SUPERCONDUCTIVITY is one of the great scientific discoveries of this century.
It has been a magnet for Nobel prizes, and promises supercomputers that work at
room temperature. Yet beyond an inner circle of researchers, few have any real
insight into the phenomenon.

While we can rationalise many of the basic properties of materials with
hand-waving models that brush aside the intricacies of quantum mechanics, this
approach isn’t good enough for superconductors—not merely because it is
based on unsound science or offends the purists, but because it just doesn’t
work. Superconductivity is an awkward phenomenon that forces us to accept that
the real world is quantum mechanical, and that trying to pretend otherwise is as
perverse as believing the Earth is flat or trusting a horoscope.

B. S. Chandrasekhar’s Why Things Are The Way They Are aims to induct
the general reader into the mysteries of quantum mechanics and apply its methods
not only to superconductors, but also to the electrical, mechanical, optical and
magnetic properties of many materials. He is keen not to discourage readers who
have little mathematical knowledge—an approach familiar to many of us who
try to teach this material at degree level—and is almost apologetic when
he introduces simple algebra. His prose is chatty and informal, and the
illustrations are obviously the fruit of years of trying to convey the
excitement of his research to friends and relatives on receipts and napkins.

Yet in many ways this reads like a textbook. There are no fleshly delights
here, no folklore nor high-tech applications to lure and seduce the reader.
Instead, we are offered enlightenment—pure, if not exactly simple.
Chandrasekhar prepares us thoroughly for this spiritual journey with
introductions to the structure and symmetry of crystals, to energy and momentum.
Our common-sense and classical prejudices are tested with wave-particle duality
and the uncertainty principle. Before we know it, we find ourselves accepting
quantisation and appreciating why atoms don’t implode. Then, just as we are
getting to grips with a single atom, we are off again, trying to cope with
zillions of them at once, first in a gas and then squeezed into a solid,
teaching us to appreciate why statistics are vital.

Finally we are in a position to do something with our new-found knowledge.
Assuming we have stayed the course (no mean feat), we are free to lose ourselves
in k space, jostled by electrons and photons and phonons as the solid conducts
or reflects or fractures. And yes, we do get to learn about superconductors in a
manner that conveys the essence of standard theory well.

The opening sequence of chapters, with concepts flowing thick and fast, is
both a strength and a weakness. Many of these concepts are treated beautifully,
presented as a series of vignettes that provide insight at many levels. The
distinction between fermions and bosons, for instance, is made as elegantly and
as faithfully as one could hope to find anywhere. But only with the benefit of
hindsight is it clear where it is all going, why each concept is necessary to
understand the intricate workings of a solid.

Chandrasekhar likens our progress through the book to a long mountain walk.
He unfolds the map and briefs us before we start out and brings us up to date at
the end of each day. But he has too much faith in our wanting to succeed, to
persevere “because it’s there”. Many will need to stop and smell the flowers or
share a joke. To those who succeed should come the satisfaction of
explanations— remarkably free of fudge or assertions—that really do
represent what working scientists believe.