That’s right you have not misread the headlines, TIME TRAVEL IS REAL! I know because I am from the future. It is amazing you guys will love it, as it is filled with so many wondrous things, of course I cannot talk about them though. It is part of the code us time travelers keep.**
**(deep, quick talking, disclaimer voice) I am only joking and the time travel in the sense you are thinking of does not exist at least not with the technology we currently have. Sadly Spalding Manik is not from the future.
Technically time travel does exist and if you think I am crazy, just keep reading and you will understand. You may or may not know that scientist and physics have been trying to come up with a set of equations and theories that can unify all of our physics, to give us a better picture of the universe we live in. The problem is that there is a huge, and I mean huge, disconnect between Quantum Mechanics (the really small stuff like atoms and such) and The Theory of Relativity (the really big stuff like planets). That is the ultimate goal of pretty much every one working in the field, to unify these two theories.
A long time ago a man named Albert Einstein came up with an equation, I am sure you have heard of it,. It is quite famous and everyone in the scientific community I am sure has heard of it and knows what it means. But if you are like me you probably had no idea, but we will get to that in a moment. Among Einstein’s many contributions to the scientific community he also proved many theories about time and how it works. Long before it was proven he theorized that time would slow down for a person traveling at a certain speed or in motion. So if your friend is traveling in a car at 100 miles per hour they are aging slower than you who is sitting on the couch watching South Park, because time for them is moving a little slower, and by a little I mean nanoseconds. This idea was proven true when scientist took two identical atomic clocks and placed one in a plane and flew it around the world, and kept the other motionless firmly on the surface. When the scientist compared the two clocks they found that the one that had been traveling around the world was a fraction of a second slower than the one that had not moved. In a very real sense the clock has time traveled. Pretty amazing!
Now let’s take that simple idea to the extreme. Einstein extrapolated this idea by saying that a person in a spaceship approaching the speed of light, if there is a clock on the spaceship it will seem to tick ever slower as the ship goes faster and faster. Whereas back on earth that an exact replica of that same clock will tick at the appropriate rate. The cool thing is that as the ship goes faster and faster seconds turn into minutes and minutes into hours. So let’s say that you are on a ship and you leave Earth traveling at near the speed of light. You leave behind all your family and your 2 year old nephew. You travel for a year at near the speed of light and return to Earth one year later, according to your clock on the ship. The interesting thing is that while you have been gone for a year, 50 years have passed on Earth. Time for you has passed much slower than for those back on earth. So your nephew is now 52 years old and you have only aged a year, so he is now older than you. So in a very real sense you have time traveled into the future. See it was not exactly what you were thinking, but still cool.
There are some issues though, remember that famous equation above, well it comes into play here. In the above explanation I made sure to use the term “near the speed of light.” The equation says that Energy (E) equals mass (M) times acceleration (C). Basically this means that it takes more and more energy to make something go faster, duhhh, but it also adds mass to the object. The problem is that a spaceship has mass along with almost everything else in the universe, I think the main exception is light and a few other weird particles, so as this spaceship approaches the speed of light it becomes more and more massive. Eventually it becomes infinitely massive, thus it would take an infinite amount of energy to make something with mass reach the speed of light. This is impossible, as it would take more energy in the universe to have an object reach the speed of light. (That last sentence may or may not be true, but I know that it would take an infinite amount of energy to reach the speed of light.) Thus scientist think faster than light travel is impossible, at least with the technology we have available currently.
Despite faster than light travel being out of our reach it is still technically possible to “time travel.” As I mentioned above it is just not the way you are thinking, and based on our technology it is only one way, to the future. Here is the interesting thing though, all of our current equations and theories do not rule out travel to the past, we just do not know how to do it. I think that is very fascinating on one hand, but on the other I would argue that our current theories and equations are probably wrong, because traveling to the past would cause so many paradoxes, among other things, and you know how much I love those. There is also a theory that if we were to travel to the past it would be the past of a different time line or dimension so anything you did or didn’t do would not mess with the time line or dimension you were from. When talking about time travel to the past it gets pretty convoluted to say the least.
The other funny thing about this topic is how much science fiction pulls from science fact. I am sure everyone has heard of a wormhole, a term made famous by almost any science fiction novel. Believe it or not most scientist believe these things exist and could possibly be used to time travel. Space and time are, most scientist thing, slightly curved. So imagine a giant square sheet, basically your bed. Now place a bowling ball in the center of your bed, after that try to roll marbles or a small ball across the bed near the bowling ball. It is quite often that the marbles will get sucked into the divot that the bowling ball makes. This is the best example of how massive objects work in our universe. The sun is very massive so it has a lot of gravity and pulls other objects in the universe close to it i.e. the planets. In essence they have enough mass to bend space time, which again is what Einstein said. So if we had some technology to create a super massive point we could theoretically bend space time back on itself.
Keeping the bowling ball experiment above in mind, now imagine a piece of paper representing the universe, on the top write and “A” and on the bottom write a “B.” A normal piece of paper is 8.5 by 11 I think, so the A and B are 11 inches apart. But again think in terms of the universe, so now they are 11 million light years apart or something crazy. Now fold the paper. See what we did there, learning is fun! Essentially we bent the paper, space time, back on itself and mad the distance from point A to B almost instant by opening a wormhole.
I have always thought his was a fascinating subject and the more you get into it you realize how much science is behind it. So next time someone brings up this idea and talks about how it is not possible and a bunch of malarkey, you can quickly disputer their claims, (again quite fast talking disclaimer voice) At least in theory!