9 ms·
As soon as I read the title of this post, the anecdote about the Grothendieck prime came to mind. Sure enough, the article kicks off with that very story! The
by susam 2y ago
As soon as I read the title of this post, the anecdote about the Grothendieck prime came to mind. Sure enough, the article kicks off with that very story! The article also links to https://www.ams.org/notices/200410/fea-grothendieck-part2.pdf https://www.ams.org/notices/200410/fea-grothendieck-part2.pd... which has an account of this anecdote. But the article does not reproduce the anecdote as stated in the linked document. So allow me to share it here as I've always found it quite amusing:
> 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 mean an actual number?” Grothendieck asked. The other person replied, yes, an actual prime number. Grothendieck suggested, “All right, take 57.”
- zellyn 2y agoOne of my pet hobbies is trying to figure out the least prime prime number and most prime composite numbers under 100. My votes are 61 or 89 for least prime-seeming primes and 87 and --yep-- 57 for more prime-seeming composites.
- xigoi 2y agoI once wrote in a Math Olympiad solution that 87 is prime. Not my brightest moment.
- im3w1l 2y agoI'm gonna vote 91, since it has large divisors that can't be seen at a glance. 57 and 87 fall apart if you remember that 60 and 90 are divisible by 3.
- expensive_news 2y agoI really enjoy this “proof” that the most prime-seeming composite is 91 https://youtu.be/S75VTAGKQpk https://youtu.be/S75VTAGKQpk
- bhasi 2y agoBut it's not prime - what am I missing? Why is this anecdote significant?
- bongodongobob 2y agoYeah I don't get it either.
- monadINtop 2y ago[dead]
- eigenket 2y agoThe point is that Grothendieck, easily one of the greatest mathematicians of all time, who regularly proved deep and fundamental facts about prime numbers, cared so little about particular numbers that he accidentally gave an easy to see non-prime as an example of a prime. He was used to working on completely different levels of abstraction, so when faced with concrete numbers he could easily make a mistake that a school-child (or hacker news commenter) could spot.