210 The Poetry of Physics and The Physics of Poetry
data. What was at issue was the aims of physics. The agreement as to
whether or not quantum mechanics is a complete theory arose from a
difference in opinion on the basic goals of science.
Einstein argued that the aim of science was to provide a causal
description of nature while Bohr maintained that the only aim was to
describe the experimental data. There was no way they could really
resolve their conflict. All the same, they argued back and forth for many
years. Einstein was continually proposing thought experiments to
demonstrate possible contradiction in the theory. Bohr was always able
to answer him satisfactorily. Einstein persisted, but finally had to admit
that the theory was self-consistent but would never concede that it was
complete. Einstein’s friend, the physicist Ehrenfest, one chastised him
for his stubbornness, “Einstein, shame on you. You are beginning to
sound like the critics of your own theories of relativity. Again and again
your arguments have been refuted but instead of applying your own rule
that physics must be built on measurable relationships and not on
preconceived notions, you continue to invent arguments based on those
same preconceptions.” It is perhaps one of the great ironies of all physics
that Einstein, the inventor of relativity, the greatest innovator physics had
ever known with the possible exception of Newton was unable to accept
quantum mechanics in spite of all his important contributions in the field.
Bohr, probably better than any one else, understood the wisdom of the
following remark attributed to von Helmholz, “The originator of a new
concept finds, as a rule, that it is much more difficult to find out why
other people do not understand him than it was to discover the new
truths.”
There is no true resolution to the Bohr–Einstein debate. The only way
that the Einstein position could truly be vindicated is for someone to
discover a complete theory which both describes the experimental data
and restores causality. Numerous attempts in this direction have been
made without any notable success. In the absence of such a theory, one is
more or less inclined to agree with Bohr. Only time will tell.
One approach of the followers of Einstein’s position is to say that
there are hidden variables that once they are found would restore
causality. All that I can conclude is that these variables are very well
hidden. But the hunt for them continues, although I do not think any will
be found. We just have to accept this is the way our universe is.