Time Travel

When my son was little, he wanted to invent a time machine when he grew up. He talked about it for a year or two, and then one day I saw that he was sitting on his bed crying. When I asked him what was wrong, he said that he had prayed and asked God to write down how to go back and forth through time and then to drop the piece of paper on my son's lap. But God hadn't done that.

So I had one of those talks with him about how God waits until we're ready before He gives us what we need. And since my son wasn't ready yet to start building a machine, then he didn't need to know about time travel at the age of five or six.

Well, my son is now a Film Studies major in college, having decided to leave time travel to other people. And now a professor at the University of Connecticutt has predicted that time travel is coming sooner than we think. PhysOrg.com News reported Tuesday that Professor Ronald Mallett may be on that road already.

“Einstein showed that mass and energy are the same thing,” said Mallett, who published his first research on time travel in 2000 in Physics Letters. “The time machine we’ve designed uses light in the form of circulating lasers to warp or loop time instead of using massive objects.”

To determine if time loops exist, Mallett is designing a desktop-sized device that will test his time-warping theory. By arranging mirrors, Mallett can make a circulating light beam which should warp surrounding space. Because some subatomic particles have extremely short lifetimes, Mallett hopes that he will observe these particles to exist for a longer time than expected when placed in the vicinity of the circulating light beam. A longer lifetime means that the particles must have flowed through a time loop into the future.

“Say you have a cup of coffee and a spoon,” Mallett explained to PhysOrg.com. “The coffee is empty space, and the spoon is the circulating light beam. When you stir the coffee with the spoon, the coffee – or the empty space – gets twisted. Suppose you drop a sugar cube in the coffee. If empty space were twisting, you’d be able to detect it by observing a subatomic particle moving around in the space.”

And according to Einstein, whenever you do something to space, you also affect time. Twisting space causes time to be twisted, meaning you could theoretically walk through time as you walk through space.

This is so cool, I can't stand it. But it raises questions, because Professor Mallett is in the Parallel Universe camp.

“The Grandfather Paradox [where you go back in time and kill your grandfather] is not an issue,” said Mallett. “In a sense, time travel means that you’re traveling both in time and into other universes. If you go back into the past, you’ll go into another universe. As soon as you arrive at the past, you’re making a choice and there’ll be a split. Our universe will not be affected by what you do in your visit to the past.”

This is where he loses me, because the Parallel Universe theory is the same one Doc Brown described in "Back to the Future." And that movie left some glaring questions, the most important of which was: What happened to the Marty who grew up with the parents that "our" Marty went back to? Did he disappear? Or did he show up later and ask what our Marty was doing there?

I'm not sure I get how there can be an infinite number of SkyePuppys inhabiting parallel universes that are only different because of the possible choices I could have made at different times in my (our?) life. But I suppose that, like God, Professor Mallett will explain it all when we're ready to know.