gwatts wrote:

...
I might pick up a signal in the middle of the AM broadcast band but it
won't be yours, you're at 16.7 kHz.

Really?

A 360 degree rotation is somehow stuck with a divisor?

Do you divide the 360 degree "rotations" of your transmitters sine wave
with a large divisor also? Or, possibly your sine waves are greater
than 360 degrees?

Interesting ...

Regards,
JS

John Smith wrote:
gwatts wrote:

...
I might pick up a signal in the middle of the AM broadcast band but it
won't be yours, you're at 16.7 kHz.

Really?

A 360 degree rotation is somehow stuck with a divisor?

Do you divide the 360 degree "rotations" of your transmitters sine wave
with a large divisor also? Or, possibly your sine waves are greater
than 360 degrees?

Interesting ...

Regards,
JS

My error, I was thinking RPS (Rotations Per Second) but wrote rpm--'ya
got me, just not used to those high speed motors :-) ... and you MOST
CERTAINLY pick up my signal now ...

And, no, this motor doesn't come apart at this speed--the metal the
motor is made of came from the UFO crash in Roswell NM ;-)

Regards,
JS

Richard Clark wrote:

...
One reason why the FCC gives exams for licenses (and an example of
self-thinning at the shallow end of the genetic pool).

73's
Richard Clark, KB7QHC

Actually, I believe 'ya!

You certainly know what you are talking about ...

Regards,
JS

K7ITM wrote:

I'm left with the impression that JS, at least, hasn't a clue about
how those little radiometers actually work. (Or perhaps he just
thinks he's having fun with a little trolling.)

Both are correct, IMO.

ac6xg

Ed Cregger wrote:



What if all things were true - and false? Personally, I'd just open the
box and ask the cat. Assuming that it was still alive, that is. G

And who was this Schroedinger guy anyway?


Ed, NM2K

If Schroedinger was doing his thing today instead of 100 years ago,
would he be heading to a prison cell like Michael Vick?

A great many students have declared that quantum mechanics is evil, but
in today's courts it might be criminal as well.

8-)

73,
Gene
W4SZ

Jim Kelley wrote:


K7ITM wrote:

I'm left with the impression that JS, at least, hasn't a clue about
how those little radiometers actually work. (Or perhaps he just
thinks he's having fun with a little trolling.)

Both are correct, IMO.

ac6xg


Actually, you are partially correct. In the cookes radiometer, the
motion cannot be ALL attributed to the radiation pressure. A nichols
radiometer can accurately measure this radiation pressure ... the effect
(photons having mass) is real ...

Regards,
JS

Richard Clark wrote:

The description you offer requires a porous plate which is absent in
every radiometer that has come down the pike

On the other hand, the absence of porous plates in operating
radiometers tends to cast some doubt on your claim that the plates
must be porous.

As for the local air, there is none in
many radiometers that are more sensitive than the Crookes.

Again, which radiometer? If you are arguing a "perfect" vacuum, then
like a free lunch, I would agree there's no such thing. The Crookes
radiometer requires a partial atmosphere to work, other radiometers
work quite fine with much less.

Depends entirely on what one intends to measure.

The distinction in the multiplicity of radiometers is significant and
relates to an effect predicted in Maxwell's work, and exhibited by
Lebedev; and Nichols, Tear, Hull, and Webb by THEIR radiometers. It
requires very little more work than stating the surface area and
rendering the expression of force in the units pascals if one wishes
to remain within their classical descriptions.

To put a number to it: 0.3 slug per sq. mile (under less than
demanding conditions)

If the twins can't cope with the crippling Newtonian math, then one
might grant them the mental prowess of scaling by area - something
within the reach of a very special fifth grader. Yet and all, this
bone that I am tossing them only answers the less than Extra special,
super duper credit question.

To keep it in pascals in conditions of sunlight, on the equator, at
noon, on the solstice: 3 µPa (one square meter is implied, but this is
certainly not the size of any radiometer's vane - hence this number
should be further reduced by roughly 1/10,000 or 300 pPa). If the
twins can follow the mathematical progression in the parenthetical
statement, they should be able to answer the less than Extra special,
super duper credit question.

There are two possible mechanisms here. One is a momentum exchange
effect which is orders of magnitude smaller than the other and can
only be observed at ultra high vacuum. The other (the one Denny
accurately described) is a radiative molecular heating effect which
creates a differential pressure and as such, can only be observed in
at most a partial vacuum. The way to recognize the difference is that
the two mechanisms produce their respective forces in opposite
directions.

73, ac6xg

John Smith wrote:
Jim Kelley wrote:



K7ITM wrote:

I'm left with the impression that JS, at least, hasn't a clue about
how those little radiometers actually work. (Or perhaps he just
thinks he's having fun with a little trolling.)


Both are correct, IMO.

ac6xg


Actually, you are partially correct.

At the time it was posted, the statment was entirely correct.

jk

On Wed, 05 Sep 2007 00:04:23 -0000, Jim Kelley
wrote:

Richard Clark wrote:

The description you offer requires a porous plate which is absent in
every radiometer that has come down the pike

On the other hand, the absence of porous plates in operating
radiometers tends to cast some doubt on your claim that the plates
must be porous.

Not "my claim," my report. The claim they must be porous arrives
through the math necessary to balance the kinetic forces. As that
math balance (from Einstein and Reynolds) has never been achieved,
then Denny's description has never been proven. Less than porous
vanes only further removes such "explanations" from the realm of
proof. In fact, as a description, Denny's is incomplete insofar as
there is no description of the turbulence created in the near vacuum
that serves as the "thrust" for the vanes which is missing in a
complete vacuum. The "thrust" is optimal only for porous plates, as
an explanation; and that explanation, as I've said, does not fully
balance.

Now, if we simply move to another radiometer (Nichols, Tear, Hull, and
Webb already recited) without that partial vacuum, the vanes still
move, and expressely by Radiation Pressure. And the problem remains
as to the balance of forces. In essence, these instruments indicate,
not measure.

As for the local air, there is none in
many radiometers that are more sensitive than the Crookes.

Again, which radiometer? If you are arguing a "perfect" vacuum, then
like a free lunch, I would agree there's no such thing. The Crookes
radiometer requires a partial atmosphere to work, other radiometers
work quite fine with much less.

Depends entirely on what one intends to measure.

The coy context of the thread was measuring the mass of a Photon.
Absolutely no SI Units have been named or any quantitative values
offered (the rather standard omission from claims made here). However,
feel free to introduce your own side thread's goal or even offer a
guess (your own quatitative value for the mass). Such additional
discussion would vastly elevate the inane repetition of claims above
the level of "Photons have the flavor of Crème brûlée."

73's
Richard Clark, KB7QHC

On the other hand, the absence of porous plates in operating
radiometers tends to cast some doubt on your claim that the plates
must be porous.

Not "my claim," my report. The claim they must be porous arrives
through the math necessary to balance the kinetic forces.
Again, which radiometer? If you are arguing a "perfect" vacuum, then
like a free lunch, I would agree there's no such thing. The Crookes
radiometer requires a partial atmosphere to work, other radiometers
work quite fine with much less.

Depends entirely on what one intends to measure.


Despite the photon torpedoes fired at me, I have not seen a convincing
physics experiment that deflates my previous arguement...

Where the F=MA arguement fails in a radiometer is that the photons
impact both sides of the paddles leaving a zero net force for
rotation...

The fact that a Crookes Radiometer requires an atmosphere is proof of
its mode of operation. The fact that it has to be a partial vacuum
further proves how it operates (more air density means too much air
drag to allow rotation by the weak local differential pressure across
the paddle)...

Those who reject local differential pressure changes due to local
heating by claiming the pressure in the bulb is static ignore the
factor of time in molecular exchange of thermal energy gains...
Carrying their argument to the logical end means sun heating cannot
cause the winds to ever blow across the ground because the net air
pressure of Terra is static...

denny
It's 10PM somewhere, have you hugged your radio today?