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Matthew Cushman

@astragalus.bsky.social

Adjunct math prof at Hunter College in NYC. Lefty. Kindness is the only thing that matters.

1,882 Followers  |  1,278 Following  |  580 Posts  |  Joined: 31.07.2023  |  2.064

Latest posts by astragalus.bsky.social on Bluesky

The cool S (which normally has a sharp hexagonal shape) but with rounded corners so it looks mostly like a regular S

The cool S (which normally has a sharp hexagonal shape) but with rounded corners so it looks mostly like a regular S

Introducing the Cool S, For Herโ„ข

08.12.2025 16:41 โ€” ๐Ÿ‘ 1536    ๐Ÿ” 281    ๐Ÿ’ฌ 31    ๐Ÿ“Œ 17

The Road (Amazon Prime Limited Series)
the boy: what is it, papa?
the man: it's an air fryer.
the boy: it fries air? why?
the man: it fries food. in dual zones.

07.12.2025 22:09 โ€” ๐Ÿ‘ 531    ๐Ÿ” 47    ๐Ÿ’ฌ 7    ๐Ÿ“Œ 0
A poster on 8.5 x 11 inch paper saga Fishtown fish facts: red lipped catfish or of ocephalus Darwini. Then a pic of that freaky fish with 4 limbs it rests on the ground and then the words โ€œstg this fish real red-lipped batfish walk ocean floor with they flippers RLBF have RBF, not they fault
RLBF have a bioluminescent lure that glows to attract dinner 
RLBF lipgloss is popping, RLBF lipgloss is cool, all the fish keep jockin, they chase RLBF after school
RLBF got scales like armor and shine bright like a diamond
Red-lipped batfish will teach you how to dougie, I can promise u that.

@yaboyni
Take a moment
And and realize the moment 
You took has already passed
Thank you
See you next time

A poster on 8.5 x 11 inch paper saga Fishtown fish facts: red lipped catfish or of ocephalus Darwini. Then a pic of that freaky fish with 4 limbs it rests on the ground and then the words โ€œstg this fish real red-lipped batfish walk ocean floor with they flippers RLBF have RBF, not they fault RLBF have a bioluminescent lure that glows to attract dinner RLBF lipgloss is popping, RLBF lipgloss is cool, all the fish keep jockin, they chase RLBF after school RLBF got scales like armor and shine bright like a diamond Red-lipped batfish will teach you how to dougie, I can promise u that. @yaboyni Take a moment And and realize the moment You took has already passed Thank you See you next time

One of my neighbors has been putting up these fish facts posters. All kinds of different fish, marine, freshwater, deep, shallow, all kinds. This is a good one. โ€œStg this real fishโ€ took me out. Good work, neighbor.

07.12.2025 15:39 โ€” ๐Ÿ‘ 8879    ๐Ÿ” 2124    ๐Ÿ’ฌ 163    ๐Ÿ“Œ 148
Post image 21.11.2025 09:00 โ€” ๐Ÿ‘ 658    ๐Ÿ” 156    ๐Ÿ’ฌ 8    ๐Ÿ“Œ 5
Figure 6. The quotientope lattice for n = 4: all quotientopes ordered by inclusion (which corresponds to refinement of the lattice congruences). We only consider lattice congruences whose fan
is essential. We have highlighted the cube (green), Lodayโ€™s associahedron [Lod04] (blue), another
one of Hohlwegโ€“Langeโ€™s associahedra [HL07] (purple), the diagonal rectangulation polytope [LR12]
(orange), and the permutahedron (red). Adapted from [PS19, Fig. 9].

Figure 6. The quotientope lattice for n = 4: all quotientopes ordered by inclusion (which corresponds to refinement of the lattice congruences). We only consider lattice congruences whose fan is essential. We have highlighted the cube (green), Lodayโ€™s associahedron [Lod04] (blue), another one of Hohlwegโ€“Langeโ€™s associahedra [HL07] (purple), the diagonal rectangulation polytope [LR12] (orange), and the permutahedron (red). Adapted from [PS19, Fig. 9].

This diagram should win some kind of prize for mathematical illustration. From arxiv.org/abs/2305.08471. ๐Ÿงฎ

05.12.2025 22:27 โ€” ๐Ÿ‘ 38    ๐Ÿ” 4    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

I AM ONCE AGAIN TAPPING THE SIGN.

04.12.2025 04:39 โ€” ๐Ÿ‘ 197    ๐Ÿ” 46    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 1
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Agents in Key Largo, Florida ripped this woman wearing medical scrubs out of her car as she screamed she is a US citizen. Agents cuffed her and put her in one of their cars.

She was eventually let go, per David Goodhue of the Miami Herald, who also took this footage:

03.12.2025 17:20 โ€” ๐Ÿ‘ 15115    ๐Ÿ” 8262    ๐Ÿ’ฌ 1833    ๐Ÿ“Œ 1389
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Colombian family files first known formal complaint over deadly US strike in Caribbean | CNN The family of a Colombian man believed to have been killed in a US strike in the Caribbean has filed whatโ€™s believed to be the first complaint against such attacks with the Inter-American Commission o...

The family of a Colombian man believed to have been killed in a US strike in the Caribbean has filed whatโ€™s believed to be the first complaint against such attacks with the Inter-American Commission on Human Rights (IACHR).

03.12.2025 04:31 โ€” ๐Ÿ‘ 7544    ๐Ÿ” 2116    ๐Ÿ’ฌ 134    ๐Ÿ“Œ 108

I want to devote my life to them

02.12.2025 21:52 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Night-time photo of a bushbaby on the trunk of a small tree, looking directly at camera. It's brown and furry and looks similar to a squirrel. But it's a primate, which explains the Afrikaans name "nagapie" - "little night monkey".

(Pic by a friend in the Lowveld)

Night-time photo of a bushbaby on the trunk of a small tree, looking directly at camera. It's brown and furry and looks similar to a squirrel. But it's a primate, which explains the Afrikaans name "nagapie" - "little night monkey". (Pic by a friend in the Lowveld)

On an unrelated note: the nagapies are out

01.12.2025 17:51 โ€” ๐Ÿ‘ 51    ๐Ÿ” 12    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 0

Cyber Monday is here and deals are going fast! These deals are diaphanous. They are receding even as we speak, becoming mere memories of deals, prices longed for but lost, hints at what could have been had for less. A golden slant of sun through window falls on an empty countertop. Act now.

01.12.2025 15:32 โ€” ๐Ÿ‘ 442    ๐Ÿ” 145    ๐Ÿ’ฌ 10    ๐Ÿ“Œ 11

Oh ok - I would quit as a matter of principle anyway but I guess as I don't have to support a family I have the luxury of living by a code

02.12.2025 01:42 โ€” ๐Ÿ‘ 7    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Flow chart from TX Tech memo showing that most class materials must be reviewed by chair, dean, and provost, and that all curricular material must be disclosed

Flow chart from TX Tech memo showing that most class materials must be reviewed by chair, dean, and provost, and that all curricular material must be disclosed

TX Tech has a flow chat for guidance on what can be taught in the university system. Two things:
1. Very little content seems to be permitted. This is partisan control of the curriculum.
2. I would not enjoy teaching under these conditions, but I really would not want to be a Chair or Dean.

01.12.2025 22:55 โ€” ๐Ÿ‘ 886    ๐Ÿ” 300    ๐Ÿ’ฌ 95    ๐Ÿ“Œ 211

Removing all content from my calc 3 class because it's not necessary for any professional license. Guess we can all stay at home? Mission accomplished?

02.12.2025 00:37 โ€” ๐Ÿ‘ 31    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
My hand holding a shortbread cookie in the shape of an airplane. There are red sprinkles in the pattern of the survivorship bias plane.

My hand holding a shortbread cookie in the shape of an airplane. There are red sprinkles in the pattern of the survivorship bias plane.

A plate of the same cookies.

A plate of the same cookies.

Does anyone want a survivorship bias shortbread

29.11.2025 04:50 โ€” ๐Ÿ‘ 15403    ๐Ÿ” 4178    ๐Ÿ’ฌ 149    ๐Ÿ“Œ 107

Ah ok so the idea is you're just happy to have an ample line bundle at all? I forgot that not all varieties are projective. But if a variety is projective you always get lots of ample line bundles right? Or does it have to be smooth and projective?

01.12.2025 20:36 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Is there any intuition for what's so special about Fano varieties? All I vaguely know is "they have lots of lines in them"

01.12.2025 18:10 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
Okay bear with me. My amazing friend Robyn (@haykebyr.bsky.social) did this amazing image based on my stupid ass joke. It's Miss Piggy photoshopped into some Sister of Battle armour, with the white bob haircut and a fleur de lys tattoo on her cheek and everything. Except she's got pink satin gloves on. The caption is "In the Grim Darkness of the Far Future there is Only Moi" because that's the whole joke. Thank you.

Okay bear with me. My amazing friend Robyn (@haykebyr.bsky.social) did this amazing image based on my stupid ass joke. It's Miss Piggy photoshopped into some Sister of Battle armour, with the white bob haircut and a fleur de lys tattoo on her cheek and everything. Except she's got pink satin gloves on. The caption is "In the Grim Darkness of the Far Future there is Only Moi" because that's the whole joke. Thank you.

โ„‘๐”ซ ๐”ฑ๐”ฅ๐”ข ๐”Š๐”ฏ๐”ฆ๐”ช ๐”‡๐”ž๐”ฏ๐”จ๐”ซ๐”ข๐”ฐ๐”ฐ ๐”ฌ๐”ฃ ๐”ฑ๐”ฅ๐”ข ๐”‰๐”ž๐”ฏ ๐”‰๐”ฒ๐”ฑ๐”ฒ๐”ฏ๐”ข, ๐”ฑ๐”ฅ๐”ข๐”ฏ๐”ข ๐”ฆ๐”ฐ ๐”’๐”ซ๐”ฉ๐”ถ ๐”๐”ฌ๐”ฆ

30.11.2025 19:29 โ€” ๐Ÿ‘ 6494    ๐Ÿ” 2007    ๐Ÿ’ฌ 94    ๐Ÿ“Œ 52
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I know a lot of footage and commentary is swirling about today but itโ€™s important to convey that the people who gathered outside that ICE garage in lower Manhattan were *so* ten toes down focused.

This person who gets maced and just calmly flips the bird & keeps going is *quintessential.*

29.11.2025 21:24 โ€” ๐Ÿ‘ 1515    ๐Ÿ” 455    ๐Ÿ’ฌ 35    ๐Ÿ“Œ 26

Ah yes the Truth

30.11.2025 01:15 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Yep, citibikes are so expensive that they might as well not exist. We should be encouraging people to ride bikes instead of driving cars but for a non member a bike ride can be comparable to a taxi. Yet another example of how everything in this city is specifically designed for rich people.

30.11.2025 00:22 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Definitely seeing this on the math side of things. Students are just checked out. To be fair, professors are too. It just feels like there's nobody home.

29.11.2025 06:13 โ€” ๐Ÿ‘ 5    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

The thing about those summary executions by the IDF in Jenin was how totally routine it looked. There was no anger or excitement, no "fog of war". After calmly executing the men they brought down the structure on top of them, perfectly choreographed like they had done it a thousand times.

28.11.2025 21:49 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Defense Secretary Pete Hegseth gave a spoken directive, according to two people with direct knowledge of the operation. "The order was to kill everybody," one of them said.
A missile screamed off the Trinidad coast, striking the vessel and igniting a blaze from bow to stern. For minutes, commanders watched the boat burning on a live drone feed.
As the smoke cleared, they got a jolt: Two survivors were clinging to the smoldering wreck.
The Special Operations commander overseeing the Sept. 2 attack - the opening salvo in the Trump administration's war on suspected drug traffickers in the Western Hemisphere โ€” ordered a second strike to comply with Hegseth's instructions, two people familiar with the matter said. The two men were blown apart in the water.

Defense Secretary Pete Hegseth gave a spoken directive, according to two people with direct knowledge of the operation. "The order was to kill everybody," one of them said. A missile screamed off the Trinidad coast, striking the vessel and igniting a blaze from bow to stern. For minutes, commanders watched the boat burning on a live drone feed. As the smoke cleared, they got a jolt: Two survivors were clinging to the smoldering wreck. The Special Operations commander overseeing the Sept. 2 attack - the opening salvo in the Trump administration's war on suspected drug traffickers in the Western Hemisphere โ€” ordered a second strike to comply with Hegseth's instructions, two people familiar with the matter said. The two men were blown apart in the water.

This is murder. www.washingtonpost.com/national-sec...

28.11.2025 18:16 โ€” ๐Ÿ‘ 7510    ๐Ÿ” 2786    ๐Ÿ’ฌ 297    ๐Ÿ“Œ 329
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What We Know About U.S.-Backed Zero Units in Afghanistan Deadly night raids. Faulty U.S. intelligence. A โ€œclassifiedโ€ war loophole. Reporter Lynzy Billingโ€™s investigation offers an unprecedented insight into the civilian casualties of Afghanistanโ€™s Zero Uni...

Hate to be posting this on a holiday, but there's been renewed interest in the CIA-backed Zero Units in Afghanistan. Here's a good summary of @propublica.org's 2022 reporting on the units and just some of the civilian casualties they were responsible for:

28.11.2025 02:11 โ€” ๐Ÿ‘ 620    ๐Ÿ” 275    ๐Ÿ’ฌ 8    ๐Ÿ“Œ 17
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"there are no third spaces anymore" wrong. blast furnace

25.11.2025 00:59 โ€” ๐Ÿ‘ 8326    ๐Ÿ” 2095    ๐Ÿ’ฌ 88    ๐Ÿ“Œ 137

Get their asses your holiness

26.11.2025 16:38 โ€” ๐Ÿ‘ 63    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Les gens : Ha ha, Candace Owens et les assassins secrets de la DGSE, nโ€™importe quoi !

Les assassins secrets de la DGSE :

25.11.2025 14:56 โ€” ๐Ÿ‘ 129    ๐Ÿ” 30    ๐Ÿ’ฌ 16    ๐Ÿ“Œ 7

exciting advances in goo

25.11.2025 19:23 โ€” ๐Ÿ‘ 8    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Capybara replacement theory

24.11.2025 16:39 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

@astragalus is following 20 prominent accounts