What is Spin? A Geometric explanation

[@bendybruce]

This is the best explanation of quantum spin in a youtube video that I have ever listened to.

[@ScienceClicEN]

🙏

[@mattmoorhouse2325]

Agreed!

[@mrt181]

Agreed, thank you for the explanation

[@johnm.v709]

​@@ScienceClicEN Sir, On KZbin There a video titled "Spin of Indivisible Particle"

[@0neIntangible]

Also agreed!... and after watching dozens of videos over the years, this one simply describes these concepts understandably... thank you.

[@Psrj-ad]

This channel is actually astonishing. Its the only channel that can breakdown such absurdly abstract and complex topics into a form that's so clearly understandable. all without sacrificing "too much" of its initial complexity.

[@scienc-ification2539]

Yeah 😊

[@carlhitchon1009]

Clear as mud.

[@TheodorusAtheist-sx1un]

You're absolutely correct. Also, I guess you could say it better than I could.

[@nocturnhabeo]

Not the only one. PBS Spacetime does a great job as well.

[@eric3813]

Just finished my Master Thesis on differential spin geometry. I must say, your video really nicely explains the origins of spinors! really enjoyed it!!

[@ScienceClicEN]

Thanks a lot! Must have been a very interesting thesis!

[@theograice8080]

If you end up publishing your thesis in an open access journal or if you get a link to a pdf of it on the university servers, I would love to take a gander at it! I may not understand much of the text at present, but I learn through exposure. :) Edit: removes reduplicated preposition.

fr

[@d3tcovax]

Do you have a link to your thesis?

[@Fiufsciak]

​@@theograice8080KZbin is an ass that dislikes links

[@FigmentHF]

This is the first time I’ve had a tangible, intuitive understanding of this concept. So thank you, and well done

fr

[@jaredf6205]

The recent PBS space time episode called “can particles be neither matter nor force” did an amazing job at explaining it. It was the first time I had ever felt like I had some understanding of spin and what it was, same with people in the comments. Now I admit, I don’t remember what it was, as it was two weeks ago and I only watched it once, but I do remember feeling like it explained spin better than anything I’ve heard before. I just started this video, but you should check out the pbs space time video, it’s very very helpful. I honestly didn’t think anyone understood spin that well.

[@teugene5850]

My opinion as well. This channel is one of the most informative on difficult topics.

[@yZempX]

This video is gold, but if you want to learn more I can suggest the book "A brief history of time" by Hawking. It's amazing how intuitive that is. When I read it I was 17 and I didn't read through all of it, but a considerable portion

[@-danR]

It didn't do much more than what I already knew: the particles do not 'spin', they _have_ a property which physicists have decided to call spin. Towards the end of the video, the author clarifies that a full understanding of what really puzzles laypersons-the element of a (macroscopic) "spinning object" which we call "angular momentum" that is in common with particles-is too advanced for this video. And frankly, I think the many people complimenting the lucidity they claim to find therein are kidding themselves that they actually _did_ grasp the relationship of particles to their state-spaces. I think the strategy of of graphically representing the latter-a fundamentally _abstract_ entity-is in part to blame for this: "Oh, rotating planes with coordinate systems... now I get it: I can _see_ them." He also only briefly touches on explaining tensors: a gnarly topic that requires at least a half dozen youTube videos just to start to wrap one's head around, not to mention when we get to the famous rigorous definition: "a tensor is something that transforms like a tensor" A definition that has been called the math equivalent of fight club.

[@p4rity]

All videos of ScienceClic should be given as a introduction for any student in physics, when exposed to these topics. This is just so intuitive, clear and well-built, like all the other videos, amazing!

[@guy9360]

I would add they should also be given to any teacher or aspiring teacher

[@danieljardim7190]

true!

[@ulti-mantis]

One example of a macroscopic object with spin ½ is USB thumb drives. Sometimes you need to turn it by 360° in order to plug them.

[@kaslon05]

In order to avoid this problem - do not observe the process of plugging in said device - let superposition decide

[@LuisSierra42]

true

[@harrypitts7389]

Ahahahaha

[@paratracker]

No, 360 degree rotation doesn't change anything. You meant 180 degrees.

[@linglong3285]

@@paratrackerit’s a joke

[@OblivionFalls]

I've been watching sci-educational KZbin for over 10 years and this is the first time I've ever felt like I have some understanding of what "spin" is. Damn good stuff, dude.

[@DanielL143]

Holey crap - this video connects math to physics in an understandable fashion without having to try to read through a 500 page tome of incomprehensible hieroglyphics. I always believed it could be done, but this channel finally did it. Technical and true without being inaccessible or insulting. Good job people. You did not put a spin on this.

[@OnePieceFan4765]

If you want to go a bit deeper Eigenchris has a great series on spinors and tensors starting from the basics

[@mastershooter64]

Do not disgrace books. A good book is an absolutely wonderful treat and will teach you more things than a video series ever could. It is not a competition between books and videos, you should use both of them in parallel.

[@alejrandom6592]

14:01 "The opposite of a quantum state is physically equivalent to it, although mathematically different" bro casually dropping the actual explanation we've been wanting for years

[@anne-mariecote5646]

Yeah, that was my eureka moment. Well said.

[@amenoum7623]

Nope, it does not have to be physically equivalent, we ASSUME it is physically equivalent by using the squaring function to represent a physical state. I have written an article about this. If interested, google amenoum blog, look for the article "Finding sense in quanta of nonsense".

[@aslpuppy1026]

Regarding that, what exactly does “physical equivalent” mean? Does it mean that no experiment can tell them apart? Or does it simply mean that the probabilities for what happens after a collapse are the same for the two particles? If what I’m saying wasn’t clear, here’s a I thought experiment. Box 1 has electrons with a spin, let’s call it Spin A. Box 2 has electrons with the opposite of Spin A, let’s call it Opp A. I give you a third box of electrons. All of Box 3’s electrons are either Spin A or Opp A, and you don’t know which one it is. Is it possible to create an experiment using electrons from the three boxes in order to determine whether box 3 has Spin A or Opp A? (And just to clarify, the exact states of Spin A and Opp A are unknown. All that’s known is that they’re opposites.)

[@Leyao14]

What does he mean by saying it's mathematically different? They both have the same probabilities, doesn't that make them identical?

[@quitchiboo]

@@Leyao14 The sign differs. Of course using Hund's rule, that doesnt matter when you extract the probability.

[@mehmetak5930]

Awesome Study!

[@ScienceClicEN]

Thank you very much for the support 🙏

[@hoggif]

What a clear explanation! I like that this cover the idea of spin (unlike many videos of how spin is like rotation but not really a rotation which leave open what is is). Just enough group theory to get the idea without diving deep into it. Absolutely best video of spin I've ever seen.

[@ScienceClicEN]

Thanks a lot, glad you liked it!

[@TristanCleveland]

My thoughts exactly.

[@sebaschan-uwu]

I'm confused. If spin isn't about actual rotation, what is it then? Something analogous to rotation? Figurative rotation?

[@hoggif]

@@sebaschan-uwu It is not movement. It is magnetic moment, a property like mass or charge. You can make magnetic moment with moving charge too in macro world, but that is totally different matter, other than that as a result there is macroscopic magnetic moment.

[@aaaaaaaaaaaa9023]

20-minute video from ScienceClic? Let's fucking go

frrrr

[@audiodead7302]

I totally share your enthusiasm.

[@Ley-line]

Great video as always! Love the animations, and specifically how the 'collapse' is contrasted by fast movements while everything else has interpolation, nice subtle detail there. In general the analogies are simple to understand for such difficult to master topics. And the 3D and Space-Time grid representations have got to be one of the best ones out there.

[@ScienceClicEN]

Thanks 🙏 Very glad you liked it!

[@hafsamadar4058]

yes i'm also asking about 3D animation so nice

[@alichohan1999]

After watching this video I can clearly say, This is the only video on the KZbin which give the whole intuition about Spin. Really Thanks. جزاك الله خيرا ! (God bless you.)

[@Memfyy]

Waking up to a ScienceClic video is something else! Excited to watch this!

[@benudharasatapathy6625]

Where is your home dude ! It is afternoon here , and you are saying it is morning , is your home in england ?

[@sebajun3784]

@@benudharasatapathy6625 fun fact people live in different parts of the world

[@vibaj16]

@@benudharasatapathy6625 and it was around 2 AM here (when it was uploaded)

[@WegWieSemmeln]

In germany it's already noon.

[@novy1198]

ye i woke up too like 3 hours ago

[@PhoticSneezeOne]

Am i the only one who´s getting unsettling existential dread feelings once the hypnotic music of scienceclic´s videos sets in?

[@rdot21]

Interesting, I feel excited when I hear it. Like, "I might not understand it all, but I know I'm about to learn something cool"

[@novakastmusic]

I've never seen such an understandable explanation of spin. All I've ever seen or read is "well it's not really spinning, it's just behaving like it is spinning", and then it gets increasingly complicated as they try to elaborate on that. There's also that knot stuff and the mobius strip thing. Very unintuitive. Your explanation however Mind blown

[@philiphunt-bull5817]

I guess you don't watch PBS Spacetime, since the belt analogy isn't on your list

[@nikankwon]

I've been getting obsessed with spinors for the last half-a-year and wow, what a fascinating conceptual entity. Without it, the entirety of electromagnetic fields, particle behavior and therefore the universe we are all familiar with wouldn't be possible (nor exist). It's a hell of a challenge learning it as a layman, but the fact that reality operates by these rules and we somehow figured out these hidden mechanics (there may be more we haven't discovered) is truly a remarkable achievement for our species, who've somehow gotten this far. Kudos to Dirac - a theoretical physicist I think that needs to be recognized and commended a lot more. For those of you want to know more of the technical aspects of spinors, I found Richard Behiel's channel excellent. They are very long videos, but wonderful.

fr

[@-_Nuke_-]

Best Science channel on KZbin period.

[@LeTtRrZ]

An interesting fact that this video failed to mention: If you take the upper beam and send it through a horizontal magnetic field, it will split evenly left and right. If you take any one of those beams and send it through another up-down device, it will split evenly up and down, even though we originally used only the upper beam from the first split. However, if you were to properly recombine the left/right beams and send it through an up/down device, it would divert 100% up as it did before the left/right split.

[@sukhisidhu003]

Yes, I have seen another video explaining this surprisingly interesting fact. I was mesmerized!!!

[@comebackata2]

why does it do so?

[@subfreak1621]

So if you were to take a single particle and do the same up/down then left/right then again up/down what would the result be ? 100% same direction or 50% of the time?

[@johneagle4384]

Wow! This is the best explanation ever I've seen about spin. No hand waving and silly analogies. Thank you!!

[@connormcmk]

Amazing visualizations and explanation on something that's been previously very mysterious. Thanks!

[@atismoke]

I never understood why spin didn't make electrons spin.... but this channel explains it perfectly and glosses over it like nothing. Simply beautiful.

[@plasmaflare5217]

Literally the best explanation that I have ever seen about spin in a KZbin video. Thank you so much for the video.

[@thorstengonschior5603]

👍 Best explanation I have seen so far.

[@ScienceClicEN]

🙏

[@TorrentUK]

Alessandro your videos are extremely engaging and easy to understand - thank you for creating them! Octave, your narration is second to none - thank you.

[@ScienceClicEN]

🙏🙏

[@THE-X-Force]

This channel is a genuine public service and everyone involved should be proud. Thank you for your incredible service to scientific education. ☮

[@guyedwards22]

Despite everything happening in the current age of chaos and confusion, I count myself infinitely lucky to be born in an era in our history where the deepest, most esoteric, and profound aspects of reality can be communicated in such accessible, creative ways. Your videos are part of what makes our modern age so distinct from other times in our history.

[@Eilraet]

This is a fantastic video, it shifted a big chunk of my (basic) understanding of spin from "I know" to "I get", as in I feel like I get some intuitive understanding of something I only had formulaic understanding of. Thanks for that

[@offy121]

Thanks

[@jimwang3084]

I am self-learning about QFT for doing research and this is the best video I have ever watched which combines both math and physics together, thank you for your great work!

[@Pikubhoi05]

Best channel ever.no one can come near it.zero fallacy.pure concept with easy understanding.

[@jakehobrath7721]

Truly brilliant. This is the best explanation of spin I’ve seen. For years I’ve been sending laymen here, specifically for your general relativity breakdown. This is another gem, great job!! Can’t wait to see what’s next.

[@billrudersdorf4187]

Thanks!

[@MrYellowAndYacello]

Many people have tried explaining spin, and now we'll get to see how ScienceClic does it.

[@ivanp7]

impressive, very nice

@@ivanp7 fr

[@danzimbr]

Bro I swear this is the best KZbin Chanel to ever exist

[@Mr-Fish0]

I already know I’m still not going to understand it

[@xthesayuri5756]

Then don't watch it and stop wasting your time.

[@Mr-Fish0]

@@xthesayuri5756 hmm someone here is having a bad day, you should pour your frustrations somewhere productive and not on youtube comments lol

[@flymousechiu]

xd

[@xthesayuri5756]

@@Mr-Fish0 Not everyone is like you Mr. Irrational. Believe it or not, but some people can listen to the video and still write comments.

[@YoutubeModsAreSnowflake]

𝛑 calling others irrational

[@RicardoAum]

This is the type of video that I want to call all my friends to my house, make popcorn and drinks and force them to watch. Such a well done video, with amazing simple to understand analogies. I wish science was always this engaging.

[@teddp]

Einstein once said if you can't explain it to a 6-year-old, you don't know it well yourself. The explanations through the simplifications of a Master on the subject, with wonderful graphics, is what I've just experienced. I can only say this to the creator, wonderful job, bravo 👏

[@omargoodman2999]

Explaining something to a six year old is fairly easy. They're naturally curious and eager to understand things. It's teenagers and adults who *actively* resist understanding and who would _fight_ your explanation who are the problem. "It's hard to win an argument with a smart person, but _impossible_ to win against an idiot."

[@noohsiraj7555]

I think he mentioned 6th graders,not 6 years old(if I am not wrong) Because making topics like this to be understood by 6 year old kids would be nearly impossible

[@teddp]

@@noohsiraj7555 I looked it up just to make sure myself but I was right he said to a six year old. If you have a very deep understanding of the subject you can simplify it enough to bring it to a level that a six year old can understand. If it is a very complicated scientific subject you may not be able to make the six year old understand it 100% but he or she will get the basics of it at least.

[@juliavixen176]

Einstein did not say that! This is one of several quotations misattributed to Einstein.

[@roncho]

In this case a very veeery smart 6year old 😂

[@somerandomguyontheinternet1553]

I cannot express how incredible this channel is.

[@GameOver-qk2ys]

Yall are killing it with the visuals 🤯 very intuitive

[@quantummotion]

Thank you for this great work!

[@stephanieparker1250]

ScienceClic, one of the channels where I quickly press play soon as I see a video drop. 👍

[@tariq3erwa]

Jus finished my undergraduate Quantum Course and this clarified much, and motivated me to undust the Abstract Algebra Textbook that I purchased a long time ago

[@rbettsx]

Superb!. One of your best yet. And I love the way your pronunciation converts the Bristolian, Paul Dirac, into a superposition of French and English! 😊

[@xyzxyzxyzxyz636]

Ha, ha, ha...AGI. Indeed "superposition" !

[@caderlocke8869]

No matter the topic, this channel will produce the clearest, easiest to understand explanation of it. They dont miss.

[@Astroo31]

Just woke up. Couldn't find a better way to start the day 🙏

[@fanBladeOne]

Must be nice. Here it's already 11 so practically noon :)

[@Astroo31]

@@fanBladeOne I think we have the same timezone (I slept at 4 😭💀)

[@vibaj16]

@@fanBladeOne must be nice. Here it's nearly 3 AM

[@vibaj16]

@@fanBladeOne also, the original comment was 18 minutes ago, and your reply was 28 minutes ago. How does that work??

[@CliffSedge-nu5fv]

​@@fanBladeOne Wake up at noon next time.

[@stdesy]

So excited for this one! Spin is so abstract it’s hard to conceptually grasp but if anyone can manage to convey it in a fundamentally understandable way, it’s ScienceClic

[@apollo261]

This channel really is underrated... it's really at the level of 3b1b, and that's an incredible achievement!!

[@NileshPatil-li1so]

You know you are helping millions by such self explanatory videos,you are also giving lots of knowledge to those who are not privileged for good education

[@Ryanisthere]

"imagine a ball spinning, except there is no ball and nothing is spinning"

[@mangalover9000]

I absorbed 20% of the info about spin and I want to rewatch it next week after I fully digest what I understand in 20mins vid. Kepp up

[@ITobjectives]

These are phenomenal videos. Just an excellent combination of math and physics, at the ideal level of depth.

[@Interestking]

Multiple times I tried to put this video into "Watch Later" because I was getting overwhelmed by all the information and struggling to process it, but each time I just found myself resuming the video and working through the confusion, rewinding when necessary. I now can say that I have an understanding of this general concept, and I absolutely love it, so thank you for making this (really well-made) video.

[@jaggerbushOG]

That intro music.... Its the auditory cue that something good is coming!

[@heavenpad-]

im always amazed at how well these videos are made, with no shortcuts or oversimplifications which lead to wrong statements abt the topic at hand. these types of videos always make me cautious, bc they remind me of pop science channels, which often spew out a lot of sensationalised oversimplified info. this channel always manages to have engaging, intuitive, good explanations without compromising the validity of the statements.

[@hullabaloo9824]

Finally, I think I have at least a rudimentary understanding of what 'spin' is. thank you

[@dexterdyall3425]

It really is incredible how you nail these things every single time. This background music while the animations and narrator make everything and anything understandable is like a religious experience with revelation after revelation 😅

[@kenneth2519]

14:53 i was completely dumbfounded before but the moment this graph shows up everything clicks together and i have a eurika moment. Such a cool explanation very intuitive

[@Leyao14]

This is the part I don't understand lol.

[@notafraidofchange]

You could say everything “ScienceClic’d” together. 😏

[@D_oktor]

Best video on this channel without a question. Best video on spin ever by far. One of the best physics videos I've ever seen.

[@M_1024]

Great video explaining spin 1/2! I always thought that |x> = -|x> was just a mathematical artifact, but it actualy does have some physical aspect! The part about antimatter at the end has blown my mind!

[@AlexHernandez-yj6qe]

I was anxiously waiting for the english version. I love the spanish one, but I started watching this particular channel at 16, 3 years ago, which changed my mind. LOVE IT!!!!

[@WhatzHappeningNow9]

Is there a more underrated science channel? This guy is amazing!

[@badguardian]

My god, you've done it. After all of the spin videos I've watched, if they had only said, that a full rotation puts a quantum object in an classically equivalent but quantum-ly different state - amazing. That makes so much sense.

[@Bertydude]

Babe wake up. ScienceClic just uploaded a new video.

[@ExistenceUniversity]

Indistinguishable from a bot.

[@thanus6636]

@@ExistenceUniversityIrony is a lot like a spinor. 1 layer of irony produces an identical result but 2 layers are needed to return it to its initial state. Conclusion - Irony is Spin 1/2

[@hamaljay]

Quiet, I'm trying to watch.

[@coltenh581]

My hopes were honestly high for finally understanding spin, and while I definitely don’t, this video blew any other explanation out of the water. This should be required viewing before anyone is ever allowed to utter the word spin in a physics class.

[@taschenfilme1573]

3 minutes in, thank you very much. I've read a bit about spin and groups, never really understood the concept. You're explanation with the gems and rotations is so intuitive

[@JonathanDawson-q8f]

Brilliantly clear, well-structured and honest. As a layperson I am able to follow this well enough to gain at least some notion of this elusive property. Thanks for making this available.

[@magicmagic8188]

This concept makes my head spin

[@Miss__Understands]

Jesus Christ! I bow to the new Feynman of Explainers! High bandwidth, god DAMN! I've never been stuffed with so much high-quality information so effectively. Give it to me straight doctor; I can take it!

[@futiled9304]

very informative

[@cwtrain]

This was FANTASTIC. I can write out electron spin on a napkin and even explain it. But to have the idea effectively projected on a 2D graph... brilliant!

[@portalmaster555]

I got a bit giddy when I saw that opposite spinors have different properties in superposition, everything clicked!

[@danielholme398]

This was bloody amazing. I wrote an essay on the stern Gerlach experiment and I thought I had good understanding of the whole process but this description of spin really made a whole bunch of things. Click for me cheers.

[@Yairiff]

Yay a new video from you, always interesting

[@RS20O0]

Incredible video. Lost for words at how powerful communication can be when done to this standard. Well done.

[@uerisc]

It's amazing how Jesus, the president of the USA, horses and dinosaurs made me watch a video about Spin

[@monky_man69]

Relatable

[@sleepyblockanimations1482]

I was looking for this comment lol

[@willywalter6366]

Mysterious as the spin! But the horses confuse me - too „normal“ for this world! 🤣

[@asheep7797]

What?

[@guy9360]

Jesus is not the president of the USA, horses OR dinosaurs, get your facts straight!

[@sectorgamma]

This channel is an absolute goldmine, providing us with masterpiece after masterpiece. The cinematic value is off the charts, and the narration is immersive, concise and intriguing. Brilliant!

[@stopper0203]

You know its gonna be a good day when ScienceClic uploads. LETS GOOOOO!!!!!

[@stopper0203]

UPDATE: THE VIDEO HAS GROUP THEORY MY FAVOURITE BRANCH OF MATHS 😁😁😁😁

[@AMusset]

Thank you ! This is the best and clearest introduction to spin I’ve seen so far! Great video

[@totallyfalconblox]

Lesson 5 Johnny!

[@DavidDude87]

It is absolutely incredible that there are people who come up with ideas like these.

[@rekire___]

Perhaps the real connection between spin and geometric is the quantum physics we made along the way

[@jakegrist8487]

It's so rare to find a truly exceptional video. This is one. Very well done.

[@mekafinchi]

4:50 AM scienceclic jumpscare?!?!?!?!

[@rogumann838]

The single best video on spin on the entire internet so far, well done

[@jaredf6205]

New reality lore drop!

[@hikuro14]

There it is. I now finally understand what spin value means and what a spinor is. Those were two topics that I had difficulty understanding.

[@bugrakaya8355]

I watched it many times but I don’t get why Green particle rotates twice with a 90 degree turn ? Red and blue particles turning 90 degree as it’s supposed to but 5:59 shows that green particle turns “twice as much” (180 degrees) instead but the apperance of green particle shows that it turned “once” ( 90 degrees) in order to stand vertically. Could somebody explain this please ? 🙏🏼

[@-Xue-]

I was confused at first too, I was digging through the comments to find an answer and I found one that made sense but i cant like link it. Basically its says red needs a 360 rotation to get to its original state, but green only needs 180, which means rotating it 360 would give it 2 original states, making it spin 2? i think? same logic for spin 1/2 where 360 only brings it halfway to its original state?

[@ilirlluka6789]

This is the first time I was able to visually internalize the concept of spin in an intuitive manner, without having to make mental perception gymnastics which at the end always failed, especially in regard to combing the concept of "point particle" and "intrinsic spin" . Until now it was inevitable for me to think about spin as if the particles did have dimensions, because the "intrinsic" nature of spin was so abstract that it did not even register in that same visualization I had in my mind. Thank you for making this so clear after all this time struggling with adapting it in my mind. I have been following you for quite a while now as I admire your understanding of physics, your ability to teach such complex concepts in an intuitive manner through an elegant use of computer graphics. Keep up the great work man. Greetings from Albania.

[@pimen1a]

5:00 What exactly do you mean by "without dimension"?

[@c.jishnu378]

No magnitude on any dimension.

[@pimen1a]

@@c.jishnu378 but what is dimension in this case? A particle having "no magnitude on any dimension" means it have zero proper length, i.e., zero spacial distance between any two points of the particle when measured simultaneously with respect to whatever frame?

[@c.jishnu378]

@@pimen1a it means it doesn't occupy any volume whatsoever in any of the space dimensions.

[@1414Abhinandan]

One of the best Teacher and one of the best Teaching Video I have ever seen. Indebted. Thank you so much.

[@dylanledermann8629]

It would be very nice of you if you could explain the connection between full integer spin particles (like spin 0 Higgs, the various spin 1 force carriers and the theoretical spin 2 gravitons) and the bosonic properties (Bose-Einstein statistics) as well as the connection between spin 1/2 particles and fermionic properties (Fermi-Dirac statistics) and really all theoretical n +1/2 integer spins behave like fermions. It is all closely connected to the spin statistics theorem. Also, there are some very exotic scenarios and specific contexts like the quantum Hall effect - a two dimensional system - in which particles like anyons can exist that have fractional spin and statistics and are neither bosonic nor fermionic. They are an exception to the spin statistics theorem and do only exist in 2D systems. Similarly, in condensed matter physics, excitations can behave as if they had fractional spin that are not of the form n + 1/2, where n is an integer and they are quasi-particles that do not correspond to any fundamental particles in the standard model. Edit: Also, there seems to be a close connection between the tensor rank and spin, at least for all positive integer spins. rank 0 is described by a scalar, rank 1 by a vector and rank 2 by a matrix. for the spinor, one can assume a matrix representation of the rank 1 tensor and decompose it into a column and a row spinor. the rank 1 tensor is then sort of a tensor product of the two ''rank 1/2'' spinor tensors, one of which is left chiral and the other right chiral.

[@DrDeuteron]

"rank 2 by a matrix". ...that is is sin. A matrix is a box with numbers in it, a rank 2 tensor is a geometric object that rotates under a 5D representation (e.g: spin-2) representation of the rotation group, which you can write as a 3x3 cartesian tensor that is symmetric and traceless.

[@dylanledermann8629]

⁠​⁠@@DrDeuteronYes, I am aware but I'm not gonna bother typing out every little detail and axioms for all the objects that we use in physics every time I comment. I assume that it is clear when you have a solid understanding of tensor calculus and lie group theory, including representation theory. From a mathematicians point of view, all rank(m,n) tensors are vectors as well, as they satisfy the vector space axioms. But physicists have a different definition of vectors. Physicists are extremely sloppy and hand-wavy with a lot of their notations and terms. A general rank(0,2) tensor such as the metric tensor is simply a linear combination of tensor products of two dual basis vectors whose components transform twice covariantly for the two covariant indices. The components of such an object can always be written as a matrix and I took it for granted that people are aware what I mean by matrix in the physics context. Clearly, even a "column vector" can be thought of as an element of Mat(m,1|R) or simply R^m for the mathematician which is a matrix too. So context matters for the terms and usually there are not too many ambiguities.

[@WolfrostWasTaken]

This is simply the best science channel on KZbin.

[@reneradojcic]

Love you videos and explanations... General rant about learning physics (non video related): The biggest problem with physics (for me) is the usage of language. We use the terms "out of the box" and this could lead to wrong understanding while learning. e.g. Spin and then in the video the first thing it is explained - the particle is not actually spinning. If only this terminology could be explained historically (why it was used, what was the initial meaning of it, etc.) it would be much easier to learn stuff and not just accept it as "as is" (at least in the beginning while you are figuring all the parts of the topic). Just by giving the background of the word you get the historical picture and context of the topic that you are learning, and this language use gives you a glimpse of what was been solved with this concepts, how it was being solved and how people where thinking about it - at least this is my frustration right now with physics in general... I understand that this is a massive field and there is too much stuff to learn at once - but at least let's not get confused with language.

[@junfour]

You have come to the same exact conclusion as I have. In university physics we don't even get to the physics problems, it's just language problems. Prof knows what the words mean, but prof has a hard time comprehending that the same definitions aren't pre-installed into the students, so only people who already know what it means know what it means, which is useless. It's like teaching Chinese in Chinese.

[@DrDeuteron]

do strange quarks taste funny?

[@racheeeed]

Maybe this is because of the underlying mathematics, since once you go beyond things that directly correlate to our physical experience every naming convention is arbitrary and has only a passing connection to the real world. If we had decided to call this property of electron "bftzkx" 1/2 it wouldn't be confused with physical spin but it would be a lot harder to intuit.

[@reneradojcic]

​@@racheeeed yes... I also see the issues on the other side of the coin..

[@Rationalific]

Even after 20 minutes, I didn't want this to end. At times, my head felt like it was spinning, though I'm not sure the exact spin number... But even so, I was still ready for more! And as usual, the music was very soothing and contemplative. I love your videos!

[@dahlia695]

After watching this, my head is spinning in an imaginary dimension. It feels the same as it did when a physicist friend was trying to explain spinning black holes to me.

[@Muketium36]

Please don't ever ever stop making videos. These are the best.

[@KnowledgewithScience]

Nice

[@tophat593]

Excellent explanation. I know linear algebra so it made solid sense. I stopped after 8 mins and change because, honestly, that's enough to know. You'd answered the question.