Over the next few months, I’m giving a bunch of talks. Be sure to check your local listings to see if I’ll be coming to a venue near you. Anyway, I decided to make a few illustrative movies on wormhole time machines. While I’m not going to spell out all of the details, a few clarifications. In each case, a particle goes into one mouth of a wormhole and comes out the other. I change the color from red to blue as a matter of clarification.
Click on the image to see the animated gif.
First, let’s look at a simple wormhole. The throats of the two mouths connect, and at some times you can “see” both the incoming and outgoing versions of the particle, depending on your perspective.
Next, I’ll remind you about the “twin paradox.” To make things realistic, we’re going to fly to a nearby star 4 light years away, but only accelerate at 9.8 m/s^2 (gravity on the earth). The ship has to decelerate about halfway through in order to come to a stop at the distant star. Note that it actually takes less than 8 years (according to the spaceship) to get to and from the star.
Finally, take one of the mouths of the wormhole and tow it to a distant star and back. Since the clocks on either side of the wormhole are calibrated (and the local spacetime is flat), when a particle goes in at some time, it comes out when the clock on the other side measures the same time. As a result, the traveling mouth ends up being a portal to the past, while the stationary mouth is a portal to the future.
If you happen to find these animations useful, by all means, use them, but please give me attribution.