Dirac's belt trick, Topology, and Spin ½ particles

ANSWERS TO FREQUENTLY ASKED QUESTIONS:
scholar.harvard.edu/files/noa...
This is my submission to 3Blue1Brown's "Summer of Math Exposition 1" #SoME1. In this video, I explain what Dirac's famous belt trick has to do with the topology of rotating spin 1/2 particles, such as electrons.
I created the 3D animations using Three.js/CCapture.js, and the math animations with Manim Community v0.8.0.
00:00 Introduction
4:14 The space of rotations
9:40 Paths through the space of rotations
18:48 Group theory & the fundamental group
31:30 Quantum spin and SU(2)
39:31 SU(2) as the double cover of SO(3)
48:26 Bringing it all together
52:22 Tying up loose ends
Music by Vincent Rubinetti
Download the music on Bandcamp:
vincerubinetti.bandcamp.com/a...
Stream the music on Spotify:
open.spotify.com/album/1dVyjw...
Largo From Concerto No 5
Exzel Music Publishing (freemusicpublicdomain.com)
Licensed under Creative Commons: By Attribution 3.0
creativecommons.org/licenses/b...

Пікірлер: 981

  • @HerbertLandei
    @HerbertLandei2 жыл бұрын

    Fun fact: All USB ports before USB-C have spin 1/2

  • @eivindtriel6107

    @eivindtriel6107

    2 жыл бұрын

    I concur. First you try and it dos not fit. Then you rotate Pi and it still dos not fit. Then you rotate it Pi again and now it fits.

  • @alicewyan

    @alicewyan

    2 жыл бұрын

    Wait, it'd be spin 2/3, right? cause you need 3 180º turns to arrive at the initial position

  • @datguy2271

    @datguy2271

    2 жыл бұрын

    Also when you don't observe it it goes into superposition, and when observed it always collapses into the state where you need to rotate twice

  • @zbstof

    @zbstof

    2 жыл бұрын

    USB Plugs were spin 2/3. PBS Space Time did this bit: kzread.info/dash/bejne/lqtl1cekl5m5hbw.html

  • @saturn9199

    @saturn9199

    2 жыл бұрын

    Yes definitely, although I got a USB a to micro port that is spin one on the a side like usb-c

  • @kiledamgaardasmussen5222
    @kiledamgaardasmussen52222 жыл бұрын

    A word of advice: if you discover a new phenomenon and immediately reach for a matrix representation to describe it, you should call your doctor and ask if the automorphism group of a vector space is right for you. Clifford Algebras provide a safe, sanitary, and intuitive alternative, and is recommended by nine out of ten dentists.

  • @nicolaihaasgiedraitis4082

    @nicolaihaasgiedraitis4082

    2 жыл бұрын

    I was going to mention this! Especially in the beginning when he rotated about an axis rather than within a plane. Can we all please rotate in planes from now on? :)

  • @ThomasMeli81

    @ThomasMeli81

    2 жыл бұрын

    This is pure genius.

  • @kashu7691

    @kashu7691

    2 жыл бұрын

    @@nicolaihaasgiedraitis4082 jesus it was disgusting to see

  • @abrarkazi2284

    @abrarkazi2284

    2 жыл бұрын

    @@nicolaihaasgiedraitis4082 hey, I know you wrote this comment 7 months ago, but I'm curious if you can tell me the timestamp of the part you're talking about. Because I'm curious about what you mean by "rotating in a plane". Edit: I just looked it up and I found that specifying the plane of rotation is useful in higher dimensions (>4) and of course, you can't rotate about an axis in 4D or higher. But in 3D, specifying the plane of rotation is equivalent to specifying an axis of rotation, which is just a vector in the 1D subspace orthogonal to the plane. So I'm not sure what the problem is with talking about an axis of rotation for 3D. Unless I misunderstood your comment (still curious about the timestamp)

  • @EvaTruve

    @EvaTruve

    Жыл бұрын

    Too much work, can I hire someone to understand this?

  • @LookingGlassUniverse
    @LookingGlassUniverse2 жыл бұрын

    When I first saw the Dirac belt trick I thought it was flippant and didn’t explain anything. I still think so, but your video explanation was beautiful 😍 thanks for making this!

  • @tricky778

    @tricky778

    2 жыл бұрын

    There's a video around showing a spin half particle has having an infinitude of belts coming from it to connect it to all points of the universe, making a continuous fibrous field instead of a scalar field. It's a nice visualisation about how the state of each point of the field includes the half-spin properties. I don't know if the electron is supposed to be spinning all the time and thus emitting ripples in that field, being electromagnetic waves including circular polarisation inline with the electron's spin vector.

  • @das_it_mane

    @das_it_mane

    2 жыл бұрын

    @@tricky778 do you remember the title of the video? Sounds interesting

  • @tricky778

    @tricky778

    2 жыл бұрын

    @@das_it_mane "electrons DO NOT spin" by PBS Spacetime. It didn't go into a lot of detail but it was interesting to see properties of their visualisation

  • @tricky778

    @tricky778

    2 жыл бұрын

    @@das_it_mane it might have been "how electrons make matter possible" on the same channel

  • @theopantamis9184

    @theopantamis9184

    2 жыл бұрын

    @@das_it_mane kzread.info/dash/bejne/l4ZtvKWwibPOmLg.html

  • @cartlundmonson5164
    @cartlundmonson51642 жыл бұрын

    "One other thing I wanted to mention is the Hopf Fibration. There. I've mentioned it." My sides. Twin Peaks reference much appreciated too.

  • @manamsetty2664
    @manamsetty26642 жыл бұрын

    I explained the belt trick to my class now everybody knows the colour of my underware

  • @Samusamu57
    @Samusamu572 жыл бұрын

    Oh my god the reference to TJ """"Henry"""" Yoshi just killed me. I love you guys

  • @JohnSmith-kc6ov

    @JohnSmith-kc6ov

    2 жыл бұрын

    me too. I can't believe the dude that makes educational videos about the deep inner workings of mario 64 was referenced by the guy that makes educational videos about the deep... hey wait maybe this isn't as big of a crossover as i though. i'm sure there's a pretty big overlap in audience

  • @daniellewilson8527

    @daniellewilson8527

    2 жыл бұрын

    What reference is that? Also what video was it from? Was this from the one who talked about parallel universes in SM64 via a TAS? I forgot who I watched that did that

  • @Samusamu57

    @Samusamu57

    2 жыл бұрын

    @@daniellewilson8527 yes that one

  • @tonyhakston536

    @tonyhakston536

    2 жыл бұрын

    @@daniellewilson8527 the KZreadr you’re looking for is Pannenkoek2012

  • @maxkee9882
    @maxkee98822 жыл бұрын

    TJ “Henry” Yoshi getting dunked on once again

  • @marcobrini
    @marcobrini2 жыл бұрын

    This is a masterpiece. Thank you for making it. Please do more of it. Animations about the bloch sphere ans the Pauli matrices would be highly appreciated.

  • @Bruno-el1jl
    @Bruno-el1jl2 жыл бұрын

    I felt very heavy vibes of the "turning a circle inside out" timeless video with the narration and imagery, especially at the first couple chapters. Amazing work! As a layman i half half understood it, which is a gigantic feat!

  • @official-obama

    @official-obama

    2 жыл бұрын

    not knot

  • @midnattssol8329

    @midnattssol8329

    2 жыл бұрын

    that's a sharp corner

  • @Jesin00

    @Jesin00

    Жыл бұрын

    The color scheme of goldish-yellow and purple for the 2 sheets of the double cover seems like a direct reference to that video.

  • @oximas
    @oximas2 жыл бұрын

    yeees another 3blue1brown style video, BRO we need more

  • @UdarRusskihPudgei
    @UdarRusskihPudgei2 жыл бұрын

    Thanks for mentioning the Hopf fibration.

  • @lewdwig
    @lewdwig2 жыл бұрын

    I think this may be the single greatest video on physics I have ever watched.

  • @krenv2052
    @krenv20522 жыл бұрын

    This video deserves to be seen over and over by anyone interested in the mathematical insight of spin. You are the first person to ever convey to me the right intuition for the Dirac belt trick. Keep up the great work, mate!

  • @__august__
    @__august__2 жыл бұрын

    you convinced me to watch the entire video with the watch for rolling rocks reference

  • @smiley_1000
    @smiley_1000 Жыл бұрын

    When I first watched this video, I remember being very confused. After reading an introduction on Lie Groups, being reminded of this video and rewatching it, I get it now. Amazing quality.

  • @flmbray
    @flmbray2 жыл бұрын

    This has such a 3B1B feeling to it... NICE WORK!

  • @tim40gabby25

    @tim40gabby25

    2 жыл бұрын

    Big complement there. Agreed

  • @voidisyinyangvoidisyinyang885

    @voidisyinyangvoidisyinyang885

    Жыл бұрын

    Grant did the audio for the vid clearly.

  • @AlericResident
    @AlericResident2 жыл бұрын

    OMG thank you for making a youtube that does NOT shy away from formula's, not even from high level math! There are so many youtubes about *interesting* concepts that in the end explain NOTHING because they restrict themselves to what they think every viewer should be able to understand (aka, nothing). This is unfair to the minority of people who CAN understand these concepts in terms of math (if explained well) and in general a disservice to humanity. That being said, after learning that my spacial insight got out of the graph and even off the edge of the paper by the professional trying to measure it; I have spent countless hours trying to imagine 4D space, thinking it has to be just lack of experience that humans "can't" imagine it (and because I suspected that it might be a reason that humanity is stuck with its understanding of physics where we are stuck). Imho it is more insightful to simply imagine a projection from cover spaces to its base space: picture the surface of a sphere as two discs at the same place: one being the projection of the upper half and one being the projection of the lower half, keeping in mind that each disc also has a "distance" (either up or down) to their respective part of the cover space. Putting the discs next to eachother is less insightful (although easier to show in a video). Obviously one then can only move from one disc to the other where this distance is zero: at the edge of the discs. Likewise and 100% equivalent: two spheres in the same place, connected at the edge (surface of the projected spheres) where the extra "up" or "down" distance is zero. Each point inside the two-sphere is then actually two points, where the distance (from the projected point in 3D space) is trivial: sqrt(1 - (distance to the center)^2).

  • @SuperMaDBrothers

    @SuperMaDBrothers

    2 жыл бұрын

    yeah I agree. Even this could have done with way more, there was 0 discussion on what a group cover actually is or a rigorous way that shows SU(2)~S3

  • @riccardoorlando2262

    @riccardoorlando2262

    2 жыл бұрын

    @@SuperMaDBrothers Well, if you want all the details, pick up an algebraic topology book and start reading. There's an optimal place to compromise, and this video pushed the boundary but earned the mathy bits with beautiful animations - without which, I'd much rather actually read a book.

  • @idontwantahandlethough

    @idontwantahandlethough

    Жыл бұрын

    Clicked on your profile pic because I thought it was funny but now I regret it. I gotta say, it's sad to see someone who clearly thinks so highly of their own intelligence and has somehow still fallen prey to blatant xenophobic propaganda. You clearly have the intellectual ability to figure things out, but lack the emotional maturity to see the reality for what it is. I hope you grow up and figure things out someday.

  • @thephilosopher7173

    @thephilosopher7173

    Жыл бұрын

    I know this is old, but regarding the part about the viewers knowing nothing: Yea many of us want to understand a concept and don't know much math (or are starting to learn). The reason why you're a minority is because the way these things are taught is backwards. If all of the science in schools today were approached with pure historic reference and first principles methods, then plenty more ppl would be able to understand it, and maybe even more would actually become scientists. Shying away from the hardcore math isn't great in some cases but it isn't bad either.

  • @AlphaCurveMath
    @AlphaCurveMath2 жыл бұрын

    'A large book' *Serge Lang's 'Algebra' emerges*

  • @DooDooDiaperShitCunt
    @DooDooDiaperShitCunt2 жыл бұрын

    This is absolutely astonishing. Please keep making more mathematics/physics content like this. I have never seen these concepts explained so darn well!

  • @simonavarne9635

    @simonavarne9635

    2 жыл бұрын

    Totally agree

  • @samevans4834
    @samevans48342 жыл бұрын

    "Wait, a 360-degree rotation is a 360-degree rotation, you can't say it's only a half!" "Well, Albert """Henry""" Einstein..."

  • @Zeus.2459

    @Zeus.2459

    2 жыл бұрын

    One of my favorite references, glad someone else got it :D

  • @LordHonkInc

    @LordHonkInc

    2 жыл бұрын

    I can't believe a speedrunning meme got so ubiquitous as to show up in a video proof of a quantum-mechanical phenomenon. I love it

  • @mauritz3912

    @mauritz3912

    2 жыл бұрын

    A man of culture!

  • @viliml2763

    @viliml2763

    2 жыл бұрын

    It's funny that this is the SECOND time I saw this reference in the #SoME1 playlist

  • @mauritz3912

    @mauritz3912

    2 жыл бұрын

    @@viliml2763 @Owen Maitzen is also a man of culture!

  • @williamrhopkins
    @williamrhopkins2 жыл бұрын

    Wow just wow. I am bit older and my math degree is from the 70's. Damn I wish we had these beautiful visualization back then. I did a little bit with knot theory and would love to see this covered in a video.

  • @alexbanks9510
    @alexbanks95102 жыл бұрын

    This was really well paced, I had several moment of "oh that must mean ..." followed by the next section confirming it. Not had that experience in a while so it was an enjoyable journey.

  • @filipo4114
    @filipo41142 жыл бұрын

    So let's mark the electron with a '+'... xD

  • @brooksbryant2478

    @brooksbryant2478

    2 жыл бұрын

    was thinking the same thing

  • @yourmom-nv9ui

    @yourmom-nv9ui

    2 жыл бұрын

    @@brooksbryant2478 charge is nothing but a ordinary element to distinguish between two different things we can say an electron is positive and a proton is negative it won't change anything

  • @yourmom-nv9ui

    @yourmom-nv9ui

    2 жыл бұрын

    Arbitrary **

  • @brooksbryant2478

    @brooksbryant2478

    2 жыл бұрын

    @@yourmom-nv9ui I know, it's just the opposite of the convention everyone else uses.

  • @numbersix8919

    @numbersix8919

    2 жыл бұрын

    Not about charge.

  • @mikaeels2691
    @mikaeels26912 жыл бұрын

    I recognise that background music from another math animation channel ;)

  • @edvogel56
    @edvogel562 жыл бұрын

    Thanks! You are illuminating the the first 300 or so pages of "math primer" in ""The Road To Reality" by Penrose.

  • @scepticalchymist
    @scepticalchymist2 жыл бұрын

    The haircut in the beginning is a double cover of the one in the end :). Great video!

  • @subhadeepreaditassubhodeep6161
    @subhadeepreaditassubhodeep61612 жыл бұрын

    This gonna blow up. This SHOULD blow up.

  • @JaxzanProditor
    @JaxzanProditor Жыл бұрын

    This is the best covering of this subject I’ve ever seen. Most of this material I’ve seen scattered across various courses like introductory topology (I had flashbacks when you put Hatcher on the screen), differential topology, non-relativistic quantum mechanics, or field theory, but no one’s ever put it all together like this with incredible visuals. Rotating an electron in the Black Lodge was just the cherry on top! I’m grateful for SoME 1 for putting this on my radar and I truly hope you do something like this again.

  • @TheErer1243
    @TheErer12432 жыл бұрын

    Well, TJ "Henry" Yoshi,

  • @hydraslair4723
    @hydraslair47232 жыл бұрын

    The intuition that a belt is a path just flipped my world upside down... Only once, so it can never go back!

  • @carlkuss
    @carlkuss27 күн бұрын

    I keep going back to this video. It shows true pedagogical skill, showing that when the point that you are making is deep enough it deserves tender loving care even if that might seem to those who don´t care it might seem tedious. Go for clarity!

  • @EricKolotyluk
    @EricKolotyluk2 жыл бұрын

    Wow! That was so astonishingly beautiful... the kind of quality I have come to expect from 3Blue1Brown... While I have an MSc in Computing Science, I was actually pretty good at math and physics as an undergrad, and continue to try to better understand quantum physics. Spin is so hard to wrap my head around (pun intended), but this really gave me such a good feel for what might be going on, a glimpse in the nature of quantum mechanics. By the end of your video, I could really appreciate how particles have angular momentum, and why fermions are so special. Thank you so much for opening my eyes...

  • @AlericResident

    @AlericResident

    2 жыл бұрын

    If you try to understand the spin of an electron by looking at it from all angles, you won't get it ;).

  • @weinsim3856
    @weinsim38562 жыл бұрын

    3:42 this is the best form of comedy there is. very well done also great video btw

  • @yurisich

    @yurisich

    2 жыл бұрын

    There's another great one right at the end, too.

  • @jordanweir7187
    @jordanweir71872 жыл бұрын

    IMO they should first introduce Topology with this sort of clearer material and call it 'Apology' thanks for content bruh

  • @shukius1
    @shukius12 жыл бұрын

    One of the best movies I have ever seen on this complicated topic. Noah you are a true genius. Keep them coing

  • @ExecutorElassus
    @ExecutorElassus2 жыл бұрын

    Putting the electron in _that_ room was very chef's-kiss, as they say.

  • @oximas
    @oximas2 жыл бұрын

    56:50 now that's peak comedy

  • @Osmomorfismo
    @Osmomorfismo2 жыл бұрын

    This is definetly the best video to explain SU(2) and spin at a fundamental level of all YT

  • @zlm001
    @zlm0012 жыл бұрын

    Once again, one seen this explained in an over simplified way so many times that leaves so much out. I think this is simplified as much as it can be while still giving some useful insights to a non-expert. Thank you.

  • @athena9098
    @athena90982 жыл бұрын

    with this video, you just stepped up your game Noah!

  • @MasterHigure
    @MasterHigure2 жыл бұрын

    One thing I'd like to mention is that the figure on the cover of Hatcher's Algebraic Topology is the Hopf fibration. Also, many find Hatcher's to not be rigorous enough. There are plenty of more formal treatments, but Hatcher has better examples and exercises than all other AT books combined. To me that's worth it. But to each their own, I guess.

  • @natywubet2175
    @natywubet2175 Жыл бұрын

    i came here for party trick and forgot why I came here, true masterpiece.

  • @ScienceAsylum
    @ScienceAsylum10 ай бұрын

    Ooooh, this looks good. I've been looking for a more thorough examination of symmetry groups. I'm bookmarking for later viewing.

  • @web2wl00p
    @web2wl00p2 жыл бұрын

    This is an amazingly well produced and didactically superbly laid out video! Kudos!

  • @WorldWaterWars14
    @WorldWaterWars142 жыл бұрын

    Thank you. I'm a senior maths student and just learned about group theory and have always been confused when I heard SU(2) and SO(3), thank you for this intuitive explanation!!

  • @f-heinze
    @f-heinze2 жыл бұрын

    That was amazing and my no 1 of the SOME so far! Thanks a lot for taking the time to explain it!

  • @DanielKRui
    @DanielKRui7 ай бұрын

    I think minutes 0-18:48 should be mandatory viewing on day 1 of a topology class. Starts with a physical phenomenon that's cool; builds up a space that motivates ideas of quotients of topological spaces and manifolds (and identifying antipodal points of spheres ---> real projective plane, Boy's surface, etc.!), then studies loops on that manifold motivating ideas of homotopy theory like contractibility (relative to some fixed endpoints) visualized in different manners, all still grounded in the hands-on real world by Dirac's belt trick. And of course all the topological content afterward: spheres as 2 disks of the same dimension glued along the boundary (i.e. forming the sphere as an adjunction space/categorical pushout of a diagram), covering spaces, the lifting lemma... truly a wealth of content here, all presented in a welcoming way! Even your proof by contradiction was presented in a welcoming way; I'm pleasantly surprised that one can make rigorous arguments with just a 40 minute "picture based" introduction to topology. The summaries were also really nice! Lecturers don't do those often enough in classes, I think.

  • @daniilzhitov9553
    @daniilzhitov95532 жыл бұрын

    This is an absolutely brilliant video! I am so glad to find this channel thanks to the SoME1.

  • @pedroth3
    @pedroth32 жыл бұрын

    Truly amazing video! Really enjoyed the philosophic conclusion.

  • @Praefectia
    @Praefectia2 жыл бұрын

    Thank you for making this! I was trying to wrap my head around the whole so3 and su2 thing and was just searching youtube for any visualization. Didnt expect to find something so high quality!

  • @stefanosamaxopoulos5285
    @stefanosamaxopoulos52852 жыл бұрын

    Bravo! You made an AMAZING work!

  • @Syntax753
    @Syntax753 Жыл бұрын

    Absolutely fantastic video! Genius presentation - thanks so much for putting this together!

  • @siyuanruan3404
    @siyuanruan34042 жыл бұрын

    ohh, 3blue1brown style, I love it! You are doing a great job in using manim

  • @frankreashore
    @frankreashore2 жыл бұрын

    Totally amazing video. Best video I have watched in months.

  • @jackmcarthur1847
    @jackmcarthur18472 жыл бұрын

    unparalleled explanation skills, suited for an actually high level audience!

  • @irodionzaytsev
    @irodionzaytsev Жыл бұрын

    I can't express how absolutely taken away I am by this video! Fantastic animation, amazing narrative! I had that feeling of awesome math discovery throughout the whole video, thank you so much for putting in an immense amount of effort and love into this video!

  • @Jop_pop
    @Jop_pop2 жыл бұрын

    It's so cool how you've used manim creatively here, especially with the white theme instead of the dark one

  • @GeoffCanyon
    @GeoffCanyon2 жыл бұрын

    Awesome video! For section 2, it might help make clearer what you're saying/doing if you point out that you can translate and scale the belt any way you like. Demonstrate that, and it becomes clearer why a single twist can't shrink to the origin: because it cuts through the edge of the sphere one time, and can't "undo" that. A two-twist belt cuts through the edge twice, forming a loop. Distort that loop as you do in the video, to show it as a loop that cuts the edge in two places, then translate to remove the cuts, then shrink to the origin.

  • @nurianav
    @nurianav2 жыл бұрын

    This is GREAT, I think I'll go back to watching it every once in a while. It is brilliant. Thank you

  • @universemaster
    @universemaster2 жыл бұрын

    Literally the best math video I have ever watched. Thank you, so much.

  • @redaabakhti768
    @redaabakhti7682 жыл бұрын

    thanks so much man I'm at 12 min and the video up till now is so much insight. I wanted to investigate paths in spaces of rotations/lie groups as well as quotient topologies for a while but I've been distracted from it, thanks again!

  • @Posesso
    @Posesso2 жыл бұрын

    I have no words to explain how good is this. I mean, I am reading The Road to Reality, specifically chapter 15 which is dealing with these matters. My background is telecommunications, so group theory is a bit alien to me. How helpful is this, I think Sir Roger Penrose would be utterly pleased by this video. I am sooooo curious what he would say. Thanks a quintillion!

  • @SpinjelloLane
    @SpinjelloLane2 жыл бұрын

    i love that you put the electron in the black lodge

  • @ModusTollendoTollens
    @ModusTollendoTollens2 жыл бұрын

    Actually really impresive. Bravo!

  • @johnitaballmer3966
    @johnitaballmer39662 жыл бұрын

    Thank you sir, keep continuing such amazing videos and interesting subjects. Please before the spotlight hits you and your channel (which I think is just a matter of time) always strive for quality and thoroughness of your videos over anything else.

  • @pranjalisharma7402
    @pranjalisharma74022 жыл бұрын

    is there any chance of u making videos on.....drum rolls.................. literally every topic of physics. I'd literally love ur videos on (statistics and physics) .

  • @_srhenry
    @_srhenry2 жыл бұрын

    This is insane video! You've explained it at the right pace and splendidly! I'm surely gonna recommend your video through all my friends

  • @davicruzpestana7329
    @davicruzpestana73292 жыл бұрын

    An absolutely delightful video, congratulations!

  • @DarCMenO
    @DarCMenO2 жыл бұрын

    Wow, this is a masterpiece 😍 I especially like the last part on the Hopf fibration

  • @amittsabary3907
    @amittsabary39072 жыл бұрын

    This video should be getting a lot more views

  • @otv9005
    @otv90052 жыл бұрын

    This is excellent. Well structured and challenging. Understandably this took great effort to put together but I hope there will be more like this.

  • @rohankapoor8289
    @rohankapoor82892 жыл бұрын

    This is a phenomenal video, it's so intuitive

  • @davidkong2792
    @davidkong27922 жыл бұрын

    Had to take several days to watch this due to time but, the realization how everything he explains relates to the belt and quantum mechanics around 45:00 felt like a hit of heroine. The satisfaction of this just completely washed over me

  • @MrBebopbob
    @MrBebopbob2 жыл бұрын

    Wonderful video. Your animations and script are very methodical without being boring. Your video reminds me that, as David Hilbert once said, 'A mathematical theory is not to be considered complete until you have made it so clear that you can explain it to the first man whom you meet on the street'. Well done.

  • @frizzarazz
    @frizzarazz2 жыл бұрын

    Best video I've seen on this topic so far. The tying up loose ends was right on the nose regarding questions I had!

  • @KipIngram
    @KipIngram Жыл бұрын

    Superb - absolutely superb video. This laid it all out more clearly than I've ever seen before. Thanks for the great work!

  • @aitorgarcia1147
    @aitorgarcia11472 жыл бұрын

    Amazingly explained, thanks a lot! But I have to say I watched it twice, because the first time I left me with a negative impression ;) Keep doing videos like this one please!

  • @renaudmathevet9374
    @renaudmathevet93742 жыл бұрын

    Fan-ta-stic! Thanks a lot for this amazing video. As a quantum mechanics teacher, I will strongly recommend it to my students and... my collegues too! This a really great job. Many thanks again :-)

  • @marcoseneto
    @marcoseneto2 жыл бұрын

    I had never seen this so well and thoroughly explained. Thank you

  • @AlexTrusk91
    @AlexTrusk912 жыл бұрын

    i love to listen to ans watch your explanation when I'm sleepy and even more when I'm fully awake.

  • @johnmccall4035
    @johnmccall40352 жыл бұрын

    That was excellent. Thank you.

  • @DrDeuteron
    @DrDeuteron2 жыл бұрын

    Phenomenal video. I'd disagree at 54:41, yes the phase of one part of the electron superposition matters, but that is a local phase. A global phase (if that's what 'overall' means), would affect both parts of the superposition, and is undetectable. A similar example is putting glass on one slit of a (laser) double slit experiment, that shifts one path's phase and moves the interference pattern. Glass on both slits shift both phases equally and doesn't change the interference pattern at the (distant) screen.

  • @noahexplainsphysics

    @noahexplainsphysics

    2 жыл бұрын

    I agree with you completely. If we are tensoring the spin Hilbert space with the center-of-mass position Hilbert space then a truly global phase could not affect any measurement. Really there would be a relative phase between the basis states our full state is a linear combination of. Having said that I couldn't figure out a good way to say this in a way appropriate for the level of the video and opted to say something which was evocative of the truth yet slightly wrong, with the expectation that people "in the know" wouldn't be thrown off

  • @frankdimeglio8216

    @frankdimeglio8216

    2 жыл бұрын

    @@noahexplainsphysics THE MATHEMATICAL PROOF THAT ELECTROMAGNETISM/ENERGY IS GRAVITY (IN WHAT CONSTITUTES A BALANCED FASHION) IS SUCCESSFULLY (AND CLEARLY) DEMONSTRATED, AS E=MC2 IS F=MA: The Maria ("lunar seas") occupy ONE THIRD of the near side of the Moon. The land surface area of the Earth is 29 percent, AND this is EXACTLY between one quarter AND one third. The Moon is about one quarter (27 percent) the size of the Earth in what is a predictable fashion, AS it is FULLY manifest as LAND. The sky is BLUE, AND the Earth is ALSO BLUE. So, consider BALANCED BODILY/VISUAL EXPERIENCE. LOOK at what is the orange Sun, and think LAVA. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Accordingly, the rotation of WHAT IS THE MOON matches it's revolution. Now, consider the fully illuminated (and setting) Moon in direct comparison with the orange Sun. They are both the size of THE EYE. Notice that the Moon is ALSO BLUE. Consider the man who IS standing on what is THE EARTH/ground. Touch AND feeling BLEND, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. The BULK DENSITY of the Moon is comparable to that of (volcanic) basaltic LAVAS on the Earth. The energy density of LAVA IS about three times that of water. Great. The human body is, in fact, about as dense as WATER !!! Think !!! "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. THE SUN AND THE EARTH are F=ma AND E=MC2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. E=MC2 is DIRECTLY AND FUNDAMENTALLY DERIVED FROM F=ma. F=ma AND E=MC2 PROVE that ELECTROMAGNETISM/ENERGY IS GRAVITY, AS ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE); AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This explains F=ma AND E=MC2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. SO, GRAVITATIONAL FORCE/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. ACCORDINGLY, ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE); AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED ELECTROMAGNETIC/GRAVITATIONAL FORCE/ENERGY, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. GREAT !!! Gravity IS ELECTROMAGNETISM/ENERGY. ELECTROMAGNETISM/ENERGY IS GRAVITY. INDEED, A PHOTON may be placed at the center of THE SUN (as A POINT, of course); AS the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT (c); AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. GREAT. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. ALL of SPACE is NECESSARILY ELECTROMAGNETIC/GRAVITATIONAL (IN BALANCE), AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=MC2 IS F=ma. Great. The ability of thought to DESCRIBE OR RECONFIGURE sensory experience is ULTIMATELY dependent upon the extent to which THOUGHT IS SIMILAR TO sensory experience. (THOUGHTS ARE INVISIBLE.) Gravity IS ELECTROMAGNETISM/ENERGY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Very importantly, outer "space" involves full inertia; AND it is FULLY INVISIBLE AND black. The perpetual motion of WHAT IS THE EARTH is NOW explained. GREAT !!! The idea that THE PLANETS are "falling" in what is "curved space" in RELATION to what is THE SUN is PROVEN to be NONSENSE. So, the falling objects must be considered in RELATION to WHAT IS THEN THE ORBITING EARTH. GREAT !!! E=MC2 IS F=ma. The stars AND PLANETS are POINTS in the night sky. I have explained why the motion of WHAT IS THE MOON matches it's revolution. E=MC2 IS F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity. Consider the man who is standing on what is THE EARTH/ground. Touch AND feeling BLEND, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. Gravity IS ELECTROMAGNETISM/energy. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=MC2 IS CLEARLY F=ma; AS ELECTROMAGNETISM/energy is gravity. Accordingly, the rotation of WHAT IS THE MOON matches it's revolution. Great. (Gravity IS ELECTROMAGNETISM/energy.) E=MC2 IS F=ma ON BALANCE. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is balanced electromagnetic/gravitational force/ENERGY, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. So, objects AND MEN fall at the SAME RATE (neglecting air resistance, of course); AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. A given PLANET (INCLUDING WHAT IS THE EARTH) sweeps out EQUAL AREAS in equal times consistent WITH/AS E=MC2, F=ma, AND what is PERPETUAL MOTION, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. The stars AND PLANETS are POINTS in the night sky. Excellent !!! E=MC2 IS F=ma ON BALANCE !!! TIME dilation ULTIMATELY proves ON BALANCE that E=MC2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. INDEED, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. It all CLEARLY makes perfect sense, AS BALANCE AND completeness go hand in hand. Gravity IS ELECTROMAGNETISM/energy. E=MC2 IS CLEARLY F=ma ON BALANCE !!! Great !!! By Frank DiMeglio

  • @thatkindcoder7510

    @thatkindcoder7510

    2 жыл бұрын

    @@frankdimeglio8216 I can feel my brain melting

  • @jillianonthehudson1739
    @jillianonthehudson17392 жыл бұрын

    This was so much fun! Advanced math, easy to understand, with your mind blown several times for good measure. Thank you! Definitely earned this new sub!

  • @fredscutler9772
    @fredscutler97722 жыл бұрын

    Without doubt, this is one of the best (if not THE best) video on this topic that I've ever seen. A big thank you!

  • @euclidofalexandria3786
    @euclidofalexandria37862 жыл бұрын

    this was a great vid thank you for your efforts in posting.

  • @davidkong2792
    @davidkong27922 жыл бұрын

    I was concerned when he said “for professionals” and he still explained everything he did beautifully

  • @thomaswatts6517
    @thomaswatts65172 жыл бұрын

    legendary video, my man summarizes at the end of each section, great technique bless you bro

  • @ccamp3175
    @ccamp3175 Жыл бұрын

    Most excruciating, enlightening hour I've spent on KZread. Excellent presentation, and thank you very much.

  • @ecdavek230
    @ecdavek2302 жыл бұрын

    Noah , this was truly excellent. Thank you for making it and doing the faq and video indexing too This brought together in a single presentation many of the concepts I’ve encountered over the years creating a type of map or perhaps a trail of breadcrumbs to be followed. I still don’t understand the nature of electron spin, but you’ve provided a wonderful foundation for appreciating the mathematics not usually discussed when looking at Dirac’s solution of relativistic wave equation. ( Dirac , Principles of QM, 3rd Ed Chap XI ). As with any good map, to appreciate one must make the journey. I’m sure I’ll be looking at this video many times as I do that. Best EC D. ps : I see you have another video on this topic. Thanks in advance.

  • @melkdoria
    @melkdoria2 жыл бұрын

    Very good video. Clear and motivacional. It is not an easy topic to explain for those with no basics on algebraic topology, but quite illustrating. Congratulations.

  • @kerolosbisheer4843
    @kerolosbisheer48432 жыл бұрын

    Thank you for explaining the basics and the notation, I really needed that.

  • @vishrutpandya3257
    @vishrutpandya32572 жыл бұрын

    I really enjoyed that the content included mathematics. This is very satisfying. Amazing 👏

  • @spiralofinspiration3653
    @spiralofinspiration36532 жыл бұрын

    Amazing work

  • @MarksmanSnir
    @MarksmanSnir Жыл бұрын

    Please make more videos like this! It feels like 3Blue1Brown but for physics, which I'm sure for many people is even more interesting. The video was amazing and interesting, so thank you.

  • @Benoit-Pierre

    @Benoit-Pierre

    11 ай бұрын

    Try minute physics

  • @markos.5539
    @markos.5539 Жыл бұрын

    You have no idea how entertaining this is for me. Suddenly certain things made for sense. Tbf, you hooked me with topology. Great video, great work!

  • @wxs199327
    @wxs199327 Жыл бұрын

    Great explanation! Thank you for making the video!

  • @mistertheguy3073
    @mistertheguy30732 жыл бұрын

    This was amazing, thank you!

  • @ChrisDjangoConcerts
    @ChrisDjangoConcerts2 жыл бұрын

    Your video is of outstanding quality. Maybe a bit advanced for a general audience, making it hard to appreciate if you are not a physicist like myself. Keep making videos like this !

  • @IncompleteTheory
    @IncompleteTheory2 жыл бұрын

    This is really well done, thanks for uploading it.

  • @pyrotas
    @pyrotas2 жыл бұрын

    Just to say, this is one little gem. Congrats, I will refer my students to this resource!