Re: How did that field get quantized, exactly...

In article <1171322325.665917.91470@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, "Edward Green" <spamspamspam3@xxxxxxxxxxx> writes:
On Feb 11, 9:16 pm, Greg Hansen <glhan...@xxxxxxx> wrote:
Edward Green wrote:
I'm trying to understand, on a simpletons' level, how the EM field
might wind up quantized so that its incremental excitations show the
characteristic E = hv .

You're no simpleton, Edward.

Oh... very well.

I admit there is some Platonic irony in my protestation, on the other
hand, when trying to understand physics I seem to swing back and forth
between the feeling that, hey, I'm a pretty smart guy, and I'll show
these people a thing or two, and, ohmigod!, there is so much and this
stuff is so dense and the people are so smart I'm never going to get
anywhere.

The reaction depends on whether at a given moment I see through the
arguments, in which case things look simple, or I don't, in which case
things look like an pathless bracken. So I make the lowest common
assumption and admit I'm a simpleton: hopefully I can at least avoid
somebody trying to prove it to me, which is far more provoking.

<...>

Thank you.

But what "confines" the EM field?

No confinement. What is the discrete spectrum of the electromagnetic
field? Without boundary conditions like a conductive cavity, the
frequencies can be anything.

I'm of two (confused) minds on this. On the one hand -- yes, the
field as a whole has a continuous spectrum, not a box in sight: on the
other -- considered as a collection of modes, each mode seems to be
"bound" in some way, like an electron is bound to a proton: the modes
act something like a mass and spring.

You may slightly "unconfuse" yourself once you'll notice that in some
of the previous posts you mix quite different "quantizations". As I
recall, you referred to the case of classical EM field within a
confined space, where you've discrete frequencies present. This is
*not at all* like the quantization of EM cavity field, where the frequency
is not quantized at all. What is quantized, is the amount of energy
corresponding to each frequency. Different beast.

Mati Meron | "When you argue with a fool,
meron@xxxxxxxxxxxxxxxxx | chances are he is doing just the same"
.