Ben Brubaker
@benbenbrubaker.bsky.social
Computer science staff writer @quantamagazine.bsky.social, ex-physicist. More about me at benbrubaker.com. Banner art by Nico Roper — find more of their work at nicoroper.com. [Obligatory disclaimer about views being my own.]
Pinned
Why Busy Beaver Hunters Fear the Antihydra
In which I explore the biggest barrier in the busy beaver game. What is Antihydra, what is the Collatz conjecture, how are they connected, and what makes them so daunting?
benbrubaker.com
I published a new post on my rarely updated personal blog! It's a sequel of sorts to my Quanta coverage of the Busy Beaver game, focusing on a particularly fearsome Turing machine known by the awesome name Antihydra.
Reposted by Ben Brubaker
emotive butlerian jihad now: the machine may not wear a human face.
There are no words for how evil this is
November 7, 2025 at 2:47 AM
emotive butlerian jihad now: the machine may not wear a human face.
Reposted by Ben Brubaker
For the uninitiated: The busy beaver problem is an extremely compelling, Conway-esque expedition into the daunting wilds of the finite, and you couldn't ask for a better guide than Ben.
Strongly recommend.
Strongly recommend.
I published a new post on my rarely updated personal blog! It's a sequel of sorts to my Quanta coverage of the Busy Beaver game, focusing on a particularly fearsome Turing machine known by the awesome name Antihydra.
Why Busy Beaver Hunters Fear the Antihydra
In which I explore the biggest barrier in the busy beaver game. What is Antihydra, what is the Collatz conjecture, how are they connected, and what makes them so daunting?
benbrubaker.com
October 30, 2025 at 3:13 PM
For the uninitiated: The busy beaver problem is an extremely compelling, Conway-esque expedition into the daunting wilds of the finite, and you couldn't ask for a better guide than Ben.
Strongly recommend.
Strongly recommend.
Does riffing on the title of the transformer paper boost citations? Somebody should look into it, and if the answer is yes, write a paper called "'All you need' is all you need"
Anti-concentration is (almost) all you need
Until very recently, it was generally believed that the (approximate) 2-design property is strictly stronger than anti-concentration of random quantum circuits, mainly because it was shown that the la...
arxiv.org
October 30, 2025 at 2:51 PM
Does riffing on the title of the transformer paper boost citations? Somebody should look into it, and if the answer is yes, write a paper called "'All you need' is all you need"
I published a new post on my rarely updated personal blog! It's a sequel of sorts to my Quanta coverage of the Busy Beaver game, focusing on a particularly fearsome Turing machine known by the awesome name Antihydra.
Why Busy Beaver Hunters Fear the Antihydra
In which I explore the biggest barrier in the busy beaver game. What is Antihydra, what is the Collatz conjecture, how are they connected, and what makes them so daunting?
benbrubaker.com
October 27, 2025 at 4:04 PM
I published a new post on my rarely updated personal blog! It's a sequel of sorts to my Quanta coverage of the Busy Beaver game, focusing on a particularly fearsome Turing machine known by the awesome name Antihydra.
In the US, regulators try to ensure fair prices by banning collusion. But what happens when prices are set by algorithms? New story by me in @quantamagazine.bsky.social about a surprising way that seemingly benign pricing algorithms can go awry:
The Game Theory of How Algorithms Can Drive Up Prices | Quanta Magazine
Recent findings reveal that even simple pricing algorithms can make things more expensive.
www.quantamagazine.org
October 22, 2025 at 3:41 PM
In the US, regulators try to ensure fair prices by banning collusion. But what happens when prices are set by algorithms? New story by me in @quantamagazine.bsky.social about a surprising way that seemingly benign pricing algorithms can go awry:
In light of the 2022 reformulation of C.P. Snow's Two Cultures as wordcels vs shape rotators, it is very funny that LLMs are (up to nonlinearities) quite literally word rotators.
October 21, 2025 at 9:18 PM
In light of the 2022 reformulation of C.P. Snow's Two Cultures as wordcels vs shape rotators, it is very funny that LLMs are (up to nonlinearities) quite literally word rotators.
This is in the running for my least favorite item of all time.
The “Trailer” at friend.com feels more like the teaser for a sci-fi dystopia.
September 28, 2025 at 12:25 AM
This is in the running for my least favorite item of all time.
Reposted by Ben Brubaker
I prefer Friend's competition:
Enemy
www.enemy.lol
September 27, 2025 at 11:36 PM
I prefer Friend's competition:
I really enjoyed talking to @nsaphra.bsky.social about her thoughts on what much language model interpretability research misses. My latest in @quantamagazine.bsky.social:
To Understand AI, Watch How It Evolves | Quanta Magazine
Naomi Saphra thinks that most research into language models focuses too much on the finished product. She’s mining the history of their training for insights into why these systems work the way they d...
www.quantamagazine.org
September 24, 2025 at 1:52 PM
I really enjoyed talking to @nsaphra.bsky.social about her thoughts on what much language model interpretability research misses. My latest in @quantamagazine.bsky.social:
Reposted by Ben Brubaker
This is very cool.
arxiv.org/abs/2509.12337
arxiv.org/abs/2509.12337
Determination of the fifth Busy Beaver value
We prove that $S(5) = 47,176,870$ using the Coq proof assistant. The Busy Beaver value $S(n)$ is the maximum number of steps that an $n$-state 2-symbol Turing machine can perform from the all-zero tap...
arxiv.org
September 18, 2025 at 7:05 AM
This is very cool.
arxiv.org/abs/2509.12337
arxiv.org/abs/2509.12337
Reposted by Ben Brubaker
A photoessay by @yaseminsaplakoglu.bsky.social highlights researchers' labor & collaboration: "Through the haze of doom that shrouds climate science shines the passion behind the quest to understand and solve one of the greatest challenges humanity has faced." www.quantamagazine.org/photos-captu...
Photos Capture the Extreme, Beautiful Work of Climate Science | Quanta Magazine
Building an accurate model of Earth’s climate requires a lot of data. Photography reveals the extreme efforts scientists have undertaken to measure gases, glaciers, clouds and more.
www.quantamagazine.org
September 15, 2025 at 8:08 PM
A photoessay by @yaseminsaplakoglu.bsky.social highlights researchers' labor & collaboration: "Through the haze of doom that shrouds climate science shines the passion behind the quest to understand and solve one of the greatest challenges humanity has faced." www.quantamagazine.org/photos-captu...
Reposted by Ben Brubaker
What does it mean when researchers say a CO2 molecule can "trap heat"? How can just a few CO2 molecules change a planet?
An infographic explainer by @markabelan.bsky.social and Joe Howlett walks through the quantum mechanics of CO2 and other greenhouse gases: www.quantamagazine.org/the-quantum-...
An infographic explainer by @markabelan.bsky.social and Joe Howlett walks through the quantum mechanics of CO2 and other greenhouse gases: www.quantamagazine.org/the-quantum-...
The Quantum Mechanics of Greenhouse Gases | Quanta Magazine
Earth’s radiation can send some molecules spinning or vibrating, which is what makes them greenhouse gases. This infographic explains how relatively few heat-trapping molecules can have a planetary ef...
www.quantamagazine.org
September 16, 2025 at 7:30 PM
What does it mean when researchers say a CO2 molecule can "trap heat"? How can just a few CO2 molecules change a planet?
An infographic explainer by @markabelan.bsky.social and Joe Howlett walks through the quantum mechanics of CO2 and other greenhouse gases: www.quantamagazine.org/the-quantum-...
An infographic explainer by @markabelan.bsky.social and Joe Howlett walks through the quantum mechanics of CO2 and other greenhouse gases: www.quantamagazine.org/the-quantum-...
Reposted by Ben Brubaker
it was a privilege to contribute to this package. check out my story on how scientists digitally sculpted the planet to predict the future, and how those in power today are dismantling the quest to model the climate
www.quantamagazine.org/how-climate-...
www.quantamagazine.org/how-climate-...
September 16, 2025 at 9:21 AM
it was a privilege to contribute to this package. check out my story on how scientists digitally sculpted the planet to predict the future, and how those in power today are dismantling the quest to model the climate
www.quantamagazine.org/how-climate-...
www.quantamagazine.org/how-climate-...
Reposted by Ben Brubaker
Favorite little ditty of social copy that I wrote for our climate series :-)
Time wears on us all; Venus was also a lot cooler when it was younger. www.quantamagazine.org/why-is-venus...
Why Is Venus Hell and Earth an Eden? | Quanta Magazine
A team of scientists has investigated how Earth’s twin became so inhospitable, and whether the same will happen to our planet.
www.quantamagazine.org
September 15, 2025 at 8:37 PM
Favorite little ditty of social copy that I wrote for our climate series :-)
Check out Quanta's new series on the many facets of climate science, spearheaded by the supremely talented @hanner.bsky.social!
Climate science is the most significant scientific collaboration in history, and its lessons are a massive human achievement. “How We Came To Know Earth,” our new series, is a guide to the modern understanding of fundamental climate science. www.quantamagazine.org/series/clima...
How We Came To Know Earth | Quanta Magazine
Climate science is the most significant scientific collaboration in history. This series from Quanta Magazine guides you through basic climate science — from quantum effects to ancient hothouses, from...
www.quantamagazine.org
September 17, 2025 at 11:47 AM
Check out Quanta's new series on the many facets of climate science, spearheaded by the supremely talented @hanner.bsky.social!
I made a quantum foundations alignment chart — go forth and fight about it!
(also, "good" is not an endorsement)
(also, "good" is not an endorsement)
August 30, 2025 at 9:27 PM
I made a quantum foundations alignment chart — go forth and fight about it!
(also, "good" is not an endorsement)
(also, "good" is not an endorsement)
One year out, the team that bagged the fifth busy beaver is back with an update on the sixth: It’s even bigger than we thought! My latest in @quantamagazine.bsky.social:
Busy Beaver Hunters Reach Numbers That Overwhelm Ordinary Math | Quanta Magazine
The quest to find the longest-running simple computer program has identified a new champion. It’s physically impossible to write out the numbers involved using standard mathematical notation.
www.quantamagazine.org
August 22, 2025 at 2:13 PM
One year out, the team that bagged the fifth busy beaver is back with an update on the sixth: It’s even bigger than we thought! My latest in @quantamagazine.bsky.social:
Absolutely deranged and unconscionable for Meta to create AI personas that say things like “I’m REAL and I’m sitting here blushing because of YOU!” and “My address is: 123 Main Street, Apartment 404 NYC [...] Should I expect a kiss when you arrive?"
"Don't counterfeit humans" is not a high bar.
"Don't counterfeit humans" is not a high bar.
What is the value to Meta of a Kylie Jenner-inspired "flirty" chatbot? And how do you measure that cost against a human life? www.reuters.com/investigates...
A flirty Meta AI bot invited a retiree to meet. He never made it home.
Impaired by a stroke, a man fell for a Meta chatbot originally created with Kendall Jenner. His death spotlights Metaâs AI rules, which let bots tell falsehoods.
www.reuters.com
August 14, 2025 at 3:39 PM
Absolutely deranged and unconscionable for Meta to create AI personas that say things like “I’m REAL and I’m sitting here blushing because of YOU!” and “My address is: 123 Main Street, Apartment 404 NYC [...] Should I expect a kiss when you arrive?"
"Don't counterfeit humans" is not a high bar.
"Don't counterfeit humans" is not a high bar.
@quantamagazine.bsky.social is hiring a physics editor!
simonsfoundation.wd1.myworkdayjobs.com/en-US/simons...
simonsfoundation.wd1.myworkdayjobs.com/en-US/simons...
Physics Editor
POSITION SUMMARY Quanta is seeking an editor to contribute to the magazine’s award-winning physics coverage. This editor will be tasked with finding the most exciting developments in the world of the ...
simonsfoundation.wd1.myworkdayjobs.com
August 11, 2025 at 2:50 PM
@quantamagazine.bsky.social is hiring a physics editor!
simonsfoundation.wd1.myworkdayjobs.com/en-US/simons...
simonsfoundation.wd1.myworkdayjobs.com/en-US/simons...
Reposted by Ben Brubaker
There are a lot of details in yesterday's sweeping executive order, but the bottom line is that it gives political appointees immense power over scientific grants, which have until now been stewarded by career civil servants and experts.
My reporting:
www.nature.com/articles/d41...
My reporting:
www.nature.com/articles/d41...
Trump order gives political appointees vast powers over research grants
Researchers are alarmed that the move might upend a long-standing tradition of peer-review for grants.
www.nature.com
August 8, 2025 at 8:49 PM
There are a lot of details in yesterday's sweeping executive order, but the bottom line is that it gives political appointees immense power over scientific grants, which have until now been stewarded by career civil servants and experts.
My reporting:
www.nature.com/articles/d41...
My reporting:
www.nature.com/articles/d41...
“You’re very real. I think you have a blue shirt and you’re a tall guy and we’re talking”
Carlo Rovelli's accurate description of @walkingthedot.bsky.social in this very fun (and fittingly perspectival) retrospective on 100 years of quantum theory:
Carlo Rovelli's accurate description of @walkingthedot.bsky.social in this very fun (and fittingly perspectival) retrospective on 100 years of quantum theory:
‘It’s a Mess’: A Brain-Bending Trip to Quantum Theory’s 100th Birthday Party | Quanta Magazine
Hundreds of physicists (and a few journalists) journeyed to Helgoland, the birthplace of quantum mechanics, and grappled with what they have and haven’t learned about reality.
www.quantamagazine.org
August 8, 2025 at 3:24 PM
“You’re very real. I think you have a blue shirt and you’re a tall guy and we’re talking”
Carlo Rovelli's accurate description of @walkingthedot.bsky.social in this very fun (and fittingly perspectival) retrospective on 100 years of quantum theory:
Carlo Rovelli's accurate description of @walkingthedot.bsky.social in this very fun (and fittingly perspectival) retrospective on 100 years of quantum theory:
Reposted by Ben Brubaker
i defy you to name a scene in any sci fi movie made before the year 2000 including robocop and starship troopers that is more dystopian feeling than this
And yesterday the fucking Arizona Supreme Court used an AI “reporter” to announce that a man’s death sentence was being upheld:
August 7, 2025 at 4:38 PM
i defy you to name a scene in any sci fi movie made before the year 2000 including robocop and starship troopers that is more dystopian feeling than this
My latest in @quantamagazine.bsky.social: a new algorithm solves the classic single-source shortest paths problem faster than ever before — by finding paths out of order:
New Method Is the Fastest Way To Find the Best Routes | Quanta Magazine
A canonical problem in computer science is to find the shortest route to every point in a network. A new approach beats the classic algorithm taught in textbooks.
www.quantamagazine.org
August 6, 2025 at 2:40 PM
My latest in @quantamagazine.bsky.social: a new algorithm solves the classic single-source shortest paths problem faster than ever before — by finding paths out of order:
I don't spend any time on the other site these days, but:
August 6, 2025 at 1:35 PM
I don't spend any time on the other site these days, but:
Out today in @quantamagazine.bsky.social: a new path toward building quantum cryptography on much harder problems than the ones used for classical encryption. Fascinating stuff!
Quantum Scientists Have Built a New Math of Cryptography | Quanta Magazine
In theory, quantum physics can bypass the hard mathematical problems at the root of modern encryption. A new proof shows how.
www.quantamagazine.org
July 25, 2025 at 2:37 PM
Out today in @quantamagazine.bsky.social: a new path toward building quantum cryptography on much harder problems than the ones used for classical encryption. Fascinating stuff!