Choate Prime Physics

[Tim May]

At 2:43 PM -0500 7/27/01, drs wrote:
>  >> 12:39 AM 7/25/2001 -0500, Jim Choate wrote:
>  >On Tue, 24 Jul 2001, Tim May wrote:
>
>
>	IAAP, so let me make a suggestion. Don't argue about physics. The
>winner comes down to the person or persons least wrong since every
>description given so far is an attempt to extend some part of an
>incomplete picture in a way that is _WRONG_, leading to arguments
>about misstatements.
>


You're a twerp worse in many ways than Choate is. I expect he will 
embrace you as his new ally. After this message, you will reside in 
my kill file.

>	Scattering is not reflection. In fact, photons do lose energy
>scattering and the first experiments that demonstrated this is where
>scattering gets its name: Compton scattering. The compton scattering
>formula is easily derived from conservation of 4-momentum. Reflection
>from a mirror is easily described by maxwell's equations, but is more
>difficult in terms of photons. While the description of the photoelectric
>effect is more or less ok, the term "thermalize" means applies to
>contimuum scattering of electrons in the conduction band through collisions
>with other electrons, not to discrete transitions. Describing a reflection
>as scattering can be done, but not in the length of this response.

Yeah, and not in the length of _my_ response. I used "scattering" as 
the shorthand name for all of the physics of incident photons being 
returned or thermalized: pure reflections, reflections off of 
asperities, and even absorbtion in the target.

There are at least three major domains for discussing Choate's claim 
that photons hit a target, "lose some energy," and are then 
re-emitted at some lower energy:


* Domain 1: Newtonian physics. Light of some color is reflected at 
the same color, minus absorbed frequencies. (Blue light reflects as 
blue light, never as red light.) Angle of incidence equals angle of 
reflection, etc.

* Domain 2: Maxwell's equations. Same basic physics, but more nuanced 
in terms of E and H fields, more details about how conductors and 
dielectrics respond to incident photons. Nevertheless, same results 
predicted as in Domain 1.

* Domain 3: Semi-philosophical stuff about whether the incident 
photon is the "same" as the returned photon. Issues of whether 
photons are really waves or corpuscles. Again, no deviation from 
Domain.

Regardless of which domain one spends time in, the notion that a 
"blue photon" loses energy and is downshifted in frequency is SIMPLY 
NOT OBSERVED. Whether one cites just the observations, that 
reflections do do NOT shift the frequencies of monochromatic light 
(what I call in shorthand "blue photons"), or one cites quauntum 
theory (no partial losses of photon energy, basically), the fact is 
that Choate is incorrect in claiming that photons lose energy 
(frequency) when reflecting or scattering off of mirrors. Beams may 
lose _intensity_, as some photons scatter at wide angles (not with 
the main angle of reflection, in other words), or are absorbed and 
thermalized by the mirror itself. But the photons DO NOT lose energy 
due to the "resistance" and the "induced currents."

A naive reading of some physics texts, even Jackson's "Classical 
Electrodynamics," might suggest to the naive reader that some weird 
interaction and ohmic loss might "downshift" the frequency of 
photons, but experiments show no such downshift, In fact, Einstein 
got the Nobel for explaining why photons don't lose ANY energy except 
when they lose ALL of their energy via the photoelectic effect.

>
>	Let me suggest that everyone defer to "Classical Electrodynamics"
>by Jackson, as a definitive reference. It's the canonical physics text on
>the subject and is practically universal as the text for a first year
>graduate course in any physics program. If you know anyone that's
>a physicist, they should have a copy.

Which I used in 1973.

As for your sentiments about how _both_ of us are wrong, you're an ass.

P L O N K.

Have fun with Jim Choate as your new best friend.


--Tim  May


-- 
Timothy C. May         tcmay at got.net        Corralitos, California
Political: Co-founder Cypherpunks/crypto anarchy/Cyphernomicon
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Personal: b.1951/UCSB/Intel '74-'86/retired/investor/motorcycles/guns