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Home Is Where The Wind Blows by Fred Hoyle, University Science Books,
California (distributed in Europe by W. H. Freeman), pp 443, £18.95/
$32.50

For nearly half a century, Fred Hoyle has been involved in major, highly
controversial scientific issues, especially those concerned with the origin
and evolution of the Universe and of life. On the whole, the contemporary
scientific establishment tends to be dismissive of Hoyle’s cosmological
and biological theories, but many of his fundamental points still need to
be answered. Whatever the ultimate judgment on those may be, there is no
doubt that his work on the origin of the elements will stand as one of the
most significant contributions to science this century.

Hoyle writes as fluently and fearlessly as he speaks, and his description
of the chain of events that led to his belief that there must be a hitherto
unknown 7.65 megaelectronvolt energy level in the isotope carbon-12 is a
splendid example of how critical scientific discoveries can emerge through
the vicissitudes of a scientist’s life. The links in this case begin with
the American physicist Hans Bethe’s 1939 paper on the conversion of hydrogen
to helium as the source of the Sun’s energy. The other links came after
the war, with a student who abandoned a problem set by Hoyle, his consequent
frustration with the Cambridge doctoral system, and a chance meeting with
the astronomer Walter Baade at the 1952 Assembly of the International Astronomical
Union in Rome. This last led to an invitation to visit Mount Wilson and
lecture at Caltech in 1953.

It was during the preparation of these lectures that Hoyle became certain
that the production of carbon from helium in the process of nucleosynthesis
could not occur unless a 7.65 MeV energy level existed in carbon-12. The
first reaction of the American nuclear astrophysicist Willy Fowler was that
‘I had somehow gone a long way off my mental compass bearings’. But Hoyle
persuaded Fowler to design a new experiment and when he heard the result
‘the orange trees smelled even sweeter’.

They might well have done, because this result led directly to Hoyle’s
1954 paper on the synthesis of elements from carbon to nickel and to the
monumental 1957 paper, written in collaboration with Fowler and astrophysicists
Geoffrey and Margaret Burbidge, on the nucleosynthesis of the elements
in the interior of the stars.

During the war Hoyle worked in the Admiralty Signals Establishment where
he met the Austrian physicists Hermann Bondi and Tommy Gold. Their conversations
led to the birth of the continuous creation, steady state theory of the
Universe. Eventually, in 1948, their historic papers on the theory were
published. The paper that Bondi and Gold wrote stressed the philosophical
aspect of a perfect cosmological principle in which the Universe would have
a high degree of uniformity on the large scale both in time and space, thereby
avoiding the scientific problems associated with a beginning at a finite
past time. Hoyle’s paper, published two months after Bondi and Gold’s, developed
the mathematical theory of the scalar field, in which the continuous creation
of hydrogen would force a precise balance between the density of matter
in the Universe and the rate of expansion.

In describing the advantages of this theory during a series of BBC broadcasts
in 1950, Hoyle used the phrase ‘big bang’ in a derisory sense as a description
of the concept that the Universe had a beginning in a hot and dense state
at a finite past time. Ironically, Hoyle’s work on the nucleosynthesis of
the elements contained the seeds of destruction of the steady state theory
in its original form. The cosmic abundance of helium is about 27 per cent
and yet only between 2 and 3 per cent can be produced in the processes of
stellar nucleosynthesis. The authors of the steady state theory drew attention
to this problem in 1955, and then Hoyle and Roger Tayler reached the conclusion
that the major helium content of the Universe must have been produced in
a high-temperature phase.

This inevitably led to a partial return to Russian physicist George
Gamow’s theory of the hot initial phase of the Universe and the primordial
synthesis of helium. Coupled with the discovery of the cosmic microwave
background in 1965, the observational evidence appeared wholly in favour
of a big bang cosmology, and for fifteen years Hoyle’s interest in cosmology
waned. However, by 1985 the unproved assertions of certain cosmologists
again stimulated Hoyle’s interest and his recent publication of the modified
steady state concept, which features the creation of the Planck particles
(‘like a big bang in itself’) and their decay, may hold the seeds of a cosmology
in which the essential elements of the steady state and big bang cosmologies
are combined. At least, there must be increasing sympathy with Hoyle’s when
he says, ‘Big bang cosmology refers to an epoch that cannot be reached by
any form of astronomy, and, in more than two decades, it has not produced
a single successful prediction.’ As with the multitude of topics covered
in this book, Hoyle’s account of these developments deserves careful attention.

All who know Hoyle must realise that below the decisive and outspoken
public figure there lies a human being of great sensitivity. All who read
this book will know it, too. At one stage, referring to his early life,
Hoyle writes ‘but all this is rather petty stuff’. But for the reader it
soon becomes a matter of vital interest whether the boy takes a left and
two right turns after leaving home and reaches school, or takes the opposite
turnings and becomes a truant for the day. That, and his dispute at the
age of five with his teacher as to whether one of his wildflowers had five
or six petals, epitomises the honoured scientist who half a century later
resigned from the Plumian chair and the directorship of the Institute of
Theoretical Astronomy because he could no longer tolerate the Cambridge
mode of university politics.

Hoyle has had a major influence on the scientific thought of the second
half of the 20th century. Here is his compelling account of the successes
and tribulations of that life. It is compelling not only because of the
science, which often has to be dug out from intervening pages of many other
topics. It is these other topics that reveal Hoyle himself, whether in his
brilliant vignettes of his mentors or the often vivid descriptions of his
mountaineering exploits. Above all, some may feel that his father’s last
words to him, recounted in this book – ‘How long is the journey, lad’?
– is a question which Hoyle himself has not yet resolved.

Bernard Lovell was the first director of Jodrell Bank Experimental Station.