Skip to content
Answering Your Questions About Reactor: Right here.
Sign up for our weekly newsletter. Everything in one handy email.

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.

About the Author

Dr. Kirtland C Peterson

Author

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 accepting Brannon Braga's invitation to pitch Star Trek scripts at Paramount in LA. Avid reader.
Learn More About Dr. Kirtland C
Subscribe
Notify of
guest
5 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments