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The Unparalleled Genius of John von Neumann (2019)

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Re: The Unparalleled Genius of John von Neumann (2019)

#51
post #32

Earlier quoted context omitted.

My understanding is that since any mathematical proof can (in principle) be reduced to manipulation with formal objects (symbols), it’s always “constructive.”

Not really. Check out the proof of Hilbert's Nullstellensatz. He got tons of criticism for proving the existence of a relation without constructing that relation.

But he did construct the proof! (So, the argument can only be about what axioms the proof is based on.)

Re: The Unparalleled Genius of John von Neumann (2019)

#52

Earlier quoted context omitted.

From a genetic standpoint, all humans are 99.9% identical beasts. There is of course some genetic components in potential abilities. But I strongly believe that most of the differences we are seeing are built on compounded interest of environmental factors, starting from a very young age.

I'm not sure this is a viable argument considering that we also share much of our DNA with apes/monkeys. It seems like minor genetic differences can create large disparities. I definitely think environmental factors can compound on a genetic baseline though, and of course the earlier you start compounding the greater the returns.

The differences between apes and humans is much larger than between humans, by at least an order of magnitude.

Re: The Unparalleled Genius of John von Neumann (2019)

#53
post #41
post #28

Earlier quoted context omitted.

> there will be a sensible way to define the zero/empty case. This is often a good test of whether you have a uniform concept that works for all n without corner cases. And so, begun the array indexing war has.

A polynomial always includes a member (monomial) with the power zero. It seems natural, therefore, to index the coefficients correspondingly. In other situations, 1 may be the more natural starting index.

The useful corner case/"neutral element" for array indexing is the zero-width interval in an arbitrary position.

Re: The Unparalleled Genius of John von Neumann (2019)

#54

Earlier quoted context omitted.

From a genetic standpoint, all humans are 99.9% identical beasts. There is of course some genetic components in potential abilities. But I strongly believe that most of the differences we are seeing are built on compounded interest of environmental factors, starting from a very young age.

Zero chance it’s environmental

Why not?

Re: The Unparalleled Genius of John von Neumann (2019)

#55
post #46
post #3

I often use von Neumann's quote, "Young man, in mathematics you don't understand things. You just get used to them.", to console myself when I have to read a math book multiple times to really understand something. The quote also has truth in it. I had no problem accepting that 0! = 1 only because I learnt that fact early in school. However, I struggled quite a bit to accept that span({}) = {0}, even though it is not…

0! = 1 is not hard to accept, since it follows a rule. You just need to look at it backwards. To get the previous factorial (Ni-1)! you need to divide the N! by N 4! = 24 ;; 24 / 4 = 6 3! = 6 ;; 6 / 3 = 2 2! = 2 ;; 2 / 2 = 1 1!= 1 ;; 1 / 1 = 1 0! = 1

Even funnier is how this roughly works for -1!

Re: The Unparalleled Genius of John von Neumann (2019)

#56
Is it just me or does it seem like there something like there were a lot of celebrity-level STEM heroes to come out of the early 20th century. These folks all seemed to work together closely.

Maybe these things take time, but it just doesn't seem like there is anything remotely like this going on today, despite far greater access to education and increases in global population.

Is it perhaps that the limelight is less on mathematicians than it was during the early 20th century?

Re: The Unparalleled Genius of John von Neumann (2019)

#57
post #38

Earlier quoted context omitted.

Yes, those two facts about zero/empty cases (and so many more) are definitely related, and this class of facts is one of my favourites! Usually, if you're dealing with something algebraic in flavour (which is a very vague concept, sorry), there will be a sensible way to define the zero/empty case. This is often a good test of whether you have a uniform concept that works for all n without corner cases. It almost irri…

Yeah, it took a while to sink into my head that many of these "wait, why is span({}) = {0}?" kinds of cases have answers that sum up as "because anything else means other rules are inconsistent, and the whole thing is either less useful or useless". It's "arbitrary", but it's either the only useful option, or sometimes a simple(st) one of many. Even just one number theory course helped a lot, since it brought that ki…

To be fair, in this case the rule is not quite arbitrary, because it, in fact, follows from the definition of span (as a subspace).

Re: The Unparalleled Genius of John von Neumann (2019)

#58

Is it just me or does it seem like there something like there were a lot of celebrity-level STEM heroes to come out of the early 20th century. These folks all seemed to work together closely. Maybe these things take time, but it just doesn't seem like there is anything remotely like this going on today, despite far greater access to education and increases in global population. Is it perhaps that the limelight is les…

It's not just you. This whole group of (Hungarian) scientists is known as "The Martians" [1]

[1] https://en.wikipedia.org/wiki/The_Martians_(scientists)

Re: The Unparalleled Genius of John von Neumann (2019)

#59

Is it just me or does it seem like there something like there were a lot of celebrity-level STEM heroes to come out of the early 20th century. These folks all seemed to work together closely. Maybe these things take time, but it just doesn't seem like there is anything remotely like this going on today, despite far greater access to education and increases in global population. Is it perhaps that the limelight is les…

They all worked closely together because they all worked on the Manhattan Project. When there’s a single huge government project requiring the nation’s smartest people and on which the survival of the nation depends, it shouldn’t be too surprising that all of the top scientists and mathematicians and engineers all end up working together. :)

The fact that so many of them specifically grew up in Hungary, went to school in Germany, and came to the United States is interesting to note though!

Re: The Unparalleled Genius of John von Neumann (2019)

#60
post #3

I often use von Neumann's quote, "Young man, in mathematics you don't understand things. You just get used to them.", to console myself when I have to read a math book multiple times to really understand something. The quote also has truth in it. I had no problem accepting that 0! = 1 only because I learnt that fact early in school. However, I struggled quite a bit to accept that span({}) = {0}, even though it is not…

I wonder if e.g. using constructive math would make things easier since every step of a constructive proof is understandable.

Unfortunately, constructive vs classical (vs linear, etc.) applies to proofs, but this is really about definitions. Proofs can be correct or incorrect pretty straightforwardly, but definitions being correct or not is really a matter of taste. (And as someone who's been formalising some mathematics in Lean recently, definitions are so much trickier to get right than proofs!)
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