horneddemon
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« on: July 15, 2011, 10:32:21 PM » |
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I've been researching variable speed of light theories in cosmology and physics. Perhaps someone with more of a physics background can answer this, but if light ever did go faster than its current constant value of 300,000 metres per second, would that not also make it travel back in time as well. According to special relativity, faster than light travel is not possible for matter or information, but what about light itself surpassing that constant value?
my mistake so roughly 300,000,000 metres per second, i was thinking kilometers
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Zarn
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« Reply #1 on: July 16, 2011, 10:28:05 AM » |
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Light seems to have a (mostly) constant speed in a vacuum. The exact speed of light can vary depending on the medium it is transmitted through. However, this also seems to be the speed of time, as information does not seem to be able to travel faster than light at any rate. So, whatever speed that light travels at in any given medium is also the maximum speed that information can travel - and thus, arguably, the speed at which time propagates.
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OldPilot
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« Reply #2 on: July 16, 2011, 07:19:11 PM » |
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No. For the same reason you cannot be younger than you were when you were born (conceived?)
The equations of Special Relativity (The Lorentz Transform) yields:
1/sq rt (1 - V^2/c^2)
Where V: object's velocity and c is the speed of light. If V is greater than c then the Lorentz Transform =
sq rt (some negative number) But The square root of a negative number does not exist ===> The calculation yields a nonsense answer.
The result of greater than light speed (if possible) is like running a movie backwards. Running a movie backwards does not reverse time
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oldprof
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« Reply #3 on: July 17, 2011, 11:40:14 AM » |
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That Lorenz Transformation the ancient aviator mentions is key to your question.
Time dilation is T = t/L(v/c); where L(v/c) = sqrt(1 - (v/c)^2)
Set v =kc, where k > 1.000, the moving platform is traveling faster than light, c.
Then L(kc/c) = L(k) = sqrt(1 - k^2) = sqrt(-n) = i sqrt(n); where i^2 = -1 is an imaginary number. 1 - k^2 < 0, some negative number (e.g., -n).
So when v > c, T L(k) = T i sqrt(n) = t. This shows that time t on board the platform, as seen from the outside, becomes an imaginary number when v > c. So time does not become negative and travel backward, as some assert, it becomes imaginary. And that is meaningless re time.
My point is this. The Lorenz Transformation is only valid between v = 0 and v = c. So using it to assert time travels backward is not valid.
Photons are stuck at the speed of light in a vacuum. Experiments show that speed is invariant with conditions. The Maxwell Equations show light speed is a constant. Finally, photons cannot go faster because that would take more energy than they have. Photons at light speed have E = hf energy. And that's all they pack. Adding energy only increases their frequencies, not their speed.
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OzoneGuy
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« Reply #4 on: July 17, 2011, 04:56:21 PM » |
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No, light describes how material objects age, not how light ages. VSL cosmologies accept that light always travels at the current speed of light, and the current speed of light defines how matter ages.
No issues.
And by the way the speed of light is:
299,279,458 m/sec. You are off by a factor of 1000 (equating km/sec to m/sec).
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