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Originally Posted by iceman2
but I was wondering about the speed of light. It travels at about 300,000 kms/sec, does this mean that its speed is constant or does a photon accelerate as it is emitted from its source and then reach a maximum speed of 300,000 kms/sec , or is this an average? :
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When an electron drops into a lower orbit around the nucleus of an atom, it emits a photon of electromagnetic radiation. All electromagnetic radiation (from radio waves to high energy X-rays) travels at about 300,000 kms per second in a vacuum. Einstein said this speed is fixed, so it will not vary from the time of emission to when it is eventually absorbed by another atom. It will not accelerate, rather is emitted at the "speed of light".
Quote:
Originally Posted by iceman2
If light can be bent, distorted or just sucked into nothingness by gravity/black holes, does this change the speed of light and hence the accuracy of distance calculations?  |
According to Einstein, as the speed of light is fixed, it does not change under any circumstances. It's path can be deflected by gravity, but it is not slowed.
However our perspective can result in us seeing superluminal velocities, where light appears to be moving faster than the speed of light, and zero velocities, such as at the event horizon at a black hole, where time appears to freeze, and we would observe a photon of light that does not appear to be moving at all. The latter is due to time slowing down.
This is really interesting stuff, and I suggest you try your local public library for anything on Einstein, cosmology, relativity and black holes. A "brief History of Time" is recommended.