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 you identify two functions if there difference has zero integral. and then D isn't defined on every element, but every element has a sequence converging to it on which D is defined, and thats sort of good enough...
its a bit of a mess
its a bit of a mess
February 10, 2026 at 5:35 AM
so you identify two functions if there difference has zero integral. and then D isn't defined on every element, but every element has a sequence converging to it on which D is defined, and thats sort of good enough...
its a bit of a mess
its a bit of a mess
notice if you write iD, it is self-adjoint
this is the "momentum operator" in the "position representation" of quantum mechanics. although there are some subtleties, because there you don't want to limit to differentiable functions. you allow all integrable functions; but then <,> is degenerate,
this is the "momentum operator" in the "position representation" of quantum mechanics. although there are some subtleties, because there you don't want to limit to differentiable functions. you allow all integrable functions; but then <,> is degenerate,
February 10, 2026 at 5:32 AM
notice if you write iD, it is self-adjoint
this is the "momentum operator" in the "position representation" of quantum mechanics. although there are some subtleties, because there you don't want to limit to differentiable functions. you allow all integrable functions; but then <,> is degenerate,
this is the "momentum operator" in the "position representation" of quantum mechanics. although there are some subtleties, because there you don't want to limit to differentiable functions. you allow all integrable functions; but then <,> is degenerate,
like Leo said, it depends on exactly which functions you let in V and U. suppose they are differentiable, integrable, and vanish at the boundary points. then, its true that -D is adjoint to D!
February 10, 2026 at 5:30 AM
like Leo said, it depends on exactly which functions you let in V and U. suppose they are differentiable, integrable, and vanish at the boundary points. then, its true that -D is adjoint to D!
> literally and metabolically
February 10, 2026 at 12:19 AM
> literally and metabolically
he had a poster about his local many-worlds at a conference last year and i thought it was very interesting
February 9, 2026 at 9:12 PM
he had a poster about his local many-worlds at a conference last year and i thought it was very interesting
did Cai Waegell speak?
February 9, 2026 at 7:11 PM
did Cai Waegell speak?
goes BONKERS
come over
come over
February 9, 2026 at 6:33 PM
goes BONKERS
come over
come over
holy shit nice dress
February 9, 2026 at 6:20 PM
holy shit nice dress
incredible story; im so invested
February 9, 2026 at 12:10 AM
incredible story; im so invested
can't wait for you enter breadtube
February 8, 2026 at 11:06 PM
can't wait for you enter breadtube
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.
do you need someone to give a short talk about closed time-like curves
February 8, 2026 at 2:40 PM
do you need someone to give a short talk about closed time-like curves
no more than necessary
February 7, 2026 at 3:19 PM
no more than necessary
oh i thought it was a scenario if there is too much dark energy
February 7, 2026 at 2:40 PM
oh i thought it was a scenario if there is too much dark energy
I'd like to see a sample of a calculation like this, which indicates a big-rip scenario
February 7, 2026 at 2:36 PM
I'd like to see a sample of a calculation like this, which indicates a big-rip scenario
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...
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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/
🧪🔭⚛️🎢
🧪🔭⚛️🎢
where matter does not form a homogeneous fluid. It makes me wonder, the stuff about the big rip, and atoms exploding, is there any reason to think that will happen?
February 7, 2026 at 2:10 PM
where matter does not form a homogeneous fluid. It makes me wonder, the stuff about the big rip, and atoms exploding, is there any reason to think that will happen?
there is no question about why earth is not ripped from the sun. it is not following one of those diverging FRWL geodesics; it is following a much more complicated one due to the local solar geometry, which was ignored in the FRWL model. the FRWL should not be at all accurate on these scales,
February 7, 2026 at 2:10 PM
there is no question about why earth is not ripped from the sun. it is not following one of those diverging FRWL geodesics; it is following a much more complicated one due to the local solar geometry, which was ignored in the FRWL model. the FRWL should not be at all accurate on these scales,
nice thread! objects diverge within FRWL because that's what the geodesics are. when objects converge we certainly don't say "space is contracting." and what else could any claim about spacetime possibly amount to, at bottom, except the patterns of motion of material bodies?
allowing that cosmic expansion is a pattern of motion through space. Because then you can tap what the students already know about (Newtonian) motion through space, and you can actually calculate some things. Including dark energy, even though that involves hand-waving at the point where Lambda 3/
February 7, 2026 at 2:07 PM
nice thread! objects diverge within FRWL because that's what the geodesics are. when objects converge we certainly don't say "space is contracting." and what else could any claim about spacetime possibly amount to, at bottom, except the patterns of motion of material bodies?
how do you pronounce Choquet-Bruhat?
February 6, 2026 at 6:13 AM
how do you pronounce Choquet-Bruhat?
I'm very interested to know, why doesn't the photoelectric effect prove the existence of photons? and what are the anti-bunching experiments?
February 6, 2026 at 1:21 AM
I'm very interested to know, why doesn't the photoelectric effect prove the existence of photons? and what are the anti-bunching experiments?
oh, we're not together. she was awful. haha.
February 5, 2026 at 10:13 PM
oh, we're not together. she was awful. haha.
i first learned some measure theory by helping my girlfriend with her homework
February 5, 2026 at 7:45 PM
i first learned some measure theory by helping my girlfriend with her homework