Atomic by Jim Baggott (2009)

This is a brilliantly panoramic, thrilling and terrifying book.

The subtitle of this book is ‘The First War of Physics and the Secret History of the Atom Bomb 1939-49‘ and it delivers exactly what it says on the tin. At nearly 500 pages Atomic is a very thorough account of its subject – the race to develop a workable atomic bomb between the main warring nations of World War Two, America, Britain, France, Germany, Italy, Russia –  with the additional assets of a 22-page timeline, a 20-page list of key characters, 18 pages of notes and sources and a 6-page bibliography.

A cast of thousands

The need for a list of key characters is an indication of one of the main learnings from the book: it took a lot of people to convert theoretical physics into battlefield nuclear weapons. Every aspect of it came from theories and speculations published in numerous journals, and then from experiments devised by scores of teams of scientists working around the industrialised world, publishing results, meeting at conferences or informally, comparing and discussing and debating and trying again.

Having just read The Perfect Theory by Pedro Ferreira, a ‘biography’ of the theory of relativity, I had gotten used to the enormous number of teams and groups and institutes and university faculties involved in science – or this area of science – each containing numerous individual scientists, who collaborated and competed to devise, work through and test new theories relating to Einstein’s famous theory.

Baggott’s tale gives the same sense of a cast of hundreds of scientists – it feels like we are introduced to two or three new characters on every page, which can make it quite difficult to keep up. But whereas progress on the theory of relativity took place at a leisurely pace over the past 100 years, the opposite is true of the development of The Bomb.

This was kick-started when a research paper showing that nuclear fission of uranium might be possible was published in 1939, just as the world was on the brink of war (hence the start date for this book). From that point the story progresses at an increasing pace, dominated by a Great Fear – fear that the Nazis would develop The Bomb first and use it without any scruples to devastate Europe.

The first three parts of the book follow the way the two warring parties – the Allies and the Nazis – assembled their teams from civilian physicists, mathematicians and chemists at various institutions, bringing them together into teams which were assembled and worked with increasing franticness, as the Second World War became deeper and darker.

If the you thought the blizzard of names of theoretical and experimental physicists, mathematicians, chemists and so on in the first part was a bit confusing, this is as nothing compared to the tsunami of names of Army administrators, security chiefs, civil servants, bureaucrats and politicians who are roped in to create and administer the facilities which were established to research and build, first a nuclear reactor, then a nuclear bomb.

Baggott unfolds the story with a kind of unflinching factual pace which is extremely gripping. Each chapter is divided into sections, often only a page long, which explain contemporaneous events at research bases in Chicago, out in the desert at Los Alamos, in Britain, in German research centres, and among Stalin’s harassed scientific community. Each one of these narratives is fascinating, but intercutting them like this creates an almost filming effect of cutting from one exciting scene to another. Baggott’s prose is spare and effective, almost like good thriller writing.

The nuclear spies

And indeed the book strays into actual thriller territory because interwoven with the gripping accounts of the British, Russian, German and American scientists, and their respective military and political masters, is the story of the nuclear spies. I read Paul Simpson’s A Brief History of The Spy a few months ago and it gives good accounts of the activities of Soviet spies Klaus Fuchs, David Greengrass, Theodore Hall, as well as the Rosenbergs. But the story of their spying and the huge amounts of top secret information they handed over to the Russians is so much more intense and exciting when it is situated in the broader story of the nail-biting scientific, chemical, logistical and political races to build The Bomb.

German failure

As everyone knows, the Nazis were not able to construct a functioning bomb before they were militarily defeated in May 1945. But it wasn’t for want of trying, and the main impression from the book was the sense of vicarious horror from the thought of what they’d done if they had made a breakthrough in the final desperate months of spring 1945. London wouldn’t be here. I wouldn’t be here.

Baggott’s account of the German bomb is fascinating in numerous ways. Basically, once the leadership were told it wouldn’t be ready in the next few years, they didn’t make it a priority. Baggott follows the end of the war with a chapter on hos most of the German nuclear scientists were flown to England and interned in a farm outside Cambridge which was bugged. Their conversations were recorded in which they were at first smugly confident that they were being detained because they were so far in advance of the Allies. Thus they were all shocked when they heard the Allies had dropped an atom bomb on Japan in August 1945. At which point they began to develop a new line, one much promoted by German historians since, which is that they could have developed a bomb if they’d wanted to, but had morals and principles and so did all they could to undermine, stall and sabotage the Nazi attempt to build an A bomb.

They were in fact ‘good Germans’ who always hated the Nazis. Baggott treats this claim with the contempt it deserves.

Summary of the science

The neutron was discovered in 1932, giving a clearer picture of what atoms are made of i.e. a nucleus with at least one proton (with a positive electric charge) balancing at least one electron (with a negative charge) in orbit around it. Heavier elements have more than one neutron and electron (always the same number) as well as an increasing number of neutrons which give weight but have no electric charge. Hence the periodic table lists the elements in order of heaviness, starting with hydrogen with one proton and going all the way to organesson, with its 118 protons. Ernest Lawrence in California invented the cyclotron, a device for smashing sub-atomic particles into nuclei to see what happened. In 1934 Enrico Fermi’s team in Italy set out to bombard the nuclei of every known element with neutrons, starting with hydrogen (1) and going through the entire periodic table.

The assumption was that, by bombarding elements with neutrons they would dislodge one or two protons in each nucleus and ‘shift’ the element down the periodic table by one or two places. When the team came to bombard one of the heaviest elements, uranium, they were amazed to discover that the process seemed to produce barium, about half the weight of uranium. The bombardment process seemed to blast uranium nuclei in half. Physics theory, influenced by Einstein, suggested that a) this breakdown would result in the release of energy b) some of the neutrons within the uranium nucleus would not be required by the barium atoms and would themselves shoot out to hit other uranium nuclei, and so on.

  • The process would create a chain reaction.
  • Although the collapse of each individual atom would release a minuscule amount of energy, the number of atoms in such a dense element suggested a theoretically amazing release of energy. If every nucleus of uranium in a 1 kilogram lump was split in half, it would release the same energy as 22,000 tons of TNT explosive.

Otto Frisch, an Austrian Jewish physicist who had fled to Niels Bohr’s lab in Copenhagen after the Nazis came to power, heard about all this from his long-time collaborator, and aunt, Lise Meitner, who was with the German team replicating Fermi’s results. He told Bohr about the discovery. Frisch named it nuclear fission.

In early 1939 papers were published in a German science journal and Nature, while Bohr himself travelled to a conference in America. In the spring of that year fission research groups sprang up around the scientific world. In America Bohr realised anomalies in the experimental results were caused by the fact that uranium comes in two isotopes, U-235 and U-238. The numbers derive from the total number of neutrons and protons in an atom: U-238 has 92 protons and 146 neutrons; U-235 has three fewer neutrons. Slowly evidence emerged that it is the U-235 which breaks down. But it is much rarer than the stable U-238 and difficult to extract and purify. In March 1939 a French team summarised the evidence for nuclear chain reactions in a paper in Nature, specifying the number of particles released by disintegrated nuclei.

All the physicists involved realised that the massive release of energy implied by the experiments could theoretically be used to create an explosive device vastly more powerful than anything then existing. And so did the press. Newspaper articles began appearing about a ‘superbomb’. In April the head of physics at the German Reich Research Council assembled a group devoted to fission research, named the Uranverein, calling for the ban of all uranium exports, and for it to be stockpiled. British MP Winston Churchill asked a friend, Oxford physicist Frederick Lindemann, to prepare a report on the feasibility of a fission bomb. Soviet scientists replicated the results of their western colleagues but didn’t bring the issue to the attention of the authorities – yet. Three Hungarian physicists who were exiles from the Nazis in America grasped the military importance of the discoveries. They approached Einstein and persuaded him to write a warning letter to President Roosevelt, which was written in August 1939 though not delivered to the president until October. Meanwhile the Germans invaded Poland on 1 September and war in Europe began. At this point the Nazis approached the leading theoretical physicist in Germany, Werner Heisenberg, and he agreed to head the Uranverein, leading German research into an atomic bomb until the end of the war.

And so the race to build the first atomic bomb began! The major challenges were to:

  • isolate enough of the unstable isotope U-235 to sustain a chain reaction
  • to kick start the chain reaction somehow, not with the elaborate apparatus available in a lab, but with something which could be packed inside a contain (a bomb) and then triggered somehow
  • a material which could ‘damp’ the process enough so that it could be controlled in experimental conditions

From the start there was debate over the damping material, with the two strongest contenders being graphite – but it turned out to be difficult to get graphite which was pure enough – or ‘heavy water’, water produced with a heavier isotope of hydrogen, deuterium. Only one chemical plant in all of Europe produced heavy water, a fertiliser factory in Norway. The Germans invaded Norway in April 1940 and a spin-off was the ability to commandeer regular supplies from this factory. That is why the factory, and its shipments of heavy water, were targeted for the commando raid and then air raids dramatised in the war movie, The Heroes of Telemark. (Baggott gives a thorough and gripping account of the true, more complex, more terrifying story of the raids.)

Learnings

I never realised that:

  • In the end the Americans built the bomb because they were the only ones with enough resources. Although Hitler and Stalin were briefed about the potential, their scientists told them it would be three or four years before a workable bomb could be made and they both had more pressing concerns. The British had the know-how but not the money or resources. There is a kind of historical inevitability to America being the first to build a bomb.
  • But I never realised there were quite so many communist sympathisers in American society and that so many of them slipped across the line into passing information and/or secrets to the Soviets. The Manhattan Project was riddled with Soviet spies.
  • And I never knew that J. Robert Oppenheimer, the man put in charge of the facilities at Los Alamos and therefore widely known as the ‘father’ of the atom bomb, was himself was such a dubious character, from the security point of view. Well-known for his left-wing sympathies, attending meetings and donating money to crypto-communist causes, he was good friends with communist party members and was approached at least once by Soviet agents to pass on information about the bomb project. No wonder elements in the Army and the FBI wanted him banned from the very project which he was in fact running.

Hiroshima

The first three parts of the book follow in considerable detail the story from the crucial discoveries on the eve of the war, and then interweaves developments in Britain, America and the USSR up until the detonation of the two A-bombs over Hiroshima and Nagasaki on August 6 and 9, 1945.

  • I was shocked all over again to read the idea that, on the eve of the first so-called Trinity test, the scientists weren’t completely confident that the chain reaction might not spread to the nitrogen in the atmosphere and set the air on fire.
  • I was dazzled by the casual way military planners came up with a short list of cities to hit with the bombs. The historic and (by all accounts) picturesque city of Kyoto was on the list but it was decided it would be a cultural crime to incinerate it. Also US Secretary of War Henry Stimson had gone there on his honeymoon, so it was removed from the list. Thus, in this new age, were the fates, the lives and agonising deaths, of hundreds of thousands of civilians decided.
  • I never knew they only did one test – the Trinity test – before Hiroshima. So little preparation and knowledge.

The justification for the use of the bomb has caused argument from that day to this. Some have argued that the Japanese were on the verge of surrendering, though the evidence presented in Baggott’s account militates against this interpretation. My own view is based on two axioms: 1. the limits of human reason 2. a moral theory of complementarity.

Limits of reason When I was a young man I was very influenced by the existentialism of Jean-Paul Sartre and Albert Camus. Life is absurd and the absurdity is caused by the ludicrous mismatch between human claims and hopes of Reason and Justice and Freedom and all these other high-sounding words – and the chaotic shambles which people have made of the world, starting with the inability of most people to begin to live their own lives according to Reason and Logic.

People smoke too much, drink too much, eat too much, marry the wrong person, drive cars too fast, take the wrong jobs, make the wrong decisions, jump off bridges, declare war. We in the UK have just voted for Brexit and Donald Trump is about to become US President. Rational? The bigger picture is that we are destroying the earth through our pollution and wastefulness, and global warming may end up destroying our current civilisation.

Given all these obvious facts about human beings, I don’t see how anyone can accuse us of being rational and logical.

But in part this is because we evolved to live in small packs or groups or tribes, and to deal with fairly simple situations in small groups. Ever since the Neolithic revolution and the birth of agriculture led to stratified and much larger societies and set us on the path to ‘civilisation’, we have increasingly found ourselves in complex situations where there is no one obviously ‘correct’ choice or path; where the notion of a binary choice between Good and Evil breaks down. Most of the decisions I’ve taken personally and professionally aren’t covered by so-called ‘morality’ or ‘moral philosophy’, they present themselves – and I make the decisions – based purely on practical outcomes.

Complementarity Early in his account Baggott explains Niels Bohr’s insight into quantum physics, the way of ‘seeing’ fundamental particles which changed the way educated people think about ‘reality’ and won him a Nobel Prize.

In the 1920s it became clear that electrons, one of the handful of sub-atomic particles, behave like waves and like particles at the same time. In Newton’s world a thing is a thing, self-identical and consistent. In quantum physics this fixed attitude has to be abandoned because ‘reality’ just doesn’t seem to be like that. Eventually, the researchers arrived a notion of complementarity i.e. that we just have to accept that electrons could be particles and waves at the same time depending on how you chose to measure them. (I understand other elements of quantum theory also prove that particles can be in two places at the same time). Conceivably, there are other ways of measuring them which we don’t know about yet. Possibly the incompatible behaviour can be reconciled at some ‘deeper’ level of theory and understanding but, despite nearly a century of trying, nobody has come up with a grand unifying theory which does that.

Meanwhile we have to work with reality in contradictory bits and fragments, according to different theories which fit, or seem to fit, to explain, the particular phenomena under investigation: Newtonian mechanics for most ordinary scale phenomena; Einstein’s relativity at the extremes of scale, black holes and gravity where Newton’s theory breaks down; and quantum theory to explain the perplexing nature of sub-atomic ‘reality’.

In the same way I’d like to suggest that everyday human morality is itself limited in its application. In extreme situations it frays and breaks. Common or garden morality suggests there is one ‘reality’ in which readily identifiable ideas of Good and Bad always and everywhere apply. But delve only a little deeper – consider the decisions you actually have to make, in your real life – and you quickly realise that there are many situations and decisions you have to make about situations which aren’t simple, where none of the alternatives are black and white, where you have to feel your way to a solution often based in gut instinct.

A major part of the problem may be that you are trying to reconcile not two points of view within one system, but two or more incompatible ways of looking at the world – just like the three worldviews of theoretical physics.

The Hiroshima decision

Thus – with one part of my mind I am appalled off the scale by the thought of a hideous, searing, radioactive death appearing in the middle of your city for no reason without any warning, vaporising half the population and burning the other half to shreds, men, women and little children, the old and babies, all indiscriminately evaporated or burned alive. I am at one with John Hersey’s terrifying account, I am with CND, I am against this anti-human abomination.

But with another part of the calculating predatory brain I can assess the arguments which President Truman had to weigh up. Using the A-bomb would:

  1. End a war which had dragged on too long.
  2. Save scores of thousands of American lives, an argument bolstered as evidence mounted that the Japanese were mobilising for a fanatical defence to the death of their home islands. I didn’;t know that the invasion of the southern island of Japan was scheduled for December 1945 and the invasion of the main island and advance on Tokyo was provisionally set to start in march 1946. Given that it took the Allies a year to advance from Normandy to Berlin, this suggests a scenario where the war could have dragged on well into 1947, with the awesome destruction of the entire Japanese infrastructure through firebombing and house to house fighting as well, of course, of vast casualties, Japanese and American.
  3. As the US commander of strategic air operations against Japan, General Curtis LeMay pointed out, America had been waging a devastating campaign of firebombing against Japanese cities for months. According to one calculation some two-and-a-half million Japanese had been killed in these air attacks to date. He couldn’t see why people got so upset about the atom bombs.

Again, I was amazed at the intransigence of the Japanese military. Baggott reports the cabinet meetings attended by the Japanese Prime Minister, Foreign Minister and the heads of the Army and Navy, where the latter refused to surrender even after the second bomb was dropped on Nagasaki. In fact, when the Emperor finally overruled his generals and issued an order to surrender, the generals promptly launched a military coup and tried to confiscate the Emperor’s recorded message ordering the surrender before it could be broadcast. An indication of the fanaticism American troops would have faced if a traditional invasion had gone ahead.

The Cold War

And the other reason for using the bombs was to prepare for after the war, specifically to tell the Soviet Union who was boss. Roosevelt had asked Stalin to join the war on Japan and this he did in August, making a request to invade the north island (the Russians being notoriously less concerned about their own troop losses than the Allies). the book is fascinating on how Stalin ordered an invasion then three days later backed off, leaving all Japan to America. But this kind of brinkmanship and uneasiness which had appeared at Yalta became more and more the dominant issue of world politics once the war was won, and once the USSR began to put in place mini-me repressive communist regimes across Eastern Europe.

Baggott follows the story through the Berlin Airlift of 1949 and the outbreak of the Korean War (June 1950), while he describes the ‘second physics war’ i.e. the Russian push to build an atomic reactor and then a bomb to rival America’s. In this the Russians were hugely helped by the Allied spies who, ironically, now Soviet brutality was a bit more obvious to the world, began to have second thoughts. In fact Klaus Fuchs, the most important conduit of atomic secrets to the Russians, eventually confessed his role.

Baggott’s account in fact goes up to the Cuban Missile Crisis of October 1962 and it is so grippingly, thrillingly written I wished it had gone right up to the fall of the Soviet Union. Maybe he’ll write a sequel which covers the Cold War. Then again, most of the scientific innovation had been achieved and the basic principles established; now it was a question of engineering, of improving designs and outcomes. Of building bigger and better bombs and more and more of them.

The last section contains a running thread about the attempts by some of the scientists and politicians to prevent nuclear proliferation, and explains in detail why they came to nothing. The reason was the unavoidable new superpower rivalry between America and Russia, the geopolitical dynamic of mutually assured destruction which dominated the world for the next 45 years (until the fall of the USSR).

A new era in human history was inaugurated in which ‘traditional’ morality was drained of meaning. Or to put it another way (as I’ve suggested above) in which the traditional morality which just about makes sense in large complex societies, reached its limits, frayed and broke.

The nuclear era exposed the limitations of not only human morality but of human reason itself, showing that incompatible systems of values could apply to the same phenomena, in which nuclear truths could be good and evil, vital and obscene, at the same time. An era in which all attempts at rational thought about weapons of mass destruction seemed to lead only to inescapable paradox and absurdity.


Credit

Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 by Jim Baggott was published in 2009 by Icon Books. All quotes and references are to the 2015 Icon Books paperback edition.

Related links

The Perfect Theory by Pedro G. Ferreira (2014)

On page three of this book, astrophysicist Pedro G. Ferreira explains that part of what enthralled him as a student studying the theory of relativity was the personalities and people behind the ideas.

I felt that I had entered a completely new universe of ideas populated by the most fascinating characters. (p.xiii)

This is the approach he takes in the 14 chapters and 250 pages of this book which skip lightly over the technicalities of the theory in order to give us an account of the drama behind the discovery of the theory. Ferreira describes relativity’s slow acceptance and spread among the community of theoretical physicists, many of whom went on to unravel unexpected consequences from his equations which Einstein hadn’t anticipated (and often fiercely opposed). He shows how the theory was eclipsed in the middle years of the century by the more fashionable theory of quantum physics, then underwent a resurgence from the 1960s onwards, until Ferreira brings the story right up to date with predictions that we are trembling on the brink of major new, relativity-inspired, discoveries.

This book isn’t about the theory of relativity so much as the story of how it was devised, received, tested, studied and expanded, and by whom. It is ‘the biography of general relativity’ (p.xv).

Thus the narrative eschews maths and scientific formulae to focus on a narrative with plenty of human colour and characters. For example, early explanations of the theory are dovetailed with accounts of Einstein’s opposition to the Great War and the political attitudes of Sir Arthur Eddington, his chief promoter in Britain, who was a Quaker. A typically vivid and grabby opening sentence of a new section reads:

While Einstein was working on his theory of general relativity, Alexander Friedmann was bombing Austria. (p.31)

Some reviews I’ve read say that – following Stephen Hawking’s example in his A Brief History of Time (1988) – there isn’t a single equation in the book, but that isn’t quite true; there’s one on page 72:

2 + 2 = 4

is the only equation in the book – which I suspect is a joke. For the most part the ideas are explained through the kind of fairly simple-to-describe thought experiments (Gedankenexperimenten) which led Einstein to his insights in the first place – simple except that they are taking place against an impossibly sophisticated background of astrophysical knowledge, maths theories, weird geometry and complex equations.

Timeline

In 1905 Albert Einstein wrote a number of short papers based on thought experiments he had been carrying out in his free time at his undemanding day job working in the Berne Patent Office. The key ones aimed to integrate Newtonian mechanics with James Clerk Maxwell’s force of electromagnetism. His breakthrough was ‘seeing’ that space and time are not fixed entities but can, under certain circumstances, bend and curve. (It is fascinating to learn that Einstein’s insights came through thought experiments, thinking through certain, fairly simple, scenarios and working through the consequences – only then trying to find the mathematical formulas which would express essentially mental concepts. Only years later was any of it subjected to experimental proof.)

The book gives a powerful sense of the rivalry and jostling between different specialisms. It’s interesting to learn that pure mathematicians often looked down on physicists; they thought physicists too ready to bodge together solutions, whereas mathematicians always strive for elegance and beauty in the equations. Physicists, for their part, suspect the mathematicians of coming up with evermore exotic and sometimes bizarre formulas, which bear little or no relation to the ‘reality’ which physicists have to work with.

So the short or ‘special’ theory of relativity – focusing on mechanics and electromagnetism – was complete by around 1907. But Einstein was acutely aware that it didn’t integrate gravity into his model of the universe. It would take Einstein another ten years to integrate gravity into his theory which, as a result, is known as the general theory of relativity.

Ferreira explains how he was helped by his friend, the mathematician Marcel Grossman, who introduced him to the realm of non-Euclidean mathematics devised by Bernhard Riemann. This is typical of how the book proceeds: by showing us the importance of personal contacts, exchanges, dialogue between scientists in different specialities.

For example, Ferreira explains that the ‘Hilbert program’ was the attempt by David Hilbert to give an unshakable theoretical foundation to all mathematics. Einstein visited Hilbert at the university of Göttingen in 1915, because his general theory still lacked complete mathematical provenance. He had intuited a way to integrate gravity into his special theory – but didn’t have the maths to prove it. Eventually, by the end of 1915, in a process Ferreira describes as Einstein dropping some of his ‘intuitions’ in order to ‘follow the maths’, Einstein completed his general theory of relativity, expressed as a set of equations which became known as the ‘Einstein field equations’.

In fact the field equations were ‘a mess’. A set of ten equations of ten functions of the geometry of space and time, all nonlinearly tangled and intertwined, so that solving any one function by itself was impossible. The theory argued that what we perceive as gravity is nothing more than objects moving in the geometry of spacetime. Massive objects affect the geometry, curving space and time.

Almost before he had published the theory (in an elegantly compact three-page paper) other physicists, mathematicians, astronomers and scientists had begun to take the equations and work through their implications, sometimes with results which Einstein himself strongly disapproved of. One of the most interesting themes in the book is the way that Einstein himself resisted the implications of his own theory.

For example, Einstein assumed, on the classical model, that matter was spread evenly through the universe; but mathematicians pointed out that, if so, Einstein’s equations suggested that at some point the universe would start to evolve i.e. large clumps of matter would be attracted to each other; nothing would stay still; potentially, the entire universe could end up collapsing in on itself. Einstein bent over backwards to exclude this ‘evolving universe’ scenario from his theory by introducing a ‘cosmological constant’ into it, a notional force which pushed back against gravity’s tendency to collapse everything: between the attraction of gravity and the repellent force of the ‘cosmological constant’, the universe is held in stasis. Or so he claimed.

Ferreira explains how the Dutch astronomer Willem de Sitter was sympathetic to Einstein’s (gratuitous) cosmological constant and worked through the equations, initially to support Einstein’s theory, but in so doing discovered that the universe could be supported by the constant alone – but it would contain very little matter, very little of the stars and planets which we seem to see. Einstein admired the maths but abhorred the resulting picture of a relatively empty universe.

In fact this was just the beginning of Einstein’s theory running away from him. The Russian astronomer and mathematician Alexander Friedmann worked through the field equations to prove that the perfectly static universe Einstein wanted to preserve – and had introduced his ‘cosmological constant’ to save – was in fact only one out of many possible scenarios suggested by the field equations – in all the others, the universe had to evolve.

Friedmann explained his findings in his 1922 paper, ‘On the Curvature of Space’, which effectively did away with the need for a cosmological constant. His work and that of the Belgian priest, Georges Lemaître, working separately, strongly suggested that the universe was in fact evolving and changing. They provided the theoretical underpinning for what astronomers had observed and named the ‘de Sitter effect’, namely the observation, made with growing frequency in the 1920s, that the furthest stars and nebulae from earth were undergoing the deepest ‘red shift’ i.e. the light emanating from them was shifted down the spectrum towards red, because they were moving away from us. Even though Einstein himself disapproved of the idea, his theory and the observations it inspired both showed us that the universe is expanding.

If so – does that mean that the universe must have had a definite beginning? When? How? And could the theory shed light on what were just beginning to be known as ‘dwarf stars’? What about the bizarre new concept of ‘black holes’ (originally developed by the German astronomer Karl Schwarzchild, who sent his results to Einstein in 1916, but died later that year)?

What Einstein called ‘the relativity circus’ was well underway – and the rest of the book continues to introduce us to the leading figures of 20th century physics, astrophysics, cosmology and mathematics, giving pen portraits of their personalities and motivations and describing the meetings, discussions, conferences, seminars, experiments, arguments and debates in which the full implications of Einstein’s theory were worked out, argued over, rejected, revived and generally played with for the past 100 years.

We are introduced:

  • To Subrahmanyan Chandrasekhar who proposed a sophisticated solution to the problem of white dwarfs and how stars die – which was rejected out of hand by Eddington and Einstein.
  • To the Soviet physicist Lev Davidovich Landau who proposed that stars shine and burn as a result of the radioactive fission of tremendously dense neutrons at their core (before he was arrested for anti-Stalin activities in 1938).
  • To J. Robert Oppenheimer who read Landau’s paper and used its insights to prove Schwarzchild’s wartime idea that stars collapse into such a dense mass that gravity itself cannot escape, and therefore a bizarre barrier is created around the star from which light, energy, radiation or gravity can emerge – the ‘event horizon’ of a ‘black hole’.

These are the main lines of research and investigation which Ferreira outlines in the first quarter or so of the book up to the start of World War Two. At this point, of course, many leading physicists and mathematicians of all nationalities were roped into the massive research projects run in America and Germany into designing a bomb which could harness the energy of nuclear fusion. This had been thoroughly investigated in theory and in observations of distant galactic phenomena – but never created on earth. Not until August 1945, that is, when the two atom bombs dropped on Japan killed about 200,000 people.

Learnings

Some of the several fascinating things to learn from this mesmerising account are:

  • How often Einstein was wrong and wrong-headed, obstinately refusing to believe the universe evolved and changed, refusing to believe (therefore) that it had an origin in some ‘big bang’, and his refusal to accept the calculations which proved the possibility of black holes.
  • That although a great genius may devise a profound theory, in the world of science he doesn’t ‘own’ it – there is literally no limit to the number of other scientists who can probe and poke and work through and analyse and falsify it – and that the strangeness and weirdness of general relativity made it more liable than most theories to produce unexpected and counter-intuitive results, in the hands of its many epigones.
  • That after early successes, namely:
    • predicting the movement of the planets more accurately than Newton’s classical mechanical theory
    • showing that light really is bent by gravity when this phenomenon was observed and measured during a solar eclipse in 1919
    • inspiring the discovery that the universe is expanding
  • the theory of relativity was increasingly thought of as a generator of bizarre mathematical exotica which had little or no relevance to the real world. We learn that ambitious physicists from the 1930s onwards preferred to choose careers in the other great theoretical breakthrough of the 20th century, quantum physics. Quantum could be tested, experimented with and promised many more practical breakthroughs.

Almost everyone’s attention was elsewhere now, enthralled by the triumph of quantum physics. Most of the talented young physicists were focusing their efforts on pushing the quantum theory further, looking for more spectacular discoveries and applications. Einstein’s general theory of relativity, with all its odd predictions and exotic results, had been elbowed out of the way and sentenced to a trek in the wilderness. (p.65)

  • And so that Einstein, now safely ensconced in the rarefied atmosphere of the Institute for Advanced Studies in Princeton, New Jersey, dedicated the last thirty years of his life (he died in 1955) to an ultimately fruitless quest for a ‘Grand Unified Theory’ which would combine all aspects of physics into one set of equations. He was, in the 1940s and 50s, an increasingly marginal figure – yesterday’s man – while the world hurried on without him. He died before the great revival of his theory in the 1960s which the second part of Ferreira’s book chronicles.

Visualisation

Again and again Ferreira shows how the researchers proceeded – or summarises the differences between their approaches and results – in terms of how they visualised the problem. Thus Schwarzchild’s vision of a relativistic universe described a spacetime that was perfectly symmetric about one point; whereas 40 years later, in 1963, New Zealander Roy Kerr modeled a solution for a spacetime that was symmetric about a line (p.121). A different way of visualising and conceiving the problem, which led to a completely different set of equations, and completely different consequences.

Other scientists take an insight like this, a new vision with accompanying new mathematics, and themselves subject it to further experimental modeling. The Soviet physicists Isaak Khalatnikov and Evgeny Lifshitz took Oppenheimer and Snyder’s 1930s model of a star collapsing – which assumed the shape of the star to be a perfect sphere – and modeled what happened if the star-matter was rough and unequal, like the surface of the earth. In this model, different bits collapsed at different rates, creating a churning of space time and never achieving the perfect collapse into a singularity modeled by Schwarzchild 60 years earlier or by Kerr more recently. This Soviet model was itself disproved by Roger Penrose, who had spent years devising his own diagrams and maths to model spacetime, and submitted a paper in 1965 which proved that ‘the issue of the final state’ always ended in singularities (pp.123-125).

And that is how the field progresses, via new ways of seeing and modeling. One revealing anecdote is how, at a conference in the 1990s on the newly hot topic of ‘dark matter’, one presenter put up a slide listing over one hundred different models for how dark matter exists, is created and works (p.192), all theoretical, derived from different sets of equations or observations, all awaiting proof.

It is not only the complexity of the subject matter which makes this such a daunting field of knowledge – it is the sheer number and variety of theories, ancient and modern, which its practitioners are called on to understand and sift and evaluate and which – as the first half makes plain – even the giants in the field, Einstein and Eddington, could get completely wrong.

The 1960s and since

In Ferreira’s account the 1960s saw a great revival of the theory of general relativity to explain the host of new astronomical phenomena which were being discovered and named – joining black holes and dwarf stars were pulsars, quasars and so on – as well as new theoretical micro-particles, like the Higgs boson. Kip Thorne called the 60s and 70s the Golden Age of Relativity, when the theory provided elegant solutions to problems about black holes, dark energy and dark matter, singularities and the Big Bang.

Over the past forty years or so new theories have arisen which take and transcend general relativity, including string theory (which rose to prominence in the 1980s but has since fallen into unpopularity) and supersymmetry (which invokes up to six extra dimensions in its quest for a total theory), loop quantum theory (where reality is comprised of minute loops of quantum gravity which bind together like chainmail), spin networks (frameworks like a children’s climbing frame, devised by Roger Penrose), Modified Newtonian Dynamics (or MOND) or a new theory to rival Einstein’s named the Tensor-Vector-Scalar theory of gravity (TeVeS).

When Ferreira and colleagues undertook a review of theories of quantum mechanics they discovered there are scores of them, ‘a rich bestiary of gravitational theories’ (p.221).

The great ambition is to incorporate quantum gravity into general relativity in order to produce a grand unified theory of everything. Although clever people bet this would happen before the end of the 20th century, it didn’t. 17 years later, we seem as far away as ever.

Thirty years after Stephen Hawking predicted the end of physics and then unleashed his black hole information paradox on an unsuspecting world, there isn’t an agreed-upon theory of quantum gravity, let alone a complete unified theory of all the fundamental forces. (p.205)

Ferreira draws together various developments in theory at the sub-atomic level to conclude that we may be on the brink of moving beyond Einstein’s vision of a curving spacetime: the real stuff of the universe is, depending on various theories, a bubbling foam of intertwining strings or structures or membranes or loops – but certainly not continuous. Newtonian mechanics still work fine at the gross level of our senses; it is only at extremes that Einstein’s theories need to be evoked. Now Ferreira wonders if it’s time to do the same to Einstein’s theories; to go beyond them at the new extremes of physical reality which are being discovered.

Notes

The deliberate non-technicality of the text is compensated by 18 pages of excellent notes, which give a chatty overview of each of the chapter topics before recommending up-to-the-minute websites for further reading, including the websites and even Facebook groups for specific projects and experiments. And there is also a detailed bibliography of books and articles.

All in all this is an immensely useful overview of the ideas and debates in this field.


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