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Sep 25, 2020

if you repeatedly square the number 5 the last n digits eventually stabilize for every n and you get a number with infinitely many digits going to the left that squares to itself. it ends ...890625

QC (in Berlin 7/29-??? w/ COVID

)

@QiaochuYuan

Sep 25, 2020

now take 1 - (this number), which you can calculate by carrying infinitely many times or by writing 1 = ...999 (this is 100% legit). you get another number which ends ...109376 which also squares to itself, which you can also compute by repeatedly taking 16 to the 5th power

@optimysticism

Sep 25, 2020

bro what do you mean "squares to itself" my head hurts

QC (in Berlin 7/29-??? w/ COVID

)

@QiaochuYuan

Sep 25, 2020

lol i mean it satisfies x^2 = x

@optimysticism

Sep 25, 2020

yeah but.... what? o_o

@optimysticism

Sep 25, 2020

that's x=1? something just isn't grokking

QC (in Berlin 7/29-??? w/ COVID

Replying to

and

it's a new kind of number that doesn't satisfy the rules you're used to, kinda like i but even weirder. in the 10-adic numbers it's not true that if x(x-1) = 0 then either x = 0 or x-1 = 0, which means the 10-adic numbers have what are called zero divisors

7:56 PM · Sep 25, 2020Twitter Web App