The Astronomy of xkcd’s Epic 3,100-Panel Comic, “Time”

The entire universe in blog form
Aug. 6 2013 8:00 AM

Xkcd and "Time"

xkcd "Time"
A frame from the huge xkcd panel "Time" (frame 403 if you're curious).

Drawing by Randall Munroe.

If you read my blog (and I enjoy self-evident statements like that) then you either already know about Randall Munroe’s amazing Web comic xkcd (and the sorta-sequel, What If?), or you should know about it. Beloved by a zillion geeks across the globe, xkcd uses only crude drawings and stick figures for visuals, but this only serves to emphasize Munroe’s extremely keen mind and sharp viewpoints.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

In April, he quietly started a new comic: Called “Time,” it automatically refreshed every half-hour with a new drawing. For quite some time it only showed two figures, a man and woman, building a sand castle. But as time went on, hints were dropped that there was more going on, and as the events unfolded, it became clear that Munroe was delivering an epic but understated tale of adventure and exploration.

Advertisement

I’ve known about “Time” for a while now, but haven’t written anything, opting to wait for the whole thing to finish. It finally has; the last panel went up July 26. A few days later, Munroe—usually quiet about such things—wrote up a short entry about it on his blog. A few days later, Wired posted a fantastic article about the whole thing, which I urge you to read.

My name is mentioned in there, so I figure it’s time for me to come clean as well. Spoilers ho.

First, as a break, xkcd fan Matthew Walker put the entire thing together as a YouTube video, which takes a whopping 40 minutes to watch. But I found it entrancing.

I’ve known Munroe for a couple of years now, and in June he sent me a note asking for a bit of astronomy help. He was already in the midst of drawing “Time,” and he gave me a synopsis of the story. It takes place 11,000 years in the future, he told me. He wanted to drop hints, subtle ones, into the story that clever people would be able to find. What astronomical events could work for that scenario?

My first thought was precession: The Earth’s rotational axis wobbles like a top’s. Right now the northern axis points very close in the sky to Polaris, but that hasn’t always been so, nor will it always be. In 11,000 years it will point in a very different part of the sky, and that will be obvious to anyone watching the constellations rise and set.

Alas—and I should’ve known—Munroe had already thought of that. The next idea was that some bright star would’ve gone supernova between now and then. Most of the brightest stars in the sky are capable of exploding, but most of them probably won’t for a long time—hundreds of thousands of years or more. (The big exception, Eta Carinae, is not visible from the Northern Hemisphere, where the comic was taking place.)

However, “unlikely” isn’t the same as “impossible,” so I suggested the red supergiant star Antares in Scorpius. It’s on its way to going supernova, it’s bright and would leave a noticeable gap in the constellation, and it’s visible from the comic’s location.

Much to my delight, Munroe used the idea. An xkcd fan, James Pryor, put together all the panels of “Time” into a movie, which you can watch at your own pace; he’s even pulled out special frames that are key to the story. Frame No. 2,393 shows what Munroe did with my suggestion:

xkcd's Time, with Scorpius and Sagittarius
Frame 2393 from "Time", showing the constellations of Sagittarius and Scorpius setting in the far future.

Drawing by Randall Munroe.

For those who are familiar with the constellations, Sagittarius is above the tree, pointing almost straight down; a bright planet (Venus?) can be seen just over the spout of the famous “teapot” shape. Below it and to the left of the tree is the tail of Scorpius, and Antares would be near the circular head of the stick-figure character sitting on the ground … but it’s not there. A hint that this takes place in the far future.

Devoted fans—of which there are many—put together a wiki (a series of explainer pages) for the comic and were extraordinarily clever in figuring out not just that this was the future, but even getting the date it takes place. Amazing.

I’m pleased, honored, and proud to have been a small part of this astonishing experiment by Munroe. xkcd is, simply put, one of the best comics on the Web: funny, thoughtful, and even profound. But that is a reflection of Munroe himself and so, I suppose, not a surprise at all.

TODAY IN SLATE

Politics

Don’t Worry, Obama Isn’t Sending U.S. Troops to Fight ISIS

But the next president might. 

The Extraordinary Amicus Brief That Attempts to Explain the Wu-Tang Clan to the Supreme Court Justices

Amazon Is Officially a Gadget Company. Here Are Its Six New Devices.

The Human Need to Find Connections in Everything

It’s the source of creativity and delusions. It can harm us more than it helps us.

How Much Should You Loathe NFL Commissioner Roger Goodell?

Here are the facts.

Altered State

The Plight of the Pre-Legalization Marijuana Offender

What should happen to weed users and dealers busted before the stuff was legal?

Surprise! The Women Hired to Fix the NFL Think the NFL Is Just Great.

You Shouldn’t Spank Anyone but Your Consensual Sex Partner

Moneybox
Sept. 17 2014 5:10 PM The Most Awkward Scenario in Which a Man Can Hold a Door for a Woman
  News & Politics
Jurisprudence
Sept. 18 2014 10:42 AM Scalia’s Liberal Streak The conservative justice’s most brilliant—and surprisingly progressive—moments on the bench.
  Business
Business Insider
Sept. 17 2014 1:36 PM Nate Silver Versus Princeton Professor: Who Has the Right Models?
  Life
The Vault
Sept. 18 2014 9:57 AM “The Sun Never Sets Upon the British Empire,” Explained in GIF by an Old Children’s Toy
  Double X
The XX Factor
Sept. 17 2014 6:14 PM Today in Gender Gaps: Biking
  Slate Plus
Slate Fare
Sept. 17 2014 9:37 AM Is Slate Too Liberal?  A members-only open thread.
  Arts
Television
Sept. 18 2014 8:53 AM The Other Huxtable Effect Thirty years ago, The Cosby Show gave us one of TV’s great feminists.
  Technology
Future Tense
Sept. 18 2014 10:07 AM “The Day It All Ended” A short story from Hieroglyph, a new science fiction anthology.
  Health & Science
Bad Astronomy
Sept. 18 2014 7:30 AM Red and Green Ghosts Haunt the Stormy Night
  Sports
Sports Nut
Sept. 17 2014 3:51 PM NFL Jerk Watch: Roger Goodell How much should you loathe the pro football commissioner?