Art Unwin wrote:
Interesting you
quote the electron gun. ... So where did this photon emerge from?

The electron is the gun, the photons are the bullets.
Quoting Feynman's "QED": "So now, I present to you the
three basic actions, from which all of the phenomena
of light and electrons arise.

-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."

For an RF antenna radiator, the electrons go from
place to place in (on) the conductor in the form
of free electrons. The photons go from place to place
in the space surrounding the conductor. Only the
photons can move at the speed of light from the
feedpoint to the ends of a dipole. Electrons move
hardly at all.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

"Cecil Moore" wrote in message
...
Art Unwin wrote:
Interesting you
quote the electron gun. ... So where did this photon emerge from?

The electron is the gun, the photons are the bullets.
Quoting Feynman's "QED": "So now, I present to you the
three basic actions, from which all of the phenomena
of light and electrons arise.

-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."

For an RF antenna radiator, the electrons go from
place to place in (on) the conductor in the form
of free electrons. The photons go from place to place
in the space surrounding the conductor. Only the
photons can move at the speed of light from the
feedpoint to the ends of a dipole. Electrons move
hardly at all.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com


I like the statement that the electrons in one's house wiring are mostly the
same ones that were there when the house was built (or last re-wired).

'Charge' is a funny one though - a bit like debt, it can take effect almost
instantaneously (does debt travel at the speed of light - I guess it often
does nowadays).

Chris

christofire wrote:
'Charge' ... can take effect almost instantaneously ...

It's akin to a 100 foot long tube of marbles.
Hit one end of the tube with a hammer and
measure the time it takes the energy impulse
to reach the other end of the tube. How fast
and how far did the energy impulse travel?
How fast and how far did each marble travel?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

"Cecil Moore" wrote in message
...
christofire wrote:
'Charge' ... can take effect almost instantaneously ...

It's akin to a 100 foot long tube of marbles.
Hit one end of the tube with a hammer and
measure the time it takes the energy impulse
to reach the other end of the tube. How fast
and how far did the energy impulse travel?
How fast and how far did each marble travel?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com


Absolutely. When the old lady in the flat below bangs on her ceiling with
her walking stick, the end of the stick hits the ceiling instantly as she
pushes it upwards. Extrapolating, if an incompressible/inextensible rod or
string could be made, wouldn't that permit communication faster than the
speed of light?

I guess inextensible and incompressible are difficult to achieve, but if
either were possible would the communication still be limited to the speed
of light?

Chris

christofire wrote:

"Cecil Moore" wrote in message
...
christofire wrote:
'Charge' ... can take effect almost instantaneously ...

It's akin to a 100 foot long tube of marbles.
Hit one end of the tube with a hammer and
measure the time it takes the energy impulse
to reach the other end of the tube. How fast
and how far did the energy impulse travel?
How fast and how far did each marble travel?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com


Absolutely. When the old lady in the flat below bangs on her ceiling with
her walking stick, the end of the stick hits the ceiling instantly as she
pushes it upwards. Extrapolating, if an incompressible/inextensible rod or
string could be made, wouldn't that permit communication faster than the
speed of light?

Nope, the energy in both the tube of marbles and the walking stick
travels at the speed of sound in the medium.

I guess inextensible and incompressible are difficult to achieve, but if
either were possible would the communication still be limited to the speed
of light?

Chris

Yes.


--
Jim Pennino

Remove .spam.sux to reply.

On Sep 7, 6:00*pm, wrote:
Nope, the energy in both the tube of marbles and the walking stick
travels at the speed of sound in the medium.

What happens when the walking stick is traveling faster than
the speed of sound?

....Keith

Keith Dysart wrote:
What happens when the walking stick is traveling faster than
the speed of sound?

Exactly how much faster?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Keith Dysart wrote:
On Sep 7, 6:00Â*pm, wrote:
Nope, the energy in both the tube of marbles and the walking stick
travels at the speed of sound in the medium.

What happens when the walking stick is traveling faster than
the speed of sound?

...Keith

It makes a big hole in the old lady's ceiling.

Actually, the energy travels through the building structure at the speed
of sound, not the walking stick, which has energy of momentum until it
hits the ceiling.

--
Jim Pennino

Remove .spam.sux to reply.

"christofire" wrote in message
...

"Cecil Moore" wrote in message
...
christofire wrote:
'Charge' ... can take effect almost instantaneously ...

It's akin to a 100 foot long tube of marbles.
Hit one end of the tube with a hammer and
measure the time it takes the energy impulse
to reach the other end of the tube. How fast
and how far did the energy impulse travel?
How fast and how far did each marble travel?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com


Absolutely. When the old lady in the flat below bangs on her ceiling with
her walking stick, the end of the stick hits the ceiling instantly as she
pushes it upwards. Extrapolating, if an incompressible/inextensible rod
or string could be made, wouldn't that permit communication faster than
the speed of light?

I guess inextensible and incompressible are difficult to achieve, but if
either were possible would the communication still be limited to the speed
of light?

Chris


predicting the properties of something that is impossible to make is
impossible.

"Dave" wrote in message
...

"christofire" wrote in message
...

"Cecil Moore" wrote in message
...
christofire wrote:
'Charge' ... can take effect almost instantaneously ...

It's akin to a 100 foot long tube of marbles.
Hit one end of the tube with a hammer and
measure the time it takes the energy impulse
to reach the other end of the tube. How fast
and how far did the energy impulse travel?
How fast and how far did each marble travel?
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com


Absolutely. When the old lady in the flat below bangs on her ceiling
with her walking stick, the end of the stick hits the ceiling instantly
as she pushes it upwards. Extrapolating, if an
incompressible/inextensible rod or string could be made, wouldn't that
permit communication faster than the speed of light?

I guess inextensible and incompressible are difficult to achieve, but if
either were possible would the communication still be limited to the
speed of light?

Chris


predicting the properties of something that is impossible to make is
impossible.


Agreed, but c is finite so is there a degree of compressibility or
expansibility below which faster-than-c communication would be possible? ...
or would the whole principle be scuppered by Lorentz contraction?

Chris


PS: oh dear, I hope no-one applies the Coriolis effect to turn this into
Penrose-Terrell rotation
(http://en.wikipedia.org/wiki/Penrose-Terrell_rotation)!