On Sep 17, 11:18*am, Cecil Moore wrote:
Richard Clark wrote:
You misspelled plonk, but baby makes three. *That makes the last one
who can't do the math.

The photon mass math is trivial.

E= mc^2 = hf

m = hf/c^2 = h/(c)lamda

If I remember correctly, a photon cannot travel slower
than the speed of light.
--
73, Cecil *http://www.w5dxp.com

Are you proposing that a photon cannot travel slower than the speed of
light in a vacuum, or it cannot travel slower than the speed of light
in water or the speed of light through glass or air? Please reference
which speed of light a photon cannot travel slower than. Assuming your
answer is the universal constrant "c", then my question is, knowing
that light travels faster through a vacuum than it does through water,
is the light travelling through water still "photons" or is that
impossible because they are travelling too slow? What are they then?
Please advise. Thanks.

wrote:
Are you proposing that a photon cannot travel slower than the speed of
light in a vacuum, or it cannot travel slower than the speed of light
in water or the speed of light through glass or air?

In any random medium, a photon cannot travel slower
than the speed of light through that medium. In
particular, photons associated with standing waves
do NOT stand still.
--
73, Cecil http://www.w5dxp.com

On Sep 17, 5:52*pm, Cecil Moore wrote:
wrote:
Are you proposing that a photon cannot travel slower than the speed of
light in a vacuum, or it cannot travel slower than the speed of light
in water or the speed of light through glass or air?

In any random medium, a photon cannot travel slower
than the speed of light through that medium. In
particular, photons associated with standing waves
do NOT stand still.
--
73, Cecil *http://www.w5dxp.com

What about Cerenkov radiation? In this case, beta particles with mass
travel faster than light in a water medium. So much for 'nothing can
travel faster than a photon'. It depends on the medium. If the medium
is a vacuum, then yes, nothing can travel faster than the speed of
light in that medium. Need to be careful. I have to Credit R. Clark
for pointinmg this out some time ago. See http://nuclear.mst.edu/research/reactor.html

wrote:
What about Cerenkov radiation?

Up until now, I haven't said anything about particles
other than photons - but what about neutrinos which
cannot catch photons in free space but overtake and
pass photons when they hit the water? Or, unlike
most photons, usually pass through the entire earth
without hitting anything.
--
73, Cecil http://www.w5dxp.com

On Wed, 17 Sep 2008 16:52:40 -0500, Cecil Moore
wrote:

wrote:
Are you proposing that a photon cannot travel slower than the speed of
light in a vacuum, or it cannot travel slower than the speed of light
in water or the speed of light through glass or air?

In any random medium, a photon cannot travel slower
than the speed of light through that medium. In
particular, photons associated with standing waves
do NOT stand still.

Try again...would you believe light as 38 miles per hour?
http://www.hno.harvard.edu/gazette/1999/02.18/light.html
or at near absolute zero, coming to a complete stop?
http://www.wired.com/science/discoveries/magazine/15-11/st_alphageek
or used in optoelectronics?
http://news.zdnet.com/2100-9584_22-145405.html
or even faster then 3*10^8 meters/sec?
http://www.scienceblog.com/light.html


Quiz: How fast do the electrons flow in a copper conductor?
Hint: It's not the speed of light.
Cheat: http://en.wikipedia.org/wiki/Electric_current



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
Try again...would you believe light as 38 miles per hour?

38 miles per hour is the speed of light in that medium
but not in a vacuum.

Quiz: How fast do the electrons flow in a copper conductor?
Hint: It's not the speed of light.

Of course not, compared to photons, electrons are massive,
capable of absorbing photons with ease.
--
73, Cecil http://www.w5dxp.com

On Thu, 18 Sep 2008 07:42:55 -0500, Cecil Moore
wrote:

Jeff Liebermann wrote:
Try again...would you believe light as 38 miles per hour?

38 miles per hour is the speed of light in that medium
but not in a vacuum.

You're still using vacuum tubes? Most of my equipment runs in a
medium, not in a vacuum.

Quiz: How fast do the electrons flow in a copper conductor?
Hint: It's not the speed of light.

Of course not, compared to photons, electrons are massive,
capable of absorbing photons with ease.

Well, to split hairs, electrons don't emit or absorb photons. The
energy or momentum from or to a photon is absorbed or emitted and
photons are either destroyed or created in the interaction in descrete
quanta levels. However, unless I heat my copper wire to
incandescence, it's is not going to emit or absorb any photons. I
just wanted to point out that the speed of propagation through a
medium is not the same as the speed of the particles involved in
conduction.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
Well, to split hairs, electrons don't emit or absorb photons.

I was just quoting "QED", by Richard Feynman:

"-Action #1: A photon goes from place to place."
"-Action #2: An electron goes from place to place."
"-Action #3: An electron emits or absorbs a photon."

I'm sorry that Feynman was not precise enough for you. :-)
--
73, Cecil http://www.w5dxp.com

wrote:

...
Are you proposing that a photon cannot travel slower than the speed of
light in a vacuum, or it cannot travel slower than the speed of light
in water or the speed of light through glass or air? Please reference
which speed of light a photon cannot travel slower than. Assuming your
answer is the universal constrant "c", then my question is, knowing
that light travels faster through a vacuum than it does through water,
is the light travelling through water still "photons" or is that
impossible because they are travelling too slow? What are they then?
Please advise. Thanks.


My gawd that is a LOT of text for a simple point! Do you have any
schooling at all? But then, there is a "velocity factor" and this is
the property of the media "it" travels ... And, the velocity of light,
or RF, though a media, is differing, yes ...And, I have nothing to add
on photons speed thought any material ... indeed ... photons and waves
are very much in debate here ... but then, if you are/were awake, you
already "know" that ...

Anyway, the short answer, think "velocity factor" and yes, "they" do
travel MUCH slower than the speed of light ...

And, actually, your question seems one posed by a complete idiot ... but
then, you DON'T REALIZE THAT, DO YOU?

Anyway, good luck in all your pursuits ... ;-)

Regards,
JS

John Smith wrote:
... "they" do travel MUCH slower than the speed of light ...

When traveling through a medium other than a vacuum
they do travel MUCH slower than the speed of light
*in a vacuum* but they travel at exactly the speed
of light *in the medium*, i.e. the photons don't
know that they have slowed down. :-)
--
73, Cecil http://www.w5dxp.com