Infinite Potential begins with a story by Bohm’s one-time student Dr David Schrum:

“It was a night and we were walking under the stars, a black sky. David looked up at the stars and said: ‘Ordinarily, when we look to the sky and we look at the stars, we think of the stars as objects far out and that they have space in between them. But there is another way we can look at it. We can look at the vacuum, the emptiness, as a plenum, as infinitely full rather than infinitely empty, and that the objects are like little bubbles – little vacancies – in that vast sea.’ So he had me look at the night sky in a different way – as one living organism.”

This conversation serves as a good introduction to Bohm’s most important theory – the idea of the implicate order – which, as the film goes on to demonstrate, has the potential to overturn our ideas about the world and about ourselves as radically as the heliocentric universe of Copernicus did in the seventeenth century.

As a theoretical physicist Bohm was driven by the desire to resolve the deep mysteries thrown up by quantum theory, and the need to reconcile it with the other great pillar of contemporary science, Einstein’s theory of relativity. But, as Paul Howard is keen to emphasise, Bohm’s scope was far wider than that. He was interested in the nature of thought and consciousness, and developed close relationships firstly with the Indian sage/philosopher Jiddu Krishnamurti and later the Dalai Lama, who called him his ‘science guru’. He also had a life-long concern with social and political change; he developed a new form of communication, called Bohm Dialogue, which aims to break through our collective modes of habitual thought, and spent time with the Blackfoot or Siksika Native Indian people, searching for a new form of language in which to express ideas in a more process-oriented way.

Although it concentrates upon the physics, these wider aspects of Bohm’s thought are also covered in the film, which brings together a remarkable group of people, including the Dalai Lama and artist Sir Antony Gormley, distinguished scientists such as Sir Roger Penrose, Basil Hiley and Yakir Aharonov, and philosophers such as Paavo Pylkkanen and Augusto Sabbadini. Paul never met Bohm but was introduced to his ideas by his long-time friend and biographer David Peat, founder of the Pari Centre for New Learning [/], and was inspired by them. The film is clearly a labour of love; he not only produced it, but also wrote it, directed it and performs the voice-over.

We spoke to Paul in his home in Dublin, where, due to the Covid-19 situation, he has been in lockdown. The film premiere took place on 22 June, in the middle of the crisis. We began by asking him how he managed in this difficult situation. “We were due to go to some film festivals and have a limited cinema release before pushing the film out to the big streaming broadcasters and territorial broadcasters like National Geographic, Discovery, the BBC etc., all of whom had expressed an interest. But suddenly we had to reconsider our options. Our distributors, Counterpoint Films, based in Los Angeles, arranged to screen the film worldwide, and so we set up a series of on-line events and seminars [/], which will continue through the autumn.”

So how has this worked? “Well actually, it has been extraordinary. To date, more than 400,000 people worldwide have watched the film, which is far more than would have done at festivals.”

Early Life and Exile

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These numbers reflect an exceptional degree of interest in a physicist working in a field which few of us can fully comprehend, and are all the more remarkable because Bohm died in relative obscurity. As the film explains, at the start of his career in the 1940s, he worked with the élite of the physics world – people like Albert Einstein, Niels Bohr and Robert Oppenheimer – at Princeton University, where the fundamentals of quantum mechanics were being thrashed out. He was considered one of the most promising physicists of his generation; he wrote a well-received textbook on quantum mechanics and did significant work on the behaviour of gas plasmas. Einstein called him his ‘spiritual son’, and wished to employ him as his assistant.

But then two things happened. Firstly, in the era of the McCarthy hearings, he was targeted because of a brief membership of the Communist Party (which he had joined, as his colleague Basil Hiley explains in the film, because he hoped to discuss the philosophy of Hegel!) and was called before the Congressional Committee. Refusing to give names of associates, he was arrested for contempt of Congress. Although he was subsequently released without charge, he lost his job, and had to leave the country to find work. This took him firstly to Brazil, then to Israel and the UK, where he worked at Bristol University and finally, in the years leading up to his death in 1992, at Birkbeck College in London.

Secondly, whilst in Brazil, he published a paper entitled ‘A Suggested Interpretation of Quantum Mechanics in Terms of “Hidden Variables”’.[1] This was a reformulation of quantum mechanics which attempted to address the fundamental indeterminacy expressed in the ideas of Niels Bohr, which at the time were becoming codified as ‘The Copenhagen Interpretation’. This paper, Paul explains in the film, would become a key component of Bohm’s intellectual legacy in the decades to come: “But in 1952, it sparked hostility and served to finish him in the eyes of the physics orthodoxy. He sent it for publication believing that it would act as a shock wave to physicists.”

But in fact he received no substantial response, either then or later. It was only years afterwards that he found out why. The film reveals that the paper was actively vetoed by Oppenheimer, then one of the most powerful figures in the physics world, having co-ordinated the war-time atomic bomb project at Los Alamos. Finding that there was no mathematical flaw in Bohm’s approach, Oppenheimer issued an instruction to his fellow scientists: “If we cannot disprove Bohm, then we must agree to ignore him.” This resulted in Bohm being effectively ostracised by major sections of the physics community for the rest of his life.

For anyone who retains a belief that science is an open-ended exploration of reality, this incident is truly shocking, especially as it was evident to those of us who knew Bohm that his exile was a source of deep sadness. Paul, however, thinks that there was an upside. “David was an extremely open-minded person, and I believe that this is the underlying reason why he had to move away from the élite scientists in Princeton during those dreadful McCarthy years. If one is sincere in one’s pursuits in life, sometimes you have to go your own way. I never knew David personally, but I have spoken to many people who did and it is clear that he was a very humble and modest person. But nevertheless, this is what he did – go his own way. So in a way you could say that Oppenheimer and the other physicists who went along with him did Bohm a favour. If he had not had to go into exile in Brazil, he may never have written that paper and could possibly have had a very safe career. And of course, this hidden variables paper that was discarded earlier on has now risen from the ashes, so to speak.”

Hidden Variables

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This ‘rising from the ashes’ forms one of the most engaging sequences in the film. The 1952 paper challenged one of the basic assumptions of orthodox quantum mechanics – that nothing could be said about the underlying processes governing quantum phenomena. Bohm and Bohr both acknowledged that the way in which a quantum particle manifests differently in different situations – appearing as either a wave or a particle depending on the form of measurement – indicates unity at a fundamental level. It means that the observer and the observed have to be treated as elements of a whole process rather than separate entities.

Bohr, however, believed that this underlying ‘wholeness’ could not be probed further or really understood; all that is possible is to develop equations to describe phenomena, and these, because of the indeterminacy expressed by Heisenberg’s uncertainty principle, use statistical methods to describe quantum behaviour. It was this aspect of the theory which led Einstein to famously remark: “God does not play dice.”

By contrast, Bohm’s paper proposed that the behaviours of quantum particles are not chance events, but are guided by what he called ‘pilot waves’. These cannot be observed but nevertheless they control a particle’s trajectory and can be mathematically expressed. Receiving no positive response to the notion, however, he moved on in the following decades to develop another – although related – theory which in his seminal 1980s publication he called the ‘implicate order’ [2] and in his posthumously published masterwork, co-authored with Basil Hiley, ‘an ontological interpretation of quantum mechanics’. [3]

Along the way he did some impressive work with Yakir Aharonov on the vector potential, which many people thought worthy of a Nobel Prize in its own right,[4] and through his teaching influenced a generation of young scientists. It was one of his lectures, for instance, that inspired the young John Bell to develop his famous Theorem [/], which led, in 1972, to the experiment on ‘non-locality’ – usually now called ‘quantum entanglement’ – in which quantum particles were shown to transmit information instantaneously, from one end of the universe to the other, across space and time.[5]

Whilst Bohm was caught up in these other projects, the 1952 paper was effectively consigned to the dustbin of history. However, in the 1970s, some of his PhD students at Birkbeck – Chris Philippidis and Chris Dewdney – resurrected it and began to develop it for a new generation. Instead of using the term ‘hidden variables’ they talked about the guiding pilot wave as ‘the quantum potential’, and, using the sophisticated computing technology that had become available in the intervening decades, were able to show that Bohm’s equations accounted for all the quantum phenomena described by the orthodox theory, including non-locality. They therefore proved his approach to be a viable alternative.

But Bohm’s theory has one big advantage over the standard approach: Dewdney was able to create a graphic simulation of the way in which the quantum potential guides the electron during the two-slit experiment, providing a means of conceiving what is really happening. This was radical. One physicist, shocked when seeing the simulations for the first time, called them ‘the hard porn of physics’ because, he said, “you shouldn’t be able to see this stuff”!

Some of these videos are included in Infinite Potential, with Chris Dewdney himself advising on the computer graphics. We mention to Paul how struck we have been by the visual effects in the film in general. “As a director,” he explains, “I see it as my job to make the physics as accessible as possible to a general audience. We were very concerned that the film should have high production values: good cinematography, a lovely sound track and so on. We created some very beautiful animations to portray these subtle quantum effects. Unfortunately, many of these had to be cut from the short version of the film; we originally made it to be 110 minutes in length, but then the distributors wanted it shorter, so we had to cut 38 minutes. This was very painful for me; we lost quite a bit of science, including the material on the Aharonov-Bohm effect and the section with Dr Leroy Little Bear on the Blackfoot language.”

The longer version, however, is available as ‘the directors cut’, and is being shown at selected events and conferences (click here [/] for information on upcoming events). It will also be released in full for broadcast later this year, and there is a possibility of it being adapted as a two- or three-part series. If this happens, Paul plans to add another part on Bohmian dialogue. “This was quite a big part of David’s life in the years before his death, and is essential to understanding how his theories find application at a political or social level. But there was so much to cover – David’s scope being so wide – that we could not fit it into the first version.”