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Alexander Grothendieck Revolutionized 20th-Century Mathematics

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Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#21

Post by seanhunter »

karmakurtisaani wrote: post #12
cbolton wrote: post #10

Earlier quoted context omitted.

I had to follow your link to get it: I hadn't realized that 57 is not prime. At least I'm in good company.

It looks like a prime, but can be caught with the second-simplest test: sum of the digits is 12, which is divisible by 3. Hence it's divisible by 3. (The simplest test being of course if the number is even and bigger than 2) Edit: now that I think about it, probably should not have tried to impose ordering to the simplicity of tests. There's of course the divisibility by 5 test, which is even simpler.

John H Conway proved that the smallest number which looks prime, but isn’t is 91. https://youtu.be/S75VTAGKQpk?si=fCGilXECmCOy7T7R

“This is an important theorem, and a result I’m very proud of.”

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#22

Post by analog31 »

cbolton wrote: post #10
susam wrote: post #5

One of my favourite Grothendieck stories from https://www.ams.org/notices/200410/fea-grothendieck-part2.pd... >: > One striking characteristic of Grothendieck's mode of thinking is that it seemed to rely so little on examples. This can be seen in the legend of the so-called "Grothendieck prime". In a mathematical conversation, someone suggested to Grothendieck that they should consider a particular prime number. "You…

I had to follow your link to get it: I hadn't realized that 57 is not prime. At least I'm in good company.

It's referred to as the Grothendieck Prime for this reason.

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#23

Post by [deleted] »

hiAndrewQuinn wrote: post #16
karmakurtisaani wrote: post #12

Earlier quoted context omitted.

It looks like a prime, but can be caught with the second-simplest test: sum of the digits is 12, which is divisible by 3. Hence it's divisible by 3. (The simplest test being of course if the number is even and bigger than 2) Edit: now that I think about it, probably should not have tried to impose ordering to the simplicity of tests. There's of course the divisibility by 5 test, which is even simpler.

In fact, most 2 digit numbers not divisible by 2, 3, or 5 are prime. [1] The only one that's likely to ruin your day is 7 * 13 == 91, but that's self-defeating because after you think about it long enough 91 falls victim to [2]. [1] https://til.andrew-quinn.me/posts/most-2-digit-numbers-not-d... [2]: https://en.wikipedia.org/wiki/Interesting_number_paradox

[deleted]

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#24

Post by srean »

throwaway81523 wrote: post #3
ian_j_butler wrote: post #2

Happy to see that it's got the obligatory monk/wizard photo. For more life and times stuff I also suggest Labatut's Cease to Understand the World book and https://theanarchistlibrary.org/library/konstantinos-foutzop...

That book is fiction with a factual veneer. I liked it a lot until I started realizing that many of the details were made up. Then I couldn't read any more. It was like when TwoSetViolin described what it was like for them to watch movies with musician characters played, unrealistically, by non-musician actors. You'd be watching the perfectly fine movie until you noticed that the bananas were blue instead of yellow,…

Very interested in reading your list of blue bananas in Oppenheimer.

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#26

Post by manfromchina1 »

susam wrote: post #5

One of my favourite Grothendieck stories from https://www.ams.org/notices/200410/fea-grothendieck-part2.pd... >: > One striking characteristic of Grothendieck's mode of thinking is that it seemed to rely so little on examples. This can be seen in the legend of the so-called "Grothendieck prime". In a mathematical conversation, someone suggested to Grothendieck that they should consider a particular prime number. "You…

27 is a Tao prime. Terence Tao suggested 27 was a prime number on The Colbert Report in 2014. He was likely very nervous.

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#27

Post by alkyon »

karmakurtisaani wrote: post #12
cbolton wrote: post #10

Earlier quoted context omitted.

I had to follow your link to get it: I hadn't realized that 57 is not prime. At least I'm in good company.

It looks like a prime, but can be caught with the second-simplest test: sum of the digits is 12, which is divisible by 3. Hence it's divisible by 3. (The simplest test being of course if the number is even and bigger than 2) Edit: now that I think about it, probably should not have tried to impose ordering to the simplicity of tests. There's of course the divisibility by 5 test, which is even simpler.

I just noticed that it's 60-3 without any divisibility tests.

Tao's 27 prime was much more embarassing but understandable as he's no a calculator.

Savants are for things like remembering the first million primes. Someone like Tao or Grothendieck can't remeber them beyond 20, but it doesn't mean they can't actuly reason about them.

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#28

Post by karmakurtisaani »

alkyon wrote: post #27
karmakurtisaani wrote: post #12

Earlier quoted context omitted.

It looks like a prime, but can be caught with the second-simplest test: sum of the digits is 12, which is divisible by 3. Hence it's divisible by 3. (The simplest test being of course if the number is even and bigger than 2) Edit: now that I think about it, probably should not have tried to impose ordering to the simplicity of tests. There's of course the divisibility by 5 test, which is even simpler.

I just noticed that it's 60-3 without any divisibility tests. Tao's 27 prime was much more embarassing but understandable as he's no a calculator. Savants are for things like remembering the first million primes. Someone like Tao or Grothendieck can't remeber them beyond 20, but it doesn't mean they can't actuly reason about them.

What's Tao's 27 prime again?

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#29

Post by alkyon »

karmakurtisaani wrote: post #28
alkyon wrote: post #27

Earlier quoted context omitted.

I just noticed that it's 60-3 without any divisibility tests. Tao's 27 prime was much more embarassing but understandable as he's no a calculator. Savants are for things like remembering the first million primes. Someone like Tao or Grothendieck can't remeber them beyond 20, but it doesn't mean they can't actuly reason about them.

What's Tao's 27 prime again?

Was mentioned in a twin thread:

"27 is a Tao prime. Terence Tao suggested 27 was a prime number on The Colbert Report in 2014. He was likely very nervous."

Re: Alexander Grothendieck Revolutionized 20th-Century Mathematics

#30

Post by [deleted] »

karmakurtisaani wrote: post #28
alkyon wrote: post #27

Earlier quoted context omitted.

I just noticed that it's 60-3 without any divisibility tests. Tao's 27 prime was much more embarassing but understandable as he's no a calculator. Savants are for things like remembering the first million primes. Someone like Tao or Grothendieck can't remeber them beyond 20, but it doesn't mean they can't actuly reason about them.

What's Tao's 27 prime again?

[deleted]
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