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Akiva Weinberger

@akivaw.bsky.social

Likes math. Asleep when you least expect it. His origins and motivations remain unclear.

425 Followers  |  262 Following  |  264 Posts  |  Joined: 30.10.2024
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Posts by Akiva Weinberger (@akivaw.bsky.social)

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If you Google "izzy dropout", Google serves you three images of not-Izzy

22.02.2026 20:46 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

They genuinely stopped teaching it in American schools. The first generation to grow up without learning cursive is now in grad school.

17.02.2026 22:20 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Anything that's wrong with R, set-theoretically, is also wrong with P(N).

Frankly, most of the weirder stuff about the reals are actually problems with P(R), which is equinumerous with P(P(N)). In fact, I'm beginning to think the issue is actually with the powerset axiom

12.12.2025 01:24 β€” πŸ‘ 6    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

I don't find it that difficult?

27.11.2025 21:25 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

(The "triangular faces" thing is so that you don't have to worry about keeping the vertices of a quadrilateral face coplanar.)

I believe the smallest polyhedron for which this is possible is a cuboctahedron with each square face cut into two triangles.

23.11.2025 03:33 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

By the way, there's a discrete version of this: there exists a convex polyhedron with triangular faces such that, by moving the vertices around space continuously, you can turn it inside out without letting any of the dihedral angles go to zero.

23.11.2025 03:33 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I think it's mainly confusing because we can't do it in real life. I truly believe that if someone invented a stretchy material that could pass through itself, people would be able to evert the sphere after a few minutes of trying, doing it hands-on

23.11.2025 03:29 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Try out one of those buttons on the microwave that you've never used before

19.11.2025 20:16 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Due to inflation, a shave and a haircut is now worth almost a whole byte

14.11.2025 19:23 β€” πŸ‘ 4    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

The fact that I can't search "jetpack joyride theme but beats 2 and 4 are swapped" on YouTube and immediately find something is a travesty

24.10.2025 05:47 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

(though of course the author has made the preprint versions freely available online for years)

20.10.2025 22:00 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Visual description: A copy of The Rising Sea: Foundations of Algebraic Geometry by Ravi Vakil

According to the website it's not published until tomorrow, so I don't know how I have it already. I hit the button labeled "preorder" and they sent it to me

20.10.2025 21:59 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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It came! #TheRisingSea #RaviVakil #algebraicgeometry

20.10.2025 21:57 β€” πŸ‘ 5    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Maybe I would retitle it to "A naive proof, and why it does not work" or "A naive proof and the reason it does not work"

10.10.2025 00:51 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

The details of this argument (for instance, that the integral is always a polynomial in pi with integer coefficients of degree at most n, and that it goes to 0 super-exponentially) are left to the reader

18.09.2025 19:54 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

IMAGE DESCRIPTION:
The table shows the value of
Integral_{x=0..pi} [sin(x) x^n (Pi-x)^n / n!] dx
for various values of n. For n=7, the exact value is
-112Pi^6 + 50400Pi^4 - 3991680Pi^2 + 34594560
and the approximate value is
0.102692917728.
For n=14, the approximate value is
0.000002476917.

18.09.2025 19:52 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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Proof that pi is irrational:

Consider the following table.
If pi=A/B, the values are an integer multiple of 1/B^n, but they tend to zero super-exponentially.
QED

(Actually this shows that pi^2 is irrational)

18.09.2025 19:47 β€” πŸ‘ 1    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0

In fact the set of _all_ functions N->R has cardinality c by the same argument

03.09.2025 16:42 β€” πŸ‘ 3    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

That's still c, isn't it? It seems to me like you're describing cardinality
c^(aleph0) = (2^aleph0)^aleph0
= 2^(aleph0xaleph0)
= 2^(aleph0) = c

03.09.2025 16:42 β€” πŸ‘ 4    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0
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I have not seen this film but these two people are playing eyeball

18.08.2025 14:23 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

The word "eyeball" sounds like it's the name of a sport

18.08.2025 14:22 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

…Godzullah

03.08.2025 18:35 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Mosura? More like Mo-surah

03.08.2025 18:23 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I hope this isn't insensitive
I just noticed the pun and ran with it

03.08.2025 18:18 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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Someone else can execute on this vision way better than I can

03.08.2025 18:17 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Halalgorithms

03.08.2025 18:03 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Robot Muslims pray towards Mecha

03.08.2025 18:02 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Four-dimensional Muslims pray facing the hyperqibla

Tesserakaʿāt

03.08.2025 18:01 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Prank tape measure that springs out instead of in

31.07.2025 19:40 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

As mayor I vow to add hair conditioner to subway stations

31.07.2025 17:25 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0