Bruno Rossi is a fine scientist, but he is a no Galileo. In his preface
to this book, Philip Morrison tries to oconjure up echoes of Galileo: the
Italian scientist creating a new astronomy amid the ravages of tyranny and
war.

Buffeted about by the great events of the time, Bruno and Nora Rossi
tell their story from a point of view that is resolutely their own.

Rossi was born in Venice in 1905. He studied physics at Florence, working
at Arcetri, where Galileo spent his final years. Here, he invented a fast-coincidence
detector of ionising radiation that permitted him to make the measurements
that led to his first great moment in the sun. At a meeting in Rome of the
Royal Italian Academy, at which Guglielmo Marconi presided, and with the
world’s most illustrious physicists in attendance, Enrico Fermi invited
Rossi to present his results. He used the occasion to demolish the theory
of the great Robert Millikan that cosmic rays (a term coined by Millikan)
were ‘the birth cries of atoms’. His experiment showed that cosmic rays
were much too energetic to have originated as Millikan imagined.

Rossi’s life may reasonably be said to be woven of four strands. One
is the great political and social events of the day. A second is the peculiar
evolution of the field of cosmic ray physics. The third is the personal,
inner story of Bruno and Nora – their passions and sorrows, rivals and supporters,
defeats and triumphs. The fourth is the story of Rossi’s work, the experimental
dilemmas that arose in his laboratories, and their resolution.

Rossi chooses to focus on the fourth of these strands. For the rest,
we must depend on only incidental glimpses, and on a final chapter written
by Nora that tells the story from her point of view. Much as I admire Bruno
Rossi as an experimental physicist, a bit more attention to the other strands
might have made for a more exciting book.

In 1928, when Rossi arrived at Arcetri, the director of the Institute
of Physics and the leading light of Florentine physics was Antonio Garbasso.
Rossi lets us know that Garbasso was, alas, no longer an active physicist,
having allowed himself to be drawn into administration. He was a senator
of the kingdom and mayor of Florence. In an omission typical of the entire
book, Rossi does not find it necessary to tell that Garbasso was a willing
Fascist.

Protected by Garbasso, physics flourished at Arcetri, to the point where
Rossi feels, with some justice, that Fermi’s collection of raqazzi on the
Via Panisperna in Rome was not Italy’s only great centre of experimental
research at the time. Along the way, Rossi managed to get a travel grant
to visit Berlin in 1930, where he caught a glimpse of Albert Einstein, Max
Planck, Otto Hahn, Lise Meitner, Max von Laue, Hermann Nernst and Werner
Heisenberg. More importantly, he found out that he could improve his Geiger-Muller
counters with which he measured the impact of cosmic rays by replacing the
steel wire with aluminium.

In 1932, while planning an expedition to observe cosmic rays in the
then Italian colony of Eritrea, Rossi was called to a chair at the University
of Padua. He accepted the responsibility of supervising the building of
a new physics institute, the building that had served Galileo (him again!)
being no longer fit for modern laboratories.

By the time the new building was finished in 1937, other matters forced
their way into Rossi’s consciousness. For one thing, he had met and married
Nora. He generously devotes nearly an entire paragraph to this. For another,
antisemitism had become a problem in Fascist Italy; the Rossis were Jewish.

Reluctantly, they left Italy. Nora’s account makes mention of her rage
when, at this frantic moment, Bruno could not bring himself to leave his
laboratory. Leave they did, however, first for Copenhagen, where the Bohrs
looked after them, and then for Manchester. Here, Patrick and Constance
Blackett provided them with a flat to live in and a laboratory in which
Rossi invented the anticoincidence method of detecting gamma rays.

Meanwhile, Compton was searching for a place for them in the US. There
were more refugee scientists than places available, but Compton invited
Rossi to a symposium on cosmic rays in Chicago. In June 1939, the Rossis
sailed for the New World.

In search of job security and cosmic rays, the Rossis went to New York,
Chicago, the mountains of Colorado, and finally, Ithaco, where Hans Bethe
found him a chair at Cornell University. But he was soon to be called away.
In 1943, issues that Rossi and Enrico Fermi had only murmured darkly about
over lunch in Chicago had taken on a terrifying reality, and Bethe invited
Rossi to Los Alamos. In the Los Alamos section of the book, Rossi gives
a particularly lucid account of the technical problems of making the atomic
bomb, and of the role he played in helping to solve them.

After the war, Rossi wound up at the Massachusetts Institute of Technology.
Artificial accelerators superseded cosmic rays as sources of high-energy
particles but – in the nick of time – the field was saved from extinction
by the emergence of space flight. Cosmic ray physicists sent their detector
gadgets into space.

All of this is told with grace, dignity, and admirable clarity. Rossi
was obviously determined to make his memoir accessible to the general reader
and, for the most part, he has. The only problem is that the part of his
story he has told is not the part the reader most wants to hear. I would
like to suggest that the Rossis try again. This time, let Nora write the
book, and Bruno fill in the details of his experiments in footnotes. The
result could be a fine read.

David Goodstein is professor of physics and applied physics, and Vice
Provost at the California Institute of Technology.

‘THERE ARE two things that make life worth living,’ Victor Weisskopf
tells his students, ‘Mozart and quantum mechanics.’ Weisskopf has lived
through cataclysmic times: the working out of quantum mechanics, the rise
and fall of Nazism and the invention and proliferation of nuclear weapons
have all been episodes in his life. What has somehow emerged from this remarkable
life is a man who views physics with passion, and everything else with unfailing
good sense. The Privilege of Being a Physicist, a collection of Weisskopf’s
essays written in the past 20 years, gives us a unique window on the sensibilities
of a man for whom Mozart and quantum mechanics represent not an escape from
reality, but rather a privileged position from which to view it.

As promised in the preface, Weisskopf’s essays span his major interests:
physics, human creativity, and modern problems, including education, the
environment and the nuclear arms race. They may also reveal more about Weisskopf
than he had intended. To be sure, he makes no secret of what he regards
to be the major influences on his life and thought. One is Niels Bohr, and
his principle of complementarity as a way of viewing far more than physics
alone. Another is the experience of Los Alamos, and what he must regard
as his personal responsibility for The Bomb, and for our present predicament.
Most important of all, however, is the fact that Weisskopf is a physicist
to the very core of his being. When he writes about complementarity between
science and art, or about the nuclear arms race, he is always sensible,
but these parts of the book are of passing interest. When Weisskopf explains
to us how quantum mechanics works, or how the Universe began, the book soars.

In the first two sections of the book, which consists of half a dozen
essays collected under the headings ‘The Life of a ÐÓ°ÉÔ­´´â€™ and ‘Science
and Culture’, Weisskopf tells us, rather than shows us, what is inside him.
The essays are actually ceremonial speeches, and even (heaven help us) a
commencement address, in which the great scientist says all the right things.
Science is a human, and humanistic enterprise (with quotations from Goethe
and Walt Whitman); science and art are complementary ways of understanding
reality, just like particles and waves (Bohr’s principle of complementarity);
and science education is important mostly for cultural reasons. All of this
is clearly right, and yet, somehow, curiously unconvincing. Were I the editor
of this book, I would not have placed these chapters first. Some readers
might give up before getting to the good parts.

Nevertheless, the last two of these essays help to prepare us for what
is to come. In ‘Art and Science’, Weisskopf tells us that when art became
free of religion, it lost the power to inspire us, that religion itself
is no longer sufficient, and that the elation of science has not proved
contagious except to scientists. In ‘The Frontiers and Limits of Science’,
we find 10 steps to the modern scientific world view. Of these, eight belong
to physics (the others are evolution and molecular biology) and one of those
is unexpected: the quantum ladder, listed separately from quantum theory.
In the following chapters, Weisskopf will expose all but the most resistant
of souls to the contagious elation of science, and he will use the quantum
ladder as one of his central organising principles of nature.

The quantum ladder expresses the fact that small dimensions are associated
in physics with larger energy thresholds. Thus, for example, at the energies
available in our common experience (solar radiation, room temperature and
so on), molecules may come apart to do chemistry and biology, but atoms
are as indivisible as their name was meant to imply. On smaller scales and
at higher energies, nuclei become divisible into neutrons and protons, and
on the next rung, these become divisible into quarks. Higher energies take
us to smaller dimensions, and also to earlier epochs in the story of the
Universe. We have not yet climbed beyond quarks on the quantum ladder, and,
correspondingly, we cannot penetrate into the first microsecond of creation.

Three essays, entitled ‘What is Quantum Mechanics’, ‘What is an Elementary
Particle’, and ‘The Origin of the Universe’, are worth the price of the
book alone. Here is Weisskopf at his best, using his deep understanding
of the subject, and his gift of straightforward, lucid prose to guide us
through this formidable territory with clarity, insight, and an unmistakable
sense of his own exhilaration. When he tells us that quantum mechanics explains
why the same flowers come back every spring, the reader may be aware that
there are a few steps missing in the argument, but we are happy to excuse
his excess of enthusiasm.

This section of the book also includes a rapid but comprehensive survey
of the ‘Contemporary Frontiers in Physics’, which certainly shows that Weisskopf
still knows what’s up. He even manages to mention the relation between 2-dimensional
and 3-dimensional melting, my own little alcove in the great house of science.
He knows how to make a reviewer happy.

The two most charming pieces in the collection concern, respectively,
Wolfgang Pauli and Werner Heisenberg. Weisskopf recalls the legendary Pauli
with rare affection, and some wonderment that Pauli chose him over Hans
Bethe to be his personal assistant (Pauli explained that he passed over
Bethe because ‘. . . he works on solid-state theory, which I don’t like,
although I started it’). The Heisenberg essay helps us to understand why
the great German theorist chose to stay at home and carve out a small ‘island
of decency’ within the Nazi regime. Many others, including Bohr and Albert
Einstein, never forgave Heisenberg as Weisskopf has done.

In the last section of the book, called ‘Science and Society’, we confront
the great issues of our time: war and peace, totalitarianism (Weisskopf
came to the US in 1937, a refugee from Hitler), the environment, and the
nuclear arms race. His views are unfailingly moderate, balanced and thoughtful.
He fears domination by a single world view (for example, that of religion
in the Middle Ages, science and technology today; this echoes his earlier
discussion of complementarity). Communism has abridged human rights, but
all things considered, it’s not as bad as Nazism. Also, American foreign
policy has been something less than a shining example. He worries about
pollution, both of the environment, and of the spirit. Finally, and above
all else, we must find a way to avoid the nuclear holocaust. Like most of
us, Weisskopf sees the problems more clearly than he sees the solutions.
His experiences, as a refugee from Hitler, and as a participant in the Los
Alamos project, command our attention, but what he has to say about these
great issues is pretty much what all other sensible people have to say.
Only when he writes about physics and physicists does this book stand apart.

Victor Weisskopf is a deeply civilised man, but he is also an old fashioned,
unregenerate physicist. The other sciences don’t even get the lip service
he pays to art and religion. To many of us still labouring in the trenches
of science, his view seems a relic from heroic times past. But it’s an exhilarating
view, one I had almost forgotten. It’s an unexpected pleasure to be reminded
of it.

David Goodstein is vice provost and professor of applied physics at
the California Institute of Technology.