文档介绍：A. Einstein, Ann. Phys. 17, 132 1905
Concerning an Heuristic Point of View Toward
the Emission and Transformation of Light
A. Einstein
Bern, 17 March 1905
(Received March 18, 1905)
Translation into English
American Journal of Physics, v. 33, n. 5, May 1965
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A profound formal distinction exists between the theoretical concepts
which physicists have formed regarding gases and other ponderable bodies
and the Maxwellian theory of ic processes in so–called empty
space. While we consider the state of a body to pletely determined
by the positions and velocities of a very large, yet finite, number of atoms
and electrons, we make use of continuous spatial functions to describe the
ic state of a given volume, and a finite number of parameters
cannot be regarded as sufficient for plete determination of such a
state. According to the Maxwellian theory, energy is to be considered a con-
tinuous spatial function in the case of all purely ic phenomena
including light, while the energy of a ponderable object should, according
to the present conceptions of physicists, be represented as a sum carried
over the atoms and electrons. The energy of a ponderable body cannot be
subdivided into arbitrarily many or arbitrarily small parts, while the energy
of a beam of light from a point source (according to the Maxwellian theory
of light or, more generally, according to any wave theory) is continuously
spread an ever increasing volume.
The wave theory of light, which operates with continuous spatial func-
tions, has worked well in the representation of purely optical phenomena
1
and will probably never be replaced by another theory. It should be kept in
mind, however, that the optical observations refer to time averages rather
than instantaneous values. In spite of plete experimental confirma-
tion of the theory as applied to diffraction, reflection, refraction, dispersion,
etc., it is still conceivable that the theory of light which operates wit