recoiling photons evidence?

In message , ralph sansbury
writes

RS The confusion is in the inadequate concept. The rest mass
of a photon is zero, its mass in motion due to the relativity
increase
is infinity so (1/2)mv^2 =(1/2)mc^4 =infinity times c^4 but also
hf where f is the frequency is equal to the kinetic energy of the
moving photon (1/2)mv^2. This says
that infinity is equal to a finite number. Because of such
confusion in the concept I am questioning conclusions like you're
here based on its use.
Re a solar sail, this involves much stronger magnetic
forces than the absorption of radiation by a distant spacecraft
antenna.

GD I'm not aware of any magnetic effect on solar sails.

RS I am aware of the light momentum photon energy argument
"that when light is emitted from a source there is a recoil
effect".
But I am suggesting that there is no evidence for cases like the
8Watt transmitter on a distant spacecraft and that solar sails
involve much greater Wattage and that light pressure on mirrors
etc involve oscillations in the source and the receiver/reflector
acting on each other. That is the mechanism(see Feynman Lectures
p34-10), Bvq, on oscillating charge moving up and down at
velocity v in the direction of the propagation of the fields E
and B causes a driving pressure in the direction of the light
beam which is called light pressure.
Do you know any evidence besides the blanket application of
the momentum argument showing
such pressure effects in cases where the emission of photons
occurs in an isolated source like the spacecraft?
Ralph



I thought your thesis was that there is no velocity?

As I'm sure you're well aware, the only way to measure the light
pressure from an 8 watt spacecraft transmitter is to look very
accurately at its motion, and then disentangle light pressure from the
other forces on it. That's being done for the "Pioneer anomalous
acceleration", for instance. What does the available power, or even the
power density, have to do with it anyway?

But light pressure is routinely being used in laboratories. Look at

MECHANICAL ACTION OF LIGHT ON ATOMS
http://www.wspc.com/books/physics/0585.html

Laser Manipulation of Atoms
http://tycho.usno.navy.mil/clockdev/slowing.htm

for instance.
--
Rabbit arithmetic - 1 plus 1 equals 10
Remove spam and invalid from address to reply.