Mon
Feb 8 2010 3:26pm
Attention All Time Travelers!

Caltech researcher, author, and Cosmic Variance blogger Sean Carroll will be publishing “The Real Rules for Time Travelers” in the March issue of Discover. To glimpse the future (and watch fascinating videos of exploding clocks), click your mouse (or tap your finger) three times.

If however, as for me, time is in short supply and you just want the rules in your wallet or on your phone right now, here they are. (Truth in advertising, these rules are from the recent past and not in the online “real rules” article.)

Rules for Time Travelers

0. There are no paradoxes.

1. Traveling into the future is easy.

2. Traveling into the past is hard—but maybe not impossible.

3. Traveling through time is like traveling through space.

4. Things that travel together, age together.

5. Black holes are not time machines.

6. If something happened, it happened.

7. There is no meta-time.

8. You can’t travel back to before the time machine was built.

9. Unless you go to a parallel universe.

10. And even then, your old universe is still there.

For an in-depth explanation of these rules, Sean Carroll is happy to provide more dendrite-destroying, mind-bending brain warp. For those girding for time-travel battle and those wishing to drill deep into the subject matter, there’s also Carroll’s new book, From Eternity to Here: The Quest for the Ultimate Theory of Time.

Next on my to do list: e-mail Sean to see about stretching time (to, say, get 27 hours in a day) and stopping time (as in just before a deadline comes due). Stay tuned.


Dr. Kirtland C. Peterson—“Cat” to his friends and colleagues—feeds his left brain with science, his right brain with the rich feast of fiction, including SF and fantasy. Among his life’s highlights are sitting in the pilot’s seat of a shuttle prepping for launch at the Kennedy Space Center, and responding to an invitation from Brannon Braga to pitch Star Trek stories at Paramount in LA. Currently reading Ursula K. Le Guin’s Cheek by Jowl: Talks & Essays on How & Why Fantasy Matters.

5 comments
Marcus W
1. toryx
I'd particularly be interested in hearing how you can slow or stop time before the end of a weekend. Or on a really great vacation.
Alex Brown
2. AlexBrown
What I don't get is why you can't go back before the time machine was built. Shouldn't that now be exempt from the timeline if you go back far enough? I mean, yeah, it can age once settled into a time (just as we can), but by travelling shouldn't you get pulled out of time passing and thus be exempt from limitations on how far back you can go? Or am I just missing something?

Oy vey, I spend way to much time thinking about this shite.
JKMerlin
3. JKMerlin
Personally i cant see how traveling back in time would work, tho apearently they have very nearly done it in labs, and the way that they do it would be better used for transporting data(say from a keyboard or your head to your computer game, getting rid of that ms delay between your click and your gun firing). This way of doing it also requires the equipment be set up so it can receive the data. notably if u ask me we should work on transfering mass into energy and back like the star trek transporter, mostly because it seems like pure energy would be easier to send either way.
JKMerlin
4. reattmore
If, time travel to the past is difficult, but not impossible . . .

. . . and if you can't travel back in time to before when the time machine was built . . .

So we build our prototype time machine now and it's of limited utility to us--we can't yet use it to travel to the past. But, as soon as we open the door to the machine, out tumble millions of people from the future, travelling back to the earliest accesible point . . .
JKMerlin
5. sofrina
but what about magic? if you're transported by spell or incantation, that negates the issue of when the machine was created. but can you travel back before the spells were created? or the wielder had that power?

Subscribe to this thread

Receive notification by email when a new comment is added. You must be a registered user to subscribe to threads.
Post a comment