Can a single scientist influence dozens fields of knowledge and application, not just in his time but also in the future? For the science writer Ananyo Bhattacharya, the answer is yes. As he said in his book “The man from the future”,  «[…] To fully understand the intellectual currents running through our century – from politics to economics, technology to psychology – one has to understand von Neumann’s life and work in the last».

“The man from the future. The visionary life of John von Neumann,” was originally published in the UK in October 2021 and recently in Italy (“L’uomo venuto dal futuro. La vita visionaria di John von Neumann”, 2023, Adelphi, translation. L. Civalleri). Bhattacharya has a background as a physicist, was a researcher in the medical field and then landed in journalism, working also for Nature and The Economist.  We spoke with him about this incredibly brilliant scientist and his enduring scientific legacy.

Where and when did you “meet” John von Neumann?  

I first started coming across him consciously about ten years ago, when I was a science correspondent at The Economist. Von Neumann’s name just kept popping up in weirdly different circumstances: whether we were covering quantum mechanics or technology, AI or computer science, he seemed to have made foundational contributions to all these fields; while talking about Nobel prizes awarded to game theorists, again it turned out von Neumann had essentially invented the field. Even in articles with a historical-political slant, related to the Cold War and nuclear strategy, his name came up because he was involved in the Manhattan Project.¹

I started wondering – just in the back of my mind, I’d been mulling over various book ideas – whether there had been a book about him. There was indeed a biography from 30 years ago by Norman Macrae, who, coincidentally, was also an editor of The Economist. However, it was quite old and very much focused on his personal life. Macrae wasn’t a science journalist; he included a nice section on game theory in the book, but the rest of the scientific topics were very vague.  I wanted to write a different kind of book.

John_von_Neumann

Ananyo-Bhattacharya

One day I came home and started randomly picking popular science books off my shelf. I think I picked out about 10 or 15 of them and von Neumann’s name was in the index of about half of them. It was crazy: they spanned very different fields, from neuroscience to economics models, from quantum physics to evolutionary biology, and von Neumann had influences all of them.  And then I realised that von Neumann is been with me in for most of my life: I studied computer science at high school, so we must have encountered the von Neumann architecture, and then I studied physics, where we inadvertently used his formulation of quantum mechanics, and my best friend studied economics, and he was constantly going on about game theory. It took me time to discover all these connections, but then I went from there.

Despite his various contributions to modern science, von Neumann is very underrepresented in popular science, but now it seems he’s starting to be more well-known. Why do you think this is happening?

Flux chart. Goldstine, Herman Heine, and John Von Neumann, 1947

Von Neumann’s name is mentioned more often now than any time in the past fifty years, and that is strange considering he died back in 1957. Now there’s almost a cult around his genius. Why are we hearing more about him now than 30 or 40 years ago? My answer to that question is that he seeded a lot of modern science and technology, and that’s why the book is called “The man from the future”. He didn’t complete all the things he seeded, but in doing so, he showed this remarkable vision, and other people then picked up those ideas and ran with them. And a lot of his contributions are still unknown, and maybe others are yet to come.

For example, he has never been recognized, as I think he should be, as a godfather of the open-source movement. Without von Neumann putting all these progress reports out there from his computer project and without Goldstein circulating the EDVAC report, computing would have taken a very different path, and arguably, it would have set us decades behind where we are now. A few companies would have had a monopoly on computers and so forth.

In the book, you create a scenario in which von Neumann’s life and scientific works unfold : you describe his life in the context of the era and the fertile scientific community in which von Neumann’s ideas developed together with the work of other scientists. What led you to choose this approach?

I tried to write the book I would want to read: I think quite a few of us physics-minded people are not really that into personal stories, like what a genius had for breakfast or how badly they treated their friends, family, or partners. I didn’t find evidence that von Neumann was a terrible human being – many of his friends and their wives praise him to the skies and talk about what a nice person he was.

Moreover, I have always been much more interested in books about ideas than about a single person. When I was young, I really appreciated the book “The Moral Animal” by the American journalist Robert Wright. Wright uses Darwin’s life as a plank to talk about evolutionary psychology. For “The man from the future” the idea was to talk about technology and science in the 20th century through the lens of von Neuman’s life. He seems to be present at almost every important juncture in science in the 20th century!

Lastly, there is this trope on geniuses which I thought was going out of fashion, but there’s a lot of still about: “hero worship”. But science is not just about one person changing everything. And even with von Neumann, who arguably did so much to seed the 21st century, other people had to develop his ideas to maturity . People like Grete Herman, an extraordinary physicist philosopher who first recognised a potential problem in von Neumann “no hidden variables theorem” (chapter 3). And also Klári Dán, von Neumann’s second wife: some of her small contributions were known, but recently historians have discovered that she wrote the first truly modern computer program.  I could talk about people like that partly because of the way that the book is structured, reflecting the fact that science is collaborative, and many people have contributed to it.

Von Neumann was a mathematician, but in his life and work he continues to move between pure math and application.

I think today the cultural role of mathematics is under-appreciated. This year, two Nobel prizes in physics were awarded to artificial intelligence, but in both cases the key point is the mathematics behind artificial intelligence, and it is relatively new mathematics, thirty or forty years old.

In this, too, we are again witnessing von Neumann’s prediction: the time it takes for mathematics and theoretical physics to get to applications is decreasing. Today, that window is narrowing again, and we are bringing mathematics into applications and society at an ever-faster rate – a phenomenon he called ‘the singularity’.

Von Neumann’s contributions in various fields are those of a refined mathematician of the highest order. What did you find most difficult to explain?

I tried really hard with von Neumann’s mathematics, and part of the reason was that I failed my first-year maths exam as a physics student!

Theory of games and economic behavior, by J. von Neumann and O. Morgenstern, 1947

As someone who studied physics, I thought I understood quantum mechanics, or at least knew enough to be able to get to grips with his contributions. But the problem is that von Neumann laid the mathematical foundations of quantum mechanics. Physicists usually don’t delve that far into the foundations of quantum, and in particular we take the formulation in Hilbert space totally for granted (chapter 3): maybe that’s why von Neumann name basically doesn’t come up in undergraduate physics lectures. But when you start digging into the history, you find out that, actually, his work is the bedrock of even modern quantum mechanics, and it’s not easy at all.

Game theory (chapter 6) was also really difficult because I don’t have a background in economics, and it was also challenging figuring out his model of dynamic equilibrium and its place in the history of economics. In mathematical logic, I had to understand the whole foundational questions for Hilbert and what Gödel did.  I had to go through various books on Gödel’s work to extract what was relevant to von Neumann’s way of thinking about computing and our modern way of thinking about computing. I was very flattered to find that one of the reviewers of the book, Stephen Budiansky, who had actually written fairly recent biography of Gödel, said my description of the incompleteness theorem was the best he’d ever read (chapter 5).

For this theme in particular I would like to mention the help of Jeremy Grey, a brilliant historian of math, emeritus from Open University. In other areas I was flying solo, and I found very clever academics I thanked in the book who were well versed in foundations and put me right about various things.

What do you think are the most important elements of von Neumann’s legacy?

The first is, of course, the von Neumann architecture for programmable computers, which we still use today. Plus, his decision to ensure everything was in the public domain – that I think has had an enormous impact.

The second is his contribution to game theory, in particular to utility theories. That has given us incredible insights both in economics and in biology. It is a very useful construct, but it can also be very damaging, leading us to think of everything as a market and forget about the human component.

There’s, of course, the legendary essay about the computer in the brain, where he compares computers and brains for the first time in a way that is still relevant today. That was the first bridge between neuroscience and computing, which was at the heart of serious thinking about artificial intelligence. He didn’t directly contribute to AI, but to compare brains and computers in this way had never been done.

Lastly, there is the theory of self-reproducing automata: his proof that machines can reproduce and evolve. I think it is something still for the future, but we will start seeing some of the consequences of that soon.

¹ the cover image shows Oppenheimer and von Neumann at Los Alamos photographed by Alan Richards (courtesy of AIP Emilio Segrè Visual Archives). The Hungarian scientist contributed significantly to the development of the American atomic bomb in the Manhattan Project, a contribution that made him a rather controversial figure in public opinion.