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Einstein
and Lasers
a
World
Without Einstein Series
Einstein
conceived the
theoretical basis for the later development
of lasers, which are nearly
ubiquitous in modern life.
After
you have enjoyed the broadcast, get the book! All of the information
presented here, and more, can be found in World
without Einstein
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Image
#1
Sketch of an electron’s orbit around the nucleus
of an atom. Upper right shows orbit cut and straightened. The
electron’s orbit must be an integral number of wavelengths in order
that the ends match properly. Hence the circumference 2πr = nw, for
wavelength w, radius r, and some integer n.
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Image
#2
Electron orbits are restricted to certain
distances and therefore energies that form a unique set for each atom
or molecule.
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Image
#3
Lasers
work because Einstein and Bose showed photons are gregarious—they tend
to join together in a common state. Electrons in many atoms are first
“pumped”, elevated to a higher energy than normal. When one drops to
the lower energy, it must emit a photon of a specific energy. This
stimulates other electrons to drop and emit similar photons, resulting
in a coherent and intense beam.
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Image
#4
Lasers are precise tools for sculpting cornea,
clearing blood vessels, or machining delicate structures.
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Image
#5
Lasers
are used to detect gravity waves at LIGO, and initiate nuclear fusion
for energy production at NIF.
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