1917-1960 - Stimulated emission - The book of science

Stimulated emission
Masers and lasers
Theoretically possible
Commentary

Albert Einstein, Charles Hard Townes, James P. Gordon, Theodore Harold Maiman physics

Stimulated emission

Studying Max Planck’s law of radiation,
Albert Einstein made the theoretical discovery
of the stimulated emission of radiation,
which led to the development of lasers and masers.
An electron energized in a field
may drop to a lower energy level and emit a photon
with the same direction, phase, frequency, and polarity
of the other photons in the field.

Masers and lasers

In 1953, the colleagues of Charles Hard Townes
told him that it wouldn’t work,
but he and James P. Gordon
built the first working maser
using stimulated emission
of ammonia molecules
to amplify microwaves.
In 1960, to construct the first laser,
Theodore Harold Maiman had to increase
the frequency of the maser fifty thousand times.
Now there are thousands of masers and lasers;
there are lasers and masers for every part of the spectrum.

Theoretically possible

1.
Kurt Gödel proved time travel is possible.
Why not table-top fusion and antigravity?
Why not create a weapon
that disables only other weapons?
How about a gun that shoots a web
to disable a man without harming him?
How about a portable X-ray microscope
to trace disease vectors through an ecosystem?
How about a glue that rejoins bones,
and a salve to restore lost hearing?
How about a lotion that cures cancer
and prevents disease?
How about developing a hardy bush that easily
grows a variety of fruit, grain, and vegetables?
How about speeding the growth of trees
to raise a giant oak in a month?
How about a comfortable garment
that shades and warms in any weather?
How about creating world peace
and improving relations between people?
2.
It’s theoretically possible
to know what you’re thinking,
but could everyone be given a means
to help in understanding each other?
And how could we prevent
people from abusing this ability?
Would it be any easier to educate people
so they appreciate poetry?

Masers and lasers have thousands of uses, such as in barcode scanners, CD players, laser printers, laser pointers, welding and cutting, and eye surgery. The International Bureau of Weights and Measures uses a hydrogen maser as an atomic frequency standard. Masers occur naturally in space, even in the tails of comets.