Waving not drowning

Another of my reviews, this from WSJ

It is their house style that puts the “Mr” in!

Book Review: ‘The Perfect Wave’ by Heinrich Päs
Does the neutrino, the ‘outlaw’ particle that weighs less than one millionth of the weight of an electron, hold the secret to the universe?
John Gribbin
April 15, 2014 6:56 p.m. ET

Some science books are good because they tell you a lot about science. Some are good because they present their examples and argument in very well written prose. A few do both. “The Perfect Wave” is one of the few.

Heinrich Päs is a particle physicist who loves his work, and it shows. That work mainly has to do with the elusive particles known as neutrinos, which have very little mass and no electric charge, and which travel very nearly at the speed of light, scarcely deigning to interact with any other particles as they zip not only through the universe but also through the solid Earth (and your body as well). Mr. Päs dubs the neutrino the “outlaw” particle because ofits bizarre properties. Why should we bother with it? Well, for a start, “although every single neutrino weighs less than one millionth of the weight of the tiny electron . . . they are so abundant that altogether they contribute about as much mass to the universe as all the stars combined.”

A couple of years back, neutrinos made headlines when results from a European experiment suggested that they might actually travel faster than light (and therefore backward in time). The experiment turned out to be faulty—there was a loose cable somewhere. But Mr. Päs suggests, in what he confesses is a speculative extrapolation from the current standard model of physics, that neutrinos really might be able to travel in time.

Yet that is merely the denouement of his intriguing story, which starts out with the ancient Greeks and carries us smoothly forward through the 20th-century development of particle physics to the present day frontiers of respectable speculation. “The Perfect Wave: With Neutrinos at the Boundary of Space and Time” provides a conventional but well-presented introduction to the mysteries of quantum mechanics, including the obligatory mention of Schrödinger’s cat, which is both dead and alive at the same time. Quantum aficionados will recall that, in 1935, Erwin Schrödinger devised this “thought experiment” in which a cat in a sealed room will die if a radioactive atom decays but will remain alive if the atom does not decay. According to the quantum rules, it remains suspended in an either/or state until someone looks to see what is going on.

Like an increasing number of his contemporaries, Mr. Päs suggests that the best resolution to the puzzles of quantum theory (such as the mystery of Schrödinger’s dead-and-alive cat) lies in the so-called Many Worlds Interpretation, or the multiverse, in which all possibilities are realized. So, for example, there is one universe with a dead cat and one with a live cat—not a single reality in which the cat is dead and alive at the same time. These universes do not interact with one another, and there is no direct evidence to prove they exist. But the recent discovery of gravitational ripples from the dawn of time suggests to some cosmologists that the idea should be taken seriously, as these ripples are evidence for the theory that the universe expanded rapidly after the Big Bang. Mr. Päs explains various scenarios for such an “inflation,” including that of “eternal inflation, in which new baby universes keep popping up like bubbles out of nothing.”

Mr. Päs is careful to build up to multiverse theory gradually, via the ideas of string theory—the notion that what we think of as “particles” (such as the electron) are actually tiny loops of vibrating “string.” This requires the possibility that our three-dimensional universe(four-dimensional if you include time) is embedded in some set of higher dimensions—an explanation that attracts Mr. Päs, in no small measure because it “could protect time travelers from ludicrous paradoxes, and in this way make time travel a meaningful physics concept.”

You have to like a scientist who can admit to such a sentiment. And, indeed, the scientific discussion in “The Perfect Wave” is leavened by the author’s account of his own life as a young researcher, excited by new discoveries and struggling to get his own ideas recognized. We meet the physicists who work at research centers such as the European particle physics laboratory CERN, and we learn about the ups and downs of “postdoc” life: ups when traveling the world to conferences in exotic places and doing work you love; downs with appointments that last for only two years at a time, with low pay. But clearly, for people like Mr. Päs, the ups outweigh the downs.

Along the way “The Perfect Wave” introduces the reader to some of the key players in the neutrino story, including Ettore Majorana, a figure as mysterious as the particle itself. A close contemporary of Werner Heisen berg and Niels Bohr, he was a near-recluse who scribbled ideas and calculations on cigarette packets, then threw the packets away when he had finished, usually without bothering to publish his results. Majorana becameodder and odder, and on March 26, 1938, he disappeared, probably after boarding the Naples-Palermo ferry. But he took with him his passport and all his money, seemingly ruling out suicide.

I will leave it to Mr. Päs to explain the significance of Majorana’s work to the story of neutrinos and the significance of neutrinos to the story of time travel. But Majorana’s ideas still make waves today: They “could, for example, make the neutrino responsible for the fact that the universe consists of matter with barely any antimatter, or explain why neutrinos could convey information about a Grand Unified Theory of all particles and forces.” This, remember, is the sober, “responsible speculation” part of the story. If contemplating such possibilities is the sort of thing that appeals to your taste, I can highly recommend “The Perfect Wave” as a pleasant and provocative way to gain insight into the way physicists think, and into the way the universe (probably) works.

A divided life

Adapt from my latest contribution to the Literary Review

Half Life


Frank Close

Frank Close used to be a research physicist who wrote rather good books on the side. Latterly, his research activity has declined, and he has devoted rather more time to writing even better books. On the evidence of Half Life, which is undoubtedly his best book so far, it is a pity for us that he did not give up the day job sooner. No longer a physicist who writes, he is now a writer with a background in physics, in the same way that after “retiring” Dick Francis became a writer with a background in horse racing.

Indeed, the story told here, of the divided life of the Italian physicist Bruno Pontecorvo, could have formed the basis of a Dick Francis type of action thriller, or a John Le Carré scientific spy story. For the first (roughly) half of his life, up until 1950, Pontecorvo was a respectable and respected member of the physics community. By then, he had already had an adventurous life. Born in Italy, he worked with the nuclear pioneer Enrico Fermi in Rome, contributing to work on radioactivity which before long became vital in the design of nuclear reactors. This is one reason for the title of Close’s book, since the “half life” of a sample of radioactive material is the time it takes for half of the atomic nuclei in the sample to decay into other elements. In 1936, Pontecorvo moved to Paris to join the internationally renowned team working under Frédéric and Irène Joliot Curie, who had already won the Nobel Prize for their work.

Pontecorvo was very much a rising star in the physics firmament, but he was also politically active, among the left-wing community in Paris. In 1940, when the Germans invaded France, he was in double danger as a left-wing Jew, and soon also became an enemy alien when Italy joined the war. He managed to escape via Spain and Portugal to the USA (an odyssey in itself), where he applied his expertise in industry until being recruited into the British-Canadian nuclear project at Chalk River, a counterpart to the work on an “atomic pile” being undertaken by Enrico Fermi (another refugee from Fascism) and his team in Chicago. At this point, the plot begins to thicken. Unknown to the British, the American authorities were unhappy about Pontecorvo’s left-wing sympathies. But this did not stop him being a member of a team that visited Chicago to discuss the progress with Fermi’s nuclear reactor there, gleaning information of immense value to the British-Canadian project. And, perhaps, he was also passing information about nuclear reactor design (although not about nuclear weapons) to the Soviet Union.

After the war, Pontecorvo made ground-breaking contributions to the theory of neutrinos, and moved to Harwell, having become a British citizen, in January 1949. Everything seemed to be going swimmingly. But just a year later, while on a family holiday in Italy, Pontecorvo, together with his wife and children, disappeared. There is no evidence that this was pre-planned. Milk and papers had been cancelled for the duration of the holiday, but with instructions for deliveries to start again the day they were scheduled to return. Clothes were hanging in the wardrobes. The speculation was that the family had gone to the USSR, but this was only confirmed when Pontecorvo resurfaced there in 1955. But what had spooked him?

It seems that the CIA had firmed up their suspicions about Pontecorvo, although still without any real evidence, and had written to the British warning them not to trust him. The letter referred to “possible communist or pro-communist tendencies”, and named Pontecorvo along withy another physicist and a biologist. This was at the time Kim Philby, the notorious double agent, was the MI6 man in Washington, liasing with the CIA. Close infers that Philby tipped off Moscow, and Moscow tipped off Pontecorvo while he was in Italy and engineered his “escape”.

The irony is that without hard evidence Pontecorvo would never have been convicted in Britain. All the Americans had was a suggestion that Pontecorvo was at least a fellow traveller and was friendly with communists. Most probably, in Britain he would no longer have been allowed access to secret work, but could have taken up a post as a professor at a university. The only real evidence we have that Pontecorvo had been spying is the fact that he did defect. So his second “half life” began as a result of a misconception.

Close is able to describe the rest of his subject’s life and the details of the “escape” in detail, thanks to the availability of documents and interview subjects made possible by the collapse of the Soviet Union. Quite apart from the personal story of Pontecorvo, this gives a fascinating insight into science behind the Iron Curtain in the 1950s and 1960s, when researchers such as Pontecorvo had no choice but to publish in Russian language journals that were scarcely read in the West, and there was no internet or email. Because some of his most important work was overlooked as a result, Pontecorvo missed out on receiving a share of the Nobel Prize, which he thoroughly deserved for his work on neutrinos.

Close, of course, gives us a clear insight into the physics, without going into any depth that might frighten non-scientists. But that is what we have come to expect from him. The unexpected delight here is the enthralling insight into the life and times of a scientist, not just his scientific work. I hope this will not be a one-off. There are plenty of other potential subjects for such a treatment, not least Pontecorvo’s contemporary Klaus Fuchs. I live I hope.

John Gribbin is a Visiting Fellow in Astronomy at the University of Sussex

His latest book, Before the Big Bang, is available as a Kindle Single