Questions About Speed of Light & Time

[chroot]

i see, i understand now, so standing still on a certain land/planet/sattelite... that objects speed that you are standing on, is not added to how fast something is traveling on the object(for instance the Earth is orbiting the sun at a speed, which i do not know, sorry, but we do not add that speed to anything traveling here on earth), instead it's speed is measured from earth, or the object in which you reside and are viewing another object from. It might not sounds like i understand it, but i do now lol. thanks

For the purposes of basic calculations, you can assume the Earth is at rest. Its velocity around the sun is not significant when compared to a spaceship going 0.99c with respect to it.

Since nothing in the universe is really "at rest," it's difficult to use real bodies in thought-experiments. The Sun is moving with respect to the galaxy, the galaxy with respect to other galaxies, and so on.

You could just label the start and end points A and B, and consider them both at rest with respect to each other. They're just two arbitrary points in space that are not moving with respect to each other. You can call one Earth and one Alpha Centauri to make the problem a bit more personable, but you have to neglect the slight (but very real) motion that the Earth and Alpha Centauri really have.

- Warren

 

[s3nn0c]

Such extrapolations are dangerous. Since it isn't possible, it's best just to say it isn't possible.

The question was very good and I can't agree with your answer, Chroot. There are real, physical objects which are moving at speed of light: photons. So, the question "what would happen to someone traveling where the is no time?" is definitely not trivial, if "someone" means a photon. IMO the answer can tell us very fundamental things about the real nature of spacetime. What is a real role of space for a photon? How is it possible that we can create and observe objects which locally don't exist in time? How is it possible that things can happen with photons, if photons doesn't move in time? How can photons "detect" points of space and react on their existence if they are frozen in time?

I don't know the answers, but it looks like we can see here the more fundamental properties of our universe than our spacetime.

 

[TheUnknown]

The question was very good and I can't agree with your answer, Chroot. There are real, physical objects which are moving at speed of light: photons. So, the question "what would happen to someone traveling where the is no time?" is definitely not trivial, if "someone" means a photon. IMO the answer can tell us very fundamental things about the real nature of spacetime. What is a real role of space for a photon? How is it possible that we can create and observe objects which locally don't exist in time? How is it possible that things can happen with photons, if photons doesn't move in time? How can photons "detect" points of space and react on their existence if they are frozen in time?

I don't know the answers, but it looks like we can see here the more fundamental properties of our universe than our spacetime.

sorry if i don't understand, or sound like a fool.. but I've always wondered this too... why does traveling faster or equivelent than light always come up with cooky answers? why can it not be possible? is it just because we really don't have any answers yet? if me and the sun's light had a race, and i beat the sun's light to earth, what is so wrong with that? i could just look back and see the light coming? (does anyone know of gravity warp/ time distortion? I'd like to know if any of that can come into place when traveling close to or above the speed of light, like if you pulled space toward you, you would in fact beat light by not traveling faster than it, would that cause any problems?)

 

[DaveC426913]

sorry if i don't understand, or sound like a fool.. but I've always wondered this too... why does traveling faster or equivelent than light always come up with cooky answers? why can it not be possible? is it just because we really don't have any answers yet? if me and the sun's light had a race, and i beat the sun's light to earth, what is so wrong with that? i could just look back and see the light coming?

Imagining it to be so is not the same as it being possible. We DO have the answers, and the answers, demonstrated uncountable times over the last century, have shown that this is not the way the universe works.

"What would stop you", you might ask, "from getting in a spaceship and doing it?"
Well in a very small nutshell (and amongst many other things), as you approached the speed of light, your mass would increase, approaching infinity. It would take an infinite amount of energy to accelerate you further.

(does anyone know of gravity warp/ time distortion? I'd like to know if any of that can come into place when traveling close to or above the speed of light, like if you pulled space toward you, you would in fact beat light by not traveling faster than it, would that cause any problems?)

No. This does not violate relativity, and is one of the speculative ways of crossing distances faster than light. (It, BTW, is the method that Star Trek uses.)

Wormholes are another way of shrinking the space between distances.

 

[TheUnknown]

thank you.

 

[jtbell]

why does traveling faster or equivelent than light always come up with cooky answers?

Look at almost any relativistic equation and you'll find a factor of

\frac {1}{\sqrt {1 - v^2 / c^2}}

in there somewhere (possibly buried inside some variable). As v approaches c, this approaches infinity, and for v > c it gives an imaginary number. People have played around with trying to make sense out of these imaginary numbers for real physical quantities, but so far there is no actual experimental evidence for any of this; it's just speculation.

For a more "physical" answer rather than a "mathematical" one, imagine pushing on an object to accelerate it towards the speed of light. In relativity theory (and as has been verified over and over again in high-energy particle accelerators), as you do more and more work on the particle, the "gains" in terms of speed diminish. Each additional joule of work gains you less and less additional speed, and in the limit as the object's speed approaches the speed of light, the amount of work necessary to make it go even a tiny bit faster approaches infinity. In other words, just to make something go at the speed of light would require an infinite amount of work (energy).