Is the speed of light constant?

[kgreen93]

I expect that I am missing something that disproves my theory, so if you know something I don't, PLEASE prove me wrong: I just watched the episode of "through the wormhole" where they discussed the possibility of faster than light travel. In the episode, various people were proposing the idea that the speed of light was not constant throughout the universe, but instead, light was capable of moving faster, depending on its proximity to a cosmic string, a photon sized superhighway that snakes throughout the universe following the path of a photon released from the big bang. This is a counter solution to the cosmic inflation theory that solves the problem of how energy could be equally dispersed over the universe, despite originating at one point and being restricted to the speed of light.

 

 

My question is two-fold: First, is it possible that the speed of light CAN be affected by increasing the starting velocity, but that the difference in total velocity would be imperceptible? Afterall, what's an extra 50 mph from a moving car, compared to the speed of light?

 

 

Second, space-time dictates that the rate of time varies depending on gravity and velocity. Imagine that the universe was like an infinite number of televisions in a row and some of the televisions were playing normal speed, some slow motion, and some fast forward, varying due to gravity. As a beam of light moved from television to television, would the speed of the photons vary according to the local speed of time, or would it remain constant regardless of the local time, meaning it would go relatively faster in the slow motion sections and relatively slower in the fast forward sections? In either case, wouldn't the speed of light be relative to location, gravity, and base velocity? Any and all help would be appreciated. Sorry for being a little longwinded.

[ajb]

Things like wormholes and cosmic strings give apparent faster than light speed travel. This is just the sort of thing you need to build a time machine.

 

There is more than one way to send light signals and this can be used to give the illusion of sending messages faster than the speed of light.

Edited August 19, 2011 by ajb

[pantheory]

I expect that I am missing something that disproves my theory, so if you know something I don't, PLEASE prove me wrong: I just watched the episode of "through the wormhole" where they discussed the possibility of faster than light travel. In the episode, various people were proposing the idea that the speed of light was not constant throughout the universe, but instead, light was capable of moving faster, depending on its proximity to a cosmic string, a photon sized superhighway that snakes throughout the universe following the path of a photon released from the big bang. This is a counter solution to the cosmic inflation theory that solves the problem of how energy could be equally dispersed over the universe, despite originating at one point and being restricted to the speed of light.

 

My question is two-fold: First, is it possible that the speed of light CAN be affected by increasing the starting velocity, but that the difference in total velocity would be imperceptible? Afterall, what's an extra 50 mph from a moving car, compared to the speed of light?

 

Second, space-time dictates that the rate of time varies depending on gravity and velocity. Imagine that the universe was like an infinite number of televisions in a row and some of the televisions were playing normal speed, some slow motion, and some fast forward, varying due to gravity. As a beam of light moved from television to television, would the speed of the photons vary according to the local speed of time, or would it remain constant regardless of the local time, meaning it would go relatively faster in the slow motion sections and relatively slower in the fast forward sections? In either case, wouldn't the speed of light be relative to location, gravity, and base velocity? Any and all help would be appreciated. Sorry for being a little longwinded.

Most standard model theories propose the speed of light is constant, according to Special and General Relativity. As to big differences in the speed of light, like wormholes etc., this is not the standard model. My expectation is that the speed of light does vary in velocity, based upon variations of gravitational fields, but probably not be much. I expect it varies a slight amount here on Earth up vs. down, but such a proposal has not been tested to such precision since the precision clocks needed to do such a test have only been around for a couple of decades.

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Edited August 19, 2011 by pantheory

[md65536]

Yes, the speed of light is constant.

 

A wormhole doesn't change the speed of light, but changes the distance between 2 points, providing a shortcut.

It's kind of a cheat. If you measure the distance between the two points with ordinary space, but allow light to travel between the two along a different distance, then light can travel at c but for a much shorter distance. To calculate a faster than light speed, you'd use the longer distance, which is a cheat because light didn't actually travel that path.

 

 

 

Personally I doubt that's possible. Defining distance with "ordinary space" seems to be consistent. Any cheats and corresponding violation of causality would probably involve inconsistencies, and the universe appears to be consistent as a rule.

[pantheory]

Yes, the speed of light is constant.

This is the mainstream part of the forum or else I would assert otherwise

 

A wormhole doesn't change the speed of light, but changes the distance between 2 points, providing a shortcut.

It's kind of a cheat. If you measure the distance between the two points with ordinary space, but allow light to travel between the two along a different distance, then light can travel at c but for a much shorter distance. To calculate a faster than light speed, you'd use the longer distance, which is a cheat because light didn't actually travel that path.

Cheaters never prosper, or fly through any wormholes either, that I know of

 

Personally I doubt that's possible. Defining distance with "ordinary space" seems to be consistent. Any cheats and corresponding violation of causality would probably involve inconsistencies, and the universe appears to be consistent as a rule.

 

I agree

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Edited August 21, 2011 by pantheory

[mississippichem]

This is the mainstream part of the forum or else I would assert otherwise

 

It's alright, you would be saying so without a valid argument anyway so...

 

*I jest harshly but in good humor.

Edited August 21, 2011 by mississippichem

[pantheory]

It's alright, you would be saying so without a valid argument anyway so...

 

*I jest harshly but in good humor.

I truly appreciate jest and good humor I have theory, reasoning, and I believe a valid argument. I have designed a test (not quite so easy) for this assertion if you wish to discuss it in the speculation forum, " alternative to Big Bang" thread. The same experiment would also be a test of my model of gravity.

 

added: What, this is the speculation forum? but not my thread. Could I start explaining my model here, or do I need to save the "differences in the speed of light" for my own thread?

//

Edited August 21, 2011 by pantheory

[kgreen93]

Most standard model theories propose the speed of light is constant, according to Special and General Relativity. As to big differences in the speed of light, like wormholes etc., this is not the standard model. My expectation is that the speed of light does vary in velocity, based upon variations of gravitational fields, but probably not be much. I expect it varies a slight amount here on Earth up vs. down, but such a proposal has not been tested to such precision since the precision clocks needed to do such a test have only been around for a couple of decades.

//

 

 

Ok, that's reasonable. Since we are in the speculations forum, let's take it a step further. If the speed of light does vary slightly due to variations in gravity on earth, but the subtle changes are imperceptible, what would happen if we were observing a photon traveling at c as it traveled towards the event horizon of a black hole? As the gravity becomes more extreme, space-time dictates that time slows down. As an unaffected observer, would the beam of light continue to move at c, or would it exponentially decelerate as it approached? Or would the photon continue to cruise along at c in our eyes, therefore moving faster than c when compared to an object that is also undergoing the gravity induced space-time crunch? Side-note: I'm a biologist, not a physicist, so I don't really know anything about the specifics of this thought experiment. If photons carry mass, which I don't know whether or not they do, is it possible that a photon with a starting velocity of c would accelerate from the added force of extreme gravity as it became closer to the event horizon? Again, I welcome any and all discussion and help.

 

Yes, the speed of light is constant.

 

A wormhole doesn't change the speed of light, but changes the distance between 2 points, providing a shortcut.

It's kind of a cheat. If you measure the distance between the two points with ordinary space, but allow light to travel between the two along a different distance, then light can travel at c but for a much shorter distance. To calculate a faster than light speed, you'd use the longer distance, which is a cheat because light didn't actually travel that path.

 

 

 

Personally I doubt that's possible. Defining distance with "ordinary space" seems to be consistent. Any cheats and corresponding violation of causality would probably involve inconsistencies, and the universe appears to be consistent as a rule.

 

 

Ok, I understand what you're referring to. I probably made a mistake in the wording of my original post. I'm not referring to light traveling at c through a shorcut, I'm questioning whether or not c is truly variable. I think that by objectively watching a photon zoom through the universe, you would actually watch it accelerate and decelerate as it passed through gravitational fields. Or, maybe, it would remain constant, therefore moving faster or slower than c in relation to the objects around it, enduring the same gravitational forces. I don't know. I'm a biologist with a crazy question that my friends can't answer and virtually zero background knowledge. Haha

[pantheory]

Ok, that's reasonable. Since we are in the speculations forum, let's take it a step further. If the speed of light does vary slightly due to variations in gravity on earth, but the subtle changes are imperceptible, what would happen if we were observing a photon traveling at c as it traveled towards the event horizon of a black hole? As the gravity becomes more extreme, space-time dictates that time slows down. As an unaffected observer, would the beam of light continue to move at c, or would it exponentially decelerate as it approached? Or would the photon continue to cruise along at c in our eyes, therefore moving faster than c when compared to an object that is also undergoing the gravity induced space-time crunch? Side-note: I'm a biologist, not a physicist, so I don't really know anything about the specifics of this thought experiment. If photons carry mass, which I don't know whether or not they do, is it possible that a photon with a starting velocity of c would accelerate from the added force of extreme gravity as it became closer to the event horizon? Again, I welcome any and all discussion and help.

There are at least two alternative models that differ from the mainstream explanation. In the first example it is known that gravity bends light. Accordingly light trying to escape a black hole would be stretched and redshifted, giving the impression that the black hole is much farther away than it really is. This would normally be only a small percentage of the light spectra since most escaping light would escape tangential to the torus of the black hole. Maybe only for certain types of galactic black holes could this effect be detected. For this small portion of the spectra to be properly identified is another matter

 

The other model relates to a particulate aether such as dark matter, Higgs particles, gravitons, field strings, etc. In this model light still moves at the same speed of light relative to the background field but the background field moves, therefore here on Earth there would be a difference in the speed of light that might now be detectable with such precision timing devices such as those in orbit used in GPS technology. I have designed an experiment to test such a small speed differential of up vs. down.

..

Edited August 29, 2011 by pantheory