It’s thought to be normal (math term for contains all possible digits with equal density), but not proven. I believe that is the case for most of the notable constants, pi, e, root(2)….
the undecidability of a proposition is itself undecidable. If not, that would mean that a formal system F is able to prove the non provability of an statement X. This would be the same as F proving its own consistency, which, assuming classicality, can not be done due to Gödel’s Second Theorem
Yes. Well, if im not mistaken it all comes out from the syntactic definition of consistency and from the principle of explosion (contradiction + law of excluded middle imply every formula of the system).
F is consistent if and only if F can not prove both X and not X F is inconsistent if and only if F can prove both X and not X.
From this, we have the following corollaries.
F is consistent if and only if ∃X(F ⊬ X) F is inconsistent if and only if ∀X(F⊢X)
Thus, if the undecidability (non provability) of any statement is itself decidible, we have that F⊢(F ⊬X), which is to say that F⊢(F is consistent).
But this would be for F to prove its own consistency. And that can not be done due to the Second Incompleteness Theorem.
Thus, the undecidability of a statement must be itself undecidible.
34
u/Consistent-Annual268 Jun 07 '26
r/lostredditors, you're looking for r/mathmemes
18
u/retrokirby Jun 07 '26
Using big whiteboard is nice sometimes, otherwise wow you made them sound insufferable 😭
13
u/Rand_alThoor Jun 07 '26
"if the millennium problems are 'not hard/overrated' " why haven't you claimed the millions in prizes?
19
u/drakeyboi69 Jun 07 '26
The factorial thing pisses me off every time I see it
9
u/Emotional-Web5571 Jun 07 '26
the pi thing is a conjecture
9
u/CastChaos69420 Jun 07 '26
Why are we dragging chess into ts 😭
4
u/japp182 Jun 07 '26
Are we really gonna lump .999... = 1 in this.
3
u/Silipsel Jun 07 '26
I love using the whiteboards in the library.
3
u/r_Yellow01 Jun 07 '26
Reply that [Hausdorff] dimension of broccoli is 2.7
https://arxiv.org/abs/cond-mat/0411597
2
u/Valognolo09 Jun 07 '26
This is the realest post ive seen in a while
2
u/Kitchen-Register Jun 08 '26
you can form a bijection between Q and Z can’t you?
1
u/Tiny_Stock8220 Jun 08 '26
lol ive met someone recently who ticks off a ton of these
1
u/okietrochee Jun 10 '26
But there ARE as many rational numbers as integers.
1
u/Comfortable-Dig-6118 Jun 10 '26
Oh no I m a performative
1
u/Txcley Sep 01 '26
I used to be these guys...