Quote:
Originally Posted by devonin
Nobody knows whether this is true or not because our understanding of physics says it is completely impossible to go faster than the speed of light.
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I was going to post the video i saw on the discovery channel a while back called the universe, but i was beaten to the punch. This may now be approaching the realm of not true because according to the video, some scientists now believe that in the big bang theory (for matter of reference) the explosion threw particles out at speeds faster than the speed of light.
One thing i think is important to keep in mind with this whole theory (obvious impossibilities aside) is that you all refer to the analogy of seeing a star that may have already went through a super nova and its 'old light'. When you try to apply this logic towards trying to see 'old light' i think that its important to realize that, unlike a star, the earth does not give off light going at light speed. It is reflected light from our sun. As small of a difference as this may be, you would have to consider the fact that if you try to look at light coming off from the earth it might go less than the speed of light.
As a point of clarification, we can actually slow light through different mediums. So then would it not be possible that the light coming off of the earth would be going at speeds that are less than the speed of light in a vacuum? Of course thinking in terms of it as either going through the atmosphere or at least touching it enough to use the particles it hits letting it slow down.
Also, im a little shaky on the whole subject of 'looking back at the earth' after speeding away from it at faster than the speed of light. To be able to see that specific planet wouldnt you have to have a direct connection of light to it so you can actually 'see' it? To explain, of course you would have light still hitting you from different directions, but i was always under the impression that to see something through a telescope you have to have its specific light hitting you already. If you have breached the light that is reflected off of the earth (of course only considering you got outside the original light reflected off of the earth at its creation) then you wouldnt be able to see the earth at all.
One last thing, simply enough, if you were moving at extremely fast speeds AWAY from the earth, why would it matter if that somehow allowed you to see it in its previous states? I mean, you wouldnt be able to communicate with it (for radio waves and the like travel MUCH slower), and you wouldnt be able to even get back to it without the light catching back up and it making no difference anyway.
To think of it realistically, look at the theory of relativity. Time moves relative to the observer right? So time would seem to move at different rates for someone on the earth as opposed to someone living on, lets just say, jupiter. Outsides the bonds of our earth we would be trying to time everything according to the system we use ON the surface of the earth which simply would not be the universal system of all the bodies in the universe. Our measuring system in accordance with the rest of the universe would feel rather useless for no matter how fast you are traveling through space, time will always feel different. Thus, time travel in essence would be a virtually useless argument outside the bonds of our own time system, or rather outsides the bonds of time relative to wherever you are.