P3D light

[John Toeppen <toeppen@xxxxxxxx>]

The some of the best references to light outside the visible band were
made in the 1860s by John Tyndall.  It is amusing to read about atenic
and calorific rays. Experiments were conducted using quinine soaked
papers and carbon arc lamps to demonstrate UV.  Iodine cells would pass
only the IR from an arc lamp and ignite paper.  They could do Thomas
Young's double slit experiments.  Light was a wave.

Photons were the discreet little packets of light that could knock
electrons off of metals in vacuum (the photoelectric effect).  The
energy of a photon was shown to be proportional to its wavelength. 
Microwaves generally behaved more like waves than particles.  Microwave
Amplification thru Stimulated Emission of Radiation was called the
MASER.  Spectroscopy became more than an act of observation when LASERs
were invented (Light Amplification thru Stimulated Emission of
Radiation).  The wave/partical duality is really the relationship of
resonant states of matter to waves of light.  It is kind of the "is
glass half full or half empty?" relationship, just complimentary way of
looking at things.

By the way, heat is also vibrational energy stored in solid mater. 
Radiant infared heat is another subject.  Any wavelength of light can
cause the heating of a body.  But something has to be really hot to
radiate in the visible or near IR (blackbody radiation).  This is why
conduction and convection is required to properly cool projection
assemblies.  Light is therefor the general term, and not heat.

If you would like a more official reference than just my casual coverage
with frequent misspellings, try this from The Advance Light Source at
UCB :

 "The lithography step in LIGA relies on a source of intense
low-divergence hard x-rays. These x-rays are produced by a synchrotron
radiation source. The newly commissioned Advanced Light Source (ALS) at
LBL is an excellent source of radiation for the deep x-ray lithography
steps and..........."
from http://crit.org/critmail/sci_nano.88-94/2207.html

I am a member of the LIGA league.......
http://www-cxro.lbl.gov/liga/ligapg.html

John Toeppen


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