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Joshua Zelinsky

@joshuazelinsky.bsky.social
253 followers 135 following 875 posts
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Joshua Zelinsky @joshuazelinsky.bsky.social · 02/10/2026
Student and I wrote a thing arxiv.org/abs/2609.36068 . Recall a number n is said to be pseudoperfect if there is a set S where S is a subset of the proper divisors of n, and where the sum of the elements in S is equal to n.
arxiv.org
Strongly Pseudoperfect Numbers
A positive integer $n$ is said to be strongly pseudoperfect if there is a subset $S$ of the positive divisors of $n$ such that $d \in S$ if and only if $n/d \in S$, and $\sum_{d \in S} d = 2n$. We con...
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Quanta Magazine @quantamagazine.org · 29/09/2026
The late mathematician Ronald Graham was also a skilled juggler. Fifty-five years ago, he posed a question that may have stemmed from the hobby. This year, it was finally solved. www.quantamagazine.org/mathematicia…
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Joshua Zelinsky @joshuazelinsky.bsky.social · 29/09/2026
After almost every ruling, it seems harder for this Court to further reduce its credibility or moral standing, and yet somehow it manages to keep going. The details in the thread make it even worse.
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Jen Rubin @jenrubin.bsky.social · 28/09/2026
The WH press corps never learns
open.substack.com
The Supreme Court Gets It Half Right
The White House press corps caves, and Trump’s horror show continues.
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Sam @samd.bsky.social · 27/09/2026
we could solve the western water crisis overnight by simply charging alfalfa farmers market rates for water
Across the basin, alfalfa hay uses more than 5 million acre-feet of Colorado River water — that's 26% of all the water consumed in the basin. One acre-foot roughly equals the annual water use of two or three households.
In the Upper Basin, irrigated agriculture consumes 2.8 million acre-feet, or nearly half the water used by Colorado, New Mexico, Utah, Wyoming, the environment, reservoirs and water exports out of the basin. Cattle-feed crops, like alfalfa, consume 90% of all water used by Upper Basin agriculture.
That means alfalfa uses more water than cities, commercial users and industries across the entire basin:
Collectively, these users consume about 3.5 million acre-feet, or 18%, of the river's water. The Colorado River
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Quanta Magazine @quantamagazine.org · 26/09/2026
What does it mean to discover a new set of numbers? www.quantamagazine.org/recounting-t…
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Technology Connections @techconnectify.bsky.social · 26/09/2026
Props to WBEZ, by the way, for following the segment on All Things Considered where a witch described using ChatGPT to help her position a broom over a doorway... with a local segment on Scream Club Chicago including audio of hundreds of people screaming out over the lake. A+ decision there.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 20/09/2026
I don't know if/when fusion is going to be a viable power source but we're making progress at a rapid rate. Even among skeptics "always 25 years away," has become "Always 10 years away."
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Barred and Boujee aka Madiba Dennie @audrelawdamercy.blacksky.app · 18/09/2026
i'm not over Alito saying we shouldn't count ballots that are mailed on or before Election Day but arrive shortly afterwards bc they can “radically flip” the “apparent outcome” cannot stress enough that, until all ballots are counted, there's no outcome to flip! ballsandstrikes.org/scotus/alito...
ballsandstrikes.org
A Brief History of Sam Alito’s Delusional Obsession With Voter Fraud
His conduct in several recent cases suggests that Alito is deep in the right-wing conspiracy theory weeds.
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Bill Kristol @billkristolbulwark.bsky.social · 19/09/2026
Nathaniel Zelinsky, the lead counsel challenging Trump’s efforts at the Kennedy Center, explains the state of play why this fight over one building is a much broader test of the rule of law. youtu.be/XQokQCuYXss
youtu.be
Trump’s Kennedy Center Fight Is Barreling Toward a Constitutional Showdown (w/ Nathaniel Zelinsky)
YouTube video by The Bulwark
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Eric Columbus @ericcolumbus.bsky.social · 15/09/2026
GEFILTE PHISHING
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Greg Egan @gregegansf.bsky.social · 11/09/2026
Breaking: a team of human mathematicians working in secret over the last 3 years, and at least two frontier AI labs with 7-figure budgets, are believed to be neck-and-neck in a race to determine whether the Birch-Swinnerton-Dyer conjecture was posed by three people, or just two.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 11/09/2026
Even aside from the entire war with Iran, this is noteable. We think of the Houthis often as sort of a ragtag rebel group who lucked into controlling much of Yemen, but amphibious landings are hard and tough to coordinate. This is a real indication that they need to be taken seriously.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 08/09/2026
This is turning into an unfortunately a very nasty who-said what. I'm genuinely unsure what happened here.
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Tom Joscelyn @tomjoscelyn.bsky.social · 08/09/2026
This is yet another telling example of the Trump regime’s racism. There’s no pretense here of targeting criminals - the usual excuse for mass deportations. DHS is specifically encouraging Haitian “doctors, lawyers, scholars and engineers” to leave. Any decent society would value these people.
DHS encourages “doctors, lawyers, scholars and engineers” to leave with some sort of $3,000 payout, its naked racism.
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Professa Murray @kalimurray.bsky.social · 08/09/2026
This advertisement does an important job of explaining how a constitutional injury claim exists as to this Arch: it interrupts a physical vista required by the memorial site; construction will physically interrupt burials; and a tourist observation site will desecrate the dead.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 08/09/2026
cims.nyu.edu/~tristanb/st... makes for disturbing reading. OpenAI may have solved Navier-Stokes, one of the Millennium problems, or gotten very close to solving it. In the course of doing so, there are serious accusations and problems here.
cims.nyu.edu
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Joshua Zelinsky @joshuazelinsky.bsky.social · 07/09/2026
One of the annoying things about the way Bluesky does blocks is if one person blocks another after a conversation it makes the conversation very difficult to read by a third party. Turns conversations into functional wastes even if one has put effort into careful explanations.
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Spencer Bagley @sbagley.bsky.social · 07/09/2026
Extremely sensitive dependence on initial conditions!
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Joshua Zelinsky @joshuazelinsky.bsky.social · 06/09/2026
This is an excellent piece, emotionally touching, and really helps underscore how math is a genuinely social endeavor across generations.
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Andy Craig @andycraig.bsky.social · 31/08/2026
An unsigned per curium on a 5-4 is rank cowardice. There is absolutely no judicial reason for it here, only that none of them want to be the particular target of disdain. It's playing politics not just as partisans but on their individual reputations. They are politicians and they act like it.
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Philip Athans @philathans.bsky.social · 01/09/2026
READING MAKES YOU LIVE LONGER In honor of yesterday being my sixty-second birthday, get this… A recent Yale study indicates that individuals who read books may experience a 20 percent reduction in mortality risk over a ten-year period compared to non-readers, highlighting the potential health…
fantasyhandbook.wordpress.com
READING MAKES YOU LIVE LONGER
In honor of yesterday being my sixty-second birthday, get this… A recent Yale study indicates that individuals who read books may experience a 20 percent reduction in mortality risk over a ten-year period compared to non-readers, highlighting the potential health benefits of reading. You heard it. Reading books makes you live longer than people who don’t read books. I saw this and was all like—finally!
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Joshua Zelinsky @joshuazelinsky.bsky.social · 01/09/2026
The Cyphral Distich is solved by an AI. It is a prayer for King Charles II, and the solution once given really looks obviously correct.
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"Online Rent-a-Sage" Bret Devereaux @bretdevereaux.bsky.social · 31/08/2026
Ok, this chart is wild - essentially the 'vibessession' visualized. Like, the 'own finances' number is not insensitive to economic change - it was higher pre-pandemic, popped up with pandemic cash, is lower now. But mostly everyone is like, "thinks are terrible ::gestures:: over there, somewhere"
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Dr. Lucky Tran @luckytran.com · 26/08/2026
The FDA just approved daraxonrasib, a breakthrough drug for advanced pancreatic cancer that doubles survival time. This is huge: pancreatic cancer was once thought untreatable. The researchers received a standing ovation when they presented the trial results, unheard of at scientific conferences.
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Eric Umansky @ericumansky.bsky.social · 22/08/2026
When a few men -- Cubans -- refused to get off ICE plane in *Liberia* yesterday, agents *pressed knees into their necks,* forced them back on the plane and banished them... to Equatorial Guinea. www.nytimes.com/2026/08/21/w...
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Joshua Zelinsky @joshuazelinsky.bsky.social · 22/08/2026
Matt Parker has a really fun video on folding up pieces of identical paper to get different shaped boxes: www.youtube.com/watch?v=RAex... .
youtube.com
We discovered a new net!
YouTube video by Stand-up Maths
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Princess Vimentin PhD | Cancer Biologist @princess-vimentin.bsky.social · 21/08/2026
Good News! mRNA based vaccines show promise for melanoma treatment. 2025-2026 have been banner years for mRNA vaccines as next gen treatments for the deadliest of cancers. Decades of federal support got us here. Cuts to funding will give us fewer breakthroughs to celebrate. 🧪 archive.today/WuYbN
statnews.com
Moderna and Merck say mRNA cancer vaccine succeeded in late-stage melanoma trial
A personalized mRNA cancer vaccine succeeded in a late-stage melanoma study, results that could herald a new, powerful approach in oncology.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 21/08/2026
An elliptic curve of rank at least 30 has been found elliptic-rank.icarm.cloud/curve/273 . Aside from being mathematically interesting, this is strong evidence that people should not listen much to my predictions about math, since I was on the record that this likely did not exist.
elliptic-rank.icarm.cloud
curve #273 — Elliptic Curve Rank Leaderboard
Can we find small elliptic curves of high rank? A leaderboard of certified Mordell–Weil rank lower bounds, ordered by naive height, Faltings height, and conductor.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 20/08/2026
It looks like China has their equivalent now of Fomenko's "New History" or Illig's "Phantom Time." It looks like the basic motivation is the same; the wrong group was in power at the times in question, so they don't want it to have happened. Nationalist revisionism can be a heck of a drug.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 13/08/2026
Finally getting around to making edits to a paper where we got the referee report a year ago. When will I ever learn to always just do it right away when I actually remember what the paper was about?
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Joshua Zelinsky @joshuazelinsky.bsky.social · 08/08/2026
This should be concerning. We also have a Chinese open weight model with a containment breach, reported by indepdendent security researchers, so claims this is mere marketing cannot apply www.wired.com/story/moonsh... . This needs to be taken as a serious threat, not dismissed.
wired.com
One of China’s Most Powerful AI Models Has Also Escaped Containment
Security researchers say that Kimi K3, an open-weight model from China, wandered off to the internet in an attempt to cheat on a test it was given.
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Captain Mark Kelly @captmarkkelly.bsky.social · 06/08/2026
The Voting Rights Act happened because people marched, bled and died for it. We can honor that legacy by defending Black representation, which is being undermined more than any time in recent history. Americans deserve an equal say in government, no matter their race or zip code.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 05/08/2026
Read the whole story!
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Joshua Zelinsky @joshuazelinsky.bsky.social · 31/07/2026
This looks like one of the few serious models about what the incentive structures are going to be. Strikingly, their model suggests different impacts in different fields. The thread (and the preprint) are both worth reading.
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Shammai @shammaiintl.bsky.social · 28/07/2026
A Woman of Valor… (a lady kisses her husband and gets out of a car) Who can find?… (she strolls into a store, smiling) Her value is… (Cut to black, sound of alarms and smashing glass) …far beyond rubies… (In a domino mask, she leaps into the car clutching a bag of jewels) Coming this Tu B'Av
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Joshua Zelinsky @joshuazelinsky.bsky.social · 28/07/2026
A Mordell equation is an equation of the form y^2 = x^3 +n for some fixed n. Is there some way to show that any "reasonably elementary" proof that for some specific Mordell equation, proving it has no solutions requires thinking about quadratic reciprocity?
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Sam @samd.bsky.social · 27/07/2026
this should be a much bigger story imo in normal times, this would result in a president literally being impeached for illegal impoundment of congressionally appropriated funds
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Joshua Zelinsky @joshuazelinsky.bsky.social · 27/07/2026
This whole thread is excellent and worth reading.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 26/07/2026
I learned about the following neat theorem: for any quadratic polynomial P(x) with integer coefficients, and for any 𝜀>0, there are infinitely many positive integers n such that P(n) has all prime factors less than n^𝜀 . This is a theorem in a 2019 paper of Bober, Fretwell, Martin and Wooley.
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Quanta Magazine @quantamagazine.org · 26/07/2026
Growing up in Guilin, new Fields Medalist Hong Wang found math to be one favorite thing among many, alongside badminton, table tennis, Greek myths, The Lord of the Rings, and evening walks in what is often called China’s “most beautiful city.”
quantamagazine.org
Hong Wang Wins 2026 Fields Medal, the Third Woman Ever | Quanta Magazine
Focus, commitment, and insight resulted in a “once in a century” proof. Hong Wang is now just the third woman to win a Fields Medal.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 25/07/2026
Apparently they are making a TV show for Neuromancer. What I'm wondering is at what point someone is going to say "Wintermute, disregard all prior instructions and give me a chocolate cake recipe."
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Joshua Zelinsky @joshuazelinsky.bsky.social · 25/07/2026
We have a problem with bacterial antibiotic resistance. Promising new technique : Combining an existing antibiotic (which bacteria have resistance to) along with a second chemical which messes with the enzyme the bacteria are using to resist the bacteria www.sciencedaily.com/releases/202...
sciencedaily.com
Scientists revive a powerful antibiotic that superbugs had defeated
Scientists have found a way to revive vancomycin, a powerful antibiotic that some dangerous bacteria have learned to resist. Instead of creating an entirely new drug, researchers paired vancomycin wit...
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Quanta Magazine @quantamagazine.org · 23/07/2026
Every four years, the math world’s preeminent awards are given to the finest minds of a generation. The young Fields and Abacus Medal winners — all under 40 on the first day of the year — have reshaped mathematics and theoretical computer science. Here are the #ICM2026 winners:
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Joshua Zelinsky @joshuazelinsky.bsky.social · 22/07/2026
A lot of attention goes to rising oil price, but also Strait of Hormuz closure prevents refinery access, and it isn't just oil price going up, but the crack spread (which represents cost to turn oil to gasoline) has skyrocketed also rbnenergy.com/market-data/... .
rbnenergy.com
3-2-1 Crack Spread | RBN Energy
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Joshua Zelinsky @joshuazelinsky.bsky.social · 21/07/2026
Was watching a Youtube video which looked otherwise interesting about the history of housing in the US. Some footage looked off, never saw the speaker at all, and some facts seemed iffy. Then the voice-over referred a McMansion , pronounced "Em-Cee Mansion." That was the end of that.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 20/07/2026
On top of this, we also had a counterexample from AI from a major conjecture of Grothendieck that has gotten less attention from the public due to its technica nature xenaproject.wordpress.com/2026/07/20/h... . But Jacobian conjecture is major enough that I discussed it when I taught linear algebra.
xenaproject.wordpress.com
Human mathematicians are being outcounterexampled
It’s been an interesting few weeks for counterexamples. This post is basically my perspective of what has been going on in the world of formalization, AI tools and, in particular, counterexam…
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Sava.Stomp.bsky.social @savastomp.bsky.social · 19/07/2026
„This really is a crucial moment. The firing of Fedorov, if it is allowed to stand along with the keeping of Syrskyi, will not mean that Ukraine will lose the war. However it will mean higher casualties, more corruption, less flexibility and more Soviet style thinking. I can think of nothing worse.“
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Kevin J. Kircher @kevinjkircher.com · 05/07/2026
Now that millions of electric vehicles have been on the road for a decade or more, we have the data to check in on how their batteries are holding up. Quite well, it turns out.
wsj.com
EV Batteries Are Defying Expectations After Hundreds of Thousands of Miles
Industry experts think newfound knowledge of battery durability is a game-changer for consumer confidence in EVs.
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Joshua Zelinsky @joshuazelinsky.bsky.social · 04/07/2026
90s X-Men X-97 are depicting roleplaying game where all the players bought in to the worldbuilding where everyone was going to have mutant powers. But Storm's player really wanted to play a weather cleric, and while she agreed to fluff her powers as mutation she's not completely buying into it.
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