Chapter 12

For a decade after his son’s execution on 7 April 1560, Jerome’s life spirals into chaos. The first three years are perhaps the gentlest on him. At first, he feels vindicated by the strange fates that befall those who condemned Giovanni. The president of the court has to feign his own death to avoid prosecution for his wife’s murder. A senator drowns after falling from a bridge. Another senator contracts phthisis, coughs up a lung, and dies. Evangelista, the Seroni family’s patriarch, is jailed, stripped of his position as a debt collector, and becomes a beggar. The prison governor is sacked and is similarly forced to beg on the streets. The prosecuting counsel loses a son to smallpox and a jurisconsult who gathered evidence against the Cardanos is jailed for corruption. ‘Of all those who brought accusation against my son not one escaped without some terrible calamity — being either smitten or destroyed,’ Jerome recalls.

Soon after all this, perhaps because of it, Jerome is greeted everywhere with suspicion. He still holds academic positions in Milan and Pavia, but he has become someone to avoid. ‘As I walked about the city men looked askance at me; and whenever I might be forced to exchange words with anyone, I felt that I was a disgraced man.’ Aware of the atmosphere, he withdraws from society. ‘I had no notion what I should do, or where I should go. I cannot say whether I was more wretched in myself than I was odious to my fellows.’

Jerome is soon convinced everyone in Milan is plotting to kill him. A return to Pavia does nothing to relieve his fears. He becomes a wanderer. It is a time he will choose not to look back upon when he writes his memoirs. Others make mention of seeing him in Padua, Milan, Bologna, and Pavia, but Jerome leaves no record of what he did in those cities or what impels him to move between them. He writes: terrible ravings, most of them, philosophical volumes strewn with nonsensical rants and asides. But there are gems, too, in the form of geometry, philosophical, and medical textbooks that will be the standard texts for decades to come. His readers will include Johannes Kepler, Johann Wolfgang von Goethe, and William Shakespeare. Scholars of the Bard have even identified an English translation of Consolation, Jerome’s three volume meditation on dealing with tragedy and disappointment, as the book Hamlet carries during the soliloquy that begins ‘To be or not to be …’

POLONIUS: What do you read, my lord?

HAMLET: Words, words, words.

What words? ‘In holy scripture, death is not accounted other than sleep, and to die is said to sleep,’ says Jerome in Consolation. ‘Seeing, therefore, with such ease men die, what should we account of death to be resembled to anything better than sleep…’ Hamlet, for his part, says, ‘To die, to sleep / — no more — and by a sleep to say we end / The heartache and the thousand natural shocks / That flesh is heir to …’

I could cite more examples, none entirely conclusive. But in 1807, Francis Douce, Keeper of Manuscripts in the British Museum, said, ‘Whoever will take the trouble of reading the whole of Cardanus as translated by Bedingfield will soon be convinced that it had been perused by Shakspeare.’ Six years later, Joseph Hunter, author of New Illustrations of the Life, Studies, and Writings of Shakespeare, cited passages of Jerome’s Consolation that ‘seem to approach so near to the thoughts of Hamlet that we can hardly doubt that they were in the Poet’s mind when he put [certain speeches] into the mouth of his hero’.

Anyway, all that is in the future. In the present, Jerome must live with a debilitating paranoia. Wooden beams and lead weights, he believes, have been balanced above doors so as to fall on his head. At mass, he thinks that the choirboys are whispering plans to poison the wicked old doctor. This, he remembers, for he writes it in a chapter of his autobiography entitled ‘Perils, Accidents, and Manifold, Diverse, and Persistent Treacheries.’ In the end he outlives all his would-be assailants: ‘all who sought my life perished,’ he says. He cannot avoid calamity forever, though.

As 1563 draws to a close, the Milanese College of Physicians withdraws his right to teach. Jerome is accused, by numerous witnesses and in sworn statements, of sodomy and incest. There is no trial, just a sentence. Now, aged sixty-three, he is an exile from Milan. ‘Reduced once more to rags, my fortune gone, my income ceased, my rents withheld, my books impounded, my only companions prejudice and calumny,’ he writes. He resides in a Padua workhouse for a time. He is permitted to treat plague victims at a monastery in nearby Gallarate, but no other work is forthcoming — and the shadow of the Inquisition is looming larger. Across Europe, thinkers and writers are being arrested, questioned, and sometimes tortured and executed in an attempt to quell the growing tide of dissent against the Church. These days, if you have published novel, provocative ideas, you can be sure they will have been read by the Inquisitors. And if you are without friends or money, you are unlikely to survive their attention unscathed.

ψ

The spirit of the Inquisition has never been fully extinguished, as David Bohm would testify if he were still among us. During the latter part of World War II, when he was a graduate student at the University of California, Berkeley, Bohm’s PhD supervisor, J Robert Oppenheimer, recruited him into the newly formed effort to build an atomic bomb. Bohm’s contributions to the Manhattan Project were so valuable that they were immediately classified and Bohm was shut out, not even being allowed to write his own PhD thesis. He did get his PhD, though, after insisting that Oppenheimer vouch for the quality of his work.

By 1950, Bohm was working with Einstein at Princeton, where his past came back to haunt him. Early in his PhD studies he had joined a trade union and, briefly, a couple of communist groups. Those communist associations, coupled with the national security implications of his PhD work, made him a target for Senator Joe McCarthy’s crusade against un-American activities.

Bohm refused to answer questions, and refused to name anyone that the McCarthyists should investigate. He was arrested. By the time he was acquitted, he had been suspended from Princeton. In 1951, unemployable in the United States, Bohm took a job in Brazil. The US authorities then confiscated his passport and he was forced to apply for Brazilian citizenship. It was as a Brazilian that he travelled to England and began a long career as a professor of theoretical physics at Birkbeck College in London. There, he successfully applied for a British passport. Then, in 1986, he won back his American citizenship in a legal battle with the US government.

Nothing in that long and painful saga distracted David Bohm from physics. He made significant contributions in a variety of areas, but it is for his interpretation of quantum physics that he is best known. In 1952, Bohm published a seminal paper that is now seen as a complementary, but independently derived, version of work begun decades before — and then abandoned — by Louis de Broglie.

Let’s go back to the experiment where we fire those quantum arrows through those slits and get a weird pattern. While the Copenhagenists would say the arrows have no definite position or momentum until they hit the target, de Broglie formulated another idea, written up in his 1924 dissertation. He brought it up again when he gave a talk in October 1927, at the same meeting where Einstein and Bohr had their famous debates over quantum theory. In his talk, he spoke about the ‘théorie de l’onde pilote’ — pilot wave theory.

According to de Broglie, each photon fired at the double slit exists as a real object. He suggested it has a definite position and momentum at all times. What you can’t know is the initial position. And since the initial position would be what you combine with the momentum to give you the final position, you can’t know the final position in advance, explaining the apparently random outcomes of each measurement.

Because it is a real object, with a well-defined position, the photon can pass through only one of the slits. However, its trajectory is guided by a ‘pilot wave’, in much the same way that a ferry entering a treacherous harbour is guided by a pilot boat. This pilot wave is also real and has properties that are a reflection of the wave function in the Schrödinger equation.

Because of this link to the Schrödinger equation’s wave function, although the particle will only pass through one of the slits, there is still a final distribution of particles determined by an interfering wave. That means the major consequence of interference — the strange clumping at certain points on the target and absence at others — will occur.

Eventually, de Broglie abandoned his idea and became a Copenhagenist. It wasn’t that the pilot wave theory was particularly flawed; it was just that Bohr was probably too powerful and charismatic a figure to resist. So the pilot wave theory sank.

In 1952, however, it resurfaced in the hands of David Bohm. Bohm’s idea of an invisible, undetectable pilot wave was roundly criticised, but a man who had survived the McCarthy witch hunts was not easily put off. Having overcome the most heinous character assassination of the era, he could take a little heat. And so he stuck to his guns, suggesting we needed to look at quantum experiments in a different way. In a 1952 paper, published in Physical Review, he said, ‘the history of scientific research is full of examples in which it was very fruitful indeed to assume that certain objects or elements might be real, long before any procedures were known which would permit them to be observed directly.’ In other words, why shouldn’t there be an as-yet-undiscovered pilot wave?

Of course, we must avoid postulating a new element for each new phenomenon. But an equally serious mistake is to admit into the theory only those elements which can now be observed … In fact, the better a theory is able to suggest the need for new kinds of observations and to predict their results correctly, the more confidence we have that this theory is likely to be good representation of the actual properties of matter and not simply an empirical system especially chosen in such a way as to correlate a group of already known facts.

So far, so good, perhaps. But there are two problems. The first is that, in order to get the predictions right about the interference effect and the ultimate distribution of the photons at the detector, you have to work backwards from the final result.

The second problem is that Bohm’s pilot wave is odd — in a way that physicists call ‘nonlocal’. This means that the properties and future state of our photon are not determined solely by the conditions and actions in its immediate vicinity. The photon’s pilot wave and the photon’s wave function are linked to the wave function of the much, much larger system in which they sit — the wave function of the whole universe, effectively. So our photon can be instantaneously affected by something that happens half a universe away.

Many physicists — most physicists — are not happy about allowing this nonlocal action. After all, such action is prohibited by Einstein’s special theory of relativity, which says an influence can’t travel faster than the speed of light.

On the plus side, it does give us an explanation for entanglement-based phenomena. And it’s not clear that accepting Bohmian mechanics is any worse than shoehorning entanglement into a relativity-friendly physics. Many fine physicists are certainly happy to talk in terms of Bohmian mechanics. In Vienna, for instance, an experimenter called Aephraim Steinberg explained his experimental results from a Bohm-eyed view; this, he says, is the easiest way to think about it. What Steinberg presented was a picture showing the trajectories of photons as they pass through the double slit apparatus. In the Copenhagen interpretation, remember, this is impossible because the photons have no meaningful existence before they are detected. Without an existence, they can’t logically have a trajectory.

So how did Steinberg come up with the photons’ trajectories? The answer is, by using Yakir Aharonov’s weak measurement. All things are indeed connected.

The de Broglie-Bohm interpretation of quantum physics, as it is now known, is not popular. Only one venerated physicist has ever really championed it: John Bell, the Irishman who came up with the test for the existence of entanglement. Here’s what Bell had to say:

While the founding fathers agonized over the question ‘particle’ or ‘wave’, de Broglie in 1925 proposed the obvious answer ‘particle’ and ‘wave’. Is it not clear from the smallness of the scintillation on the screen that we have to do with a particle? And is it not clear, from the diffraction and interference patterns, that the motion of the particle is directed by a wave? De Broglie showed in detail how the motion of a particle, passing through just one of two holes in screen, could be influenced by waves propagating through both holes. And so influenced that the particle does not go where the waves cancel out, but is attracted to where they cooperate. This idea seems to me so natural and simple, to resolve the wave-particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored.

Bell felt de Broglie-Bohm was a better bet than anything the Copenhagenists had to offer. They had elevated the issue of measurement to the status where it was fundamental to the subject without ever making clear what it actually entailed. ‘The concept of “measurement” becomes so fuzzy on reflection,’ Bell said, ‘that it is quite surprising to have it appearing in physical theory at the most fundamental level … does not any analysis of measurement require concepts more fundamental than measurement? And should not the fundamental theory be about these more fundamental concepts?’

Bell is widely venerated. Go to quantum physics conferences and his name comes up again and again, with some people quoting from his writings as if from scripture. He has the advantage, from the fame perspective, of having died suddenly and relatively young. A cerebral haemorrhage took him out of the blue in 1990, aged just sixty-two. But even his influence is not enough. When it comes to quantum interpretations, the Copenhagenists appear to have won the day. How? By sheer weight of personality.

Niels Bohr, in particular, was so influential that he controlled much of the funding available for quantum research. He was also a likeable character: people enjoyed his company, craved his approval, and tended to bow to his way of thinking. Too little is made of the importance of personality in science. Some have called Bohr a bully, but unfairly, I think: he was simply persistent in arguments and reluctant to change his mind. In one lengthy discussion he reduced Werner Heisenberg to tears. In another, Schrödinger fell ill while staying at Bohr’s house, took to his bed, but was still harangued by his host, who sat on the edge of the bed and continued their argument.

ψ

‘One man can change everything,’ Jerome says, looking around his cell.

I assume he is thinking of Nicolo Tartaglia. ‘Yes,’ I say. ‘It is astonishing what The Stammerer has done to you.’ My eyes burn through the gloom of the cell, aching with pity for poor Jerome. Tartaglia, his every action toxic with malice, has arranged for the full weight of the Holy Church to fall on Jerome. ‘He has finally wreaked his revenge.’

Jerome looks at me, puzzled. ‘I don’t think so,’ he says.

My eyes narrow in protest. ‘Yes. It was Tartaglia who alerted the authorities, who oversaw your arrest. With your son. Aldo traded your freedom for a post with the Inquisition.’

‘What makes you think that?’

‘I read it. In a book by a journalist called Alan Wykes.’

Jerome shakes his head. ‘I can believe it of Aldo,’ he says. ‘Aldo would do all you suggest, I agree.’ Jerome’s eyes are narrow, staring intently toward me as if attempting to diagnose my mental state. I can feel that something is wrong.

‘But?’

‘But Tartaglia has been dead for more than a decade.’

I don’t know what to say.