Akiva Weinberger
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akivaw.bsky.social
Akiva Weinberger
@akivaw.bsky.social
Likes math. Asleep when you least expect it. His origins and motivations remain unclear.
I don't find it that difficult?
November 27, 2025 at 9:25 PM
(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.
November 23, 2025 at 3:33 AM
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.
November 23, 2025 at 3:33 AM
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
November 23, 2025 at 3:29 AM
Try out one of those buttons on the microwave that you've never used before
November 19, 2025 at 8:16 PM
(though of course the author has made the preprint versions freely available online for years)
October 20, 2025 at 10:00 PM
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
October 20, 2025 at 9:59 PM
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"
October 10, 2025 at 12:51 AM
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
September 18, 2025 at 7:54 PM
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.
September 18, 2025 at 7:52 PM
In fact the set of _all_ functions N->R has cardinality c by the same argument
September 3, 2025 at 4:42 PM
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
September 3, 2025 at 4:42 PM
I have not seen this film but these two people are playing eyeball
August 18, 2025 at 2:23 PM
…Godzullah
August 3, 2025 at 6:35 PM
Mosura? More like Mo-surah
August 3, 2025 at 6:23 PM
I hope this isn't insensitive
I just noticed the pun and ran with it
August 3, 2025 at 6:18 PM
Halalgorithms
August 3, 2025 at 6:03 PM
Robot Muslims pray towards Mecha
August 3, 2025 at 6:02 PM