38
PHYSICS OF THE IMPOSSIBLE
had a big enough computer, you could derive the properties of the
chemical elements from the laws of the quantum theory. In the same
way that Newtonian physicists could compute the motions of all the celestial bodies in the universe if they had a big enough calculating
machine, quantum physicists claimed that they could in principle
compute all the properties of the chemical elements of the universe. If
one had a big enough computer, one could also write the wave function of an entire human being.
MASERS AND LASERS
In 1953 Professor Charles Townes of the University of California at
Berkeley and his colleagues produced the first coherent radiation in
the form of microwaves. It was christened the "maser" (for microwave
amplification through stimulated emission of radiation). He and Russian physicists Nikolai Basov and Aleksandr Prokhorov would eventually win the Nobel Prize in 1964. Soon their results were extended to
visible light, giving birth to the laser. (A phaser, however, is a fictional
device popularized in Star Trek.)
In a laser you first begin with a special medium that will transmit
the laser beam, such as a special gas, crystal, or diode. Then you pump
energy into this medium from the outside, in the form of electricity, radio, light, or a chemical reaction. This sudden influx of energy pumps
up the atoms of the medium, so the electrons absorb the energy and
then jump into the outer electron shells.
In this excited, pumped-up state, the medium is unstable. If one
then sends in a light beam through the medium, the photons will hit
each atom, causing it to suddenly decay down to a lower level, releasing more photons in the process. This in turn triggers even more electrons to release photons, eventually creating a cascade of collapsing
atoms, with trillions upon trillions of photons suddenly released into
the beam. The key is that for certain substances, when this avalanche
of photons is occurring all the photons are vibrating in unison, that is,
they are coherent.
PHYSICS OF THE IMPOSSIBLE
had a big enough computer, you could derive the properties of the
chemical elements from the laws of the quantum theory. In the same
way that Newtonian physicists could compute the motions of all the celestial bodies in the universe if they had a big enough calculating
machine, quantum physicists claimed that they could in principle
compute all the properties of the chemical elements of the universe. If
one had a big enough computer, one could also write the wave function of an entire human being.
MASERS AND LASERS
In 1953 Professor Charles Townes of the University of California at
Berkeley and his colleagues produced the first coherent radiation in
the form of microwaves. It was christened the "maser" (for microwave
amplification through stimulated emission of radiation). He and Russian physicists Nikolai Basov and Aleksandr Prokhorov would eventually win the Nobel Prize in 1964. Soon their results were extended to
visible light, giving birth to the laser. (A phaser, however, is a fictional
device popularized in Star Trek.)
In a laser you first begin with a special medium that will transmit
the laser beam, such as a special gas, crystal, or diode. Then you pump
energy into this medium from the outside, in the form of electricity, radio, light, or a chemical reaction. This sudden influx of energy pumps
up the atoms of the medium, so the electrons absorb the energy and
then jump into the outer electron shells.
In this excited, pumped-up state, the medium is unstable. If one
then sends in a light beam through the medium, the photons will hit
each atom, causing it to suddenly decay down to a lower level, releasing more photons in the process. This in turn triggers even more electrons to release photons, eventually creating a cascade of collapsing
atoms, with trillions upon trillions of photons suddenly released into
the beam. The key is that for certain substances, when this avalanche
of photons is occurring all the photons are vibrating in unison, that is,
they are coherent.