Franktalk wrote:Fence Sitter wrote:Hey Frank,
......
Please surprise me and come back with something that makes one stop and question what others have said, rather than some sort of dismissive response.
There is nothing I can do to change the mind of another. While I was buried in orthodox science no one could get me to even look at alternate explanations for many natural events. I will ask you a simple question. It is well known that light slows down when it enters a dense medium like glass. But it speeds back up again once it leaves the glass. Using your understanding of orthodox physics tell me why the light speeds back up?
Franktalk,
Fence Sitter has stated upthread that he is not all that familiar with the physics of electromagnetism. Moreover, your question is one that anybody who is the least bit familiar with physics would not ask in the first place. Because they understand special relativity, they would know that the speed of light in a vacuum (a non-dispersive medium) is the same for all observers - period.
The behavior of light is well understood to be an interaction between the photon field (characterized mainly by its frequency components and polarization) and the characteristics of the medium in which the light is propagating. These interactions are described by one or more equations that are applied, as appropriate, according to the parameter values that need to be determined (or questions being asked). That's it.
If one is referring to white light - say sunlight - then light is comprised of photons of many different frequencies and therefore different wavelengths. These have frequency dependent interactions with dispersive media such as glass and can thus be separated by wavelength (color) when passing through a glass grating or prism.
The answer to your question has to do with the index of refraction of the glass and the relationship between the speed of light in a vacuum
"c", which is a constant, and the
phase velocity of light in a dispersion medium, which is given by the simple relationship:
V
p =
c / n;
where:
V
p is the phase velocity in dispersive medium
c is the speed of light in a vacuum, and
n is the index of refraction of the dispersive medium.
In a non-dispersive medium, such as a vacuum or air at STP for example, the index of refraction is very close to 1, so there is no difference between
c and the phase velocity V
p. .
Before providing any more detail (including the implications of the fact that a photon is a gauge boson, as well as the difference between phase velocity V
p, group velocity V
g, and the propagation velocity of the wave front), it seems only fair that you give us the answer to this same question - your question - by using equations or a physical explanation based on your special knowledge.