Waves vs Particles
"AI4QJ" wrote in message
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"K7ITM" wrote in message
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On Feb 2, 2:56 pm, K7ITM wrote:
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Since this thread started on the premise that a photon
is a particle,
which it clearly is not, what did you expect?
"A photon is not a particle."
For those who might seriously wonder why I would make
such an
outrageous--some may say idiotic or insane--statement...
For those
that haven't dismissed it as lunacy... Let me first
point out that I
did NOT say that a photon isn't a quantum. Indeed, I
believe that
everything physical in our universe is quantized. But I
also believe
that until you really get to know photons (and electrons
and neutrons
and various other things we can only sense and never see
directly),
you are doing yourself a disservice by calling them by
names like
"particle" or "wave." That is because, by thinking of
them in that
way, as particles or as waves, you will miss seeing what
they really
are. On the other hand, if you call a photon a "quantum
of
electromagnetic energy," then you may wonder just what
THAT is, and
may get interested enough to study it in the language
that describes
it more accurately: the language of quantum theory or
the language of
quantum electrodynamics.
I was asked for references. I would suggest as a
starting point
Richard P. Feynman's lecture of April 3, 1962, which was
an
introduction to quantum behavior. I think the whole of
the lecture is
worthwhile, but especially the following paragraph:
" 'Quantum mechanics' is the description of the behavior
of matter in
all its details and, in particular, of the happenings on
an atomic
scale. Things on a very small scale behave like nothing
that you have
any direct experience about. They do not behave like
waves, they do
not behave like particles, they do not behave like
clouds, or billiard
balls, or weights on springs, or like anything that you
have ever
seen."
In the lecture, he offers an example of an experiment
that, he says,
you can NOT explain by using either waves or particles,
but it's
explained completely and accurately through quantum
mechanics. So why
talk about photons as if they are particles or as if they
are waves,
when they behave in total like neither? Why not talk
about them as if
they are quanta of electromagnetic radiation, which I
believe they
are?
There's more about this in other Feynman lectures;
there's lots more
about it in the many quantum mechanics texts that are
available.
Although the word 'particle' may be used, I believe it's
only through
something like quantum mechanics that we can hope to get
an accurate
picture of how these entities (photons, electrons,
mesons, pions,
etc.) behave.
The question gave me an excuse to refresh my memory about
some books
on my own bookshelf:
V. Kondratyev, "The Structure of Atoms and Molecules."
M. W. Hanna, "Quantum Mechanics in Chemistry."
H. A. Kramers, "Quantum Mechanics."
H. G. Kuhn, "Atomic Spectra."
R. E. Dodd, "Chemical Spectroscopy."
In the context of this posting, I did not find in these
books a
disagreement with the thought that a photon is not a
particle.
You may notice a slight interest in photons there among
those titles,
typically photons of shorter wavelength than we generally
use on the
ham bands. If you're going to accuse me of not knowing
anything about
them, perhaps you should get to know me a bit better
first.
I'm quite sure I don't really completely know a photon,
on its own
turf. Feynman in that same lecture told us that HE
didn't either.
But I do know better than to claim it's either a "wave"
OR a
"particle." There are plenty of times I don't have to
deal with or
think about its quantized nature to get valid practical
answers to
questions dealing with electromagnetic radiation, but
there's also no
need to waste time discussing whether a photon is
something or other
when it's clear that it's neither.
Cheers,
Tom
Yes, it is a quantum that contains mass and energy.
If you want to call it a particle, you can make a
measurement that shows it behaves as a particle
(photoelectric effect).
If you want to call it a wave, you can make a measurement
that shows it behaves as a wave.
It is either or both, depending upon how you measure it. I
agree, it is really up for grabs.
Certainly there are many experiments that will prove it is
a quanta.
AI4QJ
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I sometimes wonder if other species exist elsewhere that can
experience, through their own sensory receptors, what
quanta/quantum phenomenon really and truly are? Think of the
advantage they would have, assuming they had at least equal
intelligence to the human species.
Ed, NM2K
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