THE story of the expansion of cosmology from small beginnings to the
supergalactic present unfolds through the eyes of Astronomer Royal Martin Rees.
It all began for Rees when he was a postgraduate student of Dennis Sciama’s at
Cambridge in the 1960s, in a slower age before the Internet united researchers,
fax machines spread the word, and microwave background radiation was discovered.
It was a time when observation was still earthbound and relatively
inexpensive.

Although most subjects discussed here have been expounded in other popular
books, Rees’s version of the past 35 years of cosmology is accessible to those
who have not followed this subject before, pitched at an invitingly low
level.

He divides his text into many short, easily digestible sections, weaving
together history, science and personal details about the principal protagonists.
The style is simple and easy to follow.

The story provides eyewitness accounts of exciting past developments in
astrophysics. These include the demise of the steady-state theory proposed by
Fred Hoyle and the battle that ensued between Hoyle and Martin Ryle over the
meaning of Ryle’s observations of cosmic radio sources (which eventually led to
the dominance of the expanding Universe model).

If a single theme unites Before the Beginning, it is that of the
manifold ways in which our Universe appears peculiar in the light of all the
alternatives that we can conceive. Curiously, we are good at thinking up
possible universes. Einstein provided the recipe book. Each solution of his
equations describes an entire universe. Unfortunately, we can find only the
simplest ones. In many cases these simple-minded universes provide a good
approximation to our Universe, but they are only as detailed as the information
we put into them. We need to know all the types of matter around now and in the
past, how much of it there is, and all the ways one form of matter might decay
or change into other forms.

As we reconstruct the expanding Universe’s history back to earlier and
earlier times where temperatures exceed those we can recreate in particle
colliders, so these uncertainties become more significant. We still do not know
the identity of 90 per cent of the matter in the Universe.

Perhaps one day particle physicists will be able to complete the inventory.
In the meantime, lacking an understanding of all nature’s self-imposed
constraints, the number of alternative paths that the Universe may have taken in
its early evolution seem very great. They allow us to conceive of many different
universes and see our own “home” universe, with its particular defining laws,
structures and patterns, as just one among many self-consistent possibilities.
Rees explains how many of our Universe’s properties are not only unusual, but
apparently essential for the origin and evolution of any form of complexity at
all.

Once, he viewed this anthropic aspect as a coincidence about which little
more could be said. The advent of theories of the Universe that allow other
universes, in principle and even in reality, has changed his view. If the
evolution of the Universe gives rise to cosmic conditions that vary
significantly from place to place, or produce different quantum gravitational
realities which each claim to be an extant habitable universe, then there are
new possibilities for anthropically maladjusted universes, which cannot support
the complexity needed for life, and some meaning may even be given to the
concept of their probability of existence.

This is an accessible yet accurate account of modern cosmology that clearly
separates our store of sure knowledge about the Universe from its speculative
edge. It nicely reflects Rees’s wide-ranging interests and his powerful
intuition about astrophysical problems. If you haven’t read a single cosmology
book, this is a good place to start.

Impressive as apparently unpredictable natural events and catastrophes of nature must once have appeared, it was only by careful study of Nature’s regular habits that the foundations of science were laid. While there have been specialists who have focused their skills on an understanding of particulars, there have also been generalists who have sought to create a single all-encompassing picture of the world. From ancient creation myths to theories of everything, this imperative persists.

David Bohm, who died in 1992, belongs firmly among those seeking the big picture. He was a physicist who sought a unification of thought and experience far more thorough than most would actively contemplate. He pursued this goal throughout his life with an intensity that ultimately proved self-destructive. Bohm’s desire to express his inner convictions about the nature of reality and the character of an ideal society through physics burdened his mind with a vicarious responsibility for the tragedies of the modern world and the vagaries of human character.

In Infinite Potential: The Life and Times of David Bohm, David Peat, a long-time friend and collaborator of Bohm, has attempted to draw together the tangle of threads that formed Bohm’s life. Like a wave, Bohm’s career, periodically alternated between periods of profound research into physics and mystical interludes of self-searching and self-delusion. Peat has written a moving personal account of a figure whose life oscillated between keen physical observations, comic naiveté and a longing for cosmic links between human consciousness and the Universe that, ultimately, produced a destructive interference of depression and physical breakdowns.

Peat has done a careful job of assembling the facts: he interviewed Bohm’s friends, collaborators and acquaintances, and studied US State Department records made available under the Freedom of Information Act. For the book’s factual skeleton he draws on long interviews with Bohm himself.

Bohm’s story contains enough experiences to fill several lives. He researched plasmas, worked at the Lawrence Berkeley Radiation Laboratory in the 1940s, and wrote incisive books on quantum mechanics and relativity. As a result of his support for international socialism, he was arrested and tried under suspicion of communist sympathies and spying by the House Un-American Activities Committee in 1949. As a result, his appointment at Princeton University was not renewed; he left the US and moved to Brazil. Later, after working for a few years in Israel, he settled in England and continued his work on quantum mechanics.

Bohm also began to immerse himself in the mystic thought of the philosopher J. Krishnamurti. While Peat is sympathetic to Bohm’s scientific theories and also to many of his ideas about society, near the end of the book he appears to despair at Bohm’s almost irrational attachment to Krishnamurti, who exploited Bohm’s support.

Peat weaves his way through Bohm’s waves of physics and fantasy, but I wonder if the balance is right. We learn too little of Bohm’s work with David Pines on plasmas, and the true nature of his interpretations of “hidden-variable” quantum mechanics. Instead the book goes on and on about his long discussions with Krishnamurti, who seems to have convinced Bohm that he alone had undergone a “transformation” of consciousness—something that Bohm longed to experience.

Like Isaac Newton, who attempted to divine the books of the ancient kings and searched for the alchemists’ touchstone, Bohm was caught up in a search for the transcendental. He was a follower of Uri Geller, tutored the Dalai Lama in physics, and set up seminars which attempted to escape the shackles of language by lecturing using only verbs (without nouns—try it!).

Whereas Newton escaped from his occult world of introspection in time to finish his life as a respected citizen, Bohm does not seem to have been so lucky. His desire for unity of thought and theory was his psychological downfall. He rejected the common interpretation of quantum mechanics because it lacked causality, a key element of Marxist ideology. He saw the collective motion of plasmas as a model of collective social structures which nonetheless allowed human freedom. He thought the world must be rational in every aspect, from electrons to human actions.

But his faith in the absolute power of science, logic and human reasoning was shaken to the core by the political upheavals of 1956. Bohm seems to have felt the great disasters of human affairs personally. The Soviet invasion of Hungary was a turning point in his life, creating a crisis of conscience. Bohm became convinced that the flaws in human nature meant that no political theory could redeem it. No adherence to science could create the brave new world he hoped for.

From that time on he turned increasingly to mysticism in search of a deeper explanation of the world. But his introspection led him in circles, and Bohm spiralled into a cycle of depression and frustrated searching. Ultimately he became disenchanted with the guru he had followed so earnestly and suffered a mental and physical breakdown.

Peat has given us a scholarly account of a life in which science and mystical holism intertwine. Fred Alan Wolf’s The Spiritual Universe is something completely different. Wolf’s overall subject is the soul; his route is through the halls of science; and his vehicle is the serious abuse of quantum physics. I am afraid that this book is a product of a New Age desire to equate all the things that we don’t understand about our world. Consciousness, the soul, quantum uncertainty, vacuum fluctuations—are all mixed together into a heady brew that ends up smelling distinctly odd.

Wolf begins, soberly enough, by recounting the theories of the soul to be found in a variety of ancient writings from East and West. But then I felt as if I had wandered into Carlos Castañeda’s physics course. At first ridiculous, the book proceeds rapidly downhill. For instance: “The soul is dancing and spinning the whole universe.” Wolf puts an entirely new spin on the soul by arguing that it has quantum mechanical spin. He apparently believes that this helps explain all sorts of great mysteries, such as why souls attract each other so that people can become soulmates, and why the soul communes with the self.

Wolf proposes that we assume, “at the risk of sounding reductionistic, that the soul is composed of billions and billions of small minisouls—each a spinning particle … each minisoul is a virtual particle that has spin, negative energy and mass”. There follows an account of the physics of these minisouls, the “laws of emotional entropy”, “faster-than-light waves of past-seeking confirmation”, “quantum soul talk” and so on ad erratum.

Books of this general ilk are particularly dangerous because they mingle sense and nonsense to produce a seductive cocktail of words. Wolf makes quantum theory appear to be a branch of mysticism whose purpose is to make precise the vague speculations of mystical Eastern philosophers. The authors of such works exploit remorselessly, with compelling words and phrases, that great deceiver of minds: the false analogy. The unsuspecting reader with no scientific background finds all the problems of life glibly answered by the quantum guru.

BLACK holes have been quiet of late. They may have played a pioneering part
in the popularisation of astronomy, but they require careful handling. They are
not photogenic and they may not even be black. What’s more, overindulgent
writing about their fantastic aspect gives them the same sort of mythological
status as the Bermuda Triangle.

So there is a lot to be said for the “10 per cent” solution adopted by Kitty
Ferguson in Prisons of Light. If you can do it 10 per cent better than
it’s been done before, then you’re getting somewhere. Just say what’s been said
before, but more clearly and simply. Then add something new. Ferguson’s strategy
succeeds. Here is an engaging low-level book about black holes that takes the
science seriously. It does not try to pack too much in, yet manages to give
explanations of important features of gravity in words and pictures.

Like a Thomas Hardy novel, the book begins with a tragedy: the death of a
star. Ferguson conducts a postmortem of very massive stars, explaining why we
think their death masks are the black-hole state, before exploring the
properties we expect these relics to possess.

A problem with this level of explanation is that subtleties occasionally get
lost. For example, the presentation of black holes as dense objects whose escape
velocity equals that of light doesn’t quite work. Escape velocity is the launch
speed required to escape all the way to infinity. Just as you can leave the
surface of the Earth without attaining escape velocity, so you can move as far
away as you like from the surface of a “planet” with an escape velocity equal to
light speed without exceeding that speed. Real black holes are not like this.
Nothing can leave their “surface” (the event horizon).

Another consequence of the account of black holes Ferguson gives, beginning
as it does with those that form from the collapse of massive stars, is that it
creates an impression that they are invariably solid objects of enormous
density. While they can be, they need not be. Black holes with a mass a billion
times as great as that of the Sun would have an average density less than that
of air. We could be passing through the event horizon of such a benign beast
without noticing anything amiss.

After a clear account of classical black holes and their gymnastics, Ferguson
tells the story of how Stephen Hawking overturned the traditional view that the
mass of a black hole could only increase by suggesting that its mass could
evaporate away as particles and radiation. She then considers the astronomical
evidence for black holes.

Ferguson recounts the thinking that led to the identification of binary star
systems as likely hosts of black holes. Here is a new story to tell. Many
complicated binary systems show telltale signs of harbouring a source of
gravitation that is too massive, yet too small in size, to be anything but a
black hole.

Ferguson also makes good use of pictures to explain why astronomers expect
collimated jets of energy to be ejected from black holes encircled by discs of
accreting material. She outlines what we understand of energy sources at the
cores of quasars and active galaxies.

New discoveries of gravitational lensing, the impact of the Hubble Space
Telescope, and future prospects for gravity waves close the show. She should
have ended here, but adds two less successful sections.

All in all, Ferguson succeeds in explaining the most important aspects of
black holes at a level that will be inviting to those with little or no prior
knowledge. Her writing is lucid, her analogies good. Just when you thought it
was all over, black holes are back.