PHRSERS HMD OEflTH STRRS 37
revolution. Two hundred and fifty years of Newtonian physics was
about to be overthrown, heralding the birth pangs of a new physics.
In 1900 Max Planck in Germany proposed that energy was not continuous, as Newton thought, but occurred in small, discrete packets,
called "quanta." Then in 1905 Einstein postulated that light consisted of
these tiny discrete packets (or quanta), later dubbed "photons." With
this powerful but simple idea Einstein was able to explain the photoelectric effect, why electrons are emitted from metals when you shine a
light on them. Today the photoelectric effect and the photon form the
basis of TV, lasers, solar cells, and much of modern electronics. (Einstein's theory of the photon was so revolutionary that even Max Planck,
normally a great supporter of Einstein, could not at first believe it. Writing about Einstein, Planck said, "That he may sometimes have missed
the target... as for example, in his hypothesis of light quanta, cannot
really be held against him.")
Then in 1913 the Danish physicist Niels Bohr gave us an entirely
new picture of the atom, one that resembled a miniature solar system.
But unlike in a solar system in outer space, electrons can only move in
discrete orbits or shells around the nucleus. When electrons "jumped"
from one shell to a smaller shell with less energy, they emitted a photon of energy. When an electron absorbed a photon of a discrete energy, it "jumped" to a larger shell with more energy.
A nearly complete theory of the atom emerged in 1925, with the
coming of quantum mechanics and the revolutionary work of Erwin
Schrôdinger, Werner Heisenberg, and many others. According to the
quantum theory, the electron was a particle, but it had a wave associated with it, giving it both particle- and wavelike properties. The wave
obeyed an equation, called the Schrôdinger wave equation, which enabled one to calculate the properties of atoms, including all the
"jumps" postulated by Bohr.
Before 1925 atoms were still considered mysterious objects that
many, like philosopher Ernst Mach, believed might not exist at all. After 1925 one could actually peer deep into the dynamics of the atom
and actually predict its properties. Astonishingly, this meant that if you
revolution. Two hundred and fifty years of Newtonian physics was
about to be overthrown, heralding the birth pangs of a new physics.
In 1900 Max Planck in Germany proposed that energy was not continuous, as Newton thought, but occurred in small, discrete packets,
called "quanta." Then in 1905 Einstein postulated that light consisted of
these tiny discrete packets (or quanta), later dubbed "photons." With
this powerful but simple idea Einstein was able to explain the photoelectric effect, why electrons are emitted from metals when you shine a
light on them. Today the photoelectric effect and the photon form the
basis of TV, lasers, solar cells, and much of modern electronics. (Einstein's theory of the photon was so revolutionary that even Max Planck,
normally a great supporter of Einstein, could not at first believe it. Writing about Einstein, Planck said, "That he may sometimes have missed
the target... as for example, in his hypothesis of light quanta, cannot
really be held against him.")
Then in 1913 the Danish physicist Niels Bohr gave us an entirely
new picture of the atom, one that resembled a miniature solar system.
But unlike in a solar system in outer space, electrons can only move in
discrete orbits or shells around the nucleus. When electrons "jumped"
from one shell to a smaller shell with less energy, they emitted a photon of energy. When an electron absorbed a photon of a discrete energy, it "jumped" to a larger shell with more energy.
A nearly complete theory of the atom emerged in 1925, with the
coming of quantum mechanics and the revolutionary work of Erwin
Schrôdinger, Werner Heisenberg, and many others. According to the
quantum theory, the electron was a particle, but it had a wave associated with it, giving it both particle- and wavelike properties. The wave
obeyed an equation, called the Schrôdinger wave equation, which enabled one to calculate the properties of atoms, including all the
"jumps" postulated by Bohr.
Before 1925 atoms were still considered mysterious objects that
many, like philosopher Ernst Mach, believed might not exist at all. After 1925 one could actually peer deep into the dynamics of the atom
and actually predict its properties. Astonishingly, this meant that if you