Radiation Pressure&Photon Speculations
A typo correction "(The energy produced by a source of
radiation around an volume of space,
dxdydz is written as u=(1/2)(etaE^2+muH^2)..."
"ralph sansbury" wrote in message
...
"ralph sansbury" wrote in message
...
In the wave theory of light, the pressure due to
radiation
falling on a material body is explained as electromagnetic
momentum delivered to the body by the incident waves. But
there
is no medium for waves(Michelson Morely) and so the theory is
just another crackpot theory.
(The energy produced by a source of radiation around it
in
a
volume of space, dxdydz, is written as u=(1/2)(eE^2 + mH^2)
where
E is in Volts/meter or Newtons per Coulomb and H is in
Ampere
turns per meter, attributable whatever the actual source to
n
circles of wire per meter carrying a current of I Amperes..
This
energy travels at a speed v=c/((eta_m)(mu_m))1/2 where eta_m
and
mu_m are the dielectric constant and the magnetic
permeability
of
the medium relative to a vacuum so in free space, eta = eta_0
and mu = mu_0 and v=c.. The Poynting vector ,P = E X H in
Joules per square meter per second is the energy traveling
through a surface perpendicular to the direction of the
vector
P
and so g = (1/c^2) (E X H) in kilograms per sec per square
meter
is the pressure on that surface. Since E and H are at right
angles to each other always,
g=(1/c^2)EH =(1/c^2)E^2/(eta_0 /mu_0)^1/2 = E^2/c. Thus in
free
space, em waves carry momentum equal to the energy that they
carry divided by the speed of light. It is as if energy W had
a
mass W/c^2 and were moving at a speed c.)
In the photon theory of light, the pressure due to
radiation
falling on a material body is explained by saying that the
energy
W, indeed has a mass of W/c^2 and that the energy can be
written
as hf so that the momentum p=hf/c^2 times c, or p= h/lambda.
The
greater the frequency and the greater the number of photons,
the
greater is the pressure. But there is no measureable mass of
the
proton apart from this assertion so this is just another
crackpot
theory.
In the proposed theory, the pressure due to the light
source
on the receiver is attributed to instantaneous forces between
the
oscillations of charge in the source and the induced
oscillations
of charge in the receiver. The delay in the effect is due to
a
buildup of cumulative forces inside the receiver.
Consider first the simpler case of radio frequencies in a
powered vertical source antenna acting on a passive parallel
vertical receiving antenna. The resulting antiparallel
oscillations of charge in the two antennas produce a varying
but
always attractive force between the two antennas.
But associated with the varying longitudinal electric
fields
in each antenna are transverse electrostatic dipole fields
where
the dipoles are proportional to the longitudinal fields and
to
the distance between the source antenna and the receiver
antenna.
That is, these inverse fourth power electrostatic dipole
fields
are equivalent to inverse square magnetic fields.
These varying transverse electrostatic dipoles are
anti-collinear, oriented along the same line in opposite
directions and so repel each other. The force of repulsion is
greater the greater the velocity of the free electrons and
the
greater the force and duration of the force acting on the
lattice
nuclei between thermal collisions.
Since the force between collinear dipoles is twice as
strong
as the force between parallel dipoles as shown in the section
on
Ampere's Formula and Transverse Electrostatic Dipoles, the
net
force on the antennas is one of repulsion.
Let's consider now higher frequencies which are produced
by
the excitation of bound electrons in atoms and molecules and
by
accelerations or decelerations of electrons and ions in man
made
and non man made accelerators eg in extraterrestrial plasmas
etc.
As electrons move from a ground state to a metastable
state
and fall back to the ground state their radiation is not
cancelled and electrostatic dipoles are produced in the
electrons
transverse to their velocity. In a vertically polarized
laser
source many such oscillations are in phase and their
transverse
dipoles are in phase
The greater the frequency of oscillation of the
electrons
moving between bound states etc., the greater the velocity,
and
so just as in the case of free electrons moving in radio
antennas
at much lower frequencies, dipoles transverse to the movement
are
produced inside the electrons proportional to their velocity.
The energy supposedly in the moving photon before it
produces
an oscillation in the receiver material and the recoil as
just
described is in reality in the receiver material but of a
magnitude which has not yet reached the magnitude required to
produce an observable recoil or transition of the bound
electron
to a wider metastable orbit.
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