# Katie Mack on Reddit (u/astro_katie)

Part of Celebrities on Reddit, researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-06. Interactive version: https://www.autumn.ai/resources/celebrities-on-reddit/katie-mack

Katie Mack: Cosmologist and author of The End of Everything.

- Reddit account: [u/astro_katie](https://www.reddit.com/user/astro_katie/) (AMA only)
- How we know it's theirs: [Her 2014 r/science AMA, posted from this account](https://www.reddit.com/r/science/comments/244m55/im_dr_katie_mack_an_astrophysicist_studying_dark/)
- Where they post, in the records we retrieved: r/science (27), r/askscience (19), r/space (5), r/forbiddensnacks (1)
- Known activity in the posts we found: 2014 to 2022
- Wikipedia: https://en.wikipedia.org/wiki/Katherine_J._Mack

## Moments

### u/astro_katie in r/askscience, May 28, 2021 · Funny

Replying to a redditor:

> Hi Katie, thanks for joining us today! I'm writing this for my grandfather, whom I gave a copy of your book a few months back. He says and asks: I'd like her to know that I read The End of Everything (Astrophysically Speaking) and found it to be tremendously interesting…

> Thank you so much! :)
>
> I'm not currently working on another book. It turns out that DESTROYING THE ENTIRE UNIVERSE is a very hard act to follow, and also I have a bunch of research I should catch up on that I have neglected a bit recently. I have some vague thoughts about future book topics, but I haven't settled on anything yet.
>
> As for my research -- I'm thinking about several things lately. Mostly: dark matter's possible particle physics interactions (i.e., stuff it might do other than sit there and gravitate) and how it may have impacted the first stars and galaxies in the universe; other kinds of dark matter beyond the usual suspects; and a few things connected to vacuum decay and how we might learn about it through cosmological observations. All fun stuff. :)

Full thread: https://www.reddit.com/r/askscience/comments/nmvafn/askscience_ama_series_im_dr_katie_mack/gzs6dxv/ · 117 points as of Nov 6, 2026

### u/astro_katie in r/science, Apr 28, 2014 · Funny

In the thread "I'm Dr. Katie Mack, an astrophysicist studying dark matter, black holes, and the early universe, AMA.".

> Dark matter is way less scary than angels or demons or ghosts because it can't touch you or see you.
>
> But it is probably passing through you right now. And all the time. Your whole life. You can't escape it ever. Sorry.

Full thread: https://www.reddit.com/r/science/comments/244m55/im_dr_katie_mack_an_astrophysicist_studying_dark/ch40wn7/ · 107 points as of Nov 6, 2026

### u/astro_katie in r/askscience, May 28, 2021 · AMA answer

Replying to a redditor:

> Hello Dr. Mack! I really enjoy your work. My question is what is your favorite bad science movie? As a geologist I have a lot to pick from but the Core is probably my favorite. :)

> I'm going to interpret this as "favorite movie in which the science is not very accurate" and I'm going to specifically focus on movies featuring something astronomy related, so my answer to that is Sunshine. There is really no way that throwing nuclear bombs into the Sun could "restart" it, and for that matter the way the Sun is initially failing in the film isn't plausible either. BUT. It's a beautiful film! Gorgeous visuals! Great soundtrack! And the way the crew of the spaceship work together to figure out what to do and all that is very cool! And about 3/4 of the way into the film it suddenly and drastically changes genre, which is very unsettling! Also it has Cillian Murphy in it. So, really, what's not to like? It's very good. Highly recommended.

Full thread: https://www.reddit.com/r/askscience/comments/nmvafn/askscience_ama_series_im_dr_katie_mack/gzs6yuy/ · 154 points as of Nov 6, 2026