My Views on Time Travel

Time Travel is a delicate subject like aliens or alternate universes. It’s stuff that’s entirely possible in some form or another in the future, near or far, but it will get you ridiculed in some closed-minded circles. I’m lucky I’m not a scientist surrounded by other scientists so I can say what I want and not worry about whether my writings will be published.

Time travel is quite tricky because of all the catch-22 scenarios that are bundled with it. A famous example is of a man who travels back in time and murders his grandfather. Does that prevent his father, and by extension, him, from being born? Then if he wasn’t born he couldn’t have gone back in time to kill his grandfather, thus undoing this father from not being born. If you’re head’s spinning now, that’s fine. That’s supposed to happen.

Types of Time Travel

In order to continue we need to break down the general subject of time travel into smaller categories depending on direction and techniques. By the way, I’m making up some of the following terminology, so don't expect to find it elsewhere.

Wait-stasis- This version of time travel is basically waiting unconsciously until the future comes. Sleeping is like that, where in a sense, you time-travel to the next morning. In movies it’s more commonly done by freezing the subjects for periods of time. This gives the “traveler” the illusion of time travel because during the entire period they were frozen, no time has passed in their perspective and suddenly they wake up/thaw in the future. Obviously, this type of travel is “forward only”.

FLST (Fraction of Light Speed Travel, or Fractional Light Speed Travel)- This is another scientifically possible version of time travel. There are some advanced physics involved in this one, but in a nutshell the closer you come to traveling at the speed of light (about one billion km/hour) the more time slows down for you. Of course you don’t realize time slowing, but when you’re done traveling at a reasonable fraction of the speed of light for, say, one year, you’ll realize that the rest of the world which wasn’t traveling at a fraction of the speed of light has actually gotten more than one year older. This is another “forward only” time travel method, because when you return to find more time passed than you’ve experienced it appears to you as the future.
Read more about it in this post: Special Relativity 101 and do a google search for the “Twin Paradox”.

Point-to-point- Point to point time travel is like using a telephone. What this means is that for “travel” to happen, you will need one device to send and another to receive. This is a more traditional science fiction method for time travel where you get the good old “time machine”. The difference is that instead of a modified DeLorean you need two machines; one in the departure time and one in the destination time. This is an omnidirectional method of time travel, but with one very important limitation: you can’t go back in time further than the invention of the machine itself. When such a machine is invented, everyone in the world would instantly know. Think about this: if backwards time travel existed, there is an infinite future with infinite possibilities to send back “mistakes” that will have worldwide impacts. This method also offers an explanation for the question “if backwards time-travel is possible in the future, why haven’t we seen any travelers yet?”. The answer is simply that the “receiving” device hasn’t been invented yet.

Subspace Tunneling- This kind of time travel is not man-made, but more taking advantage of natural occurrences. Spacetime (space+time; greater than the sum of it’s parts!) could possibly have some “ripples”, “folds” or “tears” that would allow us to skip along what we perceive as the natural timeline. This is also very important if we want to do some great distance traveling without incurring FLST time distortion. The fun part about subspace tunneling is that it will probably be completely random to us, and that we’d not only travel in time, but also to other places (possibly outside of our universe). You remember “Lost in Space”?

Portable Time Travel Device- Portable in this case doesn’t necessarily mean you can carry it. It could be as big as a 12 storey building for all I care. In this case it means that you have your machine that let’s you travel in time and it travels with you. This is your converted DeLorean as seen in the “Back to the Future” trilogy. I also believe that this is the least likely method of time travel, although it would seem to be the most convenient. This type of time travel doesn’t have very many restrictions in terms of paradox prevention, so for the sake of the universe I hope that nobody invents one of these.

Fire and Forget- The last type of time travel I will discuss is similar to “point-to-point” time travel except there is no second receiver device or machine. The first machine sends the traveler into another point in time and that’s the end of the story. There are no returns, unless there is another “fire and forget” machine at the destination time. I almost want to chunk this type in with the “portable device” time travel, because what’s stopping you from sending the “fire and forget” device along with the traveler so he or she can keep moving about?

Paradoxes and other problems

Time travel is a lot of fun in movies and thought experiments and in all fairness, forward time travel is perfectly safe for the continuity of the universe. The problems arise when information, devices, or people are able to travel backwards in time. Simply put they travel back and change the past causing a form of “butterfly effect” that alters the future from whence they came.

There are 2 solutions to the paradoxes (assuming backwards time-travel is possible). The first is that backwards time travel causes a fork in the road of time, causing a different universe where the future “hasn’t happened yet” and you’re free to muck it up. The second is that backwards time travel is limited to an “observation only” clause, meaning that you are like an invisible ghost when you travel back and you can see and hear everything but you are unable to make any changes to the timeline or affect it in any way. This would be advantages for educational purposes, especially history class.

So here is my perception on time travel. I’m not dismissing anything completely and I’m sure there are some aspects I have forgotten to mention. If you have any thoughts on time travel, please don’t be afraid to mention them in the comments below.



Update: Here's a video of the Twin Paradox explained.