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1. mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:44 UTC mcc

   Was watching a video about physics last night and at a certain point they explained the Stern-Gerlach experiment and I got so angry I had to turn it off for the night

   • Triple (triple@typo.social)'s status on Thursday, 22-Aug-2024 06:51:43 UTC Triple

     in reply to

     @mcc Could you provide the link of the video so I can be mad too?

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:44 UTC mcc

     in reply to

     ME: Quantum physics isn't "weird", or mystical, or unknowable in some way that means we have to abandon the scientific ideal of understanding the universe. Quantum physics follows specific mathematical rules, and it follows them rigidly; it's just the math happens to not follow our intuition of everyday objects.

     PHYSICISTS: *Explain literally anything about quantum spin*

     ME: This is BULLSHIT and you are MAKING IT ALL UP

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:44 UTC mcc

     in reply to

     Will make another go at the video today. I'm hopeful/unhopeful because when I found the videos I was like "oh thank goodness, finally someone is going to explain to me how quantum spin works" and so far their explanation for how quantum spin works is "somehow"*

     * They have repeated that one word in almost every critical sentence of the video

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:47 UTC mcc

     in reply to

     I ask because that way non-orientedness stops being "shocking" because orientation is an irrelevant local symmetry anyway, and I could think about the unoriented spin value as like "rotation energy".

     ---

     I also was gonna ask questions about how spin fits into LQG braid matter and "holographic" universe hypotheses but such such questions are absurd and "cranky" I think I should not try to ask them until I understand the normal one. Maybe I'll see if my PhysicsForums login still works (3/3)

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:47 UTC mcc

     in reply to

     And yeah, yeah, I get it, it's okay for quantum numbers to just be arbitrary "things" that have no classical analogues, the video mentions even Pauli wants me to think of spin as "classically non-describable two-valuedness", I'm usually okay with thinking this way. But if that's what spin is then *why does it impart mechanical angular momentum, literal macroscopic classical angular momentum, when you apply it correctly*?? I have always struggled to let this go and I kind of feel like I shouldn't

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:48 UTC mcc

     in reply to

     Okay so the video was pretty good https://www.youtube.com/watch?v=pWlk1gLkF2Y and did a better job of explaining spin than anything else I've ever seen (it's sort of in a series of 3, in the next one they're gonna take a go at the spin statistics theorem… looking forward to that, that's another thing I've tried and failed to comprehend before) but I'm still lost and I'm not sure if I'm lost the expected amount or more lost than normal

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:48 UTC mcc

     in reply to

     Here is what I am trying to figure out:

     * PBS SpaceTime Guy suggests the spinor nature of fermions is best understood as the behavior of lines of connection between particles, rather than behavior of particles themselves. He notes "twisting" the lines of connection produces spinor behavior (2 rotations to return to original state) whereas a regular rotation doesn't. Fine. Here is my question:

     Does this "lines of connection, not an object" kind of rotation *also* explain non-orientation?

     (1/3)

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:48 UTC mcc

     in reply to

     He gives this useful visualization where he shows that the cube-with-attached-streamers example (which I've seen before) can be expanded to like, a high-N N-gon with a streamer on each face. So I imagine a 3D grid of 26-gons, each streamered to its adjacent/adjacent-diagonal neighbors. Then I imagine every n-gon simultaneously spinning with *random* orientations and speeds. Do they avoid tangling?

     PBS-ST-G suggests thinking about phase, not rotation. But does my 26-gon idea *work*? (2/3)

   • Santa Claes 🇸🇪🇭🇰🎅 (clacke@libranet.de)'s status on Thursday, 22-Aug-2024 06:51:53 UTC Santa Claes 🇸🇪🇭🇰🎅

     in reply to
     why does it impart mechanical angular momentum, literal macroscopic classical angular momentum

     @mcc This thread is the first time I heard this and I thank you for it. It sounds absolutely bonkers and I will watch that video this weekend.

   • Jamie McCarthy (jamiemccarthy@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:55 UTC Jamie McCarthy

     in reply to

     @mcc Where can I learn more about imparting classical angular momentum?

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:57 UTC mcc

     in reply to

     • Jamie McCarthy

     @jamiemccarthy An example would be 0:48 in the "electrons do NOT spin" video above, where he describes, but does not fully explain, an experiment involving the basic "an EM field can make a metal thing rotate" behavior.

     I have also seen an experiment described where you fire a beam of particles with a specific quantum spin at a macroscopic object and eventually it starts rotating. Because I don't have a cite on this experiment, it is possible that I have misunderstood it.

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:51:58 UTC mcc

     in reply to

     • nex

     @nex Imaginary numbers are easier for me to understand because numbers are not real. Imaginary numbers are fake but natural numbers are also fake. It doesn't really matter if they behave one way or another. They behave how we decide to define them.

     But magnets are real. They interact with things I can see and touch. So it is harder for me to just go "I guess it's just an arbitrary mathematical object with arbitrary mathematical properties"

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   • nex (nex@chaos.social)'s status on Thursday, 22-Aug-2024 06:52:03 UTC nex

     in reply to

     @mcc Suppose you're helping someone learn square roots and they're currently learning for their first test for which they need them.

     If you told them to take the square root of -1 as a practice example, you'd *want* them to say “this is BULLSHIT!”, right? I think this is a normal an necessary step towards understanding 😄

   • nex (nex@chaos.social)'s status on Thursday, 22-Aug-2024 06:52:04 UTC nex

     in reply to

     @mcc I don't see how this analogy could be helpful here; I also didn't get the impression that O'Dowd was trying to imply anything like that.

     To me this is a completely ordinary rotation, it's just that some objects (spin n + .5 where n is integer) behave like that under rotation — this seems familiar when you've used quaternions for 3D graphics or similar.

     Watching this could help: https://www.youtube.com/watch?v=pKKy2mmsziI

   • nex (nex@chaos.social)'s status on Thursday, 22-Aug-2024 06:52:04 UTC nex

     in reply to

     @mcc Btw., I just rewatched the SpaceTime video (first saw it years ago) and found it quite well made — which was definitely in part due to having seen it and similar lectures about the topic before. So I've already developed a certain tolerance to this weirdness, but still I still had to occasionally pause the video at a few points to mentally catch up. That's how I discovered that other video: YT suggested it as related and I watched it in those breaks.

   • Boba Yaga (bobayaga@blahaj.social)'s status on Thursday, 22-Aug-2024 06:52:09 UTC Boba Yaga

     in reply to

     @mcc Ah, now it makes sense

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   • Dana Fried (tess@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:10 UTC Dana Fried

     in reply to

     @mcc to be fair, a lot of QM is... "somehow shit is like this, and that's why we exist... somehow"

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:10 UTC mcc

     in reply to

     • Dana Fried

     @tess Yeah, it… I think there's some point at which that's valid but maybe one can get *too* used to doing it.

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   • Santa Claes 🇸🇪🇭🇰🎅 (clacke@libranet.de)'s status on Thursday, 22-Aug-2024 06:52:14 UTC Santa Claes 🇸🇪🇭🇰🎅

     in reply to

     • Dana Fried
     @tess @mcc I wonder if it's a statistic certainty that a universe within certain parameters produces string theorists.
   • Dana Fried (tess@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:15 UTC Dana Fried

     in reply to

     @mcc that's the thing tho - if you dig down you can keep answering "why" to a point, but then... Why SU(3)xSU(2)xU(1)?

     At some point, are the fundamental symmetries that give rise to the standard model feel arbitrary; the values of the masses of the particles, the strength of the fundamental forces, and the coupling constants feel arbitrary; this is (in part) why we still have string theorists.

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:16 UTC mcc

     in reply to

     • Santa Claes 🇸🇪🇭🇰🎅

     @clacke Note I am not sure I am completely right in my description. But the videos are interesting.

     There are another two plus one just on spinors.

     https://mastodon.social/@mcc/113000879836189669

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   • Mark T. Tomczak (mark@mastodon.fixermark.com)'s status on Thursday, 22-Aug-2024 06:52:20 UTC Mark T. Tomczak

     in reply to

     • Cowboy Who?

     @BillyGlennHoya @mcc these guys don't get enough credit for asking some very fair questions.

     I hear that lyric and I'm reminded of the story Richard Feynman would tell about how he got into physics because he had questions about how a ball in his little red wagon worked that his dad couldn't answer... And after years of working in the field he came back to his dad with an explanation of momentum and inertia and his dad hit him with something to the effect of "Sounds like you just gave names to the stuff we don't know; you didn't actually explain it."

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   • Cowboy Who? (billyglennhoya@libranigans.com)'s status on Thursday, 22-Aug-2024 06:52:24 UTC Cowboy Who?

     in reply to

     @mcc

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:26 UTC mcc

     in reply to

     • Mark T. Tomczak
     • Cowboy Who?

     @mark @BillyGlennHoya Me: Fuckin gauge perturbation of U(1). How does it work

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:28 UTC mcc

     in reply to

     • Mark T. Tomczak
     • Cowboy Who?
     • David Smith

     @Catfish_Man @mark @BillyGlennHoya It makes a lot more sense if you just disassemble one but maybe let's just let Chappel Roan keep her sense of wonder

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   • David Smith (catfish_man@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:30 UTC David Smith

     in reply to

     • Mark T. Tomczak
     • Cowboy Who?

     @mcc @mark @BillyGlennHoya and it goes even further than magnets! Chappell Roan sings about not only not knowing how kaleidoscopes work, but knowing she'll never know

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:31 UTC mcc

     in reply to

     • Mark T. Tomczak
     • Cowboy Who?
     • Ian Holmes

     @mark @ianholmes @BillyGlennHoya What's this?

     FERMION is evolving!

     FERMION became ANYON!

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   • Mark T. Tomczak (mark@mastodon.fixermark.com)'s status on Thursday, 22-Aug-2024 06:52:32 UTC Mark T. Tomczak

     in reply to

     • Cowboy Who?
     • Ian Holmes

     @ianholmes @mcc @BillyGlennHoya Couldn't tell you; I haven't followed Pokémon since Red and Blue.

   • Ian Holmes (ianholmes@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:34 UTC Ian Holmes

     in reply to

     • Mark T. Tomczak
     • Cowboy Who?

     @mcc @mark @BillyGlennHoya Fuckin prosody, how does THAT work

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:40 UTC mcc

     in reply to

     • Paul Cantrell

     @inthehands Essentially the Big Problem in physics is that every single thing got named before they understood what it did or how it worked (naturally, since they couldn't start trying to explain how it worked until it had a name to talk about it with)

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   • Paul Cantrell (inthehands@hachyderm.io)'s status on Thursday, 22-Aug-2024 06:52:41 UTC Paul Cantrell

     in reply to

     @mcc
     The terminology sure doesn’t help. “Mesons are composite gauge bosons made of quarks.” “Do right-handed neutrinos exist?” It’s like Dr. Seuss writing tech talk for ST:TNG.

   • Paul Cantrell (inthehands@hachyderm.io)'s status on Thursday, 22-Aug-2024 06:52:42 UTC Paul Cantrell

     in reply to

     @mcc
     As a developer, I relate to this deeply. And I admire the physicists for actually coming up with new words, however ridiculous, instead of using the same ones over and over (e.g. “port,” “static”).

     Still, the completely made-up ridiculous words do make the theories also •sound• completely made-up and ridiculous, even when they aren’t.

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   • Mark T. Tomczak (mark@mastodon.fixermark.com)'s status on Thursday, 22-Aug-2024 06:52:43 UTC Mark T. Tomczak

     in reply to

     @mcc Yes, I love this.

     This is the thing I sometimes think is missing from a lot of science education--- We can get so hung up on having students memorize explanations for things that we can forget that the whole point of the explanations is that there are real phenomenon that make no intuitive sense whatsoever and the explanations are the best we can do with unifying all these otherwise disparate, random, mad world behaviors into something approaching a human-shaped story.

     Time dilation sounds like nonsense idea a person made up to troll you until you find out the history of people conducting experiments to figure out the speed of light and getting baffled by the observation that the damn thing doesn't change!

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   • Mark T. Tomczak (mark@mastodon.fixermark.com)'s status on Thursday, 22-Aug-2024 06:52:44 UTC Mark T. Tomczak

     in reply to

     @mcc Recently learned that Einstein was pretty bearish on black holes also. In that case, it was because (IIUC) his process was often "Think about a possible model for how the universe works, think through the consequences of that model, test those consequences against reality..." And when he applied that reasoning to the gravitational singularities in the math he went "But that would imply there would be these... holes in space. We've been looking for thousands of years and we don't see any holes; where are all the holes?"

     I can't remember if he lived long enough for astronomers to get back to him with "Well now that we know we should be looking for 'wild bullshit happening around nothing'... We turned our telescopes towards that and UH-OH!"

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   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:45 UTC mcc

     in reply to

     • Mark T. Tomczak

     @mark time dilation is not so bad because einstein was able to come up with a picture you can intuitively visualize¹ that demonstrates it happening. The fact he could not ever find an equivalent visualization for quantum physics seems to be why he rejected it to his death.

     ¹ "Universe's lumpy"

     "What?"

     **Einstein, reloading gun, getting back into sublight rocket** "Universe's lumpy"

   • mcc (mcc@mastodon.social)'s status on Thursday, 22-Aug-2024 06:52:46 UTC mcc

     in reply to

     • Steve Canon

     @steve let me get back to you about this comment once i've thought about it for three weeks

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   • Steve Canon (steve@discuss.systems)'s status on Thursday, 22-Aug-2024 06:52:48 UTC Steve Canon

     in reply to

     @mcc I don’t even need quantum effects for this. I was in a classical mechanics colloquium given in the math department once and got there when the speaker showed that the answer just pops out magically if you take the reference frame to be the point of contact of a sphere rolling inside a cylinder and analyze the system based on the Coriolis torque.

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   • Steve Canon (steve@discuss.systems)'s status on Thursday, 22-Aug-2024 06:52:50 UTC Steve Canon

     in reply to

     @mcc (the question was “why does a golf ball roll into the hole and then pop out again?”)

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   • Santa Claes 🇸🇪🇭🇰🎅 (clacke@libranet.de)'s status on Thursday, 22-Aug-2024 06:52:50 UTC Santa Claes 🇸🇪🇭🇰🎅

     in reply to

     • Steve Canon

     @steve The sister lecture to #xkcd123. 😊

     @mcc

   • Ben Aveling (benaveling@infosec.exchange)'s status on Thursday, 22-Aug-2024 19:35:33 UTC Ben Aveling

     in reply to

     @mcc I got a HD in 1st year quantum physics. I understood nothing about quantum physics, but I could apply the formulae.

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