REVISED: Light's speed is relative to its medium's

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by DAVID</i>

...As best as I can figure out, light is not “particles” at all, but only electric and magnetic “waves”. A single photon is some kind of “wave packet” consisting of one or more wave set or group, perhaps as few as just one complete wave cycle...

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Thanks for that great explanation of the relationship between light waves and photons. I believe I have a better picture now.

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...Regarding the light clock, here is a link to a crude drawing of a laser beam light clock.

users.powernet.co.uk/bearsoft/LtClk.html

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Thanks for the reference. I will check it out. However, it may be a while since I have a lot to check.

Allen W. McCready

I’ve studied English translations of the original Planck and Einstein photoelectric papers, and they don’t mention “particles” at all. What they seem to be doing is taking the old 19th Century way of thinking of continuous light beams and breaking them down into their basic individual components, which today we call individual “photons”.

Throughout the 19th Century scientists spoke of light rays and beams as being continuous, because sunlight and starlight is continuous. But by the late 19th Century other scientists working on the new atomic theories began to discuss how light is emitted by atoms, and they came up with the individual “wave” hypothesis. One atom emitting one wave or wave group or packet at a time, and this we now call a photon.

So, basically, Planck and Einstein were trying to identify one wave packet emitted by one atom at one time. A continuous beam or ray is made up of a stream of these wave packets which are pretty much described by Einstein as oscillating electric and magnetic waves.

Interestingly, in the 19th Century scientists identified single sound waves, which are made up of a compression wave followed by a vacuum wave.

Everyone actually hears single sound waves every day, but they don’t realize it. We hear these as “clicks”. I discovered this about 45 years ago while working with optical sound tracks on film. I used to see single sound waves recorded on optical sound tracks on film. These are caused by clicks such as when someone bumps a microphone with a metal object, or if you quickly hit the edge of your table with a knife or fork. That produces a click sound. The peculiar thing is that each single click sound wave has its own "frequency” or “wavelength”. A very short click has a short wavelength, and a longer click has a long wavelength. Usually, bumping the edge of a table with a metal object will produce a short single wave, while bumping a guitar sounding board with a metal object will produce a long single wave. If you bump a guitar sound box hard enough it will continue to vibrate and produce several long waves that can be seen on an optical sound track sort of as a short “wave train”.