THE RIPE STUFF

12 Jun ‘13

Traveling Through Time: A Primer

12 Jun ‘13

In: Inspiration, / By: Chris Simental

Here at Ripe, we’re not in the business of time travel. Though sometimes I wish we were. I have been interested in the idea since I first saw Time after Time in 1979. Back then I thought it was only a matter of, um, “time” before someone cracked the code and invented a machine that would allow us to traverse back and forth through the fabric of space-time.

Admittedly, I was pretty naive about the whole concept back then. Many years and several time travel movies later I started reading some of the more accessible (as in, easier-to-understand) books on cosmology—just for fun—and came across Joao Magueijo‘s Faster Than the Speed of Light. Magueijo deftly broke down the ins and outs and feasibility of time travel based on our current understanding of the universe—largely rooted in Einstein’s Theory of Relativity.

Ways of traveling through time

The first method of time travel the author describes is one that doesn’t require the traveler to do anything at all. More specifically, no matter what any of us does, we are all going to end up in the future. Traveling through time is not only inevitable, it’s beyond our control! Okay. Well that’s very clever and all—and very true—but I’m interested in the kind of time travel that can take me into the future or back to the past and bring me back in one piece.

Luckily the author eventually elaborates on the more scientific means of time travel. The current theories say that the closer an object gets to traveling at the speed of light, the more time slows down for that object. Which means the object—and anything (or person) in it—could travel into the future with ease. The object could also travel BACK in time by traveling FASTER than the speed of light. Of course, this is all based in theory, and scientific theories can’t always be proven, but in the case of the important theories, they haven’t been DIS-proven, and that’s good enough to accomplish A LOT of cool stuff. These theories are the same ones that got a man on the moon, saved Apollo 13, put a rover on Mars, and launched a boat-load of satellites in space to give us real-time driving directions.

What about the side effects?

So it all sounds very promising, but then we find out about the complications. Like side effects on a medicine bottle, we can’t have the good without the bad. One big problem with traveling at or near the speed of light is that although time slows down for the traveler, time remains the same back on Earth. This means that while a person is gallivanting around in space, their loved ones back at home are still aging normally. What would seem like a matter of days for the time traveler would be years–maybe even decades–for those back at home. Not a very practical means of travel if you ask me.

Another complication is that traveling at or near (let alone faster than) the speed of light would create a near infinite amount of mass and require a near infinite amount of energy. We simply do not have a viable source of energy to sustain a time travel mission.

Needless to say, this book turned out to be a real heartbreak for me and my time traveling dreams. I was crushed. It also made me realize why we don’t have flying cars now. Energy is the problem! There could never be enough energy (at least not with our current sources) to do all of that. I was bummed. So I laid off the cosmology books and was pretty jaded about the whole concept for a while.

But then…

I saw the movie Primer and it got me thinking about time travel again. Not from a practical perspective, but more from a fictional/entertainment perspective. It’s fun to think through the “what ifs” and explore the notion of time travel without getting bogged down in the details of whether or not it “can” be done.

The method of time travel in the movie doesn’t require traveling at the speed of light or even a lot of energy. It uses a tricked-out box to open a channel in time. When the box is switched on, a channel begins in spacetime. That is point “A.” Later, the box is turned off. This closes the channel at point “B.” How this works is: the time travelers turn the box on in the morning, and then hide in a hotel room so they don’t run into their time-traveling doubles. Later that evening, they turn the box off and jump inside, which causes them to exit the box at point A, the morning of the same day.

After seeing the movie I was obsessed with it for a good solid week. I read everything I could find online to help me better understand how the machine worked so I could make sense of what was going on. Here’s a diagram I came across that helped me understand the space-time loop and how it was used in the story: