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[Phys-L] Re: limitation of photon hypothesis (fwd)





---------- Forwarded message ----------
Date: Sat, 18 Dec 2004 21:26:12 -0500 (EST)
From: Brian A Powell <bapowell@buffalo.edu>
To: pdev@buffalo.edu
Subject: Re: limitation of photon hypothesis

This post is in reference to the limitation of the photon hypothesis,
which I find very interesting. However, I think something is missing
from the argument.

The relationship, hf > 1/2E^2V, can be made true in a mathematical sense,
although this conveys no physical meaning. On the right, you have the
energy associated with electromagnetic waves in some volume V, on the
left you have the energy of a photon, which is *not* a wave. This is
sort of like relating apples to oranges. Light, after all, is *not* a
wave- it is a particle. This conclusion is made based on the results of
some very famous experiments throughout the 20th century- the UV
catastrophe of Rayleigh-Jeans, the Compton effect and the photoelectric
effect to name a few.

Applying the classical equations of ED to the phenomenan of light is
ultimately incorrect. The fact that we thought that light behaved like a
wave was because mathematically, we were treating it classically, and
physically, we were only doing experiments which observed the wave-like
nature of light (Young's experiment).

The wave-like properties of the photon arise due to its quantum
mechanical nature. It is the oscillations of the photon's probalility
distribution that dictate the position of the photon (what we ultimately
measure) but this 'wave function' should not be interpreted as being
something *physical* in and of itself.

The only connection one should make between the classical wave and
photon is that the classical field amplitude at a given point is equal to
the probability (per unit time) that a photon will be detected in a small
volume centered at that point. In this way, an increase in field
amplitude corresponds to an increase in the probability amplitude. This
may be achieved by adding more photons to a particular region of space.
This is one of the conclusions of the photoelectric effect- the intensity
of the light is adjusted through the addition or removal of photons.

I hope this makes sense!

Brian