1 6 4 D O C . 1 7 0 O N O V E R D E T E R M I N A T I O N
must examine whether one should indeed conclude from former endeavors and
data that it is impossible to make do with partial differential equations. Anyone
who fully appreciates the wonderful certainty with which the wave theory inter-
prets the geometrically much-convoluted phenomena of interference and diffrac-
tion of light will have difficulty believing that partial differential equations are, in
the final instance, unsuited to doing justice to the observed facts.
Taking a critical look at the Maxwell-Lorentz theory, one realizes that its foun-
dation consists of two formal, only loosely connected parts, namely, the differential
equations of the electromagnetic field and the equations of motion of the (positive
and negative) electron. The phenomena of diffraction and interference which are so
well confirmed by experiment are essentially formally governed by the field equa-
tions alone; the processes of absorption, on the contrary, which theory is unable to
render faithfully in accord with observation, are mainly defined by the laws of mo-
tion of the
electron.1)
It is hence an obvious (often expressed) thought that one
should retain the field equations but should abandon the equations of motion for
electrons. This would, of course, also entail that one can not retain the customary
theory for localizing energy within the field. This theoretical possibility was not
pursued further for the simple reason that hitherto no tractable path toward a for-
mulation of different laws of motion for the electron was found. Mie’s attempt to
extend the field equations in such a way that they also apply to the interior of elec-
trons has hitherto led to no useful
result.[6]
This method could have led to a unifi-
cation of the foundations in that it would have made special equations of motion
for electrons superfluous. Why this approach cannot contribute decisively toward
a solution to the problem of quanta either, however, will emerge from the following
consideration, which in my view leads us to the most essential point of the whole
problem.
According to existing theories, the initial state of a system can be freely chosen;
the differential equations then deliver the temporal continuation. According to our
knowledge about quantum states, as it has been developed particularly in connec-
tion with Bohr’s theory during the last decade, this feature of the theory does not
correspond to reality. The initial state of an electron moving around a hydrogen nu-
cleus cannot be freely selected. Rather, this choice must meet the quantum condi-
tions. Generally: not only the temporal continuation but also the initial state is sub-
ject to laws.
1)
The foundation of mechanics in itself contradicts already the quantum facts (failure
of the equipartition theory). The equations of motion for material points therefore have to
be abandoned, regardless of the question as to whether one can hold on to the field
theory.[9]
[p. 360]