scenes Replying to a redditor: > What is your favorite memory from working on the Human Genome Project? > Two memories: > > (1) Getting on the phone every Thursday at 11am Eastern for three years, with the same group of people around the world dedicated to a common goal. We argued with each other, yelled at each other, cajoled each other, bucked each other up. We had ups and downs, but we never doubted the mission of making the information freely and rapidly available to everyone. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/18ymad/comment/c8j6nox/ · 489 points as of Nov 7, 2026 ### **Eric Lander** (u/Eric_Lander) in r/IAmA, Feb 21, 2013 · Personal story Replying to a redditor: > Thanks for do this AmA Dr. Lander! As a biological sciences undergraduate student, I've always had a passion for life around me. What was the moment (if there was one) when you really knew biology was your future? > It came VERY late! I loved math (and hated biology) in high school, college and grad school. It was only when I was out of grad school and my brother gave me some papers to read about the brain that I got interested in biology. I started sitting in on some courses at Harvard and MIT to learn some biology. But I really got hooked when I started doing some experiments in a colleague's lab. Bottom line: It's never too late to discover a passion. Full thread: https://www.reddit.com/r/IAmA/comments/18ymad/comment/c8j7w5i/ · 294 points as of Nov 7, 2026 ### **Brian Fisher** (u/Brian_Fisher) in r/science, Aug 21, 2015 · Explains things Replying to a redditor: > Welcome Brian, I have long wondered what I am seeing when 10s of thousands of ants pour out onto the sidewalk in chaos. I've read about the long, violent wars that ants will wage, but is that what is happening? Or is it probably something else? Thank you! > Ants, like humans, have many strategies for defending their territory. One interesting example is the Pavement ant, Tetramorium sp. E. (why sp. E, well that is another story). This species is native to Eurasia but was introduced to North America about 100 years ago (note ants, like humans, are quick to colonize new words: Argentine ant, Fire ants .....) but what is cool is that it does a "play" war, right in front of your house, in almost every urban setting across North America. Two colonies will meet on a front, each colony trying to push and shove the other back, demonstrating, with little casualties, that they are superior and not to be messed with. From a standing position, it may just look like a black mat, but up close, it is a full on drama, with ants pushing and shoving. It is like that scene in Ant Man, where the toy train falls over - we have no idea what is happening in the secret world of the small. Full thread: https://www.reddit.com/r/science/comments/3hu8oe/comment/cuav3nm/ · 6 points as of Nov 7, 2026 ### **Brian Fisher** (u/Brian_Fisher) in r/science, Aug 21, 2015 · AMA answer Replying to a redditor: > Given they can cause a right old mess of my garden paths and have recently managed to dig their way into my living room, I have tended to smother ant nests with poison. I understand ants tend to be quite useful for moving and aerating soil, but are there any other benefits to… > How lucky you are!! To have ants visit you, right in your home. Nature not at your doorstep but in your own living room. I can understand how at first this may feel like an invasion. But stop, don't reach for the poison. Take a moment and learn from her ways. Watch how they communication and self organize. Realize you are dealing with an organisms that has collective intelligence that is teaching us how to develop algorithms for AI, how to develop better business structure, how to build better roads and functioning cities. Stop and realize that it is these ants that are responsible for soil in your garden - they turn over more soil than earthworms; they are the vacuum cleaners that keep the "brown cycle" humming along so that the cycle of ecosystems keep working. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3hu8oe/comment/cuawcwb/ · 5 points as of Nov 7, 2026 ### **Carl Safina** (u/Carl_Safina) in r/science, Aug 29, 2016 · AMA answer Replying to a redditor: > How would you teach children to be concerned? > I wouldn't. I would teach them to love the living world. I would show them how we act when we love and care for the world. I would let them get wet, dirty, sandy, and happy. Full thread: https://www.reddit.com/r/science/comments/504pou/comment/d71jquz/ · 16 points as of Nov 7, 2026 ### **Temple Grandin** (u/Prof_Temple_Grandin) in r/science, Nov 17, 2014 · Explains things Replying to a redditor: > I work in a small slaughterhouse. We butcher about 6 cows every week, so we dont have as much possibilities when it comes to redesigning, as industrial plants might have. What are some fundamental things we should do, or have installed, to make the process as easy and… > Often simple modifications, such as providing non-slip flooring in the stun box can make huge differences. Cattle panic when they do not have secure footing. They also do not like to enter dark spaces, so you might experiment with placing a light at the entrance to the stun box. In one plant, the cattle were refusing to enter the stainless steel race with lots of reflections, and we experimented with moving ceiling lights. This caused the reflections to disappear and the cattle then willingly entered the race. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/2mk0qz/comment/cm56dap/ · 450 points as of Nov 7, 2026 ### **Temple Grandin** (u/Prof_Temple_Grandin) in r/science, Nov 17, 2014 · Behind the scenes Replying to a redditor: > Professor Grandin, How accurately did the HBO movie portray the way you see the world? I was particularly interested in the way it depicted the mental mapping of the animal's movements. Was this a device they chose to use or something you advised them about the way you see… > Many people ask about the HBO movie, and it accurately shows how my visual thinking works. The scene that showed all the shoes appearing in rapid succession is exactly how I think. The images that appear around animal movement are from my actual drawings and diagrams that appear in my early publications. The scene where I get down on my hands and knees in the chute is something that I actually did, so I could see what the cattle were seeing. Full thread: https://www.reddit.com/r/science/comments/2mk0qz/comment/cm55ati/ · 695 points as of Nov 7, 2026 ### **Jerry Coyne** (u/Jerry_Coyne) in r/science, May 22, 2015 · Explains things Replying to a redditor: > I have a more technical question; At some point, one of our ancestors had two chromosomes fused, and the chimpanzees didn't. But didn't that render this ancestor genetically incompatible with the rest of his/her species? Or was the fused-chromosome ape, still able to reproduce… > In fact, for chromosome fissions and fusions (the latter are more common, so I'll use that as an example), there's often no selective disadvantage to the new chromosome. When it's formed, it pairs up fine with its two-chromosome ancestor in the individual that experienced the fusion. If pairing is normal (as it often is, with each of the separated chromosomes lining up alongside the homologous arm of the fused chromosome), then meiosis--the formation of sperm and eggs--will proceed normally, and there will be no sterility. Given the vagaries of reproduction, the fused chromosome can come to be "fixed" (everyone has it) in a population, as it did in our ancestors. > > The evidence that there's often no reproductive disadvantage to many fusions (or fissions) comes from both direct observation as well as the fact that some populations, such as mice in northern Italy, show individuals with all kinds of fused or "fissed" chromosomes, and when you bring them into the lab their fertility is normal. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/36v7vp/comment/crhk55y/ · 203 points as of Nov 7, 2026 ### **Heather Hendrickson** (u/Heather_Hendrickson) in r/science, Nov 8, 2016 · Explains things Replying to a redditor: > What's to stop a virus that's been implanted from mutating such that it's no longer beneficial, or perhaps even now harmful to the host? > Bacteriophages have had 2 billion years to start infecting humans and they haven't yet. To be honest, this isn't a big surprise ... there are WAY more bacterial cells on the planet to attack than there are human cells! Also, taking over a bacterial cell is relatively easy, the DNA and all of the working machinery is just sitting in the cell. Eukaryotic cells (like ours) have the DNA wrapped up and hidden in an extra organelle. Too complicated! Infecting bacteria is a pretty great job (if you can get it). At least , that is what the bacteriophages tell me. Full thread: https://www.reddit.com/r/science/comments/5blwfu/comment/d9qkxqs/ · 4 points as of Nov 7, 2026 ### **Cassandra Quave** (u/Cassandra_Quave) in r/science, May 5, 2017 · Explains things Replying to a redditor: > I'm personally against the extraction method utilized by western medicine. Such as stripping a plant down to one chemical constituent to be used in a medicine. I think plants ha e grown the way they do and have been used as traditional medicines as a whole. Not to have their… > Very good concern. Plants did not grow to become medicines; they grew to survive and give rise to progeny. And the medicinal chemicals they did produce were produced to achieve that end. So I do not think that the plant as a whole is always the optimal way to develop potent treatments to diseases. Rather, they contain medicinal value that we can utilize. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/69e7ni/comment/dh68p9c/ · 5 points as of Nov 7, 2026 ### **David Eagleman** (u/Dr_David_Eagleman) in r/IAmA, Aug 26, 2020 · Explains things Replying to a redditor: > * What do psychedelic states tell us about the brain? * What's one practical way in which anyone can utilize the plasticity of the brain to improve their lives? * Is there any potentially negative (or non-beneficial) implication of brain plasticity? Editing to say thank you for… > 3) In the book I address the issue that older people often say they would want the brain plasticity of young people. But there may be a philosophical problem here. The reason your brain has less plasticity as you age is because you have developed a better and better model of the world. If you could suddenly take a magical pill that gave you lots of brain plasticity again, you would forget your memories, your language, how to properly interact with other people, the rules of functioning in your culture, etc. So that would be the downside to increasing plasticity. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/ih4x52/comment/g2xy54x/ · 5 points as of Nov 7, 2026 ### **David Eagleman** (u/Dr_David_Eagleman) in r/IAmA, Aug 26, 2020 · Explains things Replying to a redditor: > What tradeoffs are there when expanding our senses with wearables, e.g. disrupting attention spans? > Imagine that you had a friend born blind, and she were to say to you "how in the world can you concentrate when you are capturing and analyzing billions of photons all the time? Don't you find that overwhelming?" Or imagine you have a deaf friend who says "how could you possibly concentrate when you're getting bombarded with air compression waves that carry information about all of the world around you?" > The fact is, new senses get incorporated into our daily lives such that they are somewhere between interesting and boring, but we don't really need to attend to them very much at all. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/ih4x52/comment/g2xz8s7/ · 2 points as of Nov 7, 2026 ### **David Eagleman** (u/Dr_David_Eagleman) in r/IAmA, Aug 26, 2020 · Explains things Replying to a redditor: > Ever thought about designing contact lenses that could make you see UV/IR ? In the same way that you can feel them using the wristband designed by your company? > Would be great, although quite a technological challenge. However, note that in LIVEWIRED I discuss the fact that some people with cataracts will get a synthetic lens put in their eye... and that lens can pass UV light through (unlike your normal lens). So they actually get UV light perception for free. Full thread: https://www.reddit.com/r/IAmA/comments/ih4x52/comment/g2xxa87/ · 2 points as of Nov 7, 2026 ### **Julia Shaw** (u/Dr_Julia_Shaw) in r/askscience, Feb 10, 2016 · Behind the scenes Replying to a redditor: > Has learning about this stuff changed how you use your own memories? > While I was always cautious about memory accuracy (as far as I remember, hah!), now I am convinced that no memories are to be trusted. I am confident that we create our memories every day anew, if ever so slightly. It's such a terrifying but beautiful notion that every day you wake up with a slightly different personal past. (Excerpt.) Full thread: https://www.reddit.com/r/askscience/comments/452fm7/comment/czv0pby/ · 107 points as of Nov 7, 2026 ### **Julia Shaw** (u/Dr_Julia_Shaw) in r/askscience, Feb 10, 2016 · Explains things Replying to a redditor: > I was wondering how you feel about "flash-bulb" memories, which are supposedly seared in our minds and harder to misremember. The intro textbooks said it happens but I've read studies that said they were just as vulnerable, if not more. As an example, a writer found that many… > Flashbulb memories, such as vividly remembering the twin towers get hit during 9/11, are indeed susceptible to all the same kinds of memory errors as any other kind of memory. As you say, they may even be MORE prone to distortion because we often have absurdly high confidence in them, they seem incredibly vivid, and we usually repeat these memories over and over again. Full thread: https://www.reddit.com/r/askscience/comments/452fm7/comment/czv52a2/ · 19 points as of Nov 7, 2026 ### **Julia Shaw** (u/Dr_Julia_Shaw) in r/askscience, Feb 10, 2016 · Explains things In the thread "AskScience AMA Series: I’m Dr. Julia Shaw, a memory scientist and criminal psychologist. I study how we create complex false memories. AMA!". > I like to call these early childhood false memories "stolen" memories. Many of these events probably did happen, you were just told the stories by loved ones and you appropriated them in a way that now makes them feel like your own. I actually write about being a "memory thief" here: http://blogs.scientificamerican.com/guest-blog/holiday-dinner-with-false-memories-for-dessert/ Full thread: https://www.reddit.com/r/askscience/comments/452fm7/comment/czv462h/ · 12 points as of Nov 7, 2026 ### **David Dunning** (u/Dr_David_Dunning) in r/science, Nov 13, 2014 · AMA answer Replying to a redditor: > First of all, thank you for taking the time. I'm curious as to how your research has altered or affected your view of yourself, would you feel comfortable elaborating? > I am no longer so surprised about being wrong, and much more willing to listen to the lessons that the world and other people are telling me. As I grow older, I recognize just how little I know. I forgot who said it, but one of my favorite sayings is "I am not young enough to know everything", or something like that. I believe it was Oscar Wilde...but I could be wrong. Full thread: https://www.reddit.com/r/science/comments/2m6d68/comment/cm1mmjf/ · 34 points as of Nov 7, 2026 ### **Chris French** (u/Prof_Chris_French) in r/science, Jun 29, 2015 · AMA answer Replying to a redditor: > Does [this](https://en.wikipedia.org/wiki/Shanti_Devi) fall into your area of interest? Shanti Devi case of reincarnation. I am so skeptical about this I hope this gets proven to be something madeup. > Reincarnation claims in general do fall into my area but I’m afraid I have not looked into this particular case in any detail. I do find reincarnation claims fascinating. So much so that I paid £500 last week to join the Reincarnation Society. I wasn’t sure whether to blow that much money or not but then I thought, Oh well, you only live once (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/3bi3d7/comment/csmfs9u/ · 511 points as of Nov 7, 2026 ### **Chris French** (u/Prof_Chris_French) in r/science, Oct 31, 2016 · Explains things Replying to a redditor: > What is a common theme among the people who claim to have had alien contact? > Contrary to the view offered in Hollywood movies, hypnotic regression does not provide a magical key to unlock hidden or repressed memories. Instead, it provides the perfect context for the formation of false memories based upon fragments of real memories (including those from books, films, etc.), imagination, expectation, and so on. With hypnotic regression, you tend to get what you expected to get. If you expect alien abduction memories, that’s what you get. If you expect past-life memories, that’s what you get. If you expect memories of ritual satanic abuse memories, that’s what you get. These are all almost certainly false memories. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/5abt6c/comment/d9fa3n7/ · 652 points as of Nov 7, 2026 ### **Chris French** (u/Prof_Chris_French) in r/science, Oct 31, 2016 · Personal story Replying to a redditor: > What's the most interesting case you know of a debunked paranormal experience? > I have lots of personal favourites but certainly one that would be very near the top of the list would be Melvin Harris’s masterful debunking of the so-called “Bloxham Tapes”. Arnall Bloxham was a Cardiff-based hypnotherapist who used to hypnotically regress people back into past lives and record the accounts given. In contrast to most such cases, the accounts were often detailed and largely accurate. It turned out though that the accounts of one of Bloxham’s star cases, that of Welsh housewife “Jane Evans”, were based upon historical novels based upon real historical figures. For example, Jane’s narratives included not only accounts of her interactions with historical characters who had really existed but also with the fictional characters that the author had made up just to help the plot along. Full thread: https://www.reddit.com/r/science/comments/5abt6c/comment/d9fascv/ · 227 points as of Nov 7, 2026 ### **Francis Collins** (u/NIHDirector) in r/science, Apr 25, 2016 · Explains things Replying to a redditor: > I recently had my DNA sequenced through 23andMe. They said that a percentage of my genome couldn't be sequenced because it was "too unique to definitively match" to any specific data they had. What could be so different about my genome? > If you look closely enough, all of our genomes are unique unless we have an identical twin. Each of us has about 60 new mutations that were not present in our parents and may never have been present in anyone until us. Some of those variations involve duplications of large segments of DNA, which may be difficult to map back to the reference sequence. So, don’t assume that there is something seriously awry with your genome. We are all in the same boat. Full thread: https://www.reddit.com/r/science/comments/4gcwwy/comment/d2gowcg/ · 17 points as of Nov 7, 2026 ### **Adrian Owen** (u/ProfAdrianOwen) in r/science, May 3, 2014 · Explains things Replying to a redditor: > Are these questions properly blinded? I.e. Does the person asking the question know the answer? If so, then it could be some other influence causing the responses you are seeing? Something not necessarily related to conscious thought? I remember seeing a show once about a dog… > > Does the person asking the question know the answer? > > Of course not - that would introduce the possibility of experimenter bias. Indeed, for the most part, the decision is made, not by a human at all, but by a computer applying proven statistical models (e.g. if the scan returns statistically significant activity in the expected area of the brain at exactly the expected point in time that we have asked the paint to deliver an answer to the question, then it's either a real answer - 'yes or no' - or it's an amazing coincidence. After you have 5 or 6 'amazing coincidences' in a row (it always happens and it never doesn't happen) you start to realize that they are not coincidences at all, because the possibility of that happening by chance is incalculably small. Full thread: https://www.reddit.com/r/science/comments/24jcz5/comment/ch8ggm4/ · 9 points as of Nov 7, 2026 ### **Adrian Owen** (u/ProfAdrianOwen) in r/science, Jul 18, 2017 · Explains things In the thread "Science AMA Series: I’m Dr. Adrian Owen, a neuroscientist whose research focuses on brain imaging, cognitive function and consciousness. We’re finding new ways to decode the complex workings of the brain. AMA.". > Transplants fascinate me, because they have changed medicine in so many fantastic ways, yet the idea of ‘head transplants’ really is fundamentally different. Without a heart we can live on with the help of machines. A patient with an artificial heart is still the same person. Without a liver or kidneys we can survive, personality unchanged, until the death of another person provides us with a transplanted organ with which we can resume our lives, pretty much as we did before. We can lose arms, legs, eyes, and more and remain the same people, altered but nevertheless still us. Yet without our brains we are nothing more than a memory to others. We are not even a shadow of our former selves. We are gone. I suppose what I am saying here is that a head transplant is basically a ‘person transplant’. Your brain is who you are. It’s every plan you’ve ever made, every person you’ve fallen in love with, and every regret you’ve ever had. Your brain is all there is. It’s the pulsating essence of you as a person. Without a brain (or after a ‘head transplant’), you really would be someone else. Full thread: https://www.reddit.com/r/science/comments/6o0gcr/comment/dke3u2q/ · 10 points as of Nov 7, 2026 ### **Matt Parker** (u/standupmaths) in r/IAmA, Feb 13, 2020 · Personal story Replying to a redditor: > Any progress on the three-sided coin you and Dr. Hugh Hunt were working on? > The short answer is that I flipped a normal coin 10,000 times to see how many times it would land on its edge. I had a chance to do this a while back and so I spent three days on it; it also meant I could [mention it in Humble Pi](https://imgur.com/a/SwnCGxa). I've just not had the time to sort through the results and get a video out. Blame my lack of time. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/f3cm7d/comment/fhi2dkl/ · 111 points as of Nov 7, 2026 ### **Matt Parker** (u/standupmaths) in r/IAmA, Feb 13, 2020 · Explains things Replying to a redditor: > Are there any common misconceptions that the general public typically has about a concept in math that you must get them to "unlearn?" > For the general public: that being bad at math is an immutable personal trait. I want people to realise that everyone finds math difficult to some extent and the people who are 'good to math' are just those who enjoy the fact it is difficult (or put in the effort for some other reason). > > For people who are slightly interested in math: misconceptions about what is 'allowed' and what happen when you break those rules. > > For example (and I'm going to paraphrase a lot here with non-rigorous language): taking the square root of a negative number is 'not allowed' but if you pretend you can you get i and this leads the magical world of complex numbers. Which is all great because assuming i leads to loads of rich and consistent results. > > But then I get loads of people emailing me because they have found the secret of dividing by zero, which is 'not allowed', and it is always some variation on assuming it is and giving the result a name. Which is fine. But it then does not lead to anything interesting or consistent. > > Math is a game where you can make up any rules you want. But if they don't give interesting results then we discard that idea. > > For professional mathematicians: that sometimes it is ok to paraphrase a lot with non-rigorous language. Full thread: https://www.reddit.com/r/IAmA/comments/f3cm7d/comment/fhi3lfi/ · 535 points as of Nov 7, 2026 ### **Matt Parker** (u/standupmaths) in r/AskReddit, May 20, 2019 · Normal redditor Replying to a redditor: > Wasn't it Pepsi that offered a harrier jet as a prize. Then someone collected enough points to actualy get it. If so how's that for a plot twist. They should have used a Russian sub instead lol. > Yes indeed: they put a Harrier jet in the 1995 commercial for 7,000,000 Pepsi points as a zany joke… but extra points cost 10c each and the jet was worth over $20 million. Guy called John Leonard put $700,008.50 (inc postage and handling) in escrow and sent off his order. > > In the resulting court case Pepsi had to prove it was a joke and not something a reasonable person would consider a serious offer. Pepsi did win “Leonard v. Pepsico, Inc.” and the ruling contains these gems: > > - The teenager’s comment that flying a Harrier Jet to school ‘sure beats the bus’ evinces an improbably insouciant attitude toward the relative difficulty and danger of piloting a fighter plane in a residential area, as opposed to taking public transportation. > > - No school would provide landing space for a student’s fighter jet, or condone the disruption the jet’s use would cause. > > - In light of the Harrier Jet’s well-​­documented function in attacking and destroying surface and air targets, armed reconnaissance and air interdiction, and offensive and defensive anti-​­aircraft warfare, depiction of such a jet as a way to get to school in the morning is clearly not serious. (Excerpt.) Full thread: https://www.reddit.com/r/AskReddit/comments/bqm3th/comment/eo7q6l6/ · 213 points as of Nov 7, 2026 ### **James Grime** (u/JamesGrime) in r/IAmA, Oct 28, 2014 · Explains things In the thread "I am James Grime, mathematician, Alan Turing fan, and numberphile. AMA!". > I get asked this one a lot, and I will give you the real answer - I do not have a favourite number. (shock!) > > To me they are tools, and I have not anthropomorphised the numbers. Mathematicians do get asked this a lot and I think it's like asking an author "what's your favourite letter". > > However, if you really want to put me on the spot, I'll say.... 1? Where would we be without the 1. In a semigroup, that's where. Full thread: https://www.reddit.com/r/IAmA/comments/2klw5q/comment/clmjabl/ · 115 points as of Nov 7, 2026 ### **James Grime** (u/JamesGrime) in r/IAmA, Oct 28, 2014 · Explains things Replying to a redditor: > I don't know much about Turing but I would like to hear more from you, especially as it seems you're wanting to talk about him!... So just just going off of one of your previous answers, can you tell us more about his work on mathematical biology? What part of it are you most… > If you don't know this it's pretty cool. Alan wanted to answer the question, why do Zebras have stripes, leopards have spots, cows have patches. He model the development of the pigmentation with mathematical equations similar to the equations that describe waves. He called it "waves on cows and waves on leopards". This is something he did in 1952, so after the war and a couple of years before his death. It is still a fundamental paper in mathematical biology. Full thread: https://www.reddit.com/r/IAmA/comments/2klw5q/comment/clmm2zs/ · 6 points as of Nov 7, 2026 ### **Hannah Fry** (u/HannahFry) in r/science, Mar 10, 2015 · Explains things Replying to a redditor: > Hi Hannah! I only have on question, and it's not specifically related to your book or TED talk. I just want to know, from your perspective, what is it that keeps female participation in STEM careers and studies so low? I won't burden the question with any information or… > There have been a number of qualitative surveys of maths PhD students & of the ones I've seen there is always a stark contrast between the way that boys and girls speak about things. > > Both find the PhD hard, but boys put their difficulties down to the subject itself, but girls put it down to their own ability. > > I don't know why this is, but the problem might stem from earlier on. When you’re a young woman and tell people you're studying mathematics (or similar) there’s always an element of surprise. “You’re a girl doing maths? Wow” etc. > > But if you’re a boy doing maths, there is still an element of surprise, but I'd guess that the tone is different: “You’re doing maths? Wow you must be really clever”. > > Then, when the maths gets really hard – which it does – the boys reaction is “I’m clever, it’s the maths that’s hard” > > But if girls grow up with people being surprised at their choice of subject, it’s no wonder that when the subject get’s hard, they think that they are the problem. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/2yjntv/comment/cpaefh6/ · 40 points as of Nov 7, 2026 ### **Jordan Ellenberg** (u/Jordan-Ellenberg) in r/science, Mar 2, 2018 · AMA answer In the thread "I’m Jordan Ellenberg, author of How Not To Be Wrong: The Power of Mathematical Thinking, and I’m on this week's NOVA: “Prediction By The Numbers.” Ask me anything about mathematics, predicting the future, predicting the future of mathematics, data, and number theory!". > Are you going to be trampled and left in the dust by brilliant kids? Well, we all are, eventually, right? In math, there is *always* someone stronger/faster/more advanced than you. That is not a reason not to do it. If it were, there would only be one mathematician. That would stink. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/81dvbs/comment/dv2xs5a/ · 9 points as of Nov 7, 2026 ### **Edward Frenkel** (u/EdwardFrenkel) in r/IAmA, Jul 2, 2015 · AMA answer Replying to a redditor: > Hello Dr. Frenkel, big fan of your book! Do you have any advice for an aspiring mathematician just starting his undergraduate career? > People often get frustrated with math because they feel they "don't understand." But I say: good! Life would be so boring if we could understand everything easily. :) If anything, I should be worried about what I *think* I understand. 90% of the time, when I do mathematics, I do not understand, and this is what drives my passion for learning and discovery. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/3bvydv/comment/csq0h57/ · 9 points as of Nov 7, 2026 ### **Yann LeCun** (u/ylecun) in r/MachineLearning, May 15, 2014 · Explains things Replying to a redditor: > How would you rank the real challenges/bottlenecks in engineering an intelligent 'OS' like the one demonstrated in the movie 'Her' ... given current challenges in audio processing, NLP, cognitive computing, machine learning, transfer learning, conversational AI, affective… > Something like the intelligent agent in "Her" is totally out of reach of current technology. We will need to invent new concepts, new principles, new paradigms, new algorithms. > > The agent in Her has a deep understanding of human behavior and human nature. It's going to take quite a while before we build machines that can do that. > > I think that a major component we are missing is an engine (or a paradigm) that can learn to represent and understand the world, in ways that would allow it to predict what the world is going to look like following an event, an action, or the mere passage of time. Our brains are very good at learning to model the world and making predictions (or simulations). This may be what gives us 'common sense'. > > If I say "John is walking out the door", we build a mental picture of the scene that allows us to say that John is no-longer in the room, that we are probably seeing his back, that we are in a room with a door, and that "walking out the door" doesn't mean the same thing as "walking out the dog". (Excerpt.) Full thread: https://www.reddit.com/r/MachineLearning/comments/25lnbt/comment/chiftyb/ · 42 points as of Nov 7, 2026 ### **Yann LeCun** (u/ylecun) in r/MachineLearning, Jul 20, 2016 · Normal redditor Replying to the post "[Tribute] An art made by André Pinto (Anthill Comics) for our Machine Learning Meetup". > That's really funny, and nicely drawn. > > It makes me look thinner than I am too ;-) > > I'm just slightly worried about Bender's nasty look. > He is clearly not interested in ConvNets. > He is probably thinking "I'm 30‰ ConvNet" or "kill all humans" > Either that or he is looking for the bar. Full thread: https://www.reddit.com/r/MachineLearning/comments/4tmpl9/comment/d5janzi/ · 40 points as of Nov 7, 2026 ### **Yoshua Bengio** (u/yoshua_bengio) in r/MachineLearning, Feb 27, 2014 · Behind the scenes Replying to a redditor: > Is there attempts to apply neural nets to the task of machine translation? When do you think NN based approaches replace statistical methods in commercially deployed MT systems? I mean in speech recognition(all major industry players) and vision(Google, Baidu) tasks NNs are… > Briefly, since neural nets already beat n-grams on language modeling, you can first use them to replace the language-modeling part of MT. Then you can use them to replace the translation table (after all it's just another table of conditional probabilities). Other fun stuff is going on. The most exciting and ambitious approaches would completely scrap the current MT pipeline and learn to do end-to-end MT purely with a deep model. The interesting aspect of this is that the output is structured (it is a joint distribution over sequences of words), not a simple point-wise prediction (because there are many translations that are appropriate for a given source sentence). (Excerpt.) Full thread: https://www.reddit.com/r/MachineLearning/comments/1ysry1/comment/cfq7fs9/ · 5 points as of Nov 7, 2026 ### **Jürgen Schmidhuber** (u/JuergenSchmidhuber) in r/MachineLearning, Mar 5, 2015 · Explains things Replying to a redditor: > Do you have any interesting sources of inspiration (art, nature, other scientific fields other then obviously neuroscience) that have helped you think differently about approaches, methodology, and solutions to your work? > I think the basic motivation (objective function) of artists and scientists and comedians > is data compression progress, that is, the first derivative of data compression performance on the observed history. > [I have published extensively about this](http://people.idsia.ch/~juergen/creativity.html). > > A physicist gets intrinsic reward for creating an experiment leading to observations obeying a previously unpublished physical law that allows for better compressing the data. > > A composer gets intrinsic reward for creating a new but non-random, non-arbitrary melody with novel, unexpected but regular harmonies that also permit compression progress of the learning data encoder. > > A comedian gets intrinsic reward for inventing a novel joke with an unexpected punch line, related to the beginning of his story in an initially unexpected but quickly learnable way that also allows for better compression of the perceived data. (Excerpt.) Full thread: https://www.reddit.com/r/MachineLearning/comments/2xcyrl/comment/cp51qpu/ · 15 points as of Nov 7, 2026 ### **Jeff Dean** (u/jeffatgoogle) in r/MachineLearning, Aug 11, 2016 · Explains things Replying to a redditor: > The energy efficiency of the brain vs. the large amount of power and computing resources used for conventional deep learning models are often used as an argument to do more 'brain-inspired learning': 1. Is this a fair comparison to be made? If yes, what do you believe leads to… > Regarding energy efficiency, real brains are definitely much more energy efficient and have much more computational ability than current machines. However, the gap is perhaps not as bad as it might seem, for the reason that real brains take ~20 years to "train", whereas, since we are impatient machine learning researchers, we want to do experiments in a week. If we were willing to have our experimental cycle time be 20 years instead of 1 week, we could clearly get much better energy efficiency, but we prefer the faster cycle time for experiments, even if it costs us in energy efficiency. Full thread: https://www.reddit.com/r/MachineLearning/comments/4w6tsv/comment/d6dteht/ · 7 points as of Nov 7, 2026 ### **Jeff Dean** (u/jeffatgoogle) in r/MachineLearning, Aug 11, 2016 · AMA answer Replying to a redditor: > On a scale of 1-10, 10 being tomorrow and 1 being 50 years, how far away would you all estimate we are from general AI? > A 6, but I refuse to be pinned down to whether the scale is linear or logarithmic. Full thread: https://www.reddit.com/r/MachineLearning/comments/4w6tsv/comment/d6dlrh7/ · 33 points as of Nov 7, 2026 ### **Jeff Dean** (u/jeffatgoogle) in r/MachineLearning, Aug 11, 2016 · Personal story Replying to a redditor: > How did you all get into ML ? What were you first projects involving ML? > I had to write a thesis to graduate with honors at the University of Minnesota, so I worked with my advisor, Vipin Kumar, and settled on the problem of exploring parallel training of neural nets on a 64 processor hypercube machine that the department had. Since neural nets were very computationally intensive, parallel training even back then was an attractive notion to allow scaling the approach to more realistic problems. For the thesis, I was able to get interesting speedups on training models for relatively moderately-sized problems. The computational model of neural nets, of many layers of abstraction, each building on each other, really appealed to me at the time, and I went into grad school with the intention of studying parallel computing, but ended up getting seduced by the appeal of writing compilers for high-level object-oriented languages, and did my Ph.D. research work in that area. However, that little notion that neural nets were interesting never really went away, and about five years ago, it seemed like it was worth exploring again, now that both computational power and interesting datasets had grown so much in the ~2 decades since I last revisited them. This led to the genesis of the Google Brain project (initially started by myself, Andrew Ng, and Greg Corrado). Full thread: https://www.reddit.com/r/MachineLearning/comments/4w6tsv/comment/d6dgbb1/ · 7 points as of Nov 7, 2026 ### **Luis von Ahn** (u/vonahn) in r/IAmA, May 29, 2013 · Personal story Replying to a redditor: > Thanks for doing the AMA. I am a big fan of Duolingo. How many languages can you personally speak? > I'm perfectly fluent in English and Spanish. Learning Portuguese, and failed at learning French in high school (though, in my defense, I only took it cuz I had a crush on a girl). Full thread: https://www.reddit.com/r/IAmA/comments/1fa3nu/comment/ca896oj/ · 419 points as of Nov 7, 2026 ### **Luis von Ahn** (u/vonahn) in r/IAmA, May 29, 2013 · Behind the scenes Replying to a redditor: > Is Duolingo actually making enough money the way it works now? > The other day we found a quarter under the couch. I think that's the entirety of our revenue so far. Full thread: https://www.reddit.com/r/IAmA/comments/1fa3nu/comment/ca89oed/ · 440 points as of Nov 7, 2026 ### **Luis von Ahn** (u/vonahn) in r/duolingo, Jan 3, 2017 · Behind the scenes Replying to the post "I find it slightly annoying that Duolingo always has the first word capitalised on these matching exercises, making it super obvious what the first word of the answer is.". > I hate that too! Unfortunately whenever we try removing it, more people complain and our metrics go down :/ Sometimes you just can't win. > > --Luis (CEO of Duolingo) Full thread: https://www.reddit.com/r/duolingo/comments/5ltqep/comment/dbyjxj3/ · 273 points as of Nov 7, 2026 ### **Tim Berners-Lee** (u/timbl) in r/IAmA, Mar 12, 2014 · Normal redditor Replying to a redditor: > Have you learned to spell referrer yet ? > No, my speling is still terible. Hopefully not to much or it will get into header field names without some review at this stage! Full thread: https://www.reddit.com/r/IAmA/comments/2091d4/comment/cg0xajm/ · 1,382 points as of Nov 7, 2026 ### **Tim Berners-Lee** (u/timbl) in r/IAmA, Mar 10, 2015 · Behind the scenes Replying to a redditor: > Do you remember your first thoughts, or words, when you achieved the first successful communication between a Hypertext Transfer Protocol (HTTP) client and server? > Nope. I was head down getting stuff working.... the server and client were both on my machine at that stage... I wasn't using source code control, so I could nto go back and find the critical commit with the "hmm GET seems to work" comment :-) Full thread: https://www.reddit.com/r/IAmA/comments/2ykyht/comment/cpai4fq/ · 1,110 points as of Nov 7, 2026 ### **Radia Perlman** (u/rjp2022Redmond) in r/IAmA, Sep 22, 2022 · Behind the scenes Replying to a redditor: > How/why did you name it Spanning Tree Protocol? I see the visual analogy of the interconnected tree branches to the connected internet, and am wondering how that name/title came to you, were there other candidates for names? > When my manager proposed the problem to me, he was saying "have bridges break all the symmetries and find a loop-free subset of the topology that reaches everyone". It was that night that I realized "Hey! A tree! That's a loop-free topology. Just build a tree! Well...you need to agree on a root. Use ID!" Anyway, then it was all obvious. So, "tree". And "spanning" means reach everyone. Full thread: https://www.reddit.com/r/IAmA/comments/xl6cc4/comment/iphp55h/ · 117 points as of Nov 7, 2026 ### **Radia Perlman** (u/rjp2022Redmond) in r/IAmA, Sep 23, 2022 · Normal redditor Replying to a redditor: > Hello Radia! Thank you for your work on STP - my brother is a network engineer and speaks fondly of STP but I can't profess to understand it as I once began to as I changed field. If I may, I have two questions that are completely unrelated. 1. If I stack two lasagnas atop each… > I love this question! > > I've always hated the term "Internet"....to me, if you have two networks, and connect them, you don't get an "Internet"...you get a bigger network. So I'd say that two lasagnas stacked on top of each other are just a taller lasagna. Unless it overflows your pan, in which case you get a lasagna and a messy oven. > > Not sure about pigeons, but they must have at least two, or else they couldn't have them point at each other and be called pigeon-toed. Full thread: https://www.reddit.com/r/IAmA/comments/xl6cc4/comment/ipjgq3k/ · 16 points as of Nov 7, 2026 ### **Radia Perlman** (u/rjp2022Redmond) in r/IAmA, Sep 23, 2022 · Personal story Replying to a redditor: > What did you study , did you study coding ? > I took a programming class in high school, which (from the answer to another question) I basically didn't learn anything, and was sure at that point that I wanted to avoid computers. I was taking a physics class. The TA approached me and said "I have a project and need a programmer. Would you like to be my programmer?" I said "I don't know how to program." He said "Yes, I know. That's why I'm asking you. I have no money to pay you, and if you knew how to program you'd expect to be paid. You're obviously bright (I was doing well in the class) so I'm sure you could learn." The reason I agreed was that my boyfriend at the time knew how to program, so I figured he could help me. And indeed, programming was fun. I had the whole computer (Supernova) to myself. No operating system. Only a few commands. (maybe 10 instructions?) In that environment, I enjoyed programming. But not everyone in the field just does coding. Some people enjoy it, and that's great, but I'm happy I've managed to find an ecological niche where I design distributed systems and algorithms and don't do the actual implementation. Full thread: https://www.reddit.com/r/IAmA/comments/xl6cc4/comment/ipk1tgj/ · 8 points as of Nov 7, 2026 ### **Bjarne Stroustrup** (u/bstroustrup) in r/OldSchoolCool, Sep 30, 2015 · Explains things Replying to the post "Bjarne Stroustrup, the creator of C++, circa 1979". > It is later than 1996 and earlier than 2001. It's taken in my office at AT&T Labs - Research in Florham Park, NJ Full thread: https://www.reddit.com/r/OldSchoolCool/comments/3mujvn/comment/cvir8bk/ · 63 points as of Nov 7, 2026 ### **Tom Crowther** (u/Tom_Crowther) in r/science, Feb 3, 2017 · Personal story Replying to a redditor: > Where do you get your funding? > I am funded by an EU Marie Curie research grant. So they have absolutely no agendas - they just support innovative science. In all honesty, in the proposal that I wrote to get that grant, I proposed that I would do the experiment under the expectation that the massive soil feedback would not exist. But when the results came in, it was very clear that this feedback is a real thing, which needs to be considered in future climate scenarios Full thread: https://www.reddit.com/r/science/comments/5rtksv/comment/dda9g3k/ · 22 points as of Nov 7, 2026 ### **Forrest M. Mims III** (u/Forrest_Mims) in r/science, Nov 4, 2016 · Personal story Replying to a redditor: > Not a question, but a thank you. I got started in electronics when [this book](https://www.amazon.com/Archer-Engineers-Notebook-Integrated-Applications/dp/B000OZ93JU) came out around 79. I was 13 and biked to my Radio Shack, took examples from the notebook, started jamming 555's… > You mentioned biking to Radio Shack. That reminds me about dictating my earliest Radio Shack books into a portable tape recorder while riding my bike 20 miles every afternoon. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/5b3a09/comment/d9m28i7/ · 8 points as of Nov 7, 2026 ### **Forrest M. Mims III** (u/Forrest_Mims) in r/science, Nov 4, 2016 · Explains things Replying to a redditor: > Hi! I had your Getting Started in Electronics book as a kid and still own it! I'm a biochemist now, and I'm curious how ozone detection works - what is special about the ozone molecule that allows you to track it specifically? > Ozone efficiently absorbs UV-B and UV-C wavelengths. It also absorbs in the visible, with peaks around 590 nm and 610 nm (the Chappuis band), I detect ozone with a 2- or 3-channel instrument that measures sunlight at 300 nm, 305 nm and 311 nm. Since ozone absorbs more effectively at the lower wavelengths, the ratio of any two of these wavelengths is directly proportional to the amount of ozone between an observer and the sun (when corrected for the intervening air mass, pressure, etc.). The principle also works for detecting ambient ozone. I employ the Chappuis band to detect the height of the main stratospheric layer of ozone during twilight. This works surprisingly well, and the twilight result is usually within 5-10 percent of the height measured by balloon-launched ozonesondes. The UV instruments must use very expensive filters. The twilight method uses a 50-cent orange LED that detects at 600 nm. Full thread: https://www.reddit.com/r/science/comments/5b3a09/comment/d9ljar2/ · 10 points as of Nov 7, 2026 ### **Hugh Herr** (u/Hugh_Herr) in r/science, Aug 22, 2016 · Explains things Replying to a redditor: > How well do current bionics wear with time? In other words, how much maintenance and replacement do current technologies require, and how do you see this changing in the future? Also, about how long would you estimate it will take for hand-replacing bionics to roughly match… > The performance of biological systems is of course phenomenal, one characteristic of animals is extraordinary robustness or durability. Sometimes we go 80 years or more without maintenance or repair. Engineered machines go a very short time before needing repair – for example the bionic limbs that I invented and am wearing right now (BiOMs) are designed to work and be functional for only 5 years. To get a machine to emulate a biological body part and to go for more than 5 years is an extremely hard technological challenge. To truly emulate biological function, biological durability would require that the machine repairs itself. Before we have this, our machines will be very limited in their capacity. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/4z0a06/comment/d6s20l0/ · 209 points as of Nov 7, 2026 ### **Burt Rutan** (u/Burt_Rutan) in r/science, Sep 20, 2016 · Behind the scenes Replying to a redditor: > Burt, I am an aerospace engineer for Northrop Grumman, and everyone I talk to here seems so excited to have your company be a part of us. I have two questions if you don't mind: 1) do you think we will see the glider style of spacecraft regain practical use anytime soon? I… > My original concepts for SS1 were capsules, with high-drag devices for reentry (feathers). However, an employee reminded me that I was an airplane designer and that parachutes were inherently unreliable. My focus then led to the invention of the feathering config on ss1. (Excerpt.) Full thread: https://www.reddit.com/r/science/comments/53mucs/comment/d7uvwgx/ · 81 points as of Nov 7, 2026 ### **Burt Rutan** (u/Burt_Rutan) in r/science, Sep 20, 2016 · Personal story Replying to a redditor: > What was the diciest flight you ever made? > The flat spin in the F-4E at Edwards AFB, 1969. Piloted by Jerry Gentry, with me in the back seat. It remains the only flat spin in an F4 that was followed by a normal landing, not a fireball crash. Full thread: https://www.reddit.com/r/science/comments/53mucs/comment/d7uza1g/ · 47 points as of Nov 7, 2026 ### **Burt Rutan** (u/Burt_Rutan) in r/science, Sep 20, 2016 · Normal redditor Replying to a redditor: > Your airplane and space ship designs are the kinds of things that inspired me as a child and an adult. How is it that you've been able to come up with so many odd and innovative designs for so long? What continues to inspire you and drive you? > There is nothing else to do in Mojave California. I lived in that small desert area for 46 years. Full thread: https://www.reddit.com/r/science/comments/53mucs/comment/d7v5ipb/ · 17 points as of Nov 7, 2026 ### **Robert Zubrin** (u/RobertMZubrin) in r/spacex, Sep 25, 2021 · AMA answer Replying to a redditor: > What skill sets do you think will be most important for people arriving in the first 5 years of colonization of Mars? The next 5 years (first 10)? And the next 10 years (first 20)? > first ten years- The ability to fix balky equipment and skills in field exploration. > > Second ten years- the ability to fix balky equipment and skills in construction, farming, and industrial engineering. Full thread: https://www.reddit.com/r/spacex/comments/pv91cs/comment/he98hsn/ · 110 points as of Nov 7, 2026 ### **Robert Zubrin** (u/RobertMZubrin) in r/spacex, Sep 25, 2021 · Explains things Replying to a redditor: > What are some must-have experiments or projects that need to be on the first unmanned Mars landing Starship? Also, could water be used as a radiation protection for future greenhouses, or living spaces. Like putting a bunch of water between the windows? > Greenhouses don't need radiation protection. They need sunlight. So think transparant walls for them. Exploration crews can get by without radiation protection too. But settlements should have radiation protection. Putting them under fish farms is an attractive option. Have your rooftop aquarium skylight grow your food while shielding you from cosmic rays. (Excerpt.) Full thread: https://www.reddit.com/r/spacex/comments/pv91cs/comment/he93lac/ · 179 points as of Nov 7, 2026 ### **Scott Manley** (u/illectro) in r/KerbalSpaceProgram, Jan 23, 2014 · Personal story Replying to the post "Open Letter to Scott Manley". > When I started playing KSP I had it in my mind that manually flying a rocket into orbit was probably beyond the skills of a human without computer assistance, KSP surprised me by showing that it is a learnable skill. I thought that Rendezvous, docking and landing were all the kinds of things that astronauts needed to train for years to manage, I never expected to be able to figure them out and do them on a daily basis. > > And amazingly so do many of you, some of you might have got some help from me, or some of the other great tutorials, but in truth you are all doing this on your own. You're all amazing, able to do things that I once thought were in the realm of autopilots and superhuman pilots. > > So thanks to everyone that plays KSP - Fly safe. > > (even if you think I'm overrated, I don't mind I grew up in Scotland, I have a very thick skin.) (Excerpt.) Full thread: https://www.reddit.com/r/KerbalSpaceProgram/comments/1vwm3o/comment/cewy09y/ · 134 points as of Nov 7, 2026 ### **Scott Manley** (u/illectro) in r/KerbalSpaceProgram, Jan 29, 2015 · Normal redditor Replying to the post "So I was playing around with HyperEdit and I accidentally the Sun...". > When the Mun comes between the Sun and Kerbin we get a solar eclipse, when Kerbin is between the Sun and the Mun we (should) get a munar eclipse, > When the Sun is between Kerbin and the Mun we get the Apocalpyse. Full thread: https://www.reddit.com/r/KerbalSpaceProgram/comments/2u4dbg/comment/co526oc/ · 402 points as of Nov 7, 2026 ### **Bill Nye** (u/sundialbill) in r/IAmA, Nov 5, 2014 · Explains things Replying to a redditor: > In your opinion, what is the most important discovery in the last 10 years? > That the universe is *not* slowing down in its expansion, it's accelerating. > > And, do you know why? > > NOBODY KNOWS WHY! Full thread: https://www.reddit.com/r/IAmA/comments/2le34s/comment/cltybsn/ · 3,988 points as of Nov 7, 2026 ### **Bill Nye** (u/sundialbill) in r/IAmA, Apr 19, 2017 · Explains things Replying to a redditor: > Hey Mr. Science guy! I grew up watching your show and it definitely influenced my path towards engineering. My question is what science fact absolutely blows your mind? > You and I are made of the same material as the stars. We are star dust. Therefore, you and I are at least one way that the universe knows itself. Cue the spooky music. Full thread: https://www.reddit.com/r/IAmA/comments/66ajul/comment/dggxv8b/ · 14,231 points as of Nov 7, 2026 ### **Karl Kruszelnicki** (u/DrKarlKruszelnicki) in r/IAmA, Nov 19, 2013 · Personal story Replying to a redditor: > Dr Karl, What is your opinion on the current educational apparatus as relevant to todays needs, especially with respect to the research of people such as Sir Ken Robinson. Do we need an educational seachange, or do you think that the current system is adequate. > Education. When I was in Bangkok Airport checking in a group of schoolkids (I was not the teacher, but she was in hospital, so I took over), the person behind the counter asked if I was a teacher. I said "yes" because it was too complicated to explain full story. She then upgraded me to Business Class. > Only when we all treat ALL teachers (childcare to University) with that kind of respect, will the Education System be unbroken. Full thread: https://www.reddit.com/r/IAmA/comments/1qxh6p/comment/cdhjqtu/ · 272 points as of Nov 7, 2026 ### **Karl Kruszelnicki** (u/DrKarlKruszelnicki) in r/IAmA, Nov 19, 2013 · Personal story Replying to a redditor: > what was your strangest experience as a taxi driver? > Strangest experience as a taxi driver? Getting lost in the huge Yagoona Tip(garbage dump) at 0200, with no stars to navigate out by, and out of radio range. I had to wait for dawn. Full thread: https://www.reddit.com/r/IAmA/comments/1qxh6p/comment/cdhjm15/ · 275 points as of Nov 7, 2026 ### **Derek Muller** (u/veritasium) in r/IAmA, Jun 4, 2015 · Explains things Replying to a redditor: > A simple scale analysis of the Rossby Number for such an experiment indicates that this is not possible. Rossby Number is Ro = U/(L*f), U is horizontal velocity, L is scale length, f is coriolis parameter. http://en.wikipedia.org/wiki/Rossby_number Low Rossby Numbers (<1) mean… > He notes that the 6 foot pool he used provided a 30,000 amplification of the rotation of the Earth at Boston. This is through conservation of angular momentum as the water drains from the outside towards the middle. As the radius gets smaller the velocity must increase to keep angular momentum constant. (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/38gekk/comment/cruvqze/ · 101 points as of Nov 7, 2026 ### **Derek Muller** (u/veritasium) in r/IAmA, Jun 4, 2015 · Behind the scenes Replying to a redditor: > Thanks for doing this AMA guys. Derek, how often do people really get the questions on your videos wrong? Do you have to hunt for footage of wrong answers, or is the sample you show in your videos similar to the real distribution? > This is a very important question. For most questions the vast majority of people get it wrong, I'm talking 90-95%, sometimes all of them. My goal when I edit the videos is to show people's perceptions as they are, not to embellish them, but to accurately represent what people think. Yes I generally don't show the one or two right answers I may come across because they don't fit with the flow of the video. > > So it is a little troubling how little most people know about science, and that's one of the major things that motivates me to keep making videos. It should also encourage you to talk to everyone you meet about science! Full thread: https://www.reddit.com/r/IAmA/comments/38gekk/comment/cruuhk9/ · 285 points as of Nov 7, 2026 ### **Derek Muller** (u/veritasium) in r/askscience, Nov 2, 2016 · Explains things Replying to a redditor: > Could someone explain what is meant by "local?" And I assume by "realism" you mean that there are particles not just wave functions. > Local means no interactions faster than the speed of light. And realism means if when you look at it you find a particle, then it's a particle when you're not looking at it too. Full thread: https://www.reddit.com/r/askscience/comments/5aqdso/comment/d9iqmh1/ · 103 points as of Nov 7, 2026 ### **Randall Munroe** (u/xkcd) in r/pics, Apr 29, 2009 · Explains things Replying to the post "Snake fail". > If L is the length of the snake and T is the thickness of its body wall, and the snake swallows up to length S, the snake's growing diameter is given by R=2T(1+int(L/(L-S))). > > Since the horizontal diameter of the snake-donut (measured out to the snake's axis) can't get smaller than the width of the snake, S is constrained such that 2T(1+int(L/(L-S))) is less than (L-S)/pi. > > Say the snake in the picture is 1m long and has a 1cm body wall thickness. This means it can't swallow more than 74 cm of its tail before it closes up completely. At this point it will have swallowed its own tail nearly four times. (Excerpt.) Full thread: https://www.reddit.com/r/pics/comments/8ggke/comment/c097cfj/ · 1,053 points as of Nov 7, 2026 ### **Randall Munroe** (u/xkcd) in r/science, Jan 30, 2009 · Personal story Replying to the post "The Electromagnetic Spectrum (pic)". > Whoa, that's one of my dad's sites. That poster -- that specific one in the photo -- hung above my bed as a kid, and it really helped get me interested in science. I learned so much from it. There are other versions of this poster that are more common, but they're not nearly as good. > > The parody mentioned below, [xkcd.com/273](http://xkcd.com/273/), was based directly off of it. Full thread: https://www.reddit.com/r/science/comments/7tgrd/comment/c07cxyn/ · 175 points as of Nov 7, 2026 ### **Carl Zimmer** (u/CarlZimmer) in r/IAmA, Dec 10, 2012 · Personal story Replying to a redditor: > What first got you interested in writing about science? And what made you decide to continue doing it? > Pure good fortune. Got a job as a copy editor at Discover, turned out to be bad at copy editing (too many damn commas!), and was shifted over to fact-checking. Pretty quickly realized science writing was the best kind of journalism ever invented. Been at it 20+ years, and each week there are twice as many things I want to write about than I have time to write about. Full thread: https://www.reddit.com/r/IAmA/comments/14mcvq/comment/c7edvs1/ · 17 points as of Nov 7, 2026 ### **Carl Zimmer** (u/CarlZimmer) in r/IAmA, Mar 14, 2013 · Personal story Replying to a redditor: > You all come across a lot of discoveries, what is one discovery that has just blown your mind? > This is Carl. I have to say my mind has now been blown by a virus with an immune system. I learned about this a couple weeks ago, and I can say that I NEVER thought such a thing was possible. And that was after writing a book on the friggin things. And yet the evidence is pretty overwhelming. AND it could help cure cholera. Mind blown. Details here: http://phenomena.nationalgeographic.com/2013/02/27/the-virus-that-learns/ Full thread: https://www.reddit.com/r/IAmA/comments/1aaji5/comment/c8vlii0/ · 34 points as of Nov 7, 2026 ### **Carl Zimmer** (u/CarlZimmer) in r/IAmA, Dec 10, 2012 · Explains things Replying to a redditor: > After reading some of your articles on parasites, which are both fascinating and terrifying, my primary question is how you manage to ever sleep, ever? I *want* to read Parasite Rex, because like I said it's fascinating, but I don't think I could sleep for a week if I did. As a… > If I say, "I'd like to talk to you about frequency-dependent selection, broadly neutralizing antibodies, and trophic interactions," you might say, "Err....thanks, but I'm not a bio major, so I don't have to." But if I say, "I'd like to talk to you about something that will keep you up at night," I can talk to you about exactly the same stuff. Think of me as your journalistic parasite, manipulating your mind. Full thread: https://www.reddit.com/r/IAmA/comments/14mcvq/comment/c7eejsi/ · 17 points as of Nov 7, 2026 ### **Ed Yong** (u/edyong209) in r/IAmA, Mar 14, 2013 · Explains things Replying to a redditor: > You all come across a lot of discoveries, what is one discovery that has just blown your mind? > Bees can sense the electric fields of flowers! That discovery was published last month and it completely blew my mind. Flowers obviously have bright colours and aromatic nectar, but it turns out that they’re also like electric billboards. They have subtle electric fields around them, which bees can sense. The bees can use the fields to tell the difference between differently shaped flowers, and they can distinguish between fresh flowers and those that had just been visited by another bee. > > I just love this stuff. Here’s a system—bees and pollinators—that people have studied for centuries, and yet they have this hidden communication channel that we’ve *only just discovered*? That’s amazing! What else do we not know? (Excerpt.) Full thread: https://www.reddit.com/r/IAmA/comments/1aaji5/comment/c8vljsw/ · 31 points as of Nov 7, 2026 ### **Ed Yong** (u/edyong209) in r/IAmA, Mar 14, 2013 · Explains things Replying to a redditor: > You all help to bridge the gap between technical scientific research and public awareness. What tips do you have for ''dumbing down'' the science without resorting to metaphor? What do you think could be further done to help improve scientific literacy in the general public? I… > Thanks! I have to say that I loathe the phrase "dumbing down". It's an arrogant way of describing the act of making something accessible. The best science writers never underestimate their audience's intelligence but never overestimate their knowledge either. I try to tell people to remember when their readers last encountered science at school. When they were 15? 18? Then think about how much you knew at that age. Probably not very much. Then write as if you were talking to someone who was as intelligent as you were then but who knew the same amount of bupkis. Full thread: https://www.reddit.com/r/IAmA/comments/1aaji5/comment/c8vm82t/ · 11 points as of Nov 7, 2026 ### **Ed Yong** (u/edyong209) in r/Music, Jan 3, 2012 · AMA answer Replying to a redditor: > I'd have been more worried about tripping whilst carrying around 10M dollars worth of delicate wood, in a very dimly lit hotel room, wearing goggles. One toe stubbed on something and it's matchstick wood everywhere. > That's one of the reasons why a study like this has been so long in coming. "Excuse me, can we borrow your 10M instrument so that a blindfolded stranger can play it? Wait... where are you going?" Full thread: https://www.reddit.com/r/Music/comments/o06qx/comment/c3deg63/ · 5 points as of Nov 7, 2026 ### **Alie Ward** (u/AlieWard) in r/IAmA, Oct 2, 2018 · Explains things Replying to a redditor: > Congratulations on the show and podcast Gobless. My question is: what did you learn this week? > Good question. This week I was editing the Ologies epode on #FunctionalMorphology with Dr. Joy Reidenberg and learned that sperm whale echolocation clicks are loud enough to burst human eardrums and also that the 1883 Krakatoa eruption was so loud that it straight up killed people from the noise. I also learned that International Raccoon Appreciation Day is October 1, so we all have 364 days to prep for next year and craft raccoon suits. GET ON IT MOREMUSTACHE. Full thread: https://www.reddit.com/r/IAmA/comments/9kt619/comment/e71nqpw/ · 25 points as of Nov 7, 2026 ### **Michael Stevens** (u/Michael_Stevens) in r/IAmA, Jan 26, 2017 · Personal story Replying to a redditor: > Hey Michael! In episode 1 of Mind Field there was a scene when you woke up and appeared quite disoriented and confused, so confused that you needed to open the door to the test chamber to confirm your reality. I'm dying to know what were you dreaming about? > Essentially, I had started to lose the ability to differentiate dreams from reality > > . For some reason, I was in the room in both. > > I dreamt that someone (not anyone I'd ever met, but someone who seemed familiar in the dream) had come into the room and told me I was done. That 72 hours was up. But then I woke up. But I didn't realize that I'd woken up. I saw the door closed and wondered why they'd left and closed the door behind themselves. I figured everyone was just busy or something and that I could come out when I felt like it. > > So I opened the door but it was so dark and nothing was moving. I was really confused and anxious about being confused. Who had been in the room? Why was I alone? I had been so certain that I was finished. That I could come out. But no. I was still alone. Always had been. Full thread: https://www.reddit.com/r/IAmA/comments/5qd6tz/comment/dcycejf/ · 4,894 points as of Nov 7, 2026 ### **Michael Stevens** (u/Michael_Stevens) in r/todayilearned, May 10, 2013 · Explains things Replying to the post "TIL that honey is the only food that will not rot. A jar of honey may remain edible for over 3000 years.". > Honey's resistance to "rot" has to do with its relatively low [water activity](http://en.wikipedia.org/wiki/Water_activity#Example_foods) -- a measure of how intensely a material's water content will associate with things like microorganisms. > > Honey contains water, but it's not very easy for the agents of mold and rot to take advantage of. Same goes for a dried-out McDonald's burger. Or a dehydrated anything. Full thread: https://www.reddit.com/r/todayilearned/comments/1e27dw/comment/c9w36bj/ · 248 points as of Nov 7, 2026 ## Every account, A to Z | Name | Username | Account | Page | |---|---|---|---| | Adrian Owen | [u/ProfAdrianOwen](https://www.reddit.com/user/ProfAdrianOwen/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/adrian-owen | | Alex Filippenko | [u/AlexFilippenko](https://www.reddit.com/user/AlexFilippenko/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/alex-filippenko | | Alie Ward | [u/AlieWard](https://www.reddit.com/user/AlieWard/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/alie-ward | | Andrew Ng | [u/andrewyng](https://www.reddit.com/user/andrewyng/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/andrew-ng | | Anousheh Ansari | [u/Anousheh_Ansari](https://www.reddit.com/user/Anousheh_Ansari/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/anousheh-ansari | | Anthony Aguirre | [u/Anthony_Aguirre](https://www.reddit.com/user/Anthony_Aguirre/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/anthony-aguirre | | Bill Nye | [u/sundialbill](https://www.reddit.com/user/sundialbill/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/bill-nye | | Bjarne Stroustrup | [u/bstroustrup](https://www.reddit.com/user/bstroustrup/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/bjarne-stroustrup | | Brian Cox | [u/ProfessorBrianCox](https://www.reddit.com/user/ProfessorBrianCox/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/brian-cox | | Brian Fisher | [u/Brian_Fisher](https://www.reddit.com/user/Brian_Fisher/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/brian-fisher | | Brian Greene | [u/briangreeneauthor](https://www.reddit.com/user/briangreeneauthor/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/brian-greene | | Brian Schmidt | [u/Schmidt_and_Francis](https://www.reddit.com/user/Schmidt_and_Francis/) | Shared account | https://www.autumn.ai/resources/scientists-on-reddit/brian-schmidt | | Burt Rutan | [u/Burt_Rutan](https://www.reddit.com/user/Burt_Rutan/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/burt-rutan | | Buzz Aldrin | [u/BuzzAldrinHere](https://www.reddit.com/user/BuzzAldrinHere/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/buzz-aldrin | | Carl Safina | [u/Carl_Safina](https://www.reddit.com/user/Carl_Safina/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/carl-safina | | Carl Zimmer | [u/CarlZimmer](https://www.reddit.com/user/CarlZimmer/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/carl-zimmer | | Carolyn Bertozzi | [u/Carolyn_Bertozzi](https://www.reddit.com/user/Carolyn_Bertozzi/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/carolyn-bertozzi | | Cassandra Quave | [u/Cassandra_Quave](https://www.reddit.com/user/Cassandra_Quave/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/cassandra-quave | | Chris Adami | [u/ChrisAdami](https://www.reddit.com/user/ChrisAdami/) | AMA only | No page (no licensed photo yet) | | Chris French | [u/Prof_Chris_French](https://www.reddit.com/user/Prof_Chris_French/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/chris-french | | Chris Hadfield | [u/ColChrisHadfield](https://www.reddit.com/user/ColChrisHadfield/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/chris-hadfield | | Craig DeForest | [u/Craig_DeForest](https://www.reddit.com/user/Craig_DeForest/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/craig-deforest | | David Dunning | [u/Dr_David_Dunning](https://www.reddit.com/user/Dr_David_Dunning/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/david-dunning | | David Eagleman | [u/Dr_David_Eagleman](https://www.reddit.com/user/Dr_David_Eagleman/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/david-eagleman | | David Silver | [u/David_Silver](https://www.reddit.com/user/David_Silver/) | Personal account | No page (no licensed photo yet) | | David Steadman | [u/David_Steadman](https://www.reddit.com/user/David_Steadman/) | AMA only | No page (no licensed photo yet) | | Derek Muller | [u/veritasium](https://www.reddit.com/user/veritasium/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/derek-muller | | Ed Boyden | [u/Ed_Boyden](https://www.reddit.com/user/Ed_Boyden/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/ed-boyden | | Ed Lu | [u/edluB612](https://www.reddit.com/user/edluB612/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/ed-lu | | Ed Yong | [u/edyong209](https://www.reddit.com/user/edyong209/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/ed-yong | | Edward Frenkel | [u/EdwardFrenkel](https://www.reddit.com/user/EdwardFrenkel/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/edward-frenkel | | Emily Calandrelli | [u/emilycal](https://www.reddit.com/user/emilycal/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/emily-calandrelli | | Emily Lakdawalla | [u/elakdawalla](https://www.reddit.com/user/elakdawalla/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/emily-lakdawalla | | Eric Green | [u/Eric_Green](https://www.reddit.com/user/Eric_Green/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/eric-green | | Eric Lander | [u/Eric_Lander](https://www.reddit.com/user/Eric_Lander/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/eric-lander | | Forrest M. Mims III | [u/Forrest_Mims](https://www.reddit.com/user/Forrest_Mims/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/forrest-m-mims-iii | | Francis Collins | [u/NIHDirector](https://www.reddit.com/user/NIHDirector/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/francis-collins | | Geoffrey Hinton | [u/geoffhinton](https://www.reddit.com/user/geoffhinton/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/geoffrey-hinton | | George Church | [u/George-Church](https://www.reddit.com/user/George-Church/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/george-church | | Gerbrand Ceder | [u/Gerbrand_Ceder](https://www.reddit.com/user/Gerbrand_Ceder/) | AMA only | No page (no licensed photo yet) | | Grant Sanderson | [u/3blue1brown](https://www.reddit.com/user/3blue1brown/) | Personal account | No page (no licensed photo yet) | | Hannah Fry | [u/HannahFry](https://www.reddit.com/user/HannahFry/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/hannah-fry | | Heather Hendrickson | [u/Heather_Hendrickson](https://www.reddit.com/user/Heather_Hendrickson/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/heather-hendrickson | | Hugh Herr | [u/Hugh_Herr](https://www.reddit.com/user/Hugh_Herr/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/hugh-herr | | Ian Goodfellow | [u/goodfellow_ian](https://www.reddit.com/user/goodfellow_ian/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/ian-goodfellow | | James Grime | [u/JamesGrime](https://www.reddit.com/user/JamesGrime/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/james-grime | | Jane Goodall | [u/janegoodall_official](https://www.reddit.com/user/janegoodall_official/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/jane-goodall | | Janna Levin | [u/Janna_Levin](https://www.reddit.com/user/Janna_Levin/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/janna-levin | | Jeff Dean | [u/jeffatgoogle](https://www.reddit.com/user/jeffatgoogle/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/jeff-dean | | Jeffrey Hoffman | [u/jhoffma1](https://www.reddit.com/user/jhoffma1/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/jeffrey-hoffman | | Jerry Coyne | [u/Jerry_Coyne](https://www.reddit.com/user/Jerry_Coyne/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/jerry-coyne | | John Mather | [u/johnmather](https://www.reddit.com/user/johnmather/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/john-mather | | John Novembre | [u/Dr_John_Novembre](https://www.reddit.com/user/Dr_John_Novembre/) | AMA only | No page (no licensed photo yet) | | Jordan Ellenberg | [u/Jordan-Ellenberg](https://www.reddit.com/user/Jordan-Ellenberg/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/jordan-ellenberg | | Josh Willis | [u/ClimateElvis](https://www.reddit.com/user/ClimateElvis/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/josh-willis | | Julia Shaw | [u/Dr_Julia_Shaw](https://www.reddit.com/user/Dr_Julia_Shaw/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/julia-shaw | | Jürgen Schmidhuber | [u/JuergenSchmidhuber](https://www.reddit.com/user/JuergenSchmidhuber/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/jurgen-schmidhuber | | Karl Kruszelnicki | [u/DrKarlKruszelnicki](https://www.reddit.com/user/DrKarlKruszelnicki/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/karl-kruszelnicki | | Katie Mack | [u/astro_katie](https://www.reddit.com/user/astro_katie/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/katie-mack | | Ken Buesseler | [u/Ken_Buesseler](https://www.reddit.com/user/Ken_Buesseler/) | AMA only | No page (no licensed photo yet) | | Kerry Emanuel | [u/kerryemanuel](https://www.reddit.com/user/kerryemanuel/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/kerry-emanuel | | Luis von Ahn | [u/vonahn](https://www.reddit.com/user/vonahn/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/luis-von-ahn | | Mae Jemison | [u/Dr_Mae_Jemison](https://www.reddit.com/user/Dr_Mae_Jemison/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/mae-jemison | | Matt O'Dowd | [u/Matt_ODowd](https://www.reddit.com/user/Matt_ODowd/) | AMA only | No page (no licensed photo yet) | | Matt Parker | [u/standupmaths](https://www.reddit.com/user/standupmaths/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/matt-parker | | Max Tegmark | [u/MaxTegmark](https://www.reddit.com/user/MaxTegmark/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/max-tegmark | | Michael I. Jordan | [u/michaelijordan](https://www.reddit.com/user/michaelijordan/) | Personal account | No page (no licensed photo yet) | | Michael Stevens | [u/Michael_Stevens](https://www.reddit.com/user/Michael_Stevens/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/michael-stevens | | Michio Kaku | [u/michiokakuauthor](https://www.reddit.com/user/michiokakuauthor/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/michio-kaku | | Mike Brown | [u/Dr_Mike_Brown](https://www.reddit.com/user/Dr_Mike_Brown/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/mike-brown | | Mike Massimino | [u/MikeMassimino](https://www.reddit.com/user/MikeMassimino/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/mike-massimino | | Mike Melvill | [u/Mike_Melvill](https://www.reddit.com/user/Mike_Melvill/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/mike-melvill | | Nando de Freitas | [u/nandodefreitas](https://www.reddit.com/user/nandodefreitas/) | Personal account | No page (no licensed photo yet) | | Neil deGrasse Tyson | [u/neiltyson](https://www.reddit.com/user/neiltyson/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/neil-degrasse-tyson | | Oriol Vinyals | [u/OriolVinyals](https://www.reddit.com/user/OriolVinyals/) | Personal account | No page (no licensed photo yet) | | Paul Greengard | [u/DrGreengard](https://www.reddit.com/user/DrGreengard/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/paul-greengard | | Paul Knoepfler | [u/PaulKnoepfler](https://www.reddit.com/user/PaulKnoepfler/) | Personal account | No page (no licensed photo yet) | | Radia Perlman | [u/rjp2022Redmond](https://www.reddit.com/user/rjp2022Redmond/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/radia-perlman | | Randall Munroe | [u/xkcd](https://www.reddit.com/user/xkcd/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/randall-munroe | | Randy Schekman | [u/schekman](https://www.reddit.com/user/schekman/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/randy-schekman | | Robert Sapolsky | [u/RobertSapolsky](https://www.reddit.com/user/RobertSapolsky/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/robert-sapolsky | | Robert Zubrin | [u/RobertMZubrin](https://www.reddit.com/user/RobertMZubrin/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/robert-zubrin | | Ron Garan | [u/RonGaran](https://www.reddit.com/user/RonGaran/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/ron-garan | | S. Jay Olshansky | [u/Jay_Olshansky](https://www.reddit.com/user/Jay_Olshansky/) | AMA only | No page (no licensed photo yet) | | Scott Kelly | [u/StationCDRKelly](https://www.reddit.com/user/StationCDRKelly/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/scott-kelly | | Scott Manley | [u/illectro](https://www.reddit.com/user/illectro/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/scott-manley | | Sean Carroll | [u/seanmcarroll](https://www.reddit.com/user/seanmcarroll/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/sean-carroll | | Seth Shostak | [u/sshostak](https://www.reddit.com/user/sshostak/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/seth-shostak | | Stephen Hawking | [u/Prof-Stephen-Hawking](https://www.reddit.com/user/Prof-Stephen-Hawking/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/stephen-hawking | | Stephen Wolfram | [u/StephenWolfram-Real](https://www.reddit.com/user/StephenWolfram-Real/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/stephen-wolfram | | Temple Grandin | [u/Prof_Temple_Grandin](https://www.reddit.com/user/Prof_Temple_Grandin/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/temple-grandin | | Terry Virts | [u/Astro-Terry](https://www.reddit.com/user/Astro-Terry/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/terry-virts | | Tim Berners-Lee | [u/timbl](https://www.reddit.com/user/timbl/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/tim-berners-lee | | Tom Crowther | [u/Tom_Crowther](https://www.reddit.com/user/Tom_Crowther/) | AMA only | https://www.autumn.ai/resources/scientists-on-reddit/tom-crowther | | Yann LeCun | [u/ylecun](https://www.reddit.com/user/ylecun/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/yann-lecun | | Yoshua Bengio | [u/yoshua_bengio](https://www.reddit.com/user/yoshua_bengio/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/yoshua-bengio | | Yvette Cendes | [u/Andromeda321](https://www.reddit.com/user/Andromeda321/) | Personal account | https://www.autumn.ai/resources/scientists-on-reddit/yvette-cendes | Scores are Reddit's as of Nov 7, 2026. "No posts retrieved" means our pull returned nothing for that account, not that it is inactive.