|Subject: RE: the Sansbury
experiment - have electrons a structures and what is gravity?
Date: Tue, 6 Nov 2001 17:36:06 -0600
not familiar with the experiment, so only gave it a casual glance.
the "light or no light", one has to turn to quantum
electrodynamics quantum mechanics and other models, not just the
classical theory of light flow. Involved
therein are the de Broglie waves, including two sometimes different
velocities: (1) the single wave velocity, and (2) the group velocity.
you tamper with one of them, you affect the other.
an example, in the standard two-slit experiment with photons, if you
just cover one of the slits, you get a very small little distribution
on the strike screen that shows that a "particle" of light
went through the open slit and struck the screen.
Cover that slit and leave the other open, and you get the same
type of "particle" pattern on the other end of the screen.
leave both slits open, and you get not the two previous patterns at
all! Instead, you get a
pattern strongly suggesting wave interference; that the photon went --
as a wave, not a particle -- through both slits simultaneously!
leave both slits open, until (at the speed of light from classical
theory) the photon will have passed the region of the two slits
already, but not yet reached the screen.
In other words, common sense would say that now we should get
that "wave interference" pattern, since the
"photon" must have already cleared the two slit region and
be outside the two slit box. However, that is not what happens.
Instead, if you suddenly (instantly) cover one of the slits,
you get the particle pattern as if through the other slit!
is called the Delayed Choice Experiment.
It shows that, for quantum things, you can wait until after a
"phenomenon in progress" would appear to have passed some
stage but not yet been "observed", and you can still change
what it will be when it gets "observed"!
explanations have been posited; I prefer the model that uses quantum
interference and de Broglie waves.
point is, you cannot consider the laser beam as just "light in
transit" as if it were something fixed, a wavefront, etc.
by the way, the standard wave-front moving in space illustration of an
EM wave is horribly wrong, wrong, wrong anyway.
H. Romer, then editor of AJP, "Heat
is not a noun," American Journal of Physics, 69(2), Feb.
2001, p. 107-109. Editorial
discussion by the Editor of AJP of the concept of heat in
thermodynamics, where heat is not a substance, not a thermodynamic
function of state, and should not be used as a noun.
In endnote 24, p. 109, he also takes to task "…that
dreadful diagram purporting to show the electric and magnetic fields
of a plane wave, as a function of position (and/or time?) that
besmirch the pages of almost every introductory book. …it is a
horrible diagram. 'Misleading'
would be too kind a word; 'wrong' is more accurate."
"…perhaps then, for historical interest, [we should]
find out how that diagram came to contaminate our literature in the
"simplicity" is not necessarily a valid criterion.
Nature can be very simple, and can also be very complex.
Often more complex than we think, and perhaps even more complex
than we can
think. Everytime we think
we have it "all figured out", nature turns around and
demolishes our "perfect model" as if it were a house of
physics is not absolute, and neither are models.
No model is worth anything except with respect to its ability
to make predictions. We
already know, from Godel's theorem, that no model is perfect and none
ever will be. In physics,
e.g., there are four main models (at least) of the photon, all in
disagreement. But each
applies well within its given area.
So physicists just "plug in and use" the particular
one of those models that works in a particular set of conditions.
And they don't sweat the rest.
The same with the old controversy of "is it a wave or a
question has no definitive answer, the physicists finally realized.
The question "When
is it a particle and when
is it a wave?" does appear to have a definitive answer.
At least for now, that's the best we understand.
myself, I happily use any model that will fit the experiments that I'm
interested in. I really
don't worry too much about some kind of "absolute" model.
In my personal view, any and all models are flawed and can be
improved. And the
improved model will still have some flaws as we discover more
phenomena, and then has to be improved.
And so on.
lot of useless heat and energy has been expended in arguing models.
It's a rather useless endeavor.
Just use what works.