Faster Than Light-Based Time Travel

My apologies for the long absence. Work, school, holidays, and PROCRASTINATION have kept me busy doing everything but working on this website, and when I finally got around to writing a post, it turned out to be a much hairier topic than I expected, and I took almost two months to write it. But it is finally here! Enjoy!

One thing that has bugged me a lot about science fiction is what seems to be the prevailing theory on the faster than light (FTL) method of time travel. The common concept is that, because time slows down for an object approaching the speed of light, then if that object could somehow surpass the speed of light, then it would start traveling backwards in time. In more technical terms, what this is saying is that spatial acceleration in the direction of spatial motion is either the same as, or inherently tied to, temporal acceleration in the opposite direction of temporal motion.

But what this appears to neglect is the very relativity it is based on. From the perspective of the traveler, as the ship speeds up, time for the contents of the ship proceeds as normal, while time for the outside world speeds up. However, from the perspective of a stationary observer, time for the observer will remain stationary, while time for the ship slows down. As the traveler approaches the speed of light, time for the outside world will approach an infinite speed as time proceeds normally for him, whereas from the perspective of the stationary observer, the ship will stop experiencing time altogether, though it will continue moving in space.

Wow, does my brain hurt just getting this far.

This brings up the problem of traveling at the speed of light. Depending on the perspective we look at this scenario from, we get contradictory results: from the observer’s perspective, time for the traveler stops, but from the traveler’s perspective, it does not. In mathematical terms, time becomes undefined, because we are dealing with numbers that just don’t work with our math (try calculating ∞-(∞-1), and play around with the order of operations, given that ∞-∞=0, and ∞-1=∞, and you’ll see what I mean–math just doesn’t work here)

So traveling at the speed of light appears to be a mathematical impossibility, but we can conjecture what it would look like, as long as we limit our perspective. With that foundational understanding, let’s move on to speeds greater than that of light.

The easiest way to think about FTL speeds is from the perspective of an outside observer, so that is where I will start. An observer will perceive the traveler as experiencing time more and more slowly as he approaches the speed of light, ultimately ceasing to experience time altogether at the speed of light. Thus, it is only logical that, once the speed of light is exceeded, time for the traveler will reverse, and he will travel back in time. This is the standard view of what would happen if someone exceeded the speed of light.

But this is where things really start to get interesting: from the perspective of the traveler, time for the outside world is accelerating until, when he reaches the speed of light, time for the outside world is traveling at an infinite speed, so when he accelerates past the speed of light, why would time for the outside world suddenly reverse speed? There is absolutely no reason to expect this. In fact, our entire concept of time, even altered by Einstein’s Theory of Relativity, simply breaks down.

This concept contains two instances of paradox. The first is that relativity begins to affect time in completely different ways, depending on the perspective you choose. The second is the fact that travel at speeds greater than that of light cannot follow the same rules of relativity as speed up to that point.

I  hypothesize two possible explanations for this: the first possibility is that light speed is actually is an absolute barrier, and for more reasons than we realize. I still have no idea why the universe would behave this way, or if the scientific community has any theories. It seems completely arbitrary, but if I have learned one thing, it is that God does not do arbitrary, so there must be a reason. The second possibility, both less likely and cooler to think about, is that once the speed of light is exceeded, you begin interacting with the fifth dimension. I might be able to cook up some ideas on how that would work, but right now I think this post is long enough, and has been long enough in coming, plus it’s getting pretty late, and my this topic hurts my brain at my best.

What do you guys think?

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Some More Thoughts on Relativity

I admit it, I’m a terrible blogger. At least I am when life happens. Which it kind of always does. Otherwise, I, you know, wouldn’t have one. But if I can’t keep up with a consistent posting schedule, the least I can do is follow up on a promised post. Unfortunately I haven’t done any of the math-work on the promised Special Relativity post (I’ve had enough school to do without calculating a new definition of motion), but I can update you on my discoveries about General Relativity.

As I mentioned in my last post (over two months ago…), I had a chance to talk to Korean physicist Min Seong Lee about my ideas on relativity, and what he had to say enlightened me in a few ways, both positive and negative.

First, it turns out that the problem I found in relativity is actually only a problem in the oversimplification of the theory that is used to explain it to high schoolers. To recap, my problem with the theory was that a simple warp in space time would cause particles to curve in observed space, but not at all in the way we see gravity behaving, and it would never accelerate a particle from a stationary position relative to the space-time. To solve this problem, I proposed that instead of mass warping space-time, space-time moves towards mass. What Min Seong pointed out to me is that, while a particle may be stationary relative to the three dimensions of space, no particle is ever stationary relative to time. Time is always flowing, providing the moving dimension that I proposed was necessary to create motion within space. I am still not sure entirely how this works, even though he showed me an equation that demonstrated how moving time acceleration (or if I did, I have forgotten my understanding in the months it has taken me to get this written down).

Now, the happy part of this is that, because of the moving time aspect and some of the math involved, my idea is basically just another way to say what already existed in the theory, so while I wasn’t the first to come up with this idea (though maybe the first to state it the way I did), my idea was, in fact, correct (or at least mostly so). While I may be merely following in the footsteps of minds greater than mine, it is still exciting to follow their footsteps with my own mind, rather than getting pushed along the path in a stroller. Textbooks are great for learning things, and I would never have been able to discover what I have without the foundation they gave me, but there is nothing like discovering cool science stuff for yourself.

Some Thoughts on Relativity

As I mention in my “about” page, when I was in middle school I thought I disproved Einstein’s General Theory of Relativity, but almost immediately forgot the thought process. That has created a nagging doubt in my head every time I have used his theory ever since, and I have always been annoyed at not knowing whether I was right or not. However, I just went back over his theory in my current Physics course, and something about the way this guy worded it reignited the thought process I had back in middle school, and I now know what I thought was wrong with the General Theory of Relativity.

The problem I have with the theory is actually found in its very foundation. Einstein said that Newton’s laws of motion could basically be restated by saying that “In the absence of external forces, objects travel the straightest possible path in spacetime.” To explain the “force” of gravity in a way consistent with this statement (because, due to the “principle of equivalence” and some weird reasoning that doesn’t quite make logical sense to me, Einstein thought that gravity wasn’t actually a force), Einstein said that “Mass and energy cause spacetime to curve.” Science teachers love to use the illustration of a mass in a pillow or bed sheet, with a marble rolled alongside. They point to the fact that the marble rolls and hits the mass making the depression, and say “See? Mass bends spacetime!” However, the only reason the marble ends up reaching the bottom of this depression is that there is external gravity! Thus, this illustration begs the question by using gravity to explain gravity. In order for this illustration to actually work properly, it must be in a gravity free environment.

So take this setup out to deep space. Replace the bed sheet and mass with, say, a piece of sheet metal that is warped in the middle in the same way that the mass warps the bed sheet, and replace the marble with, say, a magnetic ball, so that it stays attached to the sheet metal the entire time. Now run the experiment in your head, ignoring friction (because there would be no friction in the theory we are trying to illustrate, and you can successfully neutralize friction in a simulated experiment). First, imagine this with the ball moving very quickly: the ball rolls along, and encounters the simulated gravity well. What does it do? It enters the gravity well along its original path, and then leaves the gravity well, still traveling along the same path. Remember, there is no friction, and no external force pulling the object into the well. The only factors to consider are the ball’s velocity and the metal’s warping. There is absolutely nothing to provide a centripetal force to change the direction of the ball. Viewed from above, the ball curves towards the center of the well when it enters, but immediately begins curving back out, and ends up in the same path it was traveling on before. Now, imagine if the ball is stationary, but inside the simulated gravity well. What happens? Nothing! The ball just sits there.

Now compare this to the situation it is supposed to be illustrating. In a real gravity well, if something is moving very fast, its path will bend in response to the gravity well, but it will not be caught in it. This is consistent with the illustration: if the ball is rolling very quickly, it will curve inside the simulated gravity well, but it will leave the gravity well and continue. However, in a real gravity well, the object will have changed direction when it leaves the gravity well, and in the illustration, the final path of the object is exactly the same as the original path. Now think of an object just sitting in the air above the earth. It begins accelerating towards the earth. In the illustration, the ball just sits there, because there is no outside force acting on it.

Thus, no amount of spacetime warping can permanently change the direction of an object, so Einstein was WRONG!

That is as far as I got in middle school, but this time I was able to take it a little further and develop an amendment to his theory that would solve the theoretical problem without actually changing any of the math: instead of saying, “Mass and energy cause spacetime to curve,” I say that “Spacetime flows towards mass and energy.” Now, this statement still needs some work: for example, we now know that mass and energy are the same thing–a vibration in spacetime (see my Matter and Matter Follow-up posts), so we need to come up with a way to make this statement in a way that is consistent with those ideas, but I am fairly certain that this is how it works on the macroscopic scale.

Let’s go back to the original illustration. You have a bed sheet on the floor, and a device in the middle that sucks the threads towards it. When you roll your marble across the sheet, it will begin to curve towards the device. If it is moving quickly, it will escape the “gravity well,” and emerge traveling in a different direction. If it is moving slowly, it will begin orbiting the device, and if it is moving even more slowly, it will eventually hit the device and rest against it. Finally, if you lay the marble at rest a little away from the device, when you release the marble it will begin accelerating towards the device. This is exactly how we see gravity work in the real world!

Now, I also have idea about Special Relativity: not a correction, but a new way of thinking about things that could make Special Relativity  much easier to understand. However, it will involve a lot of math and other homework–by far the most labor and thought intensive idea I have had so far–so it may be a while before I can post it. Despite this, I am really excited about it, and wanted to give a little teaser now to piggyback on the General Relativity post: Basically, I am working on a new mathematical definition of motion that will take Special Relativity into account–essentially redefining motion as distance warped over time warped, instead of distance passed over time passed. Now, this is basically what Einstein was going for when he developed his General Theory of Relativity, so I wouldn’t be surprised in the slightest if he already did this and it just ended up using more complicated math than they want to teach non-physics majors, so I might come up dry or find I am simply reinventing the wheel, but I have stated my goal.

Now, I have had this idea for an amendment to Relativity for a while, but it was based on some other ramifications, such as the possible existence of antigravity (gravity that pushes instead of pulls), antimatter, white holes, etc., but this base has allowed me to flesh it out some more. I will try to write on the other ramifications of this amendment in my next post.

Finally, I have the image at the top linked to the page I found it on. I have not read it, but I want to read it as soon as I have the time. It appears to be a well thought out argument for another problem with Relativity, so I linked to it in case you guys were interested.

Any thoughts? I hope I explained this clearly enough, but knowing how abstract this whole concept is, I wouldn’t be surprised if I simply left your minds even more twisted than before. I know my mind went for quite a few loops while figuring this out. I would love to answer any questions you have in the comments. Also, I might be wrong about all this, and simply be misunderstanding Einstein’s theory, but I am fairly confident in my analysis, and I would love to be challenged so I can refine or recant my idea.