Posted on 03/10/2017 3:40:14 PM PST by SeekAndFind
The speed of light in a vacuum is the ultimate cosmic speed limit. Just getting close to it causes problems: the weird distortions of Einstein’s relativity kick in, so time slows down, lengths go up, masses balloon and everything you thought was fixed changes. Only things that have no mass in the first place can reach light speed – photons of light being the classic example. Absolutely nothing can exceed this cosmic max.
We have known about the special nature of light speed since an experiment by US physicists Albert Michelson and Edward Morley in the 1880s. They set two beams of light racing off, one parallel and one at right angles to the direction of Earth’s rotation, assuming the different relative motions would mean the light beams would travel at different speeds – only to find the speed was always the same.
Light’s constant, finite speed is a brake on our ambitions of interstellar colonisation. Our galaxy is 100,000 light years across, and it is more than four years’ light travelling time even to Proxima Centauri, the closest star to the sun and home, possibly, to a habitable planet rather like Earth.
Then again, if the speed of light were infinite, massless particles and the information they carry would move from A to B instantaneously, cause would sit on top of effect and everything would happen at once.
(Excerpt) Read more at newscientist.com ...
A rumor travels faster then light.
The speed of light is constant, even in matter. The ‘speed of light’ in a transparent material is just the net perceived macroscopic interference wavefront from a vast number of individual absorptions, excitations, and emissions of the constituent atoms in the material. Light travels the vacuum from atom to atom at c. Also, “the speed of light” is a much deeper concept, and is a structural constant of spacetime, and exists independent of the particular properties of photons. In a universe without electromagnetic radiation, c would still exist, but would not be quite so convenient to measure.
Venus also rotates slowly--116 days from one sunrise to the next. I read somewhere that it always has the same side facing the earth, but I'm not sure if that is correct.
You can prove the speed of light is not constant with nothing more than a sunbeam and a glass of water.
On March 4, the moon occulted the star Aldebaran (Alpha Tauri). Initial reports indicate that Aldebaran was not harmed. But light from Aldebaran which had been racing towards the earth for 65 years hit the moon a little more than a second before it would have reached its goal. What a disappointment for those rays of light—almost at their goal and splat! they hit the moon instead.
The Decreasing Speed of Light - Dr. Barry Setterfield
https://www.youtube.com/watch?v=QdTlOVTDbNU
It’s because of the time dilation effect—photons don’t experience time, so they can’t change, or fizzle, or anything while in transit. See my #14.
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Good question - to me anyway.
Are not gravity waves believed to “bend light”. If so, can/do they also effect the speed of light?
In the very tiniest early fraction of the beginning of the “big bang”, isn’t it said that it was all energy and none of it had “cooled” into any form of matter, and if true was there then no gravity yet to speak of. And that’s true then could light have been - for some period of “time” - very much faster than it is today?
Or I am too ignorant and just asking a question learned physics would say is dumb.
A photon travels at at the speed of light. A photon is a particle. What holds the particle together? A photon is made of yet smaller particles. What holds each of those smaller particles? Whatevertheyare that glue must move faster than light. We just don’t know about them yet.
Just when we thought the atom was the basic particle, we find dozens of smaller particles.
Light does not, according to our current understanding, expend energy to travel (although there are theories of ‘tired light’, too). Being massless, photons travel at the speed of light (in a vacuum). And relativity says that that is true regardless of the speed of the observer.
Nope. The speed of light is constant, but when it appears to slow down, that is the result of repeated absorption-emission cycles as it is affected by encountered matter.
Bingo. I was waiting to see what smart freeper figured it out.
Also, the ramifications mean that people will have to consider that which is anathema to science as well....uh oh.
Gravity bends space-time. Photons traversing that bent space-time will appear to have been affected by gravity by having their path changed, but that isn't how it works.
I think that light speeds up the closer you are to an intersection when the light turns yellow.
Light is affected by gravity, ie objects in space. So, not constant.
“Time does not exist for massless particles that go at the speed of light. According to Einstein, everything goes at the speed of light, either through space or through time.”
Time is not just a function of the speed of light. It is a function of the frequency of consciousness divided by the speed of light. As consciousness frequency increases and surpasses the speed of light, time collapses.
Einstein did not understand this so he assumed the speed of light as a constant.
This is just silly. The science is settled. There shall be no more debate.
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