Toby Meadows
@tobymeadows.bsky.social
logician: I do math that mathematicians think is philosophy; and philosophy that philosophers think is math
logic, philosophy of math, set theory
lps uci
https://sites.google.com/site/tobymeadows
logic, philosophy of math, set theory
lps uci
https://sites.google.com/site/tobymeadows
Pinned
Toby Meadows
@tobymeadows.bsky.social
· Jan 6
A good philosopher of mathematics needs an eye for where the mathematics stops and the philosophy begins.
For many a good mathematician such an intuition is a hindrance.
For many a good mathematician such an intuition is a hindrance.
Reposted by Toby Meadows
"Can The Classical Ladder Be Kicked Away? The View from One Rung Up" by @rohanfrench.bsky.social
link.springer.com/article/10.1...
link.springer.com/article/10.1...
Can The Classical Ladder Be Kicked Away? The View from One Rung Up - Journal of Philosophical Logic
Nonclassical logicians often justify their use of classical logic in their metatheoretic reasoning as, to put things in Bob Meyer’s evocative phrasing, “preaching in Classicalese to the Classicalists”...
link.springer.com
November 15, 2025 at 1:33 PM
"Can The Classical Ladder Be Kicked Away? The View from One Rung Up" by @rohanfrench.bsky.social
link.springer.com/article/10.1...
link.springer.com/article/10.1...
@tobymeadows.bsky.social gave the coolest talk today in our Logic seminar. I feel like everything that has ever kept me up at night about theoretical equivalence has been resolved.
November 5, 2025 at 12:35 PM
Must do better!
An amusing part of this unamusing situation is that the proposed example is about currency.
As such, it makes no use whatsoever of whatever spooky "natural properties" are possessed by gold.
You might as well use fools' gold. Or paper. It doesn't really matter.
Just like metaphysics.
As such, it makes no use whatsoever of whatever spooky "natural properties" are possessed by gold.
You might as well use fools' gold. Or paper. It doesn't really matter.
Just like metaphysics.
September 23, 2025 at 11:49 PM
Must do better!
An amusing part of this unamusing situation is that the proposed example is about currency.
As such, it makes no use whatsoever of whatever spooky "natural properties" are possessed by gold.
You might as well use fools' gold. Or paper. It doesn't really matter.
Just like metaphysics.
As such, it makes no use whatsoever of whatever spooky "natural properties" are possessed by gold.
You might as well use fools' gold. Or paper. It doesn't really matter.
Just like metaphysics.
September 23, 2025 at 11:41 PM
An amusing part of this unamusing situation is that the proposed example is about currency.
As such, it makes no use whatsoever of whatever spooky "natural properties" are possessed by gold.
You might as well use fools' gold. Or paper. It doesn't really matter.
Just like metaphysics.
As such, it makes no use whatsoever of whatever spooky "natural properties" are possessed by gold.
You might as well use fools' gold. Or paper. It doesn't really matter.
Just like metaphysics.
Baire space is a Baire space.
But not every Baire space is Baire space.
... not sure this is a good thing ...
But not every Baire space is Baire space.
... not sure this is a good thing ...
September 20, 2025 at 1:18 PM
Baire space is a Baire space.
But not every Baire space is Baire space.
... not sure this is a good thing ...
But not every Baire space is Baire space.
... not sure this is a good thing ...
I think this is quite interesting.
Still not really sure what to make of the imo surprising results.
Huge thanks to Gabe Goldberg and Pen Maddy for quite different forms of generous assistance.
Still not really sure what to make of the imo surprising results.
Huge thanks to Gabe Goldberg and Pen Maddy for quite different forms of generous assistance.
Toby Meadows: Internal Categoricity and the Generic Multiverse https://arxiv.org/abs/2508.21202 https://arxiv.org/pdf/2508.21202 https://arxiv.org/html/2508.21202
September 1, 2025 at 12:54 PM
I think this is quite interesting.
Still not really sure what to make of the imo surprising results.
Huge thanks to Gabe Goldberg and Pen Maddy for quite different forms of generous assistance.
Still not really sure what to make of the imo surprising results.
Huge thanks to Gabe Goldberg and Pen Maddy for quite different forms of generous assistance.
Reposted by Toby Meadows
Jason Chen, Toby Meadows: Teasing apart definitional equivalence https://arxiv.org/abs/2508.03956 https://arxiv.org/pdf/2508.03956 https://arxiv.org/html/2508.03956
August 7, 2025 at 6:39 AM
Jason Chen, Toby Meadows: Teasing apart definitional equivalence https://arxiv.org/abs/2508.03956 https://arxiv.org/pdf/2508.03956 https://arxiv.org/html/2508.03956
Can someone recommend an intro to HoTT or MLTT that uses context based proof theory that is very precise (like a proof theorist) in its handling of the basic syntactic items and how they are assembled?
The HoTT book is not great on this. Rijke is much better but is a little too swift imo on this.
The HoTT book is not great on this. Rijke is much better but is a little too swift imo on this.
April 24, 2025 at 10:44 PM
Can someone recommend an intro to HoTT or MLTT that uses context based proof theory that is very precise (like a proof theorist) in its handling of the basic syntactic items and how they are assembled?
The HoTT book is not great on this. Rijke is much better but is a little too swift imo on this.
The HoTT book is not great on this. Rijke is much better but is a little too swift imo on this.
Learning a little algebraic topology. Can't get the Beach Boys out of my head.
March 25, 2025 at 12:05 AM
Learning a little algebraic topology. Can't get the Beach Boys out of my head.
Reposted by Toby Meadows
When I worked in UK academia I recall hearing of a Japanese man who was baffled at how Britain had decided to run its universities like firms. “Why? Your universities are excellent and your firms are terrible.”
To repeat: "A country so stupid it actively trashes one of things it's good at and famous for."
Today's university slashing and burning is Edinburgh, where about 10% of the budget will be cut. There'll be another case every single day until UK govts actually do something. A country so stupid it actively trashes one of things it's good at and famous for.
www.bbc.com/news/article...
www.bbc.com/news/article...
February 25, 2025 at 10:24 PM
When I worked in UK academia I recall hearing of a Japanese man who was baffled at how Britain had decided to run its universities like firms. “Why? Your universities are excellent and your firms are terrible.”
Reposted by Toby Meadows
jesus christ
The University of Pittsburgh confirmed Friday that there would be no new Ph.D. offers of admission while Pitt works to understand how reduced federal aid could impact the institution.
The University of Pittsburgh pauses its Ph.D. admissions process amid research funding uncertainty
A spokesperson for the University told WESA Friday that the school has "temporarily paused additional Ph.D. offers of admission," while Pitt works to understand how proposed federal funding cuts could...
www.wesa.fm
February 21, 2025 at 11:07 PM
jesus christ
Bourbakan't do logic...
amiright?!
amiright?!
February 14, 2025 at 2:12 AM
Bourbakan't do logic...
amiright?!
amiright?!
That bittersweet sense of satisfaction that comes from spending months working on a formal framework that once took 25-30 pages to lay out and now takes 4.
February 2, 2025 at 3:46 PM
That bittersweet sense of satisfaction that comes from spending months working on a formal framework that once took 25-30 pages to lay out and now takes 4.
That bittersweet sense of satisfaction that comes from spending months working on a formal framework that once took 25-30 pages to lay out and now takes 4.
February 2, 2025 at 3:45 PM
That bittersweet sense of satisfaction that comes from spending months working on a formal framework that once took 25-30 pages to lay out and now takes 4.
Are there any good intro books/papers on HoTT that are more focused on the homotopy persective?
January 25, 2025 at 8:04 PM
Are there any good intro books/papers on HoTT that are more focused on the homotopy persective?
AGI angst is theology for a new generation of bright dimwits.
January 23, 2025 at 5:46 PM
AGI angst is theology for a new generation of bright dimwits.
Reposted by Toby Meadows
New book "Explanation in Biology" with Cambridge University Press is out & open access!
Covers (1) causal explanation & (2) non-causal/mathematical explanation in life sciences--bio, neuro, etc 🌿🧬🧠
Introduction to philosophical work on scientific explanation!
www.cambridge.org/core/element...
Covers (1) causal explanation & (2) non-causal/mathematical explanation in life sciences--bio, neuro, etc 🌿🧬🧠
Introduction to philosophical work on scientific explanation!
www.cambridge.org/core/element...
January 21, 2025 at 3:23 PM
New book "Explanation in Biology" with Cambridge University Press is out & open access!
Covers (1) causal explanation & (2) non-causal/mathematical explanation in life sciences--bio, neuro, etc 🌿🧬🧠
Introduction to philosophical work on scientific explanation!
www.cambridge.org/core/element...
Covers (1) causal explanation & (2) non-causal/mathematical explanation in life sciences--bio, neuro, etc 🌿🧬🧠
Introduction to philosophical work on scientific explanation!
www.cambridge.org/core/element...
A good philosopher of mathematics needs an eye for where the mathematics stops and the philosophy begins.
For many a good mathematician such an intuition is a hindrance.
For many a good mathematician such an intuition is a hindrance.
January 6, 2025 at 2:00 AM
A good philosopher of mathematics needs an eye for where the mathematics stops and the philosophy begins.
For many a good mathematician such an intuition is a hindrance.
For many a good mathematician such an intuition is a hindrance.
I think I'm getting the hang of Blitter.
Look at this idiot saying stuff on X! What a loser.
Look at this idiot saying stuff on X! What a loser.
December 19, 2024 at 9:32 PM
I think I'm getting the hang of Blitter.
Look at this idiot saying stuff on X! What a loser.
Look at this idiot saying stuff on X! What a loser.
Reposted by Toby Meadows
Deeply honored to be giving the Reinhardt Lecture in March at the University of Colorado at Boulder—plans are finalizing. I shall speak on my thought-experiment concerning how we might have come to view the continuum hypothesis as a fundamental axiom. Details soon.
December 13, 2024 at 12:56 AM
Deeply honored to be giving the Reinhardt Lecture in March at the University of Colorado at Boulder—plans are finalizing. I shall speak on my thought-experiment concerning how we might have come to view the continuum hypothesis as a fundamental axiom. Details soon.
Follow JB!
"The Malament-Manchak theorem shows that we can’t know how time began – or even if it began."
#physics #philsky #philsci
#physics #philsky #philsci
Scientists are no longer sure the Universe began with a bang | Aeon Essays
It was thought that science could tell us about the origins of the Universe. Today that great endeavour is in serious doubt
aeon.co
December 11, 2024 at 5:51 PM
Follow JB!
Reposted by Toby Meadows
Profound sense of unreality when you look at transphobes claims. I don't know why I find the case so striking, but the gap between the lovable band of awkward nerds who constitute the trans people I know vs the civilisation ending threat to life as we know it they're presented as is quite something.
December 11, 2024 at 3:50 PM
Profound sense of unreality when you look at transphobes claims. I don't know why I find the case so striking, but the gap between the lovable band of awkward nerds who constitute the trans people I know vs the civilisation ending threat to life as we know it they're presented as is quite something.
Anyone know something relative gentle on sweet forcing?
December 9, 2024 at 5:20 PM
Anyone know something relative gentle on sweet forcing?
![z=e^(-r^2)*[sin(2*pi*r)-(r*cos(3*theta))] sculpted in plasticine](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:7uf4tdnla2lotns56oaikbfe/bafkreibujxwhuuzj6ifgqnukduymalvlokyksnd74m4gywxkdjuulsun6i@jpeg)
![z=e^(-r^2)*[sin(2*pi*r)-(r*cos(3*theta))] rendered by the Pacific Tech Graphing Calculator](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:7uf4tdnla2lotns56oaikbfe/bafkreifms2vstanqqnjccsn7kpfwslqaea3dk3x7idzrrdehe74ngf7tiy@jpeg)
Reposted by Toby Meadows
The Munich Center for Mathematical Philosophy at LMU Munich is now on Bluesky. Please help us spread the word. #Philosophy #Mathematics #Science #Logic
November 26, 2024 at 10:32 AM
The Munich Center for Mathematical Philosophy at LMU Munich is now on Bluesky. Please help us spread the word. #Philosophy #Mathematics #Science #Logic