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Light speed and time travel

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mrfrosty
#37
Mar29-12, 09:38 AM
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A supersonic aircraft would be silent if you were in front of it, as the sound wave acts in a cone from the front of the direction of travel outwards to the rear, that is why you see a supersonic aircraft before you hear it. The sound wave is an effect from its movement.
PAllen
#38
Mar29-12, 09:43 AM
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Quote Quote by mrfrosty View Post
That's understood about infinite energy. Now if you think about the theory of the idea, and the theory that you have enough energy to propel a mass at the speed of light, if you were to slowly accelerate up to the speed of light and have the ability to take measurements of time dilation in doing so, would both the acceleration and the amount of time dilation be proportionate with each other. For example, if the speed of light was used as a speed in the equation for time dilation, would the time be '0', ie at a stand still.
No matter how much you accelerate, fast or slow, however long, the speed of light will remain the same for you, whether you emit the light or someone you are are zooming by at .9999999999999 c emits the light. The two signals will move at c past you, even if you have been accelerating at a billion gees for a billion years.
DaleSpam
#39
Mar29-12, 10:00 AM
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Quote Quote by mrfrosty View Post
A supersonic aircraft would be silent if you were in front of it, as the sound wave acts in a cone from the front of the direction of travel outwards to the rear, that is why you see a supersonic aircraft before you hear it. The sound wave is an effect from its movement.
Similarly, your logic that a superluminal object would be invisible is not correct. In fact, there is a close analogy to sonic booms for EM radiation, called Cherenkov radiation. It is very visible. True, you wouldn't see it until the particle had passed, but you still see it quite clearly.
phinds
#40
Mar29-12, 10:29 AM
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Quote Quote by mrfrosty View Post
That's understood about infinite energy. Now if you think about the theory of the idea, and the theory that you have enough energy to propel a mass at the speed of light, if you were to slowly accelerate up to the speed of light and have the ability to take measurements of time dilation in doing so, would both the acceleration and the amount of time dilation be proportionate with each other. For example, if the speed of light was used as a speed in the equation for time dilation, would the time be '0', ie at a stand still.
Since you do not experience time dilation inside your superfast ship, it would not be possible to design an experiment to measure it. Time dilation is something seem by OTHER observers, not you.
mrfrosty
#41
Mar29-12, 12:51 PM
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Lets see if I have got this right then.
1. Speed is related to time dilation, the faster the speed, the greater the time dilation.
2. Nothing can travel faster than the speed of light.
3. The speed of light is the point at which time is stationary.
4. If you could travel fast enough, you would not know that time has stopped or been dilated as it is only observed by somebody outside of your ship.
phinds
#42
Mar29-12, 01:43 PM
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Quote Quote by mrfrosty View Post
Lets see if I have got this right then.
1. Speed is related to time dilation, the faster the speed, the greater the time dilation.
2. Nothing can travel faster than the speed of light.
3. The speed of light is the point at which time is stationary.
4. If you could travel fast enough, you would not know that time has stopped or been dilated as it is only observed by somebody outside of your ship.
1) I would word #1 the other way 'round since what you have makes it sound like speed is created by time dilation.

2) correct

3) stationary relative to WHAT? Speed/time dilation is only meaningful in relationship to something. Actually, you don't get to "stationary" since that would imply traveling at c, which you can't do.

4) correct, although you don't get to a point of "stopped" since that would imply you are traveling at c, which cannot be done by anything with rest mass.
nitsuj
#43
Mar29-12, 02:16 PM
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Quote Quote by mrfrosty View Post
Lets see if I have got this right then.
1. Speed is related to time dilation,
Strickley speaking I'm not to sure.

I'd agree speed cooralates to time dilation. But I don't agree that speed is related to time dilation.

I'd raise gravitational time dilation where speed isn't required.

But I don't know enough about the details to say for sure.
kamenjar
#44
Mar30-12, 05:22 PM
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Quote Quote by c0ke View Post
...why doesn't light itself travel in to the future? ...
It actually does. The photon's time in a way stops. From photon's point of view the universe ages in an instant as it goes from one end to the other end of the universe (not that there are ends - using this as a form of expression).
Drakkith
#45
Mar30-12, 05:33 PM
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Quote Quote by kamenjar View Post
It actually does. The photon's time in a way stops. From photon's point of view the universe ages in an instant as it goes from one end to the other end of the universe (not that there are ends - using this as a form of expression).
I'm not sure a reference frame can be given for light.
kamenjar
#46
Mar30-12, 05:52 PM
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Quote Quote by Drakkith View Post
I'm not sure a reference frame can be given for light.
I don't think either
Quote Quote by kamenjar View Post
..time in a way stops.
Drakkith
#47
Mar30-12, 08:29 PM
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Quote Quote by kamenjar View Post
I don't think either
What?
mrfrosty
#48
Mar31-12, 05:33 AM
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My problem with the theory of photons is that light has a speed and although it is very fast, it is still measurable. I am convinced that the only limitation to speed is the fact that photons, the particles that allows us to see things due to them bouncing off of the object, are the limitations to speed as if the object was travelling faster than photons, theoretically, the object would be invisible, but it would still be there.
phinds
#49
Mar31-12, 06:01 AM
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Quote Quote by mrfrosty View Post
My problem with the theory of photons is that light has a speed and although it is very fast, it is still measurable. I am convinced that the only limitation to speed is the fact that photons, the particles that allows us to see things due to them bouncing off of the object, are the limitations to speed as if the object was travelling faster than photons, theoretically, the object would be invisible, but it would still be there.
The universe really doesn't care what you are convinced of. The universal speed limit is NOT based on photons and your belief is not supported by reality as it is currently understood by both experimental AND theoretical physics.
DaleSpam
#50
Mar31-12, 08:45 AM
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Quote Quote by mrfrosty View Post
My problem with the theory of photons is that light has a speed and although it is very fast, it is still measurable. I am convinced that the only limitation to speed is the fact that photons, the particles that allows us to see things due to them bouncing off of the object, are the limitations to speed as if the object was travelling faster than photons, theoretically, the object would be invisible, but it would still be there.
We already addressed this. By this logic a supersonic jet or bullet would be silent. We know that they are not silent. Therefore your logic is wrong. When your logic is shown to contradict fact then you must discard your falsified hypothesis and come up with a new theory that correctly fits the facts.
HallsofIvy
#51
Mar31-12, 09:07 AM
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Vision is not the only way we "observe" the world! Even blind people can be physicists.


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