light speed and time travel

DaleSpam

By that same logic a supersonic aircraft should be silent.

The relativistic effects are not due to appearances or light's finite speed. They are what remains after an intelligent observer accounts for light's finite speed.

mrfrosty

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.

mrfrosty

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

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

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

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

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

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

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

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

I'm not sure a reference frame can be given for light.

kamenjar

I don't think either

Drakkith

What?

mrfrosty

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

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

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

Vision is not the only way we "observe" the world! Even blind people can be physicists.