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.
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"ralph sansbury" wrote in message
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"George Dishman" wrote in message
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"ralph sansbury" wrote in message
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RS Baez FAQ says that some people want to change the
notation of
E^2=(m_0)^2c^4+p^2c^2 where p=mv=Ev/c^2. Even in the more
recent texts the distinction between rest mass and the mass
increase
due to relativity of a mass in motion is made in the description
of the formula if not in the notation.

This is part of what it says:

"These days, when physicists talk about mass in their research,
they always mean invariant mass. The symbol m for invariant
mass is used without the subscript 0. Although the idea of
relativistic mass is not wrong, it often leads to confusion,
.... Using the word "mass" unqualified to mean relativistic
mass is wrong because the word on its own will usually be taken
to mean invariant mass."

I am over 50 and have never known "mass" to mean anything but
invariant mass. I am aware of the old "relativistic mass"
but have alwys known it as a shorthand notation representing

m_r = m / sqrt(1 - (v/c)^2)

GD It is not a split but a change. It will take a long time
for old ways to die out but there is no debate about it.
As the FAQ pages say, one of the reasons the term
"relativistic mass" is being dropped is because of these
confusions that it creates.

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.

Now try it the conventional way:

The mass of the photon is zero. If it could be at rest the
mass would be zero. When it is moving it is zero. The mass
of any particle is the same whether it is moving or not.
When a particle is moving, its total energy is the sum of
its mass (times c^2) and its kinetic energy.

There you are, no confusion at all.

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".

Right, and the evidence for this is the Compton Effect
and laser manipulation of particles at small scales, lab
radiometers at medium scales and solar sails at large scale.
All rely on the principle that light carries momentum.

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.

None of that suggests that light doesn't carry momentum,
it is just a classical description of the mechanism.

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?

Pressure is nothing but the transfer of momentum and
the examples I have suggested all require momentum
transfer. If you want to use classical field theory
to describe it, there should be no problem in principle
but it might be difficult in practice.

I am still not clear what you are looking for. You started
this thread by saying:

Instances of light pressure on reflective surfaces and Compton
like scattering of xrays at lower frequencies with the missing
energy transformed into the linear movement of the electron
suggests a recoil of the electron but not of the photon.

That is incorrect since the relationships in the Compton
Effect require both the incoming and outgoing photon to
carry momentum. That is your evidence.

George

"George Dishman" wrote in message
...

"ralph sansbury" wrote in message
...

"George Dishman" wrote in message
...

"ralph sansbury" wrote in message
...



RS Baez FAQ says that some people want to change the
notation of
E^2=(m_0)^2c^4+p^2c^2 where p=mv=Ev/c^2. Even in the more
recent texts the distinction between rest mass and the mass
increase
due to relativity of a mass in motion is made in the
description
of the formula if not in the notation.

This is part of what it says:

"These days, when physicists talk about mass in their research,
they always mean invariant mass. The symbol m for invariant
mass is used without the subscript 0. Although the idea of
relativistic mass is not wrong, it often leads to confusion,
... Using the word "mass" unqualified to mean relativistic
mass is wrong because the word on its own will usually be taken
to mean invariant mass."

I am over 50 and have never known "mass" to mean anything but
invariant mass. I am aware of the old "relativistic mass"
but have alwys known it as a shorthand notation representing

m_r = m / sqrt(1 - (v/c)^2)

GD It is not a split but a change. It will take a long time
for old ways to die out but there is no debate about it.
As the FAQ pages say, one of the reasons the term
"relativistic mass" is being dropped is because of these
confusions that it creates.

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.

Now try it the conventional way:

The mass of the photon is zero. If it could be at rest the
mass would be zero. When it is moving it is zero. The mass
of any particle is the same whether it is moving or not.

Yes for the rest mass. But the mass increase according to
Einstein is (rest mass)/(1-v^2/c^2)^1/2 for
something moving at speed v =c, this implies the mass has
increased to infinity.
This appears to be what happens to electrons and protons etc in
a mass spectrometer moving at
speeds of .1c etc and so the mass of a photon at c in this
context would be infinite.

When a particle is moving, its total energy is the sum of
its mass (times c^2) and its kinetic energy
But for the photon of frequency f, it is hf which is neither zero
or infinity.

There you are, no confusion at all.
Wrong. Of course you can add other premises and
disclaimers
but this is just another form of confusion.


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".

Right, and the evidence for this is the Compton Effect
and laser manipulation of particles at small scales, lab
radiometers at medium scales and solar sails at large scale.
All rely on the principle that light carries momentum.

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.

None of that suggests that light doesn't carry momentum,
it is just a classical description of the mechanism.

Imagine an 8W light bulb and the photons emitted by the
tungsten
filament. What do the oscillations of charge magnetically push
against?
As you said before, the randomly directed pushes on each other
cancel
so that there is no net push.
Thus it seems there is only the mathematical momentum argument
in conjunction
with a self contradictory photon as evidence that there is such a
push.
Not very reliable.

"ralph sansbury" writes:

Yes for the rest mass. But the mass increase according to
Einstein is (rest mass)/(1-v^2/c^2)^1/2 for
something moving at speed v =c, this implies the mass has
increased to infinity.
This appears to be what happens to electrons and protons etc in
a mass spectrometer moving at
speeds of .1c etc and so the mass of a photon at c in this
context would be infinite.

For photons, whose rest mass is defined to be zero, the equation above
becomes 0/0, or undefined. It does not tend to infinity. Therefore
you are not using an appropriate equation.


Thus it seems there is only the mathematical momentum argument
in conjunction
with a self contradictory photon as evidence that there is such a
push.
Not very reliable.

As George pointed out, there are very nice atom trapping experiments
that rely on radiation pressure.

The papers by Grangier et al and Aspect et al are highly convincing
regarding the photon nature of light.

CM



References
1. Aspect, A. et al 1981, Phys Rev Let, 47, 460
2. Grangier, P., Roger, G. & Aspect, A. 1986, Europhys. Lett., 4, 173

"Craig Markwardt" wrote in
message news

"ralph sansbury" writes:

Yes for the rest mass. But the mass increase according to
Einstein is (rest mass)/(1-v^2/c^2)^1/2 for
something moving at speed v =c, this implies the mass has
increased to infinity.
This appears to be what happens to electrons and protons etc
in
a mass spectrometer moving at
speeds of .1c etc and so the mass of a photon at c in this
context would be infinite.

For photons, whose rest mass is defined to be zero, the
equation above
becomes 0/0, or undefined. It does not tend to infinity.

Undefined or Contradictory-in either case not very reliable.
you have to do arbitrary things to make the concept work. It is
obviously a problematic concept shown to be even more problematic
by the experiments you refer to and my experiment with Pockkels
cell shutters .

Therefore
you are not using an appropriate equation.

The choice of appropriate equation here is somewhat arbitrary
and more so than in the application of the magnetic force
equation.

Thus it seems there is only the mathematical momentum
argument
in conjunction
with a self contradictory photon as evidence that there is
such a
push.
Not very reliable.

As George pointed out, there are very nice atom trapping
experiments
that rely on radiation pressure.

I am not quarrelling with these and other facts about
radiation pressure but just pointing out that you cant
extrapolate from these to the 8watt transmitter or light bulb.

The papers by Grangier et al and Aspect et al are highly
convincing
regarding the photon nature of light.
Again irrelevant wrt spacecraft transmitter etc.
Ralph



References
1. Aspect, A. et al 1981, Phys Rev Let, 47, 460
2. Grangier, P., Roger, G. & Aspect, A. 1986, Europhys. Lett.,
4, 173

"ralph sansbury" wrote in message ...
"Craig Markwardt" wrote in
message news

"ralph sansbury" writes:

Yes for the rest mass. But the mass increase according to
Einstein is (rest mass)/(1-v^2/c^2)^1/2 for
something moving at speed v =c, this implies the mass has
increased to infinity.
This appears to be what happens to electrons and protons etc
in
a mass spectrometer moving at
speeds of .1c etc and so the mass of a photon at c in this
context would be infinite.

For photons, whose rest mass is defined to be zero, the
equation above
becomes 0/0, or undefined. It does not tend to infinity.

I am not a mathematician, but it seems to me that this situation is
only occuring when v and c are equal. When vc, if sq root(-1) is
allowed, as per the raspberries I received when suggesting
non-existent, then there is an (defined) result for the equation

Jim G

"Jim Greenfield" wrote in message
om...
"ralph sansbury" wrote in message
...
"Craig Markwardt"
wrote in
message news

"ralph sansbury" writes:

Yes for the rest mass. But the mass increase according
to
Einstein is (rest mass)/(1-v^2/c^2)^1/2 for
something moving at speed v =c, this implies the mass has
increased to infinity.
This appears to be what happens to electrons and protons
etc
in
a mass spectrometer moving at
speeds of .1c etc and so the mass of a photon at c in
this
context would be infinite.

For photons, whose rest mass is defined to be zero, the
equation above
becomes 0/0, or undefined. It does not tend to infinity.

I am not a mathematician, but it seems to me that this
situation is
only occuring when v and c are equal. When vc, if sq root(-1)
is
allowed, as per the raspberries I received when suggesting
non-existent, then there is an (defined) result for the
equation

Yes and someone called these tachyons(and it is perfectly
reasonable to suppose orbiting charged particles at such speeds
inside the electron and proton without assuming them to increase
to infinite mass and undefinedness as c is approached from
above). But to get back to the subject of reasons aside from
momentum conservation to expect aspacecraft to be shoved back by
the emission of 8Watt,GHz photons from its transmitter.
The magnetic force argument would make this possible and this
argument it seems to me is more convincing than the photon
momentum argument. given the somewhat arbitrary undefined self
contradictory nature of the photon.
That is the pushing of the oscillating electrons in the center
feed wire of a dish antenna against the reflected oscillations in
the dish might push against the dish.
Now the question is is this enough to explain the anomalous
acceleration?

"Jim Greenfield" wrote in message
om...
"ralph sansbury" wrote in message
...
"Craig Markwardt" wrote in
message news

"ralph sansbury" writes:

Yes for the rest mass. But the mass increase according to
Einstein is (rest mass)/(1-v^2/c^2)^1/2 for
something moving at speed v =c, this implies the mass has
increased to infinity.
This appears to be what happens to electrons and protons etc
in
a mass spectrometer moving at
speeds of .1c etc and so the mass of a photon at c in this
context would be infinite.

For photons, whose rest mass is defined to be zero, the
equation above
becomes 0/0, or undefined. It does not tend to infinity.

I am not a mathematician, but it seems to me that this situation is
only occuring when v and c are equal.

Exactly, v=c for photons so trying to use the old
"relativistic mass" approach doesn't work. This is
what we are trying to explain to Ralph.

When vc, if sq root(-1) is
allowed, as per the raspberries I received when suggesting
non-existent, then there is an (defined) result for the equation

This is just one of the reasons why tachyons are
considered to be unlikely in the real world. For
some things imaginary values don't seem reasonable,
in other cases they can be a useful tool.

George

"ralph sansbury" wrote in message
...

Yes and someone called these tachyons(and it is perfectly
reasonable to suppose orbiting charged particles at such speeds
inside the electron and proton without assuming them to increase
to infinite mass and undefinedness as c is approached from
above).

The mass of the photon remains zero. The factor called
reativistic mass can be useful for massive particles as
long as you remain aware of its limitations but is doesn't
work for photons as it becomes undefined (not infinite).

But to get back to the subject of reasons aside from
momentum conservation to expect aspacecraft to be shoved back by
the emission of 8Watt,GHz photons from its transmitter.
The magnetic force argument would make this possible and this
argument it seems to me is more convincing than the photon
momentum argument.

Since you seem to be saying that both would imply the
craft will experience a force, they are not in conflict
and no choice is needed.

given the somewhat arbitrary undefined self
contradictory nature of the photon.

You mean the contradictions you invent by using 19th
century concept that cannot be applied to massless
particles and trying to do just that?

That is the pushing of the oscillating electrons in the center
feed wire of a dish antenna against the reflected oscillations in
the dish might push against the dish.

If the craft is pushed by this, how is momentum conserved?
For photons, the balancing momentum is simply carried off
by the particles. In your description, the eletrons in the
feed and the dish are both attached to the craft.

Now the question is is this enough to explain the anomalous
acceleration?

No. The measured acceleration corresponds to 56W of power and
is towards the Sun while the beam is 8W and pushes the craft
away from the Sun. The anomaly is treated as 63W equivalent
since 8W worth of push is used overcoming the beam reaction.

George

In message , ralph sansbury
writes

Yes and someone called these tachyons(and it is perfectly
reasonable to suppose orbiting charged particles at such speeds
inside the electron and proton without assuming them to increase
to infinite mass and undefinedness as c is approached from
above). But to get back to the subject of reasons aside from
momentum conservation to expect aspacecraft to be shoved back by
the emission of 8Watt,GHz photons from its transmitter.
The magnetic force argument would make this possible and this
argument it seems to me is more convincing than the photon
momentum argument. given the somewhat arbitrary undefined self
contradictory nature of the photon.
That is the pushing of the oscillating electrons in the center
feed wire of a dish antenna against the reflected oscillations in
the dish might push against the dish.
Now the question is is this enough to explain the anomalous
acceleration?

It can't explain the acceleration because it's acting in the wrong
direction. Radiation pressure from the dish (or on the dish from solar
radiation) will push the spacecraft away from us, while the "Pioneer
effect" acts to slow it down, apparently pushing in the other direction.
If your theory can provide the correct acceleration for heat emission
from the RTGs people might start listening to you.
BTW, "orbiting charged particles" inside the electron would imply it has
structure, and AFAIK every observation says it doesn't.
--
Rabbit arithmetic - 1 plus 1 equals 10
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