The
German physicist Max Karl Ernst Ludwig Planck(1858-1947), developed the concept
of the quantum, or fundamental
increment of energy--basic to quantum mechanics, and a cornerstone of modern
physics.
After receiving his Ph.D.
from the University of Munich
in 1879, Planck taught at the University of Kiel (1885-89) and the University
of Berlin (1889-1926). Planck began studying blackbody radiation in 1897 and discovered
that at long wavelengths it did
not obey the distribution laws known at that time. This discovery led him
to announce (1900) his revolutionary idea that an oscillator could emit energy
only in discrete quanta, contrary to classical physical theory. The quantum theory--which
gained Planck the Nobel Prize for physics in 1918--was used by Albert Einstein
to explain (1905) the
photoelectric effect and by Niels Bohr to propose (1913) a
model of the atom with quantized electronic states; the theory was later developed
into quantum mechanics.
