Lasers :: laser lasers

Since boyhood Einstein wondered about light. He would wonder about its speed, and how it works. In fact most of Einstein's work involved light in someway or another. (Guillen) So of course when S.N.Bose sent Einstein a paper on light being a gas consisting of photons, Einstein was very interested. Bose's paper was more like a bunch of questions. For example he noticed that photons didn't behave like statistical billiard balls. Billiard balls that are shaken on a table will eventual fall in some pocket. But photons tended to fall in to one "pocket" if another photon was ready there. (Forward) Einstein and Bose continued to work together on photons and noticed that one photon was indistinguishable from another photon. This let Einstein and Bose to conclude that strange behavior or photons was just statistical probability. (Forward) For example if I have the set of numbers {1,2,3} There are 6 subsets if each position is unique: {1,2} {1,3} {2,3} {2,1} {3,1} {3,2} but if position doesn't matter then there are only 3 subsets: {1,2} {2,3} {1,3} Since {1,2} is the same as {2,1} Using this idea and many other ideas Einstein laid the foundations for the laser by theorizing about the stimulated emission of radiation. His idea was that if you had a large number of atoms full of excess energy, and they were ready to emit a photon at some random time in some random direction, if a stray photon passed by, then the atoms are stimulated by its presence, and each atom may emit there photon early. This new photon would have the same direction and the same frequency as the original photon! Repeating this process with more and more photons each time is what gives us a lasers. (Forward) Einstein did not actual build the first laser. The first laser would not be created till 1954 by Townes. He called his invention a M.A.S.E.R. : Microwave Amplification by Stimulated Emission of Radiation. but skeptics read it as: Means of Acquiring Support for Expensive Research ! (Talbot) Townes first used Microwave energy to create resonance in ammonia, if the power input was really large, the ammonia would emit energy . Most people don't consider this a laser, since it was using Microwave energy to stimulate the atoms to change energy levels, but the maser did stimulate the research that lead to the laser.