simplicissimusrex

Yes! This is what struck me about him too! When you think about other mathematical geniuses they were often quite strange characters (Paul Erdős springs effortlessly to mind). Some said that this was a facade and I suppose to an extent it was--with a brain like that, von Neumann was often quite isolated from other humans. But he genuinely did seem to enjoy parties and loud music, bad jokes and naughty limericks. I think his upbringing had a hand in this--but it's also key to his interest in applying maths to problems in the real world. He wasn't ever going to be happy in an ivory tower.

Yes I totally agree. I must say that on this point, I lean heavily in my book on 'ENIAC in Action' by Haigh and colleagues. But as I was writing it became clear to me that von Neumann was uniquely well positioned to help birth the modern computer. So you have his work on mathematical logic during the foundational crisis, the fact that he nearly anticipated Godel, he wrote a reference for Turing then worked down the hall from him and read 'On Computable Numbers'-and understood it!

But then he was practical minded enough to care about programming and engineering and the messy stuff. And enough of a visionary to understand the computer's potential (for science at least, don't think he predicted Facebook):

I think it is soberly true to say that the existence of such a computer would open up to mathematicians, physicists, and other scholars areas of knowledge in the same remarkable way that the two- hundred- inch telescope promises to bring under observation universes which are at present entirely outside the range of any instrument now existing.

-von Neumann

And yes, he was apparently a brilliant manager. He kept the chief engineer of the IAS computer, Julian Bigelow, and Herman Goldstine, the director of the project, from falling out.

He kept Herman and I from fighting by some marvellous technique,’ Bigelow remembered. ‘We got along like oil and water, or cat and dog; and von Neumann would keep this here, and this there, and smooth things over.’

Finally, von Neumann had proved his usefulness to the US government and military-a role he embraced. By the end of WWII, he was taken seriously enough that the military was willing to pay most of the costs for building his computer at the IAS--AND he managed to convince them that everything - all details of the project- should be in the public domain! This to me is remarkable--I argue that makes him the sort of godfather of the open source movement.

Then he got the rest of the money from the IAS--because they didn't want to lose their academic superstar!

So he combined all these incredible traits in a way that no one else I know of really did.

So I could be cheeky and say you should read the book (well you should) but let's see...

-the 'von Neumann architecture', which is the basis for nearly all stored program computers today, from smartphone to laptop. I'm convinced by historian Thomas Haigh's [work](https://www.tomandmaria.com/Tom/Home) which suggests that JVN was uniquely well placed to come up with the design, manage the various players involved and bring in the cash to do it

-game theory and expected utility theory. JVN didn't live long enough to get the Nobel for it (he'd been dead 40 years by the time Nash, Selten and Harsanyi picked up the first Nobel for game theory. But his proof of the minimax theorem birthed the whole field, and his book with Morgenstern, 'Theory of Games and Economic Behaviour' is the canonical text. Game theory makes Internet firms billions through keyword auctions and other ways. It's also key to thinking about nuclear strategy and expected utility theory is central to behavioural economics

-theory of self-replicating automata. by proving mathematically that machines couldd reproduce, von Neumann inspired the first nanotech pioneers as well as legions of science fiction writers and dreamers (von Neumann probes, self-replicating lunar bases).

-he designed the implosion bomb, Fat Man. He then carried out the first computer simulations ever (sadly, they were to help design better bombs and keep the USA ahead in the arms race). Later, he led the team that carried out the first computerised weather forecast.

(Pushing go now but there's more I will try to add)

Doh! Forgot his deathbed lectures on 'The Computer and the Brain'! This was the first time anyone had compared computers to human brains in a systematic manner, and made the point that while computers were serial machines, the brain was massively parallel. The lectures built a bridge between computer science and cognitive neuroscience for the first time--some would say that's been a pretty useful link!

Whoo! Now I look at this in some detail in the QM chapter of the book. You may be aware that there's a dispute over that proof that it still going today! Jeffrey Bub and, separately, Dennis Dieks have argued that von Neumann never meant to rule out all possible hidden variables– only a subset of them. They claim what he was actually arguing was that a hidden variables theory couldn't have the same mathematical structure as his own ie they cannot be Hilbert space theories. And that's true: Bohmian mechanics isn't a Hilbert space theory.

To answer your question though...it's complicated (sorry). Von Neumann seems to have been open to the idea of hidden variable theories ie he didn't think they were mathematically suspect. But my gut feeling was that he didn't see the point of them!

However, he wasn't dismissive of Bohm as other physicists were. From my book:

While Heisenberg and Pauli branded Bohm’s theory as ‘metaphysical’

or ‘ideological’, von Neumann was not dismissive, as Bohm

himself notes with some pride and more than a little relief. ‘It appears

that von Neumann has agreed that my interpretation is logically consistent

and leads to all results of the usual interpretation. (This I am

told by some people.)’ Bohm wrote to Pauli shortly before his theory

was published. ‘Also, he came to a talk of mine and did not raise any

objections.’

Bohm might have hoped for Einstein to embrace his ideas, which

restored both realism (particles exist at all times in Bohmian mechanics)

and determinism. Einstein was, however, less kind than von

Neumann. Disappointed that Bohm had not rid quantum mechanics

of ‘spooky action at a distance’ (which he could not abide) he privately

called Bohm’s theory ‘too cheap’.

Well I guess you mean his deathbed return to Catholicism? In fact, he and his brothers all converted to Catholicism after their father's death in 1928. There isn't much evidence he took religion seriously at all through his life and when he returned to the faith on his deathbed, his brother, Nicholas, couldn't bring himself to believe that it was genuine. He claimed it was because the hospital's Catholic priest was the only person fluent in ancient Greek and von Neumann wanted to chat!

Von Neumann was certainly terrified of his own death (he was only 54 years old when he died) . His daughter, Marina, says her father was thinking of Pascal’s wager and had always believed that in the face of even a small possibility of suffering eternal damnation the only logical course is to be a believer before the end: ‘My father told
me, in so many words, once, that Catholicism was a very rough religion
to live in but it was the only one to die in .’

So take your pick.