What can be gleaned from this model is that there's some sort of double rotation involved when viewed in 3 spacial dimensions. I am not fully certain but as I recall, when described using quaternions/octonions this double rotation seems to disappear or at least becomes much more natural - it might just be an artifact of the default mathematical model we use in dealing with quantum physics.
@@infinummjb there is, in fact, a sort of double-rotation in the case of a true spin-1/2 object embedded in a field. The Dirac belt trick displays this well; instead of the double-rotating element being a gear, it is the ribbon/belt. The Dirac belt trick is a closer analogy to the "real" process--in the belt trick, the distortion/displacement is a close analog to the distortion/displacement of the field under rotation. In effect, what the belt trick shows is that the *space itself* (well, the field, technically--basically a set of vectors paired to a coordinate space) can twist about through one rotation (coming to a state that is not the original state) and then all the way through a second, coming to the original state. Still, though, there is indeed a double-rotation :) it's really neat.
The reason it is an unintuitive physical property, is because it is not a physical property. There are no electrons to be spinning up out down. This is a physical representation of something that is abstractly mathematical.
@@luciazazel2683 It seems to me like spin 1/2 is very similar on a conceptual level to how imaginary numbers represent rotation. Is it almost like “rotating” through an imaginary spatial dimension? I’ve always understood spin as the quantization of angular momentum is that still a good way of describing spin when you are working with non integer spin?
@@Stalutes64 Indeed so! There is, in fact, a component there that involves the complex plane. If you look up "what causes the Pauli exclusion principle", you can find an excellent explanatory video that touches on this in a more rigorous way. Yes, spin is a type of quantized, abstract angular momentum--it's not just a heuristic, it is actually a type of angular momentum, and its effects are only tangible in non-integer-spin particles/systems (the latter referring to, principally, quasiparticles). Good observations!
It's amazing that microscopes have advanced so much that we can get such a high resolution image of real individual electrons like this. In color, too!
I doubt that, electrons are smaller than the wavelength of visible light, so we will never be able to see them in color. I rather think this is a guy with a wooden model trying to give us some intuition to what spin 1/2 means. But it could also be footage from a particle accelerator where they finally managed to resolve an electron and added color for artistic reasons, similar to the recent black hole images.
I love it how to illustrate "positrons = electrons moving backward in time", instead of simply rotating the contrivance the other way around, you actually reversed the video. Hence, literally "going back in time" 👍
@@bermchasin because that would be silly. that pencil is clearly not sticky (you can see it sliding along the contact point if you look carefully), and if he HAD gone and applied some kind of adhesive to it, it would have taken more work than just reversing the video, for zero gain. in this case the simplest assumption is the most likely.
@@wizard7314 A demonstration isn't an explanation. It looks like the intention was to just share a visualization. After all, the video's title *is not* "Explanation of Spin 1/2."
@@ralphclark is that the PBS one? I like their model with the tangled ribbons only getting untangled after a second spin. Speaking of not explaining anything- is it even possible to explain spin or charge at all?
The most common spin 1/2 object most of us have to wrangle is the 4-stroke internal combustion engine. Suck squeeze bang blow, it takes twice around to get back where you started.
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If electrons were bosons, i.e. having spin 0, 1 etc, they could all be at the same (very low) enegy level within an atom, and the universe would have looked completely different - I imagine no significant chemistry would take place as there would be energetic benefits towards formation of chemical bonds Since electrons are fermions, only one can occupy each discrete set of quantum numbers (corresponding to atomic orbitals, 1S, 2S, 2Px etc. and either a spin up or down state), they have different energies and so there is energetic incentive towards bond formation (the formation of bonds leads to lower potential energy)
Another way to think about it is to hold a cup in your hand, with its bottom in the palm, and try to rotate it without the coffee spilling out (so your cup has to stay upright during rotation). If you try to do that, you will have to turn the cup under your armpit, stretch the arm out, do a weird turning motion with your hand, and then retrieve the arm. It's a fun thing to try. If you pay attention, you'll notice that the cup will have turned 720° while performing this action.
You're not a physicist. How could I know that? Because real physicists know that the electron is not a ball that spins, so this whole video is pointless. The spin of a particle is only called that because the spin operator has the same mathematical form as the angular momentum operator. Go get your money back from whatever crap college you went to, assuming you're not just completely making it up.
Bonus points for making the positron spin clip the electron spin clip played backwards instead of just spinning the model in the other direction. They need to have these in classrooms!
There is no physical representation of spin, it's a purely mathematical "concept" that describes behavior. Nice work here, and I hope it helps folks gave a bit of intuition regarding spin.
In nature, form and function are usually intertwinned. I don't see why something that arises from mathematics must necesarily be an abstract "concept" that we use by convention and not a consequence of physical reality.
An elegant, graphical representation of an extremely complex physical phenomenon. I wish there had been lecturers like you when I was at university. Your efforts are greatly appreciated.
Very cool. I've always use the idea of a waiter holding a tray. You can rotate the palm of your hand 360 degrees without dropping the tray, but your elbow will end up pointing up. Do it again, and you're back to where you started.
Astounding! A beautiful model. Even the perpendicularity of the up and down states is shown! We know that neither electrons nor their enantichronal counterparts, positrons, rotate --which is represented by the base and its basal cog, remaining static. And yet their spin state is so clearly modeled by the remainder of the model! Many thanks. First video of yours that I've watched. Yet I subscribed immediately.
This is the best simple explanation I have seen of anything since Feynman dipped the Challenger O-ring into the ice water. I hope you are a university Physics professor because you have a gift.
This was not ever a thing I thought I'd have a mental model for. I recognize that the reality is more complex, but holy hell is this a helpful way for a layperson to feel a little closer to the subject matter. Very, very well done.
maybe it's time we start recognizing that most 'teachers' are incompetent. they also teach us nonsense like: 'English uses an alphabet' - despite the fact that every literate English speaker knows full well that English writing is not remotely alphabetic. 'English has plurals' - despite the fact that 'plural' means more than one, but you can have 'no dogs', 'one dog', 'two dogs' and 'some dogs', which makes suffix-s look more like a non-singular marker... until we consider 'every dog'. 'English has verb tenses' - despite the fact that all of the alleged tense markers also appear on nouns and adjectives, like '-ed' being an alleged past tense marker appearing on adjectives: 'a walked dog is a happy dog', '-ing' appearing anywhere: 'the shouting man is disturbing my sleeping', and '-s' being the same one that allegedly marks plural nouns: 'the dogs run fast' vs 'the dog runs fast'. and this last one, which is called 'simple present tense' when it appears on a verb indicates something that's timelessly true, like 'seven plus three is 10', with that 'is' being the standalone form of suffix-s. '1+1=2' - despite the fact that most of mathematics exists specifically because this is virtually never true. for instance concepts like, fraction addition, unit conversion, and like terms, all exist to handle cases when 1+1 is most decidedly not 2, as in the following list of examples: 1 dog +1 dog = 2 dogs; this is the only kind of example that Whitehead and Russell considered in their so-called proof which appeared in the 1910 publication Principia Mathematica 1 dog +1 quail = 2 wings; expected values, but for the wrong reason... oops 1 dog +1 quail = 6 legs 1 half +1 third = 5 sixths 1 foot +1 yard = 48 inches 1 frog +1 pond = 1 pond 1 C water +1 C dirt = some mud '2^3 is 2 multiplied by itself 3 times' - despite the fact that this describes 2^4, since 2 multiplied by itself once would be 2*2, which isn't 2^1, but 2^2, so 2*2*2 isn't 2^2, but 2^3, and 2*2*2*2, or 2 multiplied by itself 3 times, is most decidedly 2^4, and not 2^3. and even if we say this slightly more correctly as: '2^3 is 3 copies of 2 multiplied together' this doesn't remotely explain zero exponents or negative exponents, which also can't be explained by what Euler said in Introductio inAnalysin Infinitorum Vol. 1 Ch. 6 #97-99, where he simply asserted that zero exponents yield 1, negative exponents yield unit fractions, and this can be shown by way of taking a random positive exponent and decrementing it. this is nonsense because even Euler partially realizes his mistake in #99 when he notes that a base of 0 doesn't behave as he's claimed, but he still doesn't really fix his mistake, he just treats this as a special case, which ends up giving us some of the indeterminate forms. but, if you pay attention just a tiny little bit you'll notice that the 1 which appears when the exponent is non-positive is always there as the initial condition to exponentiation, and that this should be extremely obvious. since exponentiation is iterated multiplication by definition its initial condition must be the multiplicative identity, which is 1. so 2^3 isn't really 2*2*2 as everyone conventionally claims. instead 2^3 = 1 *2 *2 *2, which now yields 3 multiplications by 2. and this now explains why 2^0 = 1, since this has zero multiplications by 2. and why 2^-3 = (((1 /2) /2) /2), since this has -3 multiplications, or 3 divisions, by 2. and now there's also no mystery as to why 0^0 = 1, since the value of the base is completely irrelevant when the exponent is 0, by definition.
@@beeble2003 In chemistry, you usually learn how orbitals are filled with electrons, using the Pauli exclusion principle and knowing that electrons prefer to fill orbitals with lowest energies. This has a very intimate relationship with quantum numbers. Specifically, principal, azimuthal, magnetic, and, most importantly, spin projection. If you remember about two arrows in a box, that corresponds to two different spin projections
It’s infuriating that we have such deep understanding of the mathematics of quantum objects, yet are so completely and utterly unable to have an intuition of what it really looks like (probably nothing, actually). Our brain is just ill equiped to truly understand quantum mechanics, because it doesn’t relate to much of our experience of the world.
@@hundredfireify But we cannot also deny that there is a possibility that the human brain will evolve a new way of looking at things. We often take it for granted that we look at a 3d representation of the world on a 2d surface of our computers and phones. The first time people saw moving pictures on a screen was probably quite shocking. Now, we expect moving pictures on glass screens. Granted, it may not be as close to the quantum world, our intuition will improve even more. I'd like to think Einstein's general relativity has improve our intuition on spac as more than a "gap in something" but as the actual something where things "actually happen". Whether there is a biological marker for remains to be seen. Probably future generations. Our eyes will of course always fail us because we will never be able to see the quantum world firsthand but how our brain processes information about that world can be approximated. My guess is that the main driver will be the change in how our brain handles expectation about the world around us. People who will be born with the height of virtual reality technology will probably become more susceptible to concepts not grounded on purely tactile experience. Just like we don't question the fact that when you are talking to someone on the phone, you don't mistake them being inside the device or in your ears, they'll be able to process the concept of quantum mechanics without much resistance from expecting things needing to be "actually touching".
The electron is a sphere of light and the muon is a sphere of darkness that acts as gravity. It is this pair from which all elements are made. This is rather controversial, as it proves God, "In the beginning, God created light & he divided it from darkness" The fact we broke down the atom into quanta and all we're left with is a {sphere of light} attached to a {sphere of darkness} is quite concerning for particle physicist. So instead of acknowledging God and his creation they would rather confuse themselves in lost equations that lead to nowhere.
@@IZn0g0uDatAll We have not quantized the electron any further and all evidence suggest its energy or spin is infinite. We are in agreement the electron is a building block of life & I'm explaining to you this {electron} is quite literally a {sphere of light} that proves the existence of God when it was said "In the Beginning, God created light" as we now understand light to be the building block of all matter, or in this case, the electron, a literal {sphere of light} that has {infinite energy} [never stops spinning] You don't seem genuinely interested so I'd rather not waste my time explaining why the 'muon' is actually just gravity/dark matter/energy.
@@grandunifier3169 i think if you believe in god, you shoukd just keep it at that instead of trying to justify your belief with some very badly digested pseudo scientific mumbo jumbo. None of what you writes makes any sense.
Let me get this straight. The electron is like a spinning ball that spins twice before it gets back to where it was....but it's not a ball, and it doesn't spin, and we don't really know where it is because it's actually just a wave of probability until we observe it. Yeah, that really clears it up 4 me.
I love how the example at the end loops like four times. Demonstrations like this really should always include a long looping sequence at the end of the video
Given we're often told that "spin" is something of a misnomer for what's going on way, way, WAY down there at the subatomic level. Still, your geared wooden discs demonstration is a BRILLIANT way to visualize what is probably an impossible-to-see phenomena. And as your quote at the end suggests, even Feynman didn't come up with this. So THANK YOU, Sir Watts, for helping me better grasp what I've always found elusive!
Excellent!!! My professor told be don't try to visualise it. Just think like it's there. Now my head feels more relax than before for such visualisation. Thanks a lot.
Beautiful woodcraft! A little critique: It certainly looks like an elegant implementation of the most simple double cover possible (a circle double covering a circle). However, the double cover seems only superficially related to the sphere double covering SO(3), which I think is the origin of sphin and which I believe is the effect you tried to emulate in lower dimensions. To go further, I am not quite sure how your representations of up and down actually relate to spin up and spin down. However, I am just a lowly geometer whose attempts to pierce the deep mysteries of quantum mechanical geometry have yet to succeed, so maybe by doubt is wrongly placed...
that description of the positron as an "electron going backwards in time" was striking. i've wondered if all the "missing" anti-matter of the big bang didn't head off with an opposite arrow of time to ours into an anti-universe
@@TheZenytram thanks i do get that but that question of mine remains. i've seen it pop up elsewhere. i've also wondered on a related note if certain particle/anti-particle asymmetries would disappear if they could (somehow) be observed in opposing arrows of time
OK. So first we agree that the 4D environment known as Space-Time exists. With that being the case, a particle's spin axis, is in no way limited to being only a spatial axis. The axis itself can extend across the dimension of time as well. Different axis angles, will determine different spin properties. If for instance the specific angle set the axis extending equal amounts across both space and time, the spin result would appear somewhat odd. A half of a 4D complete rotation, would appear as having been a full spatial rotation, however from the spatial point of observation, it would be noted that the particle's orientation is now the opposite of what it was beforehand. It will not return to its original orientation until it has completed a complete 4D rotation, which to us would appear to have been two spatial rotations. So, 1/2 of 4D spin equals one spatial spin, and 1 4D spin equals 2 spatial rotations.
This breaks my brain. So... possibly related question: If a 2-D object rotates about a 0-D point, a 3-D object rotates about a 1-D axis, does a 4-D object rotate about a 2-D plane? How do you even visualize that? But anyway, I'm skeptical that there could be a true rotation in the time domain because things are always moving forward. There might be a better way to say that. Any oscillation would produce a wave rather than a static object. And if it was a true rotation in time, there would be a definite start and end to its existence, because it would just be a loop that goes between two points in time, like a bad Star Trek episode. I think the spin half phenomenon speaks more to the way in which particles are connected to the fields around them, as seen with the "belt trick" czcams.com/video/JaIR-cWk_-o/video.html and czcams.com/video/Vfh21o-JW9Q/video.html
I just love how people persist in not coping with the knowledge about the wave/field aspect of sub-atomic things. to understand that, review the clip in another channel about turning a sphere inside out. From there you will start to see the energy state , only 8 or less in the outer shell make more sense. the shell is the field and the electron doesn't actually exist in the atom, just the field. Oh, and the 1/2 comes from how many times it has to turn inside out to get back to origin state. and that will help you understand the other spins like 1/3 & -2/3.
So 1/3 means that it has to turn 3 times? It's unintuitive because in my mind 1/2 get translated into "half" and 1/3 into "a third" of something, not 3 times. 2/3 is even more confusing, I guess it means it reverses every two third of a rotation. Though it doesn't tell me how many rotations it needs to return to the original state, 6 maybe?
@@souljastation5463 - that is what the planar illustration has a limited use. 1/2 would be turn inside out twice to be a full oscillation. For negative, more like turn outside in. For 2/3 or 1/3 you are dealing with 2-d objects in 3-d space, so 1/3rd = invert 3 dimensions to get a full oscillation; or 2/3 means invert 3 dimensions to get 2 oscillations. The trick is not assuming those dimensions are automatically x,y,z Better to think of it like changing color which means changing wavelength or harmonic.
Where does the "need to spin twince to get back where it started" apply for an electron? Does that mean the spin causes changes in the electron physically or something? Is there a practical observation of this ? If it is how does it behave and mean in that situation?
Spin is not rotation, it's a property that gives the particle "angular momentum", just as rotation would. But it's not a rotation. The visualization is just a bad analogy.
The duration is 3:14 🥺😭 my heart melted their. So much thankful for the video, it helped a lot❤❤❤ when he says he says a positron is an electron moving back in time, chef's kiss🤌🤌🤌
Query: With the notations given, could there be a theoretical particle that has two electrons and two positrons orbiting the nucleus? Is that how those matrices are to be read? With the models in mind, I know that it would be impossible, and I know about matter-antimatter annihilation, but then why are there two separate vectors for going around the other direction?
Feynman … still even more correct after all these years…. The fact that nothing is actually spinning probably escapes most that now think they understood something.
@@robertw1871 I was just kidding, we know it's more complex than that. Actually, except for the entanglement experiments, the analogy shown in the video works pretty well.
@@En_theo It really doesn’t, as what is called spin is a quantum of magnetic moment and nothing is actually spinning, it’s just telling you what state the magnetic feild is in. It’s a good analog of the mathematics, but not an actual electron. It’s a case of exactly how Richard explained it, if you think you understand it then you don’t, man was a genius. You’re trying to imagine an object doing something, it’s not an object, it has no dimensions or form so that’s the difficulty. It’s just a set of properties at a point in a feild.
@@robertw1871 It's ironical that you talk about not understanding QM, because the theory does not actually know what's happening in there. It's not that "it does not spin", it's more like "we don't know what's going on". So yes, the analogy works very well except for entanglement. How could you tell the difference if particles had a specific internal structure (or something like chords) and that inside it, spinning is possible because FTL movement would be possible on small scales (that's just an example). You cannot say "it does not spin", you can just say that the idea of spinning can't be explained with the rules we established so far for large scales objects. What happens inside a particle is a mystery so far.
Interesting statement from Feynman from 1965. I have seen other representations using differing models (PBS Space Time's version) which I personally think shows the physical properties a bit better but this simple one does do an excellent representation of how these properties align to the mathematical matrices so thanks!
@@Anankin12thank you for the info! It left me with more questions! The SG experiment explanations online seem to cover two flavors, electrons and magnets which deflect in "patterns"... the former being discreet and the latter continuous. Consider that the magnets only appear continuous because some parts have spin up and some spin down. Each individual particle always deflects by a specific force/direction. If you get three up and two down the forces would sum somewhere in between but closer to up. So, I was wondering if you knew if we could build matter where all of the particles (that have 1/2 spins) have the same spin orientation? How would that stuff deflect in the SG experiment? Would this stuff act like a monopole magnet? How fucked would chemistry be? I could be in left field as well! If you have time/are willing to answer of course. :)
Nothing about an electron actually spins, it’s a statistical method of defining a property. What an electron actually is can’t be visualized, but it’s more charge moving in a feilds, or a disturbance in the feild itself that couples to other feilds….
Despite really nice models: how real is this for wave equations? Some say the electron spin is lile such a rotation, others say it is not, so that there isnt anything rotating classically. Still electrons create a magnetic momentum
I am pretty sure electrons don’t actually spin. It is true that they have a magnet momentum, but if you measure its magnetism and use the upper limit of size of an electron then calculate the speed which they rotate you get a result faster than light, so we can conclude that its magnetism doesn’t come from a classical rotation.
@@brunojambeiro6776 hmmmm but magnetic moment is believed to be a direct result from the spin of the electron and its angular momentum, and so are you taking the the magnetic moment that results from angular momentum into your calculations as well?
@@dylanmiley5642 Not exactly sure what you mean by that. The magnetic moment the electron have is a result of its angular momentum, which is connected to it’s spin, but despite it being called spin, electrons don’t rotate around its own axis. It’s angular momentum is intrinsic to the particle. What i had showed is that such angular momentum could not be a result a classical rotation of the electron. Btw I an no expert, try searching science asylum spin, I belive he gives a better explanation in the video.
@@brunojambeiro6776 im not an expert either, im simply a masters student in electrical engineering with an interest in this realm. From my understanding (and with reference to the textbook "Magnetism and Magnetic Materials" ) within a magnetic material, electrons both have an orbital angular momentum as well as spin, and as magnetism is a relativistic correction to the coulomb force, both of these components lead to magnetic moment.
the problem with this demonstration is that you can make any gear ratio you want - it could also be "spin 1/3". But there is fundamentally no spin 1/3 in reality.
It can be represented by a wave graph, and it also can be split into its composite wave-forms by Fourier's transform, right? Wouldn't that give us some insight or ideas on what an electron's wave is composed of?
@@En_theo , yes by lowering their energy level they can shoot out photons, but can they disappear completely broken into photons, by leaving nothing else?
But the cog angles are arbitrary, they could be any 360 degrees so you don't have two spin states, but infinitely many. Also the cog ratios are arbitrary so you have an arbitrary number of rotations required for return to previous state. You might say that these up/down 1/2 spins represent two classes of behaviour of this model, but many more classes of behaviour might be imagined. So the model although interesting does not throw any light on the spin phenomenon.
This is what I was thinking, the idea that you have to spin a spin 1/2 system by 720° to get it to return some state has some links but I don’t think anything else in the video is relevant to an actual quantum mechanical spin 1/2 system
Spin is an integral characteristic of a substance, like its mass, density, etc. American science again confuses people this time not with Schrödinger's cats, but replacing the terms rotational mechanical moment and quantum number.
Naaaaah we call it spin bc in the equation, in which it was first derived, it looks like angular momentum. I mean it's no more confusing than talking about color charges or positive and negative charges, they're merely ways of expressing a new concept that words did not exist for.
We’re just observing the properties and assigning a somewhat arbitrary way that has some relation to what is being observed. If you see something glowing but not consistently bright, you might assign it a property called brightness. Here, they don’t really know, but that something can be imagined as a spin, so it is described as so.
Exactly…. It’s a twisted loop of charge, like a knot, but it’s not spinning… nobody knows, that’s absolutely certain… Even Feynman couldn’t visualize it, so we meager mortals have almost no chance. The more you understand the weirder and less sense it makes. It’s beyond difficult to visualize a model that explains all of its properties at the same time. Unfortunately for the curious there seems no way to use intuition. This demonstration is nothing more than a mathematical analog that has nothing to do with electrons, and I’m not sure if’s it’s helpful or harmful…
Yes. However, spin is a measurement of energy (angular momentum). In the g-2 muon experiment, the spin was determined from the amount of energy in the electrons which decayed from the muons. It has been proposed that electrons are made of two massless particles with opposite “chirality “(yet another insufficient analogy) , which is like “right-handed” “ left-handed “ rotation. The flipping back and forth of chirality is said to be the cause of mass. We don’t know what an electron is it’s just the math that makes us come up with more ideas.
"quire knowledge about the internal parts of the electrons, " There is no present evidence for an electron having internal parts. Characteristics yes, parts no. Which is the problem for physical representations of spin. I really like this demo BUT its an analogy and not related to how electrons really do anything. The are the best tested fit to the idea of a fundamental particle.
This spin 1/2 representation is equivalent to Möbius torus knot, in which case the aether has to flow twice around the electron to get to the same spot in the original orientation.
Most commom spin 1/2 object is the USB connector. You have to place it twice on the same position in order to achieve the perfect match
This is vastly relatable
Thank you!
This is actually the best comment on CZcams
of macro objects
On behalf of every human being I want to thank you for this comment
I love how casually he says "A positron can be seen as an electron moving backwarsa in time" like its the most basic thing ever
Well, it is (in the standard model of physics)
One may even say it's: elementary.
It's actually going to get this video taken down
Or you can view it as electron debt.
Oh come on, man. Any time you watch an electron moving backwards in time, WHAT DOES IT LOOK LIKE TO YOU? Positron, dumbfuck. Jeesh.
That's a brilliant, brilliant explanation of an utterly unintuitive physical property. Kudos for achieving such clarity, simplicity, and conciseness.
What can be gleaned from this model is that there's some sort of double rotation involved when viewed in 3 spacial dimensions. I am not fully certain but as I recall, when described using quaternions/octonions this double rotation seems to disappear or at least becomes much more natural - it might just be an artifact of the default mathematical model we use in dealing with quantum physics.
@@infinummjb there is, in fact, a sort of double-rotation in the case of a true spin-1/2 object embedded in a field. The Dirac belt trick displays this well; instead of the double-rotating element being a gear, it is the ribbon/belt. The Dirac belt trick is a closer analogy to the "real" process--in the belt trick, the distortion/displacement is a close analog to the distortion/displacement of the field under rotation. In effect, what the belt trick shows is that the *space itself* (well, the field, technically--basically a set of vectors paired to a coordinate space) can twist about through one rotation (coming to a state that is not the original state) and then all the way through a second, coming to the original state. Still, though, there is indeed a double-rotation :) it's really neat.
The reason it is an unintuitive physical property, is because it is not a physical property. There are no electrons to be spinning up out down. This is a physical representation of something that is abstractly mathematical.
@@luciazazel2683 It seems to me like spin 1/2 is very similar on a conceptual level to how imaginary numbers represent rotation. Is it almost like “rotating” through an imaginary spatial dimension? I’ve always understood spin as the quantization of angular momentum is that still a good way of describing spin when you are working with non integer spin?
@@Stalutes64 Indeed so! There is, in fact, a component there that involves the complex plane. If you look up "what causes the Pauli exclusion principle", you can find an excellent explanatory video that touches on this in a more rigorous way.
Yes, spin is a type of quantized, abstract angular momentum--it's not just a heuristic, it is actually a type of angular momentum, and its effects are only tangible in non-integer-spin particles/systems (the latter referring to, principally, quasiparticles).
Good observations!
It's amazing that microscopes have advanced so much that we can get such a high resolution image of real individual electrons like this. In color, too!
Turns out they are made from wood, who would have thought.
And you can clearly see the magic stick of god making them move!
@@Lolleka nah you just have to spin them by hand.
🤣🤣🤣
I doubt that, electrons are smaller than the wavelength of visible light, so we will never be able to see them in color. I rather think this is a guy with a wooden model trying to give us some intuition to what spin 1/2 means.
But it could also be footage from a particle accelerator where they finally managed to resolve an electron and added color for artistic reasons, similar to the recent black hole images.
I love it how to illustrate "positrons = electrons moving backward in time", instead of simply rotating the contrivance the other way around, you actually reversed the video. Hence, literally "going back in time" 👍
how can you tell he just "reversed the video"... are you suggesting you were able to detect the DECREASE is overall entropy?!?!?
@@bermchasinHis pencil was “pulling” the gear instead of pushing it in the bottom 2 videos
how do you know it wasnt a sticky pencil? @@gautamknambiar
@@bermchasin because that would be silly. that pencil is clearly not sticky (you can see it sliding along the contact point if you look carefully), and if he HAD gone and applied some kind of adhesive to it, it would have taken more work than just reversing the video, for zero gain. in this case the simplest assumption is the most likely.
i dont know man....maybe its made of tachyons@@EC_Orion
This is the most elegant visualisation I've seen to date. Excellent work.
Except it doesn't explain anything
after first rotation up becomes down and vice versa
@@wizard7314 A demonstration isn't an explanation. It looks like the intention was to just share a visualization. After all, the video's title *is not* "Explanation of Spin 1/2."
This one is more useful and more realistic. It’s based on Dirac’s belt trick but I think it’s clearer.
czcams.com/video/Nat-EsReXtQ/video.html
@@ralphclark is that the PBS one? I like their model with the tangled ribbons only getting untangled after a second spin. Speaking of not explaining anything- is it even possible to explain spin or charge at all?
The fact that the video is 3 minutes 14 seconds long is the icing on the cake🤯
He only had so many electrons he could spare.
Icing on the pie:)
Coincidence? I think not!
opened it because of that)
3 min 13 seconds ...
I'm a retired engineer from the semiconductor industry. This is the best demonstration of "spin 1/2" I've ever seen.
It's semiconductor crisis out there. Come on back to work my man!
@@RuePerrue I don't speak Chinese.
@@gordonsirek9001 isn't tsmc in Taiwan?
@@demp11 Guess what they speak in Taiwan buddy
@@rabarber9610 Taiwanese !
(/s)
The most common spin 1/2 object most of us have to wrangle is the 4-stroke internal combustion engine. Suck squeeze bang blow, it takes twice around to get back where you started.
Good analogy!
Who ho ho (*tugs collar) sounds like my ex wife!
@@ericray7173 And now all you have is a Wankel. Six times as many power strokes, but always blowing seals.
@@mal2ksc Those lucky seals
Glad you provided an everyday analogy with the engine. I still don’t get how these scientist figured this out with an electron!!
So an electron does have internal structure, little wooden gears.
...and a pencil to push it all around.
@@SpaceCadet4Jesus and a man with a smooth voice to do the pushing, and the ground he stands on, and..., and... xd
@Rahul in its infinite boredom, it half-spins the electrons around xd
His tinker-toy set is so much better than mine.
@@no-better-name only when someone is watching lol
this is like a secret youtube section of quality, no fluff, no sponsorships,no bs. Thank you
Your name is perfect for that comment. Lol
you might like sponsorblock
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Beyond the cleverness of the visualization, I'm also really impressed by how smoothly those wooden models spin. Very well done!
The best approach I've ever seen to explain it, love it!
Except 'spin' is just the term we use to describe election motion, despite the fact that they don't actually 'spin...
@@NorthernChev knew that
well this video explained really well a bad analogy,
I have absolutely no idea why it matters that electrons have spin 1/2, but I'm glad I know it now
If electrons were bosons, i.e. having spin 0, 1 etc, they could all be at the same (very low) enegy level within an atom, and the universe would have looked completely different - I imagine no significant chemistry would take place as there would be energetic benefits towards formation of chemical bonds
Since electrons are fermions, only one can occupy each discrete set of quantum numbers (corresponding to atomic orbitals, 1S, 2S, 2Px etc. and either a spin up or down state), they have different energies and so there is energetic incentive towards bond formation (the formation of bonds leads to lower potential energy)
Another way to think about it is to hold a cup in your hand, with its bottom in the palm, and try to rotate it without the coffee spilling out (so your cup has to stay upright during rotation). If you try to do that, you will have to turn the cup under your armpit, stretch the arm out, do a weird turning motion with your hand, and then retrieve the arm. It's a fun thing to try. If you pay attention, you'll notice that the cup will have turned 720° while performing this action.
Dirac proposed a similar puzzle with a belt, aka "the Dirac's belt trick", to untwist a twisted belt with a fixed end without rotating the other end.
I just tried it. Its even better than the video in a way that there is more fun in playing with the demonstration yourself!
Don't play around with this too much, you might unravel the universe.
@@SpaceCadet4Jesus sounds like fun :P
@@mahxylim7983 The belt trick or with the cup?
Superb visuals. I'm a physicist and this is the best demo of spin I've ever seen.
Sir,I can provide you link of a video on Y.T for spin if interested let me know
How come it's the best demo? Do we even know what an electron is, let alone how we should attempt to portray it using macroscopic objects?
@@getsideways7257never mind the fact that electrons don't actually spin either.
@@Bane_of_the_Moonsea An electron is such a weird thing, the notion of actual spin is probably not more applicable to it than "flavor" to a quark.
You're not a physicist. How could I know that? Because real physicists know that the electron is not a ball that spins, so this whole video is pointless. The spin of a particle is only called that because the spin operator has the same mathematical form as the angular momentum operator. Go get your money back from whatever crap college you went to, assuming you're not just completely making it up.
USB connectors also have spin 1/2. You have to flip it over _twice_ before it will fit.
confirmed! happened today...again.
Absolutely. One of the mysteries of the universe.
Curiously this even applies to USB-C connectors.
Bonus points for making the positron spin clip the electron spin clip played backwards instead of just spinning the model in the other direction. They need to have these in classrooms!
yup, we can see the stick being followed by the gear, and not the gear being pushed by the stick :))
By far the best spin 1/2 video I've come across in like 3 years. These models are fantastic
a 1:2 gear ratio with the gears attached by a rigid rod... a fine analogy sir
Equivalent to Möbius strip.
Will the name get trashed when some genius invests a gear with 1:3 ratio?
There is no physical representation of spin, it's a purely mathematical "concept" that describes behavior. Nice work here, and I hope it helps folks gave a bit of intuition regarding spin.
electrons are a good representation! good luck seeing them LOL
Why not just say that a spin is this behavior?
@@plantae420 that sounds rather oversimplified to me, though i dont know partical physics
In nature, form and function are usually intertwinned. I don't see why something that arises from mathematics must necesarily be an abstract "concept" that we use by convention and not a consequence of physical reality.
@@schlierenguy cause it's not
Brilliant demonstration and illustration. Many a high school physics teacher will be using these precious 3:14 min of top pedagogy!
3.14
An elegant, graphical representation of an extremely complex physical phenomenon.
I wish there had been lecturers like you when I was at university.
Your efforts are greatly appreciated.
Very cool. I've always use the idea of a waiter holding a tray. You can rotate the palm of your hand 360 degrees without dropping the tray, but your elbow will end up pointing up. Do it again, and you're back to where you started.
Astounding!
A beautiful model.
Even the perpendicularity of the up and down states is shown!
We know that neither electrons nor their enantichronal counterparts, positrons, rotate --which is represented by the base and its basal cog, remaining static. And yet their spin state is so clearly modeled by the remainder of the model!
Many thanks.
First video of yours that I've watched. Yet I subscribed immediately.
This is the best simple explanation I have seen of anything since Feynman dipped the Challenger O-ring into the ice water. I hope you are a university Physics professor because you have a gift.
I like how he actually played the video backwards for the positron to highlight it moving backwards in time.
This was not ever a thing I thought I'd have a mental model for. I recognize that the reality is more complex, but holy hell is this a helpful way for a layperson to feel a little closer to the subject matter. Very, very well done.
U just taught me something that I never caught in an entire year of chemistry in just 3 mins 14 sec. 👏👏👏👏
i mean, you were being taught chemistry. not quantum physics. so it makes sense
Why would this be mentioned in chemistry at all? It has nothing to do with chemistry.
maybe it's time we start recognizing that most 'teachers' are incompetent.
they also teach us nonsense like:
'English uses an alphabet' - despite the fact that every literate English speaker knows full well that English writing is not remotely alphabetic.
'English has plurals' - despite the fact that 'plural' means more than one, but you can have 'no dogs', 'one dog', 'two dogs' and 'some dogs', which makes suffix-s look more like a non-singular marker... until we consider 'every dog'.
'English has verb tenses' - despite the fact that all of the alleged tense markers also appear on nouns and adjectives, like '-ed' being an alleged past tense marker appearing on adjectives: 'a walked dog is a happy dog', '-ing' appearing anywhere: 'the shouting man is disturbing my sleeping', and '-s' being the same one that allegedly marks plural nouns: 'the dogs run fast' vs 'the dog runs fast'. and this last one, which is called 'simple present tense' when it appears on a verb indicates something that's timelessly true, like 'seven plus three is 10', with that 'is' being the standalone form of suffix-s.
'1+1=2' - despite the fact that most of mathematics exists specifically because this is virtually never true. for instance concepts like, fraction addition, unit conversion, and like terms, all exist to handle cases when 1+1 is most decidedly not 2, as in the following list of examples:
1 dog +1 dog = 2 dogs; this is the only kind of example that Whitehead and Russell considered in their so-called proof which appeared in the 1910 publication Principia Mathematica
1 dog +1 quail = 2 wings; expected values, but for the wrong reason... oops
1 dog +1 quail = 6 legs
1 half +1 third = 5 sixths
1 foot +1 yard = 48 inches
1 frog +1 pond = 1 pond
1 C water +1 C dirt = some mud
'2^3 is 2 multiplied by itself 3 times' - despite the fact that this describes 2^4, since 2 multiplied by itself once would be 2*2, which isn't 2^1, but 2^2, so 2*2*2 isn't 2^2, but 2^3, and 2*2*2*2, or 2 multiplied by itself 3 times, is most decidedly 2^4, and not 2^3. and even if we say this slightly more correctly as: '2^3 is 3 copies of 2 multiplied together' this doesn't remotely explain zero exponents or negative exponents, which also can't be explained by what Euler said in Introductio inAnalysin Infinitorum Vol. 1 Ch. 6 #97-99, where he simply asserted that zero exponents yield 1, negative exponents yield unit fractions, and this can be shown by way of taking a random positive exponent and decrementing it. this is nonsense because even Euler partially realizes his mistake in #99 when he notes that a base of 0 doesn't behave as he's claimed, but he still doesn't really fix his mistake, he just treats this as a special case, which ends up giving us some of the indeterminate forms.
but, if you pay attention just a tiny little bit you'll notice that the 1 which appears when the exponent is non-positive is always there as the initial condition to exponentiation, and that this should be extremely obvious. since exponentiation is iterated multiplication by definition its initial condition must be the multiplicative identity, which is 1. so 2^3 isn't really 2*2*2 as everyone conventionally claims. instead 2^3 = 1 *2 *2 *2, which now yields 3 multiplications by 2. and this now explains why 2^0 = 1, since this has zero multiplications by 2. and why 2^-3 = (((1 /2) /2) /2), since this has -3 multiplications, or 3 divisions, by 2. and now there's also no mystery as to why 0^0 = 1, since the value of the base is completely irrelevant when the exponent is 0, by definition.
@@beeble2003electron states and whatnot
fuck chemistry anyways
@@beeble2003 In chemistry, you usually learn how orbitals are filled with electrons, using the Pauli exclusion principle and knowing that electrons prefer to fill orbitals with lowest energies. This has a very intimate relationship with quantum numbers. Specifically, principal, azimuthal, magnetic, and, most importantly, spin projection. If you remember about two arrows in a box, that corresponds to two different spin projections
It’s infuriating that we have such deep understanding of the mathematics of quantum objects, yet are so completely and utterly unable to have an intuition of what it really looks like (probably nothing, actually).
Our brain is just ill equiped to truly understand quantum mechanics, because it doesn’t relate to much of our experience of the world.
@@hundredfireify But we cannot also deny that there is a possibility that the human brain will evolve a new way of looking at things. We often take it for granted that we look at a 3d representation of the world on a 2d surface of our computers and phones. The first time people saw moving pictures on a screen was probably quite shocking. Now, we expect moving pictures on glass screens. Granted, it may not be as close to the quantum world, our intuition will improve even more. I'd like to think Einstein's general relativity has improve our intuition on spac as more than a "gap in something" but as the actual something where things "actually happen". Whether there is a biological marker for remains to be seen. Probably future generations. Our eyes will of course always fail us because we will never be able to see the quantum world firsthand but how our brain processes information about that world can be approximated. My guess is that the main driver will be the change in how our brain handles expectation about the world around us. People who will be born with the height of virtual reality technology will probably become more susceptible to concepts not grounded on purely tactile experience. Just like we don't question the fact that when you are talking to someone on the phone, you don't mistake them being inside the device or in your ears, they'll be able to process the concept of quantum mechanics without much resistance from expecting things needing to be "actually touching".
The electron is a sphere of light and the muon is a sphere of darkness that acts as gravity.
It is this pair from which all elements are made.
This is rather controversial, as it proves God, "In the beginning, God created light & he divided it from darkness"
The fact we broke down the atom into quanta and all we're left with is a {sphere of light} attached to a {sphere of darkness} is quite concerning for particle physicist. So instead of acknowledging God and his creation they would rather confuse themselves in lost equations that lead to nowhere.
@@grandunifier3169 lol what the hell are you talking about hahaha
@@IZn0g0uDatAll We have not quantized the electron any further and all evidence suggest its energy or spin is infinite. We are in agreement the electron is a building block of life & I'm explaining to you this {electron} is quite literally a {sphere of light} that proves the existence of God when it was said "In the Beginning, God created light" as we now understand light to be the building block of all matter, or in this case, the electron, a literal {sphere of light} that has {infinite energy}
[never stops spinning]
You don't seem genuinely interested so I'd rather not waste my time explaining why the 'muon' is actually just gravity/dark matter/energy.
@@grandunifier3169 i think if you believe in god, you shoukd just keep it at that instead of trying to justify your belief with some very badly digested pseudo scientific mumbo jumbo.
None of what you writes makes any sense.
This is probably the best explanation of electron spin I've ever encountered. It makes such intuitive sense when presented this way.
Let me get this straight. The electron is like a spinning ball that spins twice before it gets back to where it was....but it's not a ball, and it doesn't spin, and we don't really know where it is because it's actually just a wave of probability until we observe it. Yeah, that really clears it up 4 me.
See? Its not so difficult!
That's a very interesting property for a fundamental particle to have when you put it like this.
I love how the example at the end loops like four times. Demonstrations like this really should always include a long looping sequence at the end of the video
Given we're often told that "spin" is something of a misnomer for what's going on way, way, WAY down there at the subatomic level. Still, your geared wooden discs demonstration is a BRILLIANT way to visualize what is probably an impossible-to-see phenomena. And as your quote at the end suggests, even Feynman didn't come up with this. So THANK YOU, Sir Watts, for helping me better grasp what I've always found elusive!
If all teachers demonstrated and explained like this, no one would miss their classes!
Ahh, things our profs never told us. This spin thing makes complete sense
You've managed to explain something I could never quite get my head around in the space of a few minutes. Genuinely impressed!
I've kinda heard about these concepts before but never really understood them. This is a great way to show what is going on. Thanks for sharing!
Excellent!!! My professor told be don't try to visualise it. Just think like it's there. Now my head feels more relax than before for such visualisation. Thanks a lot.
Excellent visualisation! It would be fantastic if there was a visualisation of how the Pauli Exclusion principle applies in atomic/molecular orbitals.
Thanks for that beautiful presentation. It's brilliantly simple, and very well put together.
This is more than brilliant, one of the best things I have ever seen.
Thanks a ton Sir
Absolutely beautiful little bit of intuition! Fantastic demonstration
The fact this is 1 year old and every comment is maximum 1 day old.
That didn't age well :)
This is AWESOME!
This is the first time I have been able to visualise this concept. Brilliant!
It is a crime that this channel has only 900 subscribers. This content is ingenious!!!
Amazing analogy! I just blindly calculate without thinking about these stuffs, but maybe that's not very optimal.
this is amazing!
This is the most elegant visualisation I've seen to date. Good work
That is why the maximum electrons per orbital is 2. It pushes each other in circular motion and turns into 1/2 orbit.
Beautiful woodcraft!
A little critique: It certainly looks like an elegant implementation of the most simple double cover possible (a circle double covering a circle). However, the double cover seems only superficially related to the sphere double covering SO(3), which I think is the origin of sphin and which I believe is the effect you tried to emulate in lower dimensions. To go further, I am not quite sure how your representations of up and down actually relate to spin up and spin down.
However, I am just a lowly geometer whose attempts to pierce the deep mysteries of quantum mechanical geometry have yet to succeed, so maybe by doubt is wrongly placed...
that description of the positron as an "electron going backwards in time" was striking. i've wondered if all the "missing" anti-matter of the big bang didn't head off with an opposite arrow of time to ours into an anti-universe
they go forwards in time, his simplification about them going backward is just to make the math easier.
@@TheZenytram thanks i do get that but that question of mine remains. i've seen it pop up elsewhere. i've also wondered on a related note if certain particle/anti-particle asymmetries would disappear if they could (somehow) be observed in opposing arrows of time
This is a stray anti-comment.
@@SpaceCadet4Jesus bravo
! ° ∆
°∆
Aa
A a
Aa a
A a a
A aa a
A aaa a
A aa a a
A a a a aa
A a a a a a
And Im a stray Gamma Ray!
Thank you, this model makes it much easier to imagine and understand what happens in the subatomic level.
Thanks for the concise and intuitive demonstration of spin 1/2. It makes the concept easy to visualise.
pretty cool models!
4 years ago??? HOW?
@@dioptre lol
@@dioptre Lorenzo is a positron who is moving backwards in time :)
4 years ago!? I wish! Would have been a really cool visual for me while deriving the Dirac equation for my research paper
OK. So first we agree that the 4D environment known as Space-Time exists. With that being the case, a particle's spin axis, is in no way limited to being only a spatial axis. The axis itself can extend across the dimension of time as well. Different axis angles, will determine different spin properties. If for instance the specific angle set the axis extending equal amounts across both space and time, the spin result would appear somewhat odd. A half of a 4D complete rotation, would appear as having been a full spatial rotation, however from the spatial point of observation, it would be noted that the particle's orientation is now the opposite of what it was beforehand. It will not return to its original orientation until it has completed a complete 4D rotation, which to us would appear to have been two spatial rotations. So, 1/2 of 4D spin equals one spatial spin, and 1 4D spin equals 2 spatial rotations.
Except we don't all agree 4D spacetime exists. Many fundamental theories postulate that spacetime is an emergent property.
@@mal2ksc Well you could also check my YT videos and see how common sense can lead you to a whole lot of mathematical equations.
This breaks my brain. So... possibly related question: If a 2-D object rotates about a 0-D point, a 3-D object rotates about a 1-D axis, does a 4-D object rotate about a 2-D plane? How do you even visualize that? But anyway, I'm skeptical that there could be a true rotation in the time domain because things are always moving forward. There might be a better way to say that. Any oscillation would produce a wave rather than a static object. And if it was a true rotation in time, there would be a definite start and end to its existence, because it would just be a loop that goes between two points in time, like a bad Star Trek episode. I think the spin half phenomenon speaks more to the way in which particles are connected to the fields around them, as seen with the "belt trick" czcams.com/video/JaIR-cWk_-o/video.html and czcams.com/video/Vfh21o-JW9Q/video.html
this is SUCH a good demonstration/analogy for half spin!
What elegant woodworking and explanation. The world makes slightly more sense to me now.
I just love how people persist in not coping with the knowledge about the wave/field aspect of sub-atomic things.
to understand that, review the clip in another channel about turning a sphere inside out.
From there you will start to see the energy state , only 8 or less in the outer shell make more sense. the shell is the field and the electron doesn't actually exist in the atom, just the field.
Oh, and the 1/2 comes from how many times it has to turn inside out to get back to origin state. and that will help you understand the other spins like 1/3 & -2/3.
So 1/3 means that it has to turn 3 times? It's unintuitive because in my mind 1/2 get translated into "half" and 1/3 into "a third" of something, not 3 times.
2/3 is even more confusing, I guess it means it reverses every two third of a rotation. Though it doesn't tell me how many rotations it needs to return to the original state, 6 maybe?
Which video?
@@souljastation5463 - that is what the planar illustration has a limited use. 1/2 would be turn inside out twice to be a full oscillation. For negative, more like turn outside in.
For 2/3 or 1/3 you are dealing with 2-d objects in 3-d space, so 1/3rd = invert 3 dimensions to get a full oscillation; or 2/3 means invert 3 dimensions to get 2 oscillations. The trick is not assuming those dimensions are automatically x,y,z
Better to think of it like changing color which means changing wavelength or harmonic.
Where does the "need to spin twince to get back where it started" apply for an electron? Does that mean the spin causes changes in the electron physically or something? Is there a practical observation of this ? If it is how does it behave and mean in that situation?
I don't know either, but what I know is that the explanation is going to be complicated
because of that
czcams.com/video/EK_6OzZAh5k/video.html
Spin is not rotation, it's a property that gives the particle "angular momentum", just as rotation would. But it's not a rotation. The visualization is just a bad analogy.
This is one of the best visual representations I've seen
The duration is 3:14 🥺😭 my heart melted their. So much thankful for the video, it helped a lot❤❤❤ when he says he says a positron is an electron moving back in time, chef's kiss🤌🤌🤌
Query: With the notations given, could there be a theoretical particle that has two electrons and two positrons orbiting the nucleus? Is that how those matrices are to be read?
With the models in mind, I know that it would be impossible, and I know about matter-antimatter annihilation, but then why are there two separate vectors for going around the other direction?
Following because I was about to ask the same question
- Richard Feynmann : "if you think you understood QM, then you have not understood it"
- CZcams : "Not so fast..."
Feynman … still even more correct after all these years…. The fact that nothing is actually spinning probably escapes most that now think they understood something.
@@robertw1871
I was just kidding, we know it's more complex than that. Actually, except for the entanglement experiments, the analogy shown in the video works pretty well.
@@En_theo It really doesn’t, as what is called spin is a quantum of magnetic moment and nothing is actually spinning, it’s just telling you what state the magnetic feild is in. It’s a good analog of the mathematics, but not an actual electron. It’s a case of exactly how Richard explained it, if you think you understand it then you don’t, man was a genius. You’re trying to imagine an object doing something, it’s not an object, it has no dimensions or form so that’s the difficulty. It’s just a set of properties at a point in a feild.
@@robertw1871
It's ironical that you talk about not understanding QM, because the theory does not actually know what's happening in there. It's not that "it does not spin", it's more like "we don't know what's going on". So yes, the analogy works very well except for entanglement. How could you tell the difference if particles had a specific internal structure (or something like chords) and that inside it, spinning is possible because FTL movement would be possible on small scales (that's just an example).
You cannot say "it does not spin", you can just say that the idea of spinning can't be explained with the rules we established so far for large scales objects. What happens inside a particle is a mystery so far.
We dont know whats happening, but its not spinning.
Interesting statement from Feynman from 1965. I have seen other representations using differing models (PBS Space Time's version) which I personally think shows the physical properties a bit better but this simple one does do an excellent representation of how these properties align to the mathematical matrices so thanks!
Years trying to wrap my head around spin one half. Superb visualization. Thanks
I’m curious about how these spins manifest themselves in the lab and how we ever knew they existed.
Stern Gerlach
Also the math needed to understand this is a little bit complicated, but if you're familiar with vectors you should be able to kinda follow it
@@Anankin12thank you for the info! It left me with more questions! The SG experiment explanations online seem to cover two flavors, electrons and magnets which deflect in "patterns"... the former being discreet and the latter continuous. Consider that the magnets only appear continuous because some parts have spin up and some spin down. Each individual particle always deflects by a specific force/direction. If you get three up and two down the forces would sum somewhere in between but closer to up. So, I was wondering if you knew if we could build matter where all of the particles (that have 1/2 spins) have the same spin orientation? How would that stuff deflect in the SG experiment? Would this stuff act like a monopole magnet? How fucked would chemistry be? I could be in left field as well! If you have time/are willing to answer of course. :)
@@skougi SG experiment already splits particles into those with the same orientations...
Nothing about an electron actually spins, it’s a statistical method of defining a property. What an electron actually is can’t be visualized, but it’s more charge moving in a feilds, or a disturbance in the feild itself that couples to other feilds….
Excellent!!
I don't know how to thank you for these great explanation and demonstration!!
Someone told me that 1/2 spin means 2 rounds to its original state few years ago, I can't imagine until I watch your video, thank you.
They don’t ACTUALLY spin. Electrons are points. A point can’t spin.
@@steveshadforth I know they do not spin in a classical physics way. But they are not 'points' either.
@@mingchiisuen2576 yes they are
Despite really nice models: how real is this for wave equations? Some say the electron spin is lile such a rotation, others say it is not, so that there isnt anything rotating classically. Still electrons create a magnetic momentum
I am pretty sure electrons don’t actually spin. It is true that they have a magnet momentum, but if you measure its magnetism and use the upper limit of size of an electron then calculate the speed which they rotate you get a result faster than light, so we can conclude that its magnetism doesn’t come from a classical rotation.
I am suspicious that electron has a size in classical sense as well.
@@brunojambeiro6776 hmmmm but magnetic moment is believed to be a direct result from the spin of the electron and its angular momentum, and so are you taking the the magnetic moment that results from angular momentum into your calculations as well?
@@dylanmiley5642 Not exactly sure what you mean by that. The magnetic moment the electron have is a result of its angular momentum, which is connected to it’s spin, but despite it being called spin, electrons don’t rotate around its own axis. It’s angular momentum is intrinsic to the particle. What i had showed is that such angular momentum could not be a result a classical rotation of the electron. Btw I an no expert, try searching science asylum spin, I belive he gives a better explanation in the video.
@@brunojambeiro6776 im not an expert either, im simply a masters student in electrical engineering with an interest in this realm. From my understanding (and with reference to the textbook "Magnetism and Magnetic Materials" ) within a magnetic material, electrons both have an orbital angular momentum as well as spin, and as magnetism is a relativistic correction to the coulomb force, both of these components lead to magnetic moment.
Thanks for giving me a intuitive explanation for this concept of spin 1/2 particles.
Great analogy, probably nothing like reality but still a really good analogy.
the problem with this demonstration is that you can make any gear ratio you want - it could also be "spin 1/3". But there is fundamentally no spin 1/3 in reality.
It can be represented by a wave graph, and it also can be split into its composite wave-forms by Fourier's transform, right?
Wouldn't that give us some insight or ideas on what an electron's wave is composed of?
Somehow it's a taboo question in Physics. Electrons are supposed to be elementary particles despite the fact that they can be broken into photons.
@@En_theo , yes by lowering their energy level they can shoot out photons, but can they disappear completely broken into photons, by leaving nothing else?
@@blueckaym
Yes, by meeting a positron. Both particles will explode into photons.
@@En_theo yes, but that's something different.
The wave of an electron is a probability wave.
Great work. Beautiful representation of the spin.
Wow. That was so succinct and satisfying. Thank you very much for the explanation.
But the cog angles are arbitrary, they could be any 360 degrees so you don't have two spin states, but infinitely many. Also the cog ratios are arbitrary so you have an arbitrary number of rotations required for return to previous state. You might say that these up/down 1/2 spins represent two classes of behaviour of this model, but many more classes of behaviour might be imagined. So the model although interesting does not throw any light on the spin phenomenon.
which it didn't claim. The title of the video is "Demonstration of Spin 1/2", which is exactly what it does.
This is what I was thinking, the idea that you have to spin a spin 1/2 system by 720° to get it to return some state has some links but I don’t think anything else in the video is relevant to an actual quantum mechanical spin 1/2 system
Spin is an integral characteristic of a substance, like its mass, density, etc. American science again confuses people this time not with Schrödinger's cats, but replacing the terms rotational mechanical moment and quantum number.
нельзя сконфузить тех кто в этом все равно ничего не понимает. так что не переживай, все ок с американской наукой.
Naaaaah we call it spin bc in the equation, in which it was first derived, it looks like angular momentum. I mean it's no more confusing than talking about color charges or positive and negative charges, they're merely ways of expressing a new concept that words did not exist for.
yeah those damn Americans inventing quantum physics alone without the help of any other nations
That is the best demonstration of spin I have ever seen! Thanks a lot!!
Thanks for making those! They turned out great!! 🎉
Why did you quote Feynman talking about how Dirac's equation is wrong (incomplete or inaccurate).?
feynman said there was no physical way to visualize spin 1/2 states, which this video proved wrong
@@franzkiefer9303 Ah. Okay. I interpreted "physical view" as a physics equation, not a visualization.
The best explanation, never understood like this before,...... don't know why.....but loved it a lot❤️❤️❤️❤️❤️♥️♥️♥️♥️❤️❤️❤️❤️❤️❣️❣️❣️❣️
Holy crap dude.
This is the best video I’ve watched this year!
As a hobbyist woodworker, this makes me proud.
Nevertheless, what exactly is the 'electron', 'positron' doing.
That's what I'm wondering because the "spin" is just an abstract representation of something happening.
I suppose the most accurate answer is that nobody actually knows, though someone please correct me if I'm wrong
We’re just observing the properties and assigning a somewhat arbitrary way that has some relation to what is being observed. If you see something glowing but not consistently bright, you might assign it a property called brightness. Here, they don’t really know, but that something can be imagined as a spin, so it is described as so.
It's doing: being an electron
Exactly…. It’s a twisted loop of charge, like a knot, but it’s not spinning… nobody knows, that’s absolutely certain… Even Feynman couldn’t visualize it, so we meager mortals have almost no chance. The more you understand the weirder and less sense it makes. It’s beyond difficult to visualize a model that explains all of its properties at the same time. Unfortunately for the curious there seems no way to use intuition. This demonstration is nothing more than a mathematical analog that has nothing to do with electrons, and I’m not sure if’s it’s helpful or harmful…
I love how the positron model actually are reversed clip instead of just mere counter rotational
Well done. That was incredibly simple to understand once you have shown it like this.
Great info packed into just 3 minutes! The only criticism I have is that the energy and excitement in your voice woke me up several times.
But doesn't this require knowledge about the internal parts of the electrons, which we don't have?
Of course it does, that's why I have no clue.
Yes. However, spin is a measurement of energy (angular momentum). In the g-2 muon experiment, the spin was determined from the amount of energy in the electrons which decayed from the muons. It has been proposed that electrons are made of two massless particles with opposite “chirality “(yet another insufficient analogy) , which is like “right-handed” “ left-handed “ rotation. The flipping back and forth of chirality is said to be the cause of mass. We don’t know what an electron is it’s just the math that makes us come up with more ideas.
"quire knowledge about the internal parts of the electrons, "
There is no present evidence for an electron having internal parts. Characteristics yes, parts no. Which is the problem for physical representations of spin. I really like this demo BUT its an analogy and not related to how electrons really do anything. The are the best tested fit to the idea of a fundamental particle.
This spin 1/2 representation is equivalent to Möbius torus knot, in which case the aether has to flow twice around the electron to get to the same spot in the original orientation.
Not a bad setup - but unfortunately this is spin 3/2, the larger wheel rotates 3 times for every 2 times you circle around the base.
*UTTERLY BRILLIANT* making the ridiculously complicated easily understandable is a true gift.
Nice gizmos! And thank you for the fantastic illustration 👌👏
There is no classical equivalent of quantum spin. Neat demo though.
Absolutely brilliant !
You, Sir, are a complete and total badass. Subscribed.
The best "as if" I've seen about electrons' spin!
thanks man, as a non scientist, this is the explanation I was looking for a long time!