How Analogy Drives Physics
Many new ideas in theoretical
physics come from analogies to older ideas in physics. For instance, the
abstract notion of “isospin” (or isotopic spin) originated in the prior concept
of “spin” (quantized angular momentum); likewise, the concept of “phonon”
(quantum of sound, or quantized collective excitation of a crystal) was based
on the prior concept of “photon” (quantum of light, or quantized element of the
electromagnetic field). But these two examples, far from being
exceptions, in fact represent the bread and butter of inventive thinking in
physics. In a nutshell, intraphysics analogy-making -- borrowing by
analogy with something already known in another area of physics -- is central
to the progress of physics. The
aim of this talk is to reveal the pervasiveness -- indeed, the indispensability
-- of this kind of semi-irrational, wholly intuitive type of thinking (as
opposed to more deductive mathematical inference) in the mental activity known
as “doing physics”. Speculations as to why wild analogical leaps are so
crucial to the act of discovery in physics (as opposed to other disciplines)
will be offered.