# Randall Munroe on Reddit (u/xkcd)

Part of Scientists on Reddit, researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-07. Interactive version: https://www.autumn.ai/resources/scientists-on-reddit/randall-munroe

Randall Munroe: Cartoonist behind xkcd, former NASA roboticist.

- Reddit account: [u/xkcd](https://www.reddit.com/user/xkcd/) (Personal account)
- How we know it's theirs: [Listed as his Reddit account on Wikidata; posts about his own comics](https://www.wikidata.org/wiki/Q285048)
- Where they post, in the records we retrieved: r/reddit.com (735), r/science (80), r/programming (72), r/technology (58), r/pics (39), r/funny (21)
- Known activity in the posts we found: 2006 to 2014
- Wikipedia: https://en.wikipedia.org/wiki/Randall_Munroe

## Moments

### 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

### 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

### 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