Is there any place for personal taste in science?
Vacation post No 3. I will be out of the virtual office until Monday 31 August.
It has long been the case that physicists talk approvingly about a
physical theory as being `elegant’ or even `beautiful’. Like so much
else, this seems to have become commonplace in the 1960s. More recently
I have become aware of similar sentiments being expressed in
mathematics. In that case one can see that some particular proof, say,
might be preferred to another, purely on grounds of economy or clarity
or conciseness. However, in the case of physics, one might expect that a
comparison of a theory’s predictions with experimental results should be
the deciding factor.
There is an old adage in engineering design to the effect that `if it
looks right, then it is right’. Obviously, there are constraints on this
in that your design for a motor car must look as if it is capable of
being a motor car. This latter point is an instance of the precept `form
follows function’ which originated in architectural design in the early
part of the last century. But the adage refers to quality, and is
supposedly a way of separating a good design from other designs that are
merely adequate. So the implication is that a purely aesthetic judgement
can lead to a design that satisfies various, perhaps quantitative,
criteria which give a universal meaning to the term `good design’ in
some particular context.
Of course the insertion of the word `probably’ into the engineering
adage might lead to its justification in practice. That is, if it looks
right then it `probably’ is right. So the adage could offer a guide as
to whether or not one should take a particular design idea further. For
this to work there must exist some consensus on what is meant by `looks
right’. And this undoubtedly changes with time. A motor car which was at
the leading edge of design in the 1960s will look distinctly
old-fashioned nowadays.
But there is always some unease about using a personal value judgement
to determine a matter which will ultimately be settled on a
quantitative basis. And there are other complications too, even when the
quantitative aspect is not present, as for example in the arts. An awful
warning may be found in the well known crisis in painting at the end of
the nineteenth century. This was triggered by the invention of
photography, which in turn led to artists becoming experimental in order
to avoid producing paintings which were no more than (in effect)
photographs. Such attempts were reviled and even the formation of
schools of activity (e.g. Fauves, impressionists) did not at first lead
to acceptance.
Unfortunately the fact that impressionist paintings are now highly
valued appears to have led to the pendulum swinging too far in the other
direction of uncritical acceptance. Even so, those who are specialists
in the world of art, literature or music can argue that their
`informed’ eye or ear gives their opinion a special weight. And no
doubt that is a tempting argument in science too. Indeed, in the case of
string theory or the idea of the multiverse, where testing against
experiment is impossible, it is arguable that aesthetic criteria may be
all that one has. But, if consensus develops, this can then lead to the
creation of schools of opinion and standard models, which in turn can have the
perverse effect of shutting down other approaches to the problem. This
is not the case in the arts. Indeed, the non-specialist can say `I know
what I like’, and there is an end to it. One does not have that freedom
in science. Or at least, not if one expects to get published in the learned
journals.
Therefore, it does seem that there are dangers from importing purely
personal aesthetic considerations into science. It is interesting to
note that the greatest physicist of all had some words to say on this
particular subject. In the preface to his 1916 book, entitled
`Relativity’, Einstein stated that he had followed the precepts of that
other great theoretical physicist, Boltzmann, `… according to whom,
matters of elegance ought to be left to the tailor and to the cobbler’.
