If the speed of light relative to us is slowing, then is time slowing as well?

Question

Though it is still at the point of debate, I believe the speed of light relative to us is actually slowing down and has been since the beginning of time as we know it. It is widely believed and has been shown through evidence that as one approaches the speed of light, in a jet plane or a spaceship for instance, one's time actually slows down. The most famous example occurred in the 1970s when an atomic clock was given to one man essentially stagnant in space, while a second atomic clock was given to a second man who traveled with it around the world at approx. 600 mph. When the second man reached the first man, the second clock was several billionths of a second behind the first clock. This theory was predicted by Einstein decades before this experiment occurred. Assuming, then, that the speed of light, in fact, slowing down, would time itself slow as we approached it? Or perhaps is time slowing somehow which makes it appear to us that light is slowing? Could time and/or light stop? Would we become infinite mass or complete energy (because of E=mc*2)? The implications of this are enormous. I acknowledge that I'm a freshman student and am far from being any sort of genius (I don't even like to study science) and that I could have this idea way skewed. It's possible, for instance, that Einstein's theories would actually imply time's speeding up instead of slowing down and would be making a fool of myself by asking this question in the first place. But if that's case then I ask you all essentially the same questions. Any help (preferably with references) would be appreciated. Thanks!

Answer 1

Though DDFR made some good comments, I believe he missed the entire point of the question. This question is not about time dilation or relativity. This question is about changes in fundamental constants. And yes, there are theories that suggest the fundamental constants are changing, although very slowly. These theories are not due to Einstein, and came much later. These are actually more related to the Standard Model. There are a number of such theories, and they all predict one or more of the fundamental constants are slowly varying in time. Though most concern has been focused on small changes in the fine structure constant (alpha), the speed of light could also be changing. There have been a number of experiments testing for such changes, and with each new experiment that has greater accuracy, the failure to see such an effect pushes down the limit at which this drift could be occurring, in the process cutting out a number of theories that made predictions above the new limit.



So, assuming the speed of light is slowly drifting, which it probably isn't, would time also be slowing down? Not in the same way it occurs in relativity. The reason for the drift would not be at all related to time dilation in relativity. In relativity, time dilates, but length also contracts. In relativity, these two things occur to keep c constant, which is exactly not what is occuring in a drift of c. So you should not be thinking about these time drifts and time dilation in the same sense.



But could time be slowing down without length contraction? Well, it seems like you could always cast the problem in that way. But you could also say that length is slowly drifting. Or you could say that the ratio constant between time and space in Lorentzian space/time is changing. Hmmm, I'm even confusing myself. It's a bit complicated. But the point is the speed of light is tied into physics in several ways at a very fundamental level. You can think about it that way if you want to, but you can think about it other ways as well. And I don't see thinking about it in terms of time being very helpful.



As far as your questions about light stopping, that all depends on the theory. Since there are multiple theories, there are multiple behaviors. However, it is disputed as to whether changes in c, or any of the other fundamental constants, would actually be meaningful (in that they would change the way things work). If those who believe it is not meaningful are correct, then you can assume the speed of light can't stop. And that's probably the best guess at this point. At the very least, I would assume it would asymptote to zero, never actually getting there.



The only fundamental constant that everyone agrees could change in a meaningful way is alpha, which is why it is the focus of the most of the efforts looking into changes in constants. And there's no reason as of yet, to believe it actually does change.

Answer 2

I think you have confused a couple of things.



The speed of light is a constant and is ALWAYS the same. It never slows, speeds up or anything else. This answers half of your question before that light cannot stop.



The speed of light only appears to go slower relative to us because the relative time of that light is slower than us because a nearby mass has slowed its time down.



As you go toward the speed of light you slow down and this is where your confusion came from.



Something like us for example with a mass, will gain even more mass as it speeds up to a hypothetical - though not possible to attain* - infinite mass at the speed of light. This mass then causes more and more gravity, which slows down time more and more as we approach the speed of light.



Light however has no mass, thus no gravity, thus no reduction in time even at the speed of light. If light had mass, we would never see anything as light would not be moving forward in time at all and would be forever - from out relative perspective - at its point of origin.



* As you cannot reach the spead of light with a mass, time cannot slow to zero.



I would reccomend you look up the 'twin paradox' to see the effect of time changes, as this takes the speed element out and should reduce the confusion.

Answer 3

The pace of sunshine is a steady for an observer in each reference body. That is the elemental notion at the back of the (precise) conception of relativity. Since that's the (axiomatic) beginning factor additionally for the average conception of relativity (that is a conception of gravitation), of path all calculations to investigate the pace of sunshine for an observer in one other reference body will continually come to be restoring the "enter": The pace of sunshine is a steady in each reference body. In that case it's an round reasoning: c =const. => tons of mathematical gymnastics => c = const. (whilst performed correct) So, to take a look at to exhibit that the pace of sunshine isn't a steady, utilising the speculation of relativity (and gravitation is a relativistic end result) is a vain attempt. In reality, in case you uncover that the pace of sunshine is *no longer* steady, is a optimistic evidence that you just made a few errors for your calculations, absolutely combined up a few reference frames. Don't fear, that still occurs to expeirenced physicist every now and then.