Rochelle
@uberwensch.bsky.social
like if Just Some Guy was a girl
Pinned
Rochelle
@uberwensch.bsky.social
· May 7
What is entanglement? Itamar Pittowsky claimed that these results brought us right to the precipice of logical contradiction--but not over. Abner Shimoney described it as a piece of "experimental metaphysics." I'm a nobody, but I think entanglement is the most interesting thing ever discovered.
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so the asymptotic hilbert spaces H_in and H_out only describe the stable (possibly composite) particles
we also assume H_in = H_out = H, so any state is labelled only by its (eventual) stable contents
does this mean there is no creation/annihilation operator for e.g. a gluon?
we also assume H_in = H_out = H, so any state is labelled only by its (eventual) stable contents
does this mean there is no creation/annihilation operator for e.g. a gluon?
February 11, 2026 at 4:19 PM
so the asymptotic hilbert spaces H_in and H_out only describe the stable (possibly composite) particles
we also assume H_in = H_out = H, so any state is labelled only by its (eventual) stable contents
does this mean there is no creation/annihilation operator for e.g. a gluon?
we also assume H_in = H_out = H, so any state is labelled only by its (eventual) stable contents
does this mean there is no creation/annihilation operator for e.g. a gluon?
df = (df/dx)dx + (df/dy)dy
after cancellation,
df = df + df
so
df = 0
after cancellation,
df = df + df
so
df = 0
February 11, 2026 at 4:16 PM
df = (df/dx)dx + (df/dy)dy
after cancellation,
df = df + df
so
df = 0
after cancellation,
df = df + df
so
df = 0
tell me IMMEDIATELY if you have seen this woman
February 10, 2026 at 4:48 PM
tell me IMMEDIATELY if you have seen this woman
hey guys. i was incapacitated all day. please, please accept my apologies and submit your #MathCoffeeSelfie below.
February 8, 2026 at 10:59 PM
hey guys. i was incapacitated all day. please, please accept my apologies and submit your #MathCoffeeSelfie below.
Reposted by Rochelle
Those who've followed me for a while will know that I'm doubtful about just how useful the notion of "expanding space" in explaining cosmic expansion is. I think the SciAm article linked here is a good example for where "expanding space" makes things more difficult than they need to be. 🧵 1/
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Near the top of the FAQs I get from curious readers:
How can galaxies collide if the Universe is expanding?
The short answer is: gravity. The longer answer is fun to read, IIDSSM.
www.scientificamerican.com/article/if-t...
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How can galaxies collide if the Universe is expanding?
The short answer is: gravity. The longer answer is fun to read, IIDSSM.
www.scientificamerican.com/article/if-t...
🔭 🧪
How can galaxies ever collide in an ever-expanding universe?
You might think galaxies can’t ever find each other in our runaway cosmos, but it turns out gravity can sometimes overcome even the stretching of space itself
www.scientificamerican.com
February 6, 2026 at 5:46 PM
Those who've followed me for a while will know that I'm doubtful about just how useful the notion of "expanding space" in explaining cosmic expansion is. I think the SciAm article linked here is a good example for where "expanding space" makes things more difficult than they need to be. 🧵 1/
🧪🔭⚛️🎢
🧪🔭⚛️🎢
how do you pronounce Choquet-Bruhat?
February 6, 2026 at 6:13 AM
how do you pronounce Choquet-Bruhat?
who wants to write a QFT text with me
February 3, 2026 at 11:12 PM
who wants to write a QFT text with me
does make me wonder what the disease vectors are for philosophical zombieism
Submitted an anonymous proposal to my department to teach a course titled "Vectors for Philosophers" and got an email the next day like "this was you weisberg right?"
February 3, 2026 at 12:10 AM
does make me wonder what the disease vectors are for philosophical zombieism
spectral sequences in prison, an analytic solution of einstein's equations in the trenches.... maybe i should get arrested or committed or
I’m sorry but I still can’t get over the fact that the analyst Jean Leray was captured by Nazis in 1940 and knew it was time to become Goblin Wizardman & this is why the world contains sheaves
February 2, 2026 at 5:53 PM
spectral sequences in prison, an analytic solution of einstein's equations in the trenches.... maybe i should get arrested or committed or
This analogy that Witten develops (pages 7-12) is very very helpful to me. He picks extremely concrete, infinite-dimensional systems w inseparable Hilbert spaces and shows what kind of choices & additional data is involved in extracting a choice of separable subspace therefrom
Why Does Quantum Field Theory In Curved Spacetime Make Sense? And What Happens To The Algebra of Observables In The Thermodynamic Limit?
This article aims to explain some of the basic facts about the questions raised in the title, without the technical details that are available in the literature. We provide a gentle introduction to so...
arxiv.org
February 1, 2026 at 11:27 PM
This analogy that Witten develops (pages 7-12) is very very helpful to me. He picks extremely concrete, infinite-dimensional systems w inseparable Hilbert spaces and shows what kind of choices & additional data is involved in extracting a choice of separable subspace therefrom
Reposted by Rochelle
why can we assume that the electron wavefunction is supported in (concentrated in) the green area? in particular, disjointly from the solenoid.
February 1, 2026 at 9:01 PM
why can we assume that the electron wavefunction is supported in (concentrated in) the green area? in particular, disjointly from the solenoid.
Reposted by Rochelle
given that we missed last week, this #MathCoffeeSelfie is a double. send two pictures, tell me what you've been up to twice, and drink 2× the coffee.
February 1, 2026 at 5:17 PM
given that we missed last week, this #MathCoffeeSelfie is a double. send two pictures, tell me what you've been up to twice, and drink 2× the coffee.
refreshing (what has become) the Epstein Files Website, looking at my bookshelf, refreshing again,
February 1, 2026 at 6:57 PM
refreshing (what has become) the Epstein Files Website, looking at my bookshelf, refreshing again,
given that we missed last week, this #MathCoffeeSelfie is a double. send two pictures, tell me what you've been up to twice, and drink 2× the coffee.
February 1, 2026 at 5:17 PM
given that we missed last week, this #MathCoffeeSelfie is a double. send two pictures, tell me what you've been up to twice, and drink 2× the coffee.
Reposted by Rochelle
pressing the button that makes life worth living
January 31, 2026 at 10:43 PM
pressing the button that makes life worth living
would you believe it if i told you that the discussion of ICE on BoardGameGeek.com is... not particularly enlightened
January 31, 2026 at 9:38 PM
would you believe it if i told you that the discussion of ICE on BoardGameGeek.com is... not particularly enlightened
i am under the impression that a lot of people are not moved by Jaynes' arguments (that thermodynamical entropy is information entropy), but what are some good responses to him?
January 31, 2026 at 8:32 PM
i am under the impression that a lot of people are not moved by Jaynes' arguments (that thermodynamical entropy is information entropy), but what are some good responses to him?
women only love diamonds in this world. they love squares in all worlds.
January 29, 2026 at 7:45 PM
women only love diamonds in this world. they love squares in all worlds.
is there a renormalization scheme that takes the spacetime support of the interaction to be compact, and then enlarges it? would this work?
January 29, 2026 at 7:10 PM
is there a renormalization scheme that takes the spacetime support of the interaction to be compact, and then enlarges it? would this work?
Reposted by Rochelle
Huh, I don't remember having that conversation!
Weyl classified finite-dimensional irreps of GL(n,R), and these correspond to irreducible "tensor densities" of various kinds. Indeed, there's a kind that you can integrate over a (n-1)-dimensional-surface with oriented normal bundle.
(1/n)
Weyl classified finite-dimensional irreps of GL(n,R), and these correspond to irreducible "tensor densities" of various kinds. Indeed, there's a kind that you can integrate over a (n-1)-dimensional-surface with oriented normal bundle.
(1/n)
January 27, 2026 at 1:21 AM
Huh, I don't remember having that conversation!
Weyl classified finite-dimensional irreps of GL(n,R), and these correspond to irreducible "tensor densities" of various kinds. Indeed, there's a kind that you can integrate over a (n-1)-dimensional-surface with oriented normal bundle.
(1/n)
Weyl classified finite-dimensional irreps of GL(n,R), and these correspond to irreducible "tensor densities" of various kinds. Indeed, there's a kind that you can integrate over a (n-1)-dimensional-surface with oriented normal bundle.
(1/n)
damn, i think i looked really hot in that picture with stalin. i can't wait till he posts it on his instagram.
January 27, 2026 at 4:27 AM
damn, i think i looked really hot in that picture with stalin. i can't wait till he posts it on his instagram.
Reposted by Rochelle
(butting into a conversation) heh. that's a pretty good layman's explanation. but actually "particles" aren't real. *pushes up my glasses* see the universe is actually uhm. its.. uh. it's this kinda... uhm. it's some kind of. y'know. fucked up math thing. waves and shit
January 27, 2026 at 2:56 AM
(butting into a conversation) heh. that's a pretty good layman's explanation. but actually "particles" aren't real. *pushes up my glasses* see the universe is actually uhm. its.. uh. it's this kinda... uhm. it's some kind of. y'know. fucked up math thing. waves and shit
I think I have been grappling with something similar: the question of whether E&M "uses" a spacetime orientation or not.
The Maxwell equations are dF=0 and d * F = * J, (* the Hodge star)
so a choice of orientation threatens to enter via *. However, the alternate choice should scale the equation
The Maxwell equations are dF=0 and d * F = * J, (* the Hodge star)
so a choice of orientation threatens to enter via *. However, the alternate choice should scale the equation
The ongoing discussion on MathOverflow on whether it is possible to define the trace of a linear map (on a finite-dimensional vector space over a field) without “picking a basis” — or what this phrase even means — is mathematically and sociologically fascinating: mathoverflow.net/q/507049/17064
Precise meaning of "picking a basis"?
Some years ago, Kevin Buzzard wrote a blog post asking whether the trace of a linear map $\phi \colon V \to V$ on a vector space $V$ can be defined "without picking a basis." He had some ...
mathoverflow.net
January 26, 2026 at 11:40 PM
I think I have been grappling with something similar: the question of whether E&M "uses" a spacetime orientation or not.
The Maxwell equations are dF=0 and d * F = * J, (* the Hodge star)
so a choice of orientation threatens to enter via *. However, the alternate choice should scale the equation
The Maxwell equations are dF=0 and d * F = * J, (* the Hodge star)
so a choice of orientation threatens to enter via *. However, the alternate choice should scale the equation
I am familiar with the theoretical side of this result but I have always wondered how tf did they experimentally measure this so precisely?
In the years since Kusch’s work, precision measurements of the electron magnetic moment have determined its g-factor to 12 or 13 decimal places.
That’s like measuring the circumference of the Earth’s equator with a precision comparable to the width of a human hair. (14/n)
That’s like measuring the circumference of the Earth’s equator with a precision comparable to the width of a human hair. (14/n)
January 26, 2026 at 5:21 PM
I am familiar with the theoretical side of this result but I have always wondered how tf did they experimentally measure this so precisely?