🚀 go-pugleaf

On May 2, 11:38 am, John J <n...@droffats.ten> wrote:
> http://www.wired.com/wiredscience/2009/05/extremelaser/
>
> I don't know if the above has yet been cited. Perhaps it is relevant to
> this thread.

It's relevant to past discussions of the photoelectric effect, but it
has nothing to do with phase waves and superluminal velocities.

Some time back during the course of a discussion about the
photoelectric effect I predicted that an extremely high intensity beam
would cause photoelectron ejection, even though the frequency of the
beam was below the cutoff frequency for the metal surface. This was
based upon a complex wave model of the photoelectric effect. Briefly,
the theory is that at any given moment any atom is subject to em waves
from a virtually infinite number of sources (charges). Ordinarily we
call this the thermal radiation background. This background noise is
usually incoherent, and thus tends to do no more than to transfer heat
energy, which is of course why it's called thermal radiation.
However, heat energy is internal kinetic energy, and for the metal
surface this involves an amplification or "pumping" of the orbital
electron's energies.  On average, at normal room temps, these energies
are below the work function of the metal surface. Even so, because of
the chaos, electrons will evaporate from the surface, just as
molecules evaporate from the surface of a liquid. The velocity
distribution fits a Bell curve. So in the real world (as opposed to
the modified forms of reality presented in some texts), there are
electrons being ejected from the surface even before we shine a light
beam on it. These evaporated electrons form a "space charge", which,
because of the lack of a direct source of light above the cutoff
frequency, already seem defy the photoelectric theory of Einstein's.
Well, the theory isn't defeated just yet. Thermal radiation is a
spread spectrum, of which the infrared region just happens to be the
peak. So there is already light impinging on the surface at
frequencies above the cutoff frequency.  Now by the wave theory, this
means that the surface is pumped. For every electron within the
surface that is ejected by thermal radiation, there are electrons who
came just a fraction short of gaining enough KE to break free. It is
this percentage of the electrons that starts to be ejected when a
light beam strikes the surface. Each gains just enough extra energy to
go ahead and jump off the surface. These electrons do not absorb an
entire photons worth of energy, but just sufficient energy, added to
the energy that they already had, to break free.  The remainder of the
photons worth of energy emitted by the light source becomes just that
much more heat energy in the surface, barring the amount of it that is
reemitted as em radiation.  The energy of the photoelectrons
corresponds to the energy of the source photons only because
conservation of energy requires it. If these didn't match, then energy
will have been lost from or gained by the system. It's just
conservation of energy.
Now the reason for the frequency dependence is this, the electron in
the surface is oscillating wrt positive protons, and what is required
is a boost in it's KE of a sufficiently short interval. Longer
wavelengths of radiation would tend to accelerate both charges
together, in the same direction, or in other words tend to only jiggle
the atoms as a whole. Higher frequencies are required to produce
opposing forces on these charges, i.e. to split them apart.  It's a
time limiting contstraint moreso than an energy limiting constraint.
For this reason, a very intense beam of coherent radiation of a
frequency below the cutoff frequency could still produce sufficient
separating forces between these charges. And apparently this has been
verified by the experiment that you mention.