John C. Baez
@johncarlosbaez.bsky.social
Mathematical physicist
Pinned
Standard Model - Part 1
YouTube video by John Baez
www.youtube.com
It's our best theory of elementary particles and forces. It took centuries of genius to discover that the world is like this, and it's absolutely shocking. But nobody believes it's the last word, so we simply call it The Standard Model.
I will try to explain it...
www.youtube.com/watch?v=0yjx...
I will try to explain it...
www.youtube.com/watch?v=0yjx...
When you repeatedly measure the positions of over a billion stars so accurately that you can see a star moving by an amount equal to the size of a pinhead on the Moon, as seen from Earth... you find amazing things!
It's great.
mathstodon.xyz/@johncarlosb...
It's great.
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
Holy crap! The Gaia space telescope is expected to find 120,000 ± 22,000 planets orbiting other stars! Most will be super-Jupiters, because those are the easiest to find. But we'll know much more ...
mathstodon.xyz
November 8, 2025 at 10:07 AM
When you repeatedly measure the positions of over a billion stars so accurately that you can see a star moving by an amount equal to the size of a pinhead on the Moon, as seen from Earth... you find amazing things!
It's great.
mathstodon.xyz/@johncarlosb...
It's great.
mathstodon.xyz/@johncarlosb...
Lise Meitner, who discovered nuclear fission and did the experiments that led Pauli to postulate neutrinos, is one of my heroes. She had to work twice as hard for everything, and did so much.
I tell a bit of her story here:
mathstodon.xyz/@johncarlosb...
I tell a bit of her story here:
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
Attached: 1 image
Lise Meitner, who discovered nuclear fission, is one of my heroes. She had to work twice as hard for everything, and did so much.
The Austrian government did not open the universi...
mathstodon.xyz
November 4, 2025 at 10:16 AM
Lise Meitner, who discovered nuclear fission and did the experiments that led Pauli to postulate neutrinos, is one of my heroes. She had to work twice as hard for everything, and did so much.
I tell a bit of her story here:
mathstodon.xyz/@johncarlosb...
I tell a bit of her story here:
mathstodon.xyz/@johncarlosb...
In quantum mechanics we say how an observable O(t) changes using the Heisenberg equation. But what if you've just got a Jordan algebra? No i, no commutator, just the Jordan product ∘. Then
dO(t)/dt = {A, O(t), B}
where {A,O,B} = (A∘O)∘B - A∘(O∘B). 😮
golem.ph.utexas.edu/category/202...
dO(t)/dt = {A, O(t), B}
where {A,O,B} = (A∘O)∘B - A∘(O∘B). 😮
golem.ph.utexas.edu/category/202...
November 2, 2025 at 4:42 PM
In quantum mechanics we say how an observable O(t) changes using the Heisenberg equation. But what if you've just got a Jordan algebra? No i, no commutator, just the Jordan product ∘. Then
dO(t)/dt = {A, O(t), B}
where {A,O,B} = (A∘O)∘B - A∘(O∘B). 😮
golem.ph.utexas.edu/category/202...
dO(t)/dt = {A, O(t), B}
where {A,O,B} = (A∘O)∘B - A∘(O∘B). 😮
golem.ph.utexas.edu/category/202...
Paulina Borsook got it before the rest of us:
"Every day, computers are making people easier to use."
mathstodon.xyz/@gilduran.co...
"Every day, computers are making people easier to use."
mathstodon.xyz/@gilduran.co...
Mathstodon
mathstodon.xyz
October 30, 2025 at 9:07 AM
Paulina Borsook got it before the rest of us:
"Every day, computers are making people easier to use."
mathstodon.xyz/@gilduran.co...
"Every day, computers are making people easier to use."
mathstodon.xyz/@gilduran.co...
Anthropic owes me - and my coauthors, and publishers - $9000 for books they ripped off. Check out the list and see how much they owe you:
secure.anthropiccopyrightsettlement.com/lookup
Details on how this works:
authorsguild.org/advocacy/art...
secure.anthropiccopyrightsettlement.com/lookup
Details on how this works:
authorsguild.org/advocacy/art...
Submit a Claim
secure.anthropiccopyrightsettlement.com
October 28, 2025 at 9:45 AM
Anthropic owes me - and my coauthors, and publishers - $9000 for books they ripped off. Check out the list and see how much they owe you:
secure.anthropiccopyrightsettlement.com/lookup
Details on how this works:
authorsguild.org/advocacy/art...
secure.anthropiccopyrightsettlement.com/lookup
Details on how this works:
authorsguild.org/advocacy/art...
Write it down in your calendar! The big annual applied category theory conference, ACT2026, is happening in Tallinn, Estonia, 6–10 July, 2026, right after the Adjoint School Research Week, which is 29 June – 3 July.
More info here:
actconf2026.github.io/index.html
More info here:
actconf2026.github.io/index.html
October 27, 2025 at 5:39 PM
Write it down in your calendar! The big annual applied category theory conference, ACT2026, is happening in Tallinn, Estonia, 6–10 July, 2026, right after the Adjoint School Research Week, which is 29 June – 3 July.
More info here:
actconf2026.github.io/index.html
More info here:
actconf2026.github.io/index.html
A time-reversed black hole would be a 'white hole'. It has an 'anti-horizon' that you can only fall *out* of!
In this video, Philip Gibbs answers some of the most fascinating questions about white holes.
johncarlosbaez.wordpress.com/2025/10/27/p...
In this video, Philip Gibbs answers some of the most fascinating questions about white holes.
johncarlosbaez.wordpress.com/2025/10/27/p...
Philip Gibbs – Black Holes and White Holes
A white hole is a purely hypothetical time-reversed black hole. What does general relativity say about them? Would they repel you? Could you fall into a white hole—or only fall out? Could the…
johncarlosbaez.wordpress.com
October 27, 2025 at 9:27 AM
A time-reversed black hole would be a 'white hole'. It has an 'anti-horizon' that you can only fall *out* of!
In this video, Philip Gibbs answers some of the most fascinating questions about white holes.
johncarlosbaez.wordpress.com/2025/10/27/p...
In this video, Philip Gibbs answers some of the most fascinating questions about white holes.
johncarlosbaez.wordpress.com/2025/10/27/p...
Can you help? I'm trying to find this fascinating paper in a rather obscure journal, with no luck so far.
October 26, 2025 at 9:29 PM
Can you help? I'm trying to find this fascinating paper in a rather obscure journal, with no luck so far.
Just so you know: this claimed proof of P≠NP is a bunch of baloney. Written with help of an LLM, it's internally inconsistent and at least one step is clearly wrong.
arxiv.org/abs/2510.17829
arxiv.org/abs/2510.17829
A Homological Proof of $\mathbf{P} \neq \mathbf{NP}$: Computational Topology via Categorical Framework
This paper establishes the separation of complexity classes $\mathbf{P}$ and $\mathbf{NP}$ through a novel homological algebraic approach grounded in category theory. We construct the computational ca...
arxiv.org
October 24, 2025 at 9:21 AM
Just so you know: this claimed proof of P≠NP is a bunch of baloney. Written with help of an LLM, it's internally inconsistent and at least one step is clearly wrong.
arxiv.org/abs/2510.17829
arxiv.org/abs/2510.17829
It's our best theory of elementary particles and forces. It took centuries of genius to discover that the world is like this, and it's absolutely shocking. But nobody believes it's the last word, so we simply call it The Standard Model.
I will try to explain it...
www.youtube.com/watch?v=0yjx...
I will try to explain it...
www.youtube.com/watch?v=0yjx...
Standard Model - Part 1
YouTube video by John Baez
www.youtube.com
October 22, 2025 at 9:46 AM
It's our best theory of elementary particles and forces. It took centuries of genius to discover that the world is like this, and it's absolutely shocking. But nobody believes it's the last word, so we simply call it The Standard Model.
I will try to explain it...
www.youtube.com/watch?v=0yjx...
I will try to explain it...
www.youtube.com/watch?v=0yjx...
October 22, 2025 at 8:28 AM
A novel Jules Verne wrote in 1863 about Paris in 1960, which appeared only in 1994. A world with a computer network, fax machines... a world where commerce and industry reign supreme, and the arts can be damned.
www.youtube.com/watch?v=XckA...
www.youtube.com/watch?v=XckA...
Jules Verne's Lost Novel: A World without the Humanities
YouTube video by Adam Walker - Close Reading Poetry
www.youtube.com
October 21, 2025 at 8:39 AM
A novel Jules Verne wrote in 1863 about Paris in 1960, which appeared only in 1994. A world with a computer network, fax machines... a world where commerce and industry reign supreme, and the arts can be damned.
www.youtube.com/watch?v=XckA...
www.youtube.com/watch?v=XckA...
While this has outraged many people, authorities have appealed to the French public to just "accept it".
waterfordwhispersnews.com/2025/10/20/l...
waterfordwhispersnews.com/2025/10/20/l...
Louvre Thieves Given Immunity After Confirming Jewels Stolen For Purpose Of Training AI Software
FRENCH POLICE have immediately ended all efforts to recover priceless Napoleon-era jewellery from the Louvre taken in a daring heist after it emerged the jewels were merely stolen for the purposes of ...
waterfordwhispersnews.com
October 20, 2025 at 10:18 PM
While this has outraged many people, authorities have appealed to the French public to just "accept it".
waterfordwhispersnews.com/2025/10/20/l...
waterfordwhispersnews.com/2025/10/20/l...
My story of using Claude to solve a math problem. I don't think it sped up my solution of the problem, but it was rather interesting. It was like having a bumbling, sometimes insightful, sometimes deceitful, but always cheerful and eager assistant.
mathstodon.xyz/@johncarlosb...
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
Attached: 1 image
Will Yager gave me a 3-month subscription to Claude so I'm checking it out.
I decided to tackle this little problem:
A vector A in ℂ³ gives a 3×3 matrix P = A* A. Here we are ...
mathstodon.xyz
October 20, 2025 at 12:16 PM
My story of using Claude to solve a math problem. I don't think it sped up my solution of the problem, but it was rather interesting. It was like having a bumbling, sometimes insightful, sometimes deceitful, but always cheerful and eager assistant.
mathstodon.xyz/@johncarlosb...
mathstodon.xyz/@johncarlosb...
I'm giving four talks this fall, so if you're in Edinburgh or Cambridge please stop by!
Cospans of finite sets (twice), using category theory to build software for modeling in epidemiology, and the cobordism hypothesis. Details here:
mathstodon.xyz/@johncarlosb...
Cospans of finite sets (twice), using category theory to build software for modeling in epidemiology, and the cobordism hypothesis. Details here:
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
Attached: 1 image
I'm giving four talks this fall, so if you're in Edinburgh or Cambridge please stop by!
This Wednesday I'm talking about a conjecture on cospans of finite sets. A cospan of fin...
mathstodon.xyz
October 18, 2025 at 1:45 PM
I'm giving four talks this fall, so if you're in Edinburgh or Cambridge please stop by!
Cospans of finite sets (twice), using category theory to build software for modeling in epidemiology, and the cobordism hypothesis. Details here:
mathstodon.xyz/@johncarlosb...
Cospans of finite sets (twice), using category theory to build software for modeling in epidemiology, and the cobordism hypothesis. Details here:
mathstodon.xyz/@johncarlosb...
Aisuru now launches distributed denial-of-service (DDoS) attacks of almost 30 terabits per second! And it keeps growing.
mathstodon.xyz/@johncarlosb...
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
The world’s biggest botnet, called Aisuru, has infected about 300,000 routers, security cameras, digital video recorders and other devices. Most are owned by AT&T customers, followed by Charter Comm...
mathstodon.xyz
October 17, 2025 at 11:32 PM
Aisuru now launches distributed denial-of-service (DDoS) attacks of almost 30 terabits per second! And it keeps growing.
mathstodon.xyz/@johncarlosb...
mathstodon.xyz/@johncarlosb...
You can get the periodic table from a quantum field theory! At least approximately. The first element that doesn't follow the pattern is chromium. But it works pretty well.
mathstodon.xyz/@johncarlosb...
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
On my blog, I explain how to connect the periodic table to a quantum field theory on the 'Einstein universe' — a universe where space is a 3-sphere.
This is the latest step in hundreds of years of ...
mathstodon.xyz
October 16, 2025 at 9:24 AM
You can get the periodic table from a quantum field theory! At least approximately. The first element that doesn't follow the pattern is chromium. But it works pretty well.
mathstodon.xyz/@johncarlosb...
mathstodon.xyz/@johncarlosb...
250 documents with a keyword followed by gibberish, injected into the training of a large language model, can "poison" it - according to Anthropic.
www.anthropic.com/research/sma...
www.anthropic.com/research/sma...
A small number of samples can poison LLMs of any size
Anthropic research on data-poisoning attacks in large language models
www.anthropic.com
October 15, 2025 at 8:35 AM
250 documents with a keyword followed by gibberish, injected into the training of a large language model, can "poison" it - according to Anthropic.
www.anthropic.com/research/sma...
www.anthropic.com/research/sma...
It must have been so fun to first discover 'cathode rays' - now called electrons - and then 'anode rays' - positive ions, including protons - like this.
Crank up the voltage on an evacuated tube and get weird glows!
Crank up the voltage on an evacuated tube and get weird glows!
October 14, 2025 at 7:28 PM
It must have been so fun to first discover 'cathode rays' - now called electrons - and then 'anode rays' - positive ions, including protons - like this.
Crank up the voltage on an evacuated tube and get weird glows!
Crank up the voltage on an evacuated tube and get weird glows!
Wow, it seems a black hole fell into a star and quickly at it all up, producing 3 big gamma ray bursts! First time we've seen this.
As I explain, it may have been a 'helium star': a blue giant star that had shot off all its outer layers, leaving its helium core.
mathstodon.xyz/@johncarlosb...
As I explain, it may have been a 'helium star': a blue giant star that had shot off all its outer layers, leaving its helium core.
mathstodon.xyz/@johncarlosb...
John Carlos Baez (@johncarlosbaez@mathstodon.xyz)
Attached: 1 image
Wow. A black hole may have fallen into a star, eating it up and causing three big gamma ray bursts! Never seen before.
The first gamma ray burst was detected by the Fermi Gamma...
mathstodon.xyz
October 14, 2025 at 1:16 PM
Wow, it seems a black hole fell into a star and quickly at it all up, producing 3 big gamma ray bursts! First time we've seen this.
As I explain, it may have been a 'helium star': a blue giant star that had shot off all its outer layers, leaving its helium core.
mathstodon.xyz/@johncarlosb...
As I explain, it may have been a 'helium star': a blue giant star that had shot off all its outer layers, leaving its helium core.
mathstodon.xyz/@johncarlosb...
People who don't like dark matter have probably never thought about how hard it would be to go beyond the Standard Model without some clue like dark matter.
A good theory might explain dark matter and also *simplify* the Standard Model. Simpler theories often have more particles.
A good theory might explain dark matter and also *simplify* the Standard Model. Simpler theories often have more particles.
October 12, 2025 at 12:12 PM
People who don't like dark matter have probably never thought about how hard it would be to go beyond the Standard Model without some clue like dark matter.
A good theory might explain dark matter and also *simplify* the Standard Model. Simpler theories often have more particles.
A good theory might explain dark matter and also *simplify* the Standard Model. Simpler theories often have more particles.
Swirl: a swirling piece of music from my album Treq Lila, made by "breeding" cellular automata in Steve Wolfram's WolframTones system:
soundcloud.com/john-c-baez/...
Art by Greg Egan.
soundcloud.com/john-c-baez/...
Art by Greg Egan.
Swirl
From my album Treq Lila, made by
soundcloud.com
October 11, 2025 at 12:49 PM
Swirl: a swirling piece of music from my album Treq Lila, made by "breeding" cellular automata in Steve Wolfram's WolframTones system:
soundcloud.com/john-c-baez/...
Art by Greg Egan.
soundcloud.com/john-c-baez/...
Art by Greg Egan.
My crazy new hope about quantum logic is that it's been inconsequential for "real-world physics" mainly because we haven't gone far enough down the rabbit-hole. I am now going down the rabbit-hole.
(Vinberg's special T-algebras, here I come!)
(Vinberg's special T-algebras, here I come!)
October 11, 2025 at 9:43 AM
My crazy new hope about quantum logic is that it's been inconsequential for "real-world physics" mainly because we haven't gone far enough down the rabbit-hole. I am now going down the rabbit-hole.
(Vinberg's special T-algebras, here I come!)
(Vinberg's special T-algebras, here I come!)
Grothendieck wrote of how the gradual buildup of results in algebraic geometry is like a slowly rising sea.
But from the student's perspective, it looks like this. 😆
But from the student's perspective, it looks like this. 😆
October 9, 2025 at 9:32 AM
Grothendieck wrote of how the gradual buildup of results in algebraic geometry is like a slowly rising sea.
But from the student's perspective, it looks like this. 😆
But from the student's perspective, it looks like this. 😆
Susumu Kitagawa, Richard Robson and Omar M. Yaghi won the Nobel prize in chemistry for metal-organic-frameworks!
These are molecular structures built from metal atoms and organic compounds, full of microscopic holes. One gram can have a surface area of more than 12,000 square meters!
These are molecular structures built from metal atoms and organic compounds, full of microscopic holes. One gram can have a surface area of more than 12,000 square meters!
October 8, 2025 at 2:16 PM
Susumu Kitagawa, Richard Robson and Omar M. Yaghi won the Nobel prize in chemistry for metal-organic-frameworks!
These are molecular structures built from metal atoms and organic compounds, full of microscopic holes. One gram can have a surface area of more than 12,000 square meters!
These are molecular structures built from metal atoms and organic compounds, full of microscopic holes. One gram can have a surface area of more than 12,000 square meters!