To see subtitles in other languages: Click on the gear symbol under the video, then click on "subtitles." Then select the language (You may need to scroll up and down to see all the languages available). --To change subtitle appearance: Scroll to the top of the language selection window and click "options." In the options window you can, for example, choose a different font color and background color, and set the "background opacity" to 100% to help make the subtitles more readable. --To turn the subtitles "on" or "off" altogether: Click the "CC" button under the video. --If you believe that the translation in the subtitles can be improved, please send me an email.
These physics principles are seemingly so simple, but yet sometimes so hard to grasp. Your videos present them in the most clear way possible. Excellent!
Great animation but it is impossible to make a measurement with 100 per cent certainty!!RE1: Heisenberg Uncertainty my Simple thought experiment :tell me one physical measurement that does not involve at least one photon
@@EugeneKhutoryansky in the minute 2:21 i didn't understand if we measure the z components of spining or you mean that the electron spins along z-axis
@@EugeneKhutoryansky man, of course its all probability and i find it funny ITS ALL PROBABILITY BECAUSE WE CANT CREATE A PROPER DETECTOR the others detectors will change the movement of the spin because they are interfearing
i love all your videos, and the great music at the background, are you going to make more animation about electrical engineering, especially in electronics part?
I'm just commenting to give the youtube algorithm something to bite on when the person is looking for electron movement and its visualization in a 3D - Enviroment. love the vid keep it up
Thanks Eugene. Even though my job has nothing to do with Physics, I really enjoy watching your videos and get a better understanding of the amazing world around us.
I’m no physics student, but I still find this kind of stuff to be fascinating. Unfortunately, for the layman like me, it’s hard to find scientific explanations for things that aren’t either way above my level or ridiculously simplified. This seems to be a perfect middle ground, and has excellent visuals! This helped me understand spin better than any other source I tried looking at. Thank you and have a great day!
OMG thank you SO MUCH!!! I've seen tons of videos, read tons of articles, researched every possible thing about spin, and THIS is the first one that actually made me understand it finally!
I've just come across your videos for the first time today. Your animations are superb - in fact the best I've seen. I lecture in these topics myself and I will certainly be directing students to your wonderful visualizations. I've also viewed your video on entanglement and can't wait to see the rest of your brilliant and clear explanations.
Man, more people who make videos like yours need to get whatever program you use for the animations. Nice visuals. They are a work of art in themselves.
works of art indeed - I would recommend anyone especially interested in the visual quality of these concepts to check out Roberto matta who tried to give visual form to these concepts in painting
Always a good day when I see a new physics video from you. Keep up the great work! I know I'll be watching a lot more of you in the upcoming months as I review for the GRE.
I am a physicist and I wished every student of physics was exposed to these animations to bring some clarity to some rather difficult to understand subjects, or simply subjects that required large infrastructure knowledge, excellent!!
I love these videos. Thank you for making them. One suggestion: explain entanglement first and then offer observation as a special case of entanglement. Newcomers often get an inflated sense of ego when we first describe the effect of observation and then spend only a little time talking about entanglement. Measurement is entanglement.
As in the Double Slit Experiment i have to presume that the act of measuring anything like the position of an electron or the spin of an electron changes the condition of the propertie of the electron. By measuring the property, we force the electron to assume a condition. The fact that we measure the condition Spin Up the first time and Spin Down later on (after measuring it in a different direction) kinda proofs that we alter the property (read: force it to assume one of the possible conditions that we propose).... Although that's how far my understanding goes at this given point. Feel free to point out mistakes in my train of thought!
You can help translate this video by adding subtitles in other languages. To add a translation, click on the following link: th-cam.com/users/timedtext_video?ref=share&v=3k5IWlVdMbo You will then be able to add translations for all the subtitles. You will also be able to provide a translation for the title of the video. Please remember to hit the submit button for both the title and for the subtitles, as they are submitted separately. Details about adding translations is available at support.google.com/youtube/answer/6054623?hl=en Thanks.
Here is a question for you: We assume that quantum mechanics is this spooky undefinable world where we can know the position of an particle or its velocity but never both. The example you show us emphasis that even more. You can only ever know the spin of an electron in one direction on the 3d axis and never more than one at a time. Furthermore we note the very weird quality of quantum physics where the state of a particle appears dependent on whether we measure it. The classic is the splitting of a photon through to holes where when we don't measure it the light shows as a wave but when we do we get a single point and the average of those points appears in the lines highlighted in that wave. In your example once we measure the spin of a particle in a direction the particle randomly changes in the other two. In both case you show the obvious nature of quantum theory where things show up as probabilities. We can't show where the particle is only where it could possibly be. The average of those events over time will reflect those probabilities very closely. The assumption is that particles can be in two places at a time and have several values or may be in several dimensions we don't see but there is never an exact finding in the universe we can see that can exist. My question is how do we know that assumption is true? My conjecture is that when we analyze how we detect the particles and forces of our world we only can sense things using the electromagnetic force of nature. While we can detect the effects of the strong or weak force in accelerators or feel the force of gravity we do not use the strong, weak or gravimetric forces to detect these things. The particles show off in accelerators are shown via photons which are carriers of the electromagnetic force. When we feel gravity we feel the push back on the atoms in our cells from the electromagnetic fields of the electromagnetic fields of the objects we are in contact with. It seem safe to conclude that all our information regarding the universe is filtered through the electromagnetic force. We can deduce an awful lot about the other three by what we can detect but is there not information we cannot perceive due to this filter. Effects within the other three forces that don't transfer to the electromagnetic spectrum in meaningful ways. Could it be that the uncertainty is not actually the fuzziness of the quantum states but the fact that the only way we have to detect changes, electromagnetic forces, by their nature must interact with the elements we are trying to observe. This would explain why we get particles when we measure which hole the photon went througn and waves when we don't The states are not the same. In one we affect the expierment through our attempt to observe and in the other we do not. This also explains why the act of measuring the other axis of electron spin means we lose information regarding the other axis. It is not that observation changes things but rather we are interacting with that electron to measure it which means we by default affect its state. Why do we assume that it is a spooky undefinable nature of quantum mechanics and not a flaw in the only way we can observe the quantum world.? I have no clue what the answer to that question is?
You put it well. The act of observation is an act of interaction and therefore results in entanglement of states and an alteration in the inherent state of a quantum particle.
You are without a doubt one of the most underrated TH-camrs of all time! You could explain and simulate anything to any academic level while making it fun! I appreciate literally every video that you put out and I hope you keep making more. It is unfortunate that TH-cam's algorithms don't give enough to content creators like you and favor duller, more mundane TH-camrs like video game players and vloggers. I don't understand how people can pass over such amazing content such as yours. Forever a fan!
Definitely the best visuals I've ever seen for a science video on youtube. Still don't fully understand the concept but pretty sure thats just cause this concept, like most quantum mechanical concepts, is abstract af.
This is okay for an introduction, but it just brings more questions for me. The universe doesn’t care which direction is up, so the fact that these matrices depend on direction is baffling. Forgetting about imaginary numbers, this spin is a 4-dimensional quantity. So it has 3 dimensions of space and one dimension of probability. There has to be a way to show that the relationship between probability and direction “looks the same” no matter what direction you choose as the z axis.
These videos graphically illustrate the what, and not very well. Complex number attributes are thrown in without explanation. The _why_ of particle spin is entirely absent, and from beginning to end, the author resolutely maintains a visual representation of electron _SPIN_ as though it were still present in the classical sense of a non-point mass whose space-filling extent rotates about an axis. Since that is not what quantum spin means, people are being left with the classical meaning still filling their visual cortices as a sort of vestigial useless organ that they will have trouble _unseeing_ years down the road.
I’ve been struggling to understand this principle in relation to fundamental particles. But this made it make so much sense. I really wish there was a way to have more of these types of animations demonstrated in classes.
It seems clear to me that measuring the spin of the electron in a direction that is not aligned with the actual direction of spin, this changes the actual direction of spin.
I never thought I would feel this much stress and suspense in a seemingly boring physics video. But god was I wrong. Tension was at the peak when it was revealed how supernatural electron spin is my detecting their directions with the detectors. The music doubled the excitement.
classical physics, spin is represented by an arrow indicating the rate and direction of rotation. However, in quantum mechanics, spin behaves differently. While classical spin can have any value and be measured in all three dimensions simultaneously, quantum spin measurements are limited. An electron's spin can only be measured in one direction at a time, and there's a fixed length for all three spin components. Quantum spin is described by mathematical states, with two complex numbers representing probabilities. These probabilities determine the likelihood of measuring spin in various directions. When observing one spin component, the system's state changes to one where that component is certain, but others become uncertain. The video also introduces matrices associated with spin in each dimension and discusses the implications of quantum entanglement on spin states.
6:19 Minor point of English grammar. Subject and verb need to agree in number (i.e., singular or plural). So the sentence should read "The probabilities of measuring the electron's spin in all possible directions, including directions not necessarily aligned with one of these axes, -are- determined by what we call the quantum spin state of the electron." Or perhaps it might be clearer if it was written "The probability of measuring the electron's spin in any possible direction, including a direction not necessarily aligned with one of these axes, is determined by what we call the quantum spin state of the electron." But I am unsure whether this sentence has the same meaning as the first.
The proper method to determine the probability is to multiply by the complex conjugate. For operations that only involve real numbers this is the same as squaring but because of the nature of complex numbers the math isn't as simple. Not trying to be pedantic but it's actually kind of important because the math doesn't work if you just square complex numbers.
When you multiply a number by its complex conjugate, you get the square of the magnitude of the complex number, which in this video, is always represented by the square of the lengths of the lines in the animation, which is what I was referring to. Nowhere in this video did I ever refer to the "square of a complex number."
The thing you are calling spin is usually called angular momentum. The vector [0,1] has the same angular momentum as [-1,0], but they will interfere destructively because they have opposite spins. You can see the destrucive interference because their dot product is 0. The essential thing about fermions is that they have this separate spin internal degree of freedom that is unobservable unless you are doing interference experiments. This is why you can have the Fermi exclusion principle and still have two electrons in the same lowest energy state in a helium atom. They have opposite spins.
"Although the first number can also have an imaginary component, we will just show examples where the imaginary component of the first number is zero, due to the fact that this animation is limited to showing only three spatial dimensions." Agh I can't wrap my head around that.. Subatomic particles don't actually "spin", but they have this attribute that is called spin. And I don't really understand what that means. I also don't understand how they can spin in more than three spatial dimensions. Or whatever they do that is called spin. Can you explain, Eugene? Great video, though, as always!
The graph was never representing spin in any number of spatial dimensions, the graph was instead representing the numbers that determine the probabilities associated with the spin. It is spin in 3 dimensions. The graph itself would be in 4 dimensions, because it would be graphing a,b,c, and d for the numbers C1 and C2, which are of the form a + bi and c + di respectively (4 variables). When you plot only two variables (x,y) you get a 2d graph, if you plot 3 (x,y,z) you get a 3d graph, as shown when they assume that d (w) = 0. But to get the full 'picture' you would need to have a 4d graph, which is only possible through animation, with time representing change in the fourth dimension. Do you know what a complex number is? If you did it would be clear. In summary, the spin is in 3 dimensions, it is merely the graph of the probabilities that is in 4 dimensions, because there are 4 variables, that determine 3 axes of rotation.
We are familiar with ordinary objects that spin (wheels, balls, etc), but we should not be hasty in assuming that all objects that exist behave this way. If we rotate an ordinary object around some axis over an angle alpha its aspect changes in a certain way. We describe this by vectors in 3 dimensions, and their components 'mix' in familiar ways in terms of cos(alpha) and sin(alpha). Electron spin also transforms under rotation, but in a different way. Clearly it is a geometric object, but it is not vector in 3 dimensions. What we need is an abstract generalization of geometry to deal with this. Abstraction means ignoring some aspects and elevating other aspects to be 'essential'. We will be ignoring the specific character of vectors, and instead focus on the systematics of combining rotation operations. Why? Because it works, to an amazing extent beyond any reasonable expectation. Rotations form a 'group' in the mathematical sense. This means that you can combine rotations by applying them sequentially and the net result is some net rotation. You can undo every rotation by a rotation around the same axis but turning the other way. And finally a rotation over angle zero has no effect whatsoever. Satisfying this trivial sounding definition of a group unlocks the power of Group Theory. Rotations in 3 dimensions do not commute, i.e. the order in which you apply rotations matters. This is crucial for the structure of the rotation group in 3 dimensions. We can work this out, as all physics students must, but to understand the logic we don't have to. The key question to ask is: could there be other objects besides 3-vectors that transform under rotations with the same systematics, i.e. with the same group structure? In jargon: are there other representations of the rotation group in 3 dimensions besides the defining representation? To keep the mental image straight: we are still applying rotations with the systematics of rotations in 3D, but allow for the possibility that they work on objects that have a different dimension. One silly way to think of it is a gear box. Suppose I try to rotate an object, but instead of grabbing it directly, I turn a shaft that is connected to the object through gears. The gear ratio determines over which angle the object will actually turn, which may be different from the shaft turn angle. This contrived contraption yields a (somewhat trivial) different representation of rotations about one axis only. Although we cannot possibly build it, could there be some sort of abstract 'gear box' that makes objects turn differently from the angle we apply while still respecting all the systematics of rotations in 3D? Or do we end up in a mathematical contradiction? It turns out that there ARE other representations of the rotation group in 3D. In fact, there is a representation in every (finite) dimension n. This means for example, that there are 'vectors' with 2 components that follow all the systematics of compounding rotations, but they 'turn more slowly' over half the applied angle. These are the 2-component 'spinors' shown in the video. For n=3 we have the familiar 3-vectors. For n=4 we get faster rotating stuff, with the same weirdness as n=2. For n=5 we have double rotation speeds, and the objects are related to ordinary tensors, which may be somewhat familiar. To emphasize, spinors are geometrical objects because their components change upon rotation, but they behave differently from vectors. We say that spin is 'intrinsic' to particles, by which we mean that we don't directly see it, and cannot describe it in terms of positions of things ('parts of the particle' going around in a circle). But spin DOES relate to space, unlike intrinsic properties like electric charge, which (as far as we know now) have nothing to do with space. WHY don't we experience these weird objects like spinors in our daily lives? Because of the Pauli principle, or more precisely the theorem of spin and statistics. When combining Special Relativity and Quantum Mechanics, we are forced into Quantum Field Theory. It is impossible to construct a sensible QFT in which spin 1/2 fields can be excited with more than a single quantum in any given state. Therefore spin 1/2 fields cannot be excited into the domain where they manifest as classical fields. The excitations of spin 1/2 fields manifest as isolated objects. This is contrary to spin 1, i.e. a vector field such as the photon field, which can be excited with many quanta so as to manifest as a classical electromagnetic field. We cannot directly experience the electron field like we can experience the electromagnetic field, e.g. in optics while playing with polarizers. But what about indirect observations? Special Relativity puts severe limits on the mathematical form that physical theories can have. This aspect is not so well-known among laymen, but absolutely crucial in modern physics. Quantum Mechanics requires the existence of quantum amplitudes, and leads to a formulation in terms of a Lagrangian, which is where all modeling of fundamental interactions starts. The combination of SR and QM allows only terms of certain forms in the Lagrangian, and the spins always combine in such a way that some of their weirdness (but not all) remains hidden from direct observation.
The graph just shows how to measure it. Most of the Quantum Mechanics is based upon the idea of waves-particle duality that's why unit circles are used a lot
As far as I understand it, the term spin was used, because scientist back then thought that magnetic field produced by an electron was due to it's spinning (angular movement). Only when it was calculated, that outer layer would have to rotate with many time the speed of light it was changed. Now there is quantum spin, and angular momentum that each particle have. Two separate, not related (?) characteristics of the particle.
Hello, please Eughene would it be possible to make video on spinors ? Something simple and short , like introduction. F.e. notation, basic operation, what do they represent , or relation to weyl and dirac spinors ? Thanks , greetings from Slovakia
The problem is that spin is an intrinsic property and is not akin to the same physical models of angular momentum and spin that classical physics apply to
+Mr Jasonekos Yes, we get that. That's why he said *discover* a physical basis of Spin. As in, find a model / basis *we don't know yet*. So, instead of knowing what it is *not* like, we are saying we would like to know what it *is* like.
...and the first step forward in this direction is by altogether ditching the misnomer "spin" and adopting a new, more accurate name. Perhaps smt like Intrinsic Magnetic Moment or simply, Quantum Moment might sound more accurate
excellent point about physical basis....little did i know but magnetic moments are quantized as well....have to find the text book from which i got this information
As a lay person amateur scientist what we are observing is free fall matter i.e. the electron with spin. without a fixed reference point we are unable to determine the true components of the spin hence when the measurement is against another electron it forces a pseudo reference point which allows you to measure spin relative to the other however without a fixed reference point we are unable to determine the true essence of the spin trajectory. My observations of the universe is that all matter is in free fall with some initial spin trajectory at conception
![กิโลเมตรที่ 0 เดินทางรอบโลกไม่ใช้เครื่องบิน [Around The World Ep. 1]](http://i.ytimg.com/vi/toJG9oofLFY/mqdefault.jpg)
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Very informative. Thanks for sharing, Lord-Jesus-Christ com
i know it's kinda randomly asking but do anyone know a good website to stream newly released tv shows online ?
@Dwayne Trace Flixportal :D
@Milan Ahmad thank you, signed up and it seems like they got a lot of movies there =) Appreciate it!!
@Dwayne Trace Glad I could help xD
These physics principles are seemingly so simple, but yet sometimes so hard to grasp. Your videos present them in the most clear way possible. Excellent!
Thanks for the compliment about my videos.
Great animation but it is impossible to make a measurement with 100 per cent certainty!!RE1: Heisenberg Uncertainty my Simple thought experiment :tell me one physical measurement that does not involve at least one photon
@@EugeneKhutoryansky in the minute 2:21 i didn't understand if we measure the z components of spining or you mean that the electron spins along z-axis
@@EugeneKhutoryansky man, of course its all probability and i find it funny
ITS ALL PROBABILITY BECAUSE WE CANT CREATE A PROPER DETECTOR the others detectors will change the movement of the spin because they are interfearing
This is the single best visualization I've seen of spin. Keep up all the great content.
Thanks for the compliment.
thank for visualizing this hard-inmaginating concept
You are welcome and thanks.
i love all your videos, and the great music at the background, are you going to make more animation about electrical engineering, especially in electronics part?
Qais, yes I will be making more animations on electrical engineering. Thanks.
I'm just commenting to give the youtube algorithm something to bite on when the person is looking for electron movement and its visualization in a 3D - Enviroment.
love the vid keep it up
Thank you for your service.
Your visualisations are absolutely eugenious!
Keep up the good work. :)
Thanks for the compliment.
Thanks Eugene. Even though my job has nothing to do with Physics, I really enjoy watching your videos and get a better understanding of the amazing world around us.
Thanks. I am glad you enjoy my videos.
I’m no physics student, but I still find this kind of stuff to be fascinating. Unfortunately, for the layman like me, it’s hard to find scientific explanations for things that aren’t either way above my level or ridiculously simplified. This seems to be a perfect middle ground, and has excellent visuals! This helped me understand spin better than any other source I tried looking at. Thank you and have a great day!
Right? Even in college they tried to teach us indeterminacy and it went right over my head. They should've just played us this video instead 😭
OMG thank you SO MUCH!!! I've seen tons of videos, read tons of articles, researched every possible thing about spin, and THIS is the first one that actually made me understand it finally!
Glad my video was helpful. Thanks.
If you like this video, you can help more people find it in their TH-cam search engine by clicking the like button, and writing a comment. Thanks.
This channel will be in the millions in a few months.
Thanks Eugene.
I just love you for doing this hard work. Thanks!
Physics Videos by Eugene Khutoryansky
godsadog
I've just come across your videos for the first time today. Your animations are superb - in fact the best I've seen. I lecture in these topics myself and I will certainly be directing students to your wonderful visualizations. I've also viewed your video on entanglement and can't wait to see the rest of your brilliant and clear explanations.
Thanks for the compliment. I am glad you like my videos and I hope your students will like them too.
I thought spin isn't spin at all it's just an intrinsic character of the particle 🙄
@@alenlukoselukose5662 thought isn't thought
Man, more people who make videos like yours need to get whatever program you use for the animations. Nice visuals. They are a work of art in themselves.
Unfortunately, there aren't any more people like him.
works of art indeed - I would recommend anyone especially interested in the visual quality of these concepts to check out Roberto matta who tried to give visual form to these concepts in painting
keep up the good work! I love how you give the concepts enough time to sink in - very helpful
Thanks.
I feel really really lucky to came by this channel.the way you visualized this...is just great!
Thanks.
The best series of educational videos I have ever seen in youtube! Excellent!
Thanks for the compliment about my videos.
@@EugeneKhutoryansky
You are very welcome!
Always a good day when I see a new physics video from you. Keep up the great work! I know I'll be watching a lot more of you in the upcoming months as I review for the GRE.
Thanks. I am glad you like my videos, and good luck with the GRE.
I must say, this is absolutely brilliant. Well done.
Thanks for the compliment.
As usual, brilliant exposition and animation. Should be a must-watch for all physics students starting QM.
Thanks for the compliments.
I am a physicist and I wished every student of physics was exposed to these animations to bring some clarity to some rather difficult to understand subjects, or simply subjects that required large infrastructure knowledge, excellent!!
Thanks for the compliment about my animations.
I love these videos. Thank you for making them. One suggestion: explain entanglement first and then offer observation as a special case of entanglement. Newcomers often get an inflated sense of ego when we first describe the effect of observation and then spend only a little time talking about entanglement. Measurement is entanglement.
Entanglement, Spin
th-cam.com/video/nnkvoIHztPw/w-d-xo.html
incredible videos man, the visualisations and slow paced explanations really help in understanding these abstract concepts
Thanks for the compliment about my videos.
As in the Double Slit Experiment i have to presume that the act of measuring anything like the position of an electron or the spin of an electron changes the condition of the propertie of the electron. By measuring the property, we force the electron to assume a condition. The fact that we measure the condition Spin Up the first time and Spin Down later on (after measuring it in a different direction) kinda proofs that we alter the property (read: force it to assume one of the possible conditions that we propose).... Although that's how far my understanding goes at this given point. Feel free to point out mistakes in my train of thought!
Very very easy explanation of the quantum spin. Thanks for making this video.
Glad you liked my explanation. Thanks.
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Thanks.
Please make videoes on spectroscopy, condensed matter physics and cosmology.
Bcoz i only understand through your videos.
I thought your videos were wonderful before, but improving the accessibility of them this way makes them even better! Cheers!
Excellent video Mr. Khutoryansky! You are a hero!
Thanks. Glad you liked my video.
Thanks for the great animation!
Love SU(2)!
Thanks.
Bestest explanation of such a hard imaginative topic ......God Bless you .
Thank for the compliment.
Here is a question for you:
We assume that quantum mechanics is this spooky undefinable world where we can know the position of an particle or its velocity but never both. The example you show us emphasis that even more. You can only ever know the spin of an electron in one direction on the 3d axis and never more than one at a time.
Furthermore we note the very weird quality of quantum physics where the state of a particle appears dependent on whether we measure it. The classic is the splitting of a photon through to holes where when we don't measure it the light shows as a wave but when we do we get a single point and the average of those points appears in the lines highlighted in that wave. In your example once we measure the spin of a particle in a direction the particle randomly changes in the other two.
In both case you show the obvious nature of quantum theory where things show up as probabilities. We can't show where the particle is only where it could possibly be. The average of those events over time will reflect those probabilities very closely.
The assumption is that particles can be in two places at a time and have several values or may be in several dimensions we don't see but there is never an exact finding in the universe we can see that can exist.
My question is how do we know that assumption is true?
My conjecture is that when we analyze how we detect the particles and forces of our world we only can sense things using the electromagnetic force of nature. While we can detect the effects of the strong or weak force in accelerators or feel the force of gravity we do not use the strong, weak or gravimetric forces to detect these things. The particles show off in accelerators are shown via photons which are carriers of the electromagnetic force. When we feel gravity we feel the push back on the atoms in our cells from the electromagnetic fields of the electromagnetic fields of the objects we are in contact with.
It seem safe to conclude that all our information regarding the universe is filtered through the electromagnetic force. We can deduce an awful lot about the other three by what we can detect but is there not information we cannot perceive due to this filter. Effects within the other three forces that don't transfer to the electromagnetic spectrum in meaningful ways.
Could it be that the uncertainty is not actually the fuzziness of the quantum states but the fact that the only way we have to detect changes, electromagnetic forces, by their nature must interact with the elements we are trying to observe. This would explain why we get particles when we measure which hole the photon went througn and waves when we don't The states are not the same. In one we affect the expierment through our attempt to observe and in the other we do not. This also explains why the act of measuring the other axis of electron spin means we lose information regarding the other axis. It is not that observation changes things but rather we are interacting with that electron to measure it which means we by default affect its state.
Why do we assume that it is a spooky undefinable nature of quantum mechanics and not a flaw in the only way we can observe the quantum world.? I have no clue what the answer to that question is?
So you are asking we are limited to see by the very kind of measurement people apply on particles on a small scale?
You put it well. The act of observation is an act of interaction and therefore results in entanglement of states and an alteration in the inherent state of a quantum particle.
You are without a doubt one of the most underrated TH-camrs of all time! You could explain and simulate anything to any academic level while making it fun! I appreciate literally every video that you put out and I hope you keep making more.
It is unfortunate that TH-cam's algorithms don't give enough to content creators like you and favor duller, more mundane TH-camrs like video game players and vloggers. I don't understand how people can pass over such amazing content such as yours. Forever a fan!
Whenever I start making more money I will most definitely subscribe to your Patreon, you have my promise. (As long as you keep making videos ☺ )
Thanks. I really appreciate the support, and I am glad that you like my videos.
These videos are hypnotically watchable and also fantastically useful for people like me who need to visualise to understand. Thank you.
Thanks. I am glad you like my videos.
Definitely the best visuals I've ever seen for a science video on youtube. Still don't fully understand the concept but pretty sure thats just cause this concept, like most quantum mechanical concepts, is abstract af.
Your videos are awesome, thank you
Thanks. I am glad you like my videos.
Great animations and explanations. Thank you
Thanks for the compliment about my animations and my explanations.
This is a really good video to join up with the MIT lectures on quantum physics here on TH-cam.
Electrons playing a sick joke on the observers. DAMN YOU!
I could not help thinking that the electron's behavior maximizes frustration.
I've just discovered your videos. They are awesome, thank you very much.
I am glad you like my videos. Thanks.
this is the first video to simplify the calculations thank you and well done!
Thanks.
"or in any other direction" had me ducked the duck up 🦆
Thank you so much. Just used a Bell-Basis in my bachelor thesis and couldn't imagine the whole story behind it. Got it now :)
Glad to hear my video was helpful.
This video is so usefull to visualize quantum-mechanical spin! Please do not stop making videos and really thank you for your help! :)
Thanks. More videos are on their way.
Amazing visual aids and explanations. Flawless delivery as usual, I'm addicted to all these videos.
Thanks for the compliment.
months ago i ask u to make a video on this topic of quantum spin. m glad to see the best explanation on spin on youtube:)
Thanks. :)
you're an absolute legend i finally understood what spin looks like and why imaginary numbers are needed
Thanks!
Excellent video as always!
Glad you liked it. Thanks.
Magnificent! No more mentally struggling to create this imagery :-) Thank you!
Thanks.
This is okay for an introduction, but it just brings more questions for me. The universe doesn’t care which direction is up, so the fact that these matrices depend on direction is baffling. Forgetting about imaginary numbers, this spin is a 4-dimensional quantity. So it has 3 dimensions of space and one dimension of probability. There has to be a way to show that the relationship between probability and direction “looks the same” no matter what direction you choose as the z axis.
These videos graphically illustrate the what, and not very well. Complex number attributes are thrown in without explanation.
The _why_ of particle spin is entirely absent, and from beginning to end, the author resolutely maintains a visual representation of electron _SPIN_ as though it were still present in the classical sense of a non-point mass whose space-filling extent rotates about an axis. Since that is not what quantum spin means, people are being left with the classical meaning still filling their visual cortices as a sort of vestigial useless organ that they will have trouble _unseeing_ years down the road.
Your visualisations are masterful!
Brilliant! I can not imagine a better introductory description.
Thanks for the compliment.
Sir...I have no words to thank You sir...May GOD bless You...
Thanks for the compliments.
thanks for these wonderful videos.
You are welcome and thanks.
Thanks for this video and the larger series!
Thanks.
amazing video. You won't find an explanation more clear than this anywhere
Thanks for the compliment about my video.
thank you very much
You are welcome and thanks.
With one hundred percent certainty: this is an amazing vedio...
Thanks.
Brilliant presentation ! thanks Eugene!
Thanks for the compliment.
Just got done reading about this aspect of quantum mechanics. This video helped a lot in clearing things up
love this channel
Thanks. I am glad you like my videos.
Great analogy and explication! 🇧🇷
Thanks.
I’ve been struggling to understand this principle in relation to fundamental particles.
But this made it make so much sense. I really wish there was a way to have more of these types of animations demonstrated in classes.
Glad my video was helpful.
Spin of Indivisible Particle :
th-cam.com/video/nnkvoIHztPw/w-d-xo.html
This video is misleading. I hope you researched a bit more and didn't take everything from this video for how electron particles actually behave
Thanks for the effort to explain this by a video!
You are welcome and thanks.
Amazing visualizations, helped me a lot!
Thanks. Glad my video was helpful.
8:40 quantum spin states. Excellent explanation.
best explanation by far of spin
Thanks for the compliment.
It seems clear to me that measuring the spin of the electron in a direction that is not aligned with the actual direction of spin, this changes the actual direction of spin.
Another amazing video. Keep it up! Great Channel
Thanks. Glad you liked it.
Brilliant.
Thanks.
I never thought I would feel this much stress and suspense in a seemingly boring physics video. But god was I wrong. Tension was at the peak when it was revealed how supernatural electron spin is my detecting their directions with the detectors. The music doubled the excitement.
This is just love. Keep up the good work.
Thanks. I am glad you like my videos.
Thank you,the rest of the animation of education is good and all but yours describes and informs me wonderful.
Thanks.
+Physics Videos by Eugene Khutoryansky your welcome
Awesome as always!
Thanks. Glad you liked it.
That's how Gyro's steel ball works lol
thanks for making this easier to understand
classical physics, spin is represented by an arrow indicating the rate and direction of rotation. However, in quantum mechanics, spin behaves differently. While classical spin can have any value and be measured in all three dimensions simultaneously, quantum spin measurements are limited. An electron's spin can only be measured in one direction at a time, and there's a fixed length for all three spin components. Quantum spin is described by mathematical states, with two complex numbers representing probabilities. These probabilities determine the likelihood of measuring spin in various directions. When observing one spin component, the system's state changes to one where that component is certain, but others become uncertain. The video also introduces matrices associated with spin in each dimension and discusses the implications of quantum entanglement on spin states.
This is absolutely fascinating
Spin of Indivisible Particle :
th-cam.com/video/nnkvoIHztPw/w-d-xo.html
Why an entangled particle any x spin component can not be known with %100 certainty?
Pure Perfection …
Great that videos like this exist!
Well Done Eugene! Godspeed!!!
To Infinity & Beyond …°°∆^°
Thanks. I am glad you like my videos.
Brilliant visualization.
amazing !!!!! thank you for this
Thanks. Glad you liked my video.
6:19 Minor point of English grammar. Subject and verb need to agree in number (i.e., singular or plural). So the sentence should read
"The probabilities of measuring the electron's spin in all possible directions, including directions not necessarily aligned with one of these axes, -are- determined by what we call the quantum spin state of the electron."
Or perhaps it might be clearer if it was written
"The probability of measuring the electron's spin in any possible direction, including a direction not necessarily aligned with one of these axes, is determined by what we call the quantum spin state of the electron." But I am unsure whether this sentence has the same meaning as the first.
The best explanation ever. Thanks
Thanks for the compliment.
@@EugeneKhutoryansky what software do you use for such animation ? AutoCAD sure not, Maya, Houdini ? or more simple ?
I make my 3D animations with "Poser."
@@EugeneKhutoryansky WoW thanks, it is much easier than Houdini. Interesant.
This helped me ALOT! Thank you so much for doing this video! Forever thankfull!
I am glad my video was helpful. Thanks.
Thanks again for such a great video😀
Thanks.
This is a great video, especially for beginners in Physics!
Thanks.
The proper method to determine the probability is to multiply by the complex conjugate. For operations that only involve real numbers this is the same as squaring but because of the nature of complex numbers the math isn't as simple. Not trying to be pedantic but it's actually kind of important because the math doesn't work if you just square complex numbers.
When you multiply a number by its complex conjugate, you get the square of the magnitude of the complex number, which in this video, is always represented by the square of the lengths of the lines in the animation, which is what I was referring to. Nowhere in this video did I ever refer to the "square of a complex number."
The thing you are calling spin is usually called angular momentum. The vector [0,1] has the same angular momentum as [-1,0], but they will interfere destructively because they have opposite spins. You can see the destrucive interference because their dot product is 0.
The essential thing about fermions is that they have this separate spin internal degree of freedom that is unobservable unless you are doing interference experiments. This is why you can have the Fermi exclusion principle and still have two electrons in the same lowest energy state in a helium atom. They have opposite spins.
3:45 Nope! I remember which way it was pointing in the Z-direction! ... I'm kidding, don't kill me.
Congratulations!! You won the Nobel prize in physics for violating this law in quantum mechanics.
Very nice piece of work!
Thanks for the compliment.
Absolutely brilliant explanation!
Thanks.
This really helps, thanks very much
thanks for all of your videos.
really suberb animation and explanation.... hatts off to your efforts....
Thanks.
So there can be almost total control over the magnetic field of a quantum particle by simply measuring in the direction you wish the field to be.
"Although the first number can also have an imaginary component, we will just show examples where the imaginary component of the first number is zero, due to the fact that this animation is limited to showing only three spatial dimensions."
Agh I can't wrap my head around that.. Subatomic particles don't actually "spin", but they have this attribute that is called spin. And I don't really understand what that means. I also don't understand how they can spin in more than three spatial dimensions. Or whatever they do that is called spin. Can you explain, Eugene? Great video, though, as always!
The graph was never representing spin in any number of spatial dimensions, the graph was instead representing the numbers that determine the probabilities associated with the spin.
It is spin in 3 dimensions. The graph itself would be in 4 dimensions, because it would be graphing a,b,c, and d for the numbers C1 and C2, which are of the form a + bi and c + di respectively (4 variables).
When you plot only two variables (x,y) you get a 2d graph, if you plot 3 (x,y,z) you get a 3d graph, as shown when they assume that d (w) = 0. But to get the full 'picture' you would need to have a 4d graph, which is only possible through animation, with time representing change in the fourth dimension.
Do you know what a complex number is? If you did it would be clear.
In summary, the spin is in 3 dimensions, it is merely the graph of the probabilities that is in 4 dimensions, because there are 4 variables, that determine 3 axes of rotation.
We are familiar with ordinary objects that spin (wheels, balls, etc), but we should not be hasty in assuming that all objects that exist behave this way. If we rotate an ordinary object around some axis over an angle alpha its aspect changes in a certain way. We describe this by vectors in 3 dimensions, and their components 'mix' in familiar ways in terms of cos(alpha) and sin(alpha). Electron spin also transforms under rotation, but in a different way. Clearly it is a geometric object, but it is not vector in 3 dimensions. What we need is an abstract generalization of geometry to deal with this.
Abstraction means ignoring some aspects and elevating other aspects to be 'essential'. We will be ignoring the specific character of vectors, and instead focus on the systematics of combining rotation operations. Why? Because it works, to an amazing extent beyond any reasonable expectation.
Rotations form a 'group' in the mathematical sense. This means that you can combine rotations by applying them sequentially and the net result is some net rotation. You can undo every rotation by a rotation around the same axis but turning the other way. And finally a rotation over angle zero has no effect whatsoever. Satisfying this trivial sounding definition of a group unlocks the power of Group Theory.
Rotations in 3 dimensions do not commute, i.e. the order in which you apply rotations matters. This is crucial for the structure of the rotation group in 3 dimensions. We can work this out, as all physics students must, but to understand the logic we don't have to.
The key question to ask is: could there be other objects besides 3-vectors that transform under rotations with the same systematics, i.e. with the same group structure? In jargon: are there other representations of the rotation group in 3 dimensions besides the defining representation? To keep the mental image straight: we are still applying rotations with the systematics of rotations in 3D, but allow for the possibility that they work on objects that have a different dimension.
One silly way to think of it is a gear box. Suppose I try to rotate an object, but instead of grabbing it directly, I turn a shaft that is connected to the object through gears. The gear ratio determines over which angle the object will actually turn, which may be different from the shaft turn angle. This contrived contraption yields a (somewhat trivial) different representation of rotations about one axis only. Although we cannot possibly build it, could there be some sort of abstract 'gear box' that makes objects turn differently from the angle we apply while still respecting all the systematics of rotations in 3D? Or do we end up in a mathematical contradiction?
It turns out that there ARE other representations of the rotation group in 3D. In fact, there is a representation in every (finite) dimension n. This means for example, that there are 'vectors' with 2 components that follow all the systematics of compounding rotations, but they 'turn more slowly' over half the applied angle. These are the 2-component 'spinors' shown in the video. For n=3 we have the familiar 3-vectors. For n=4 we get faster rotating stuff, with the same weirdness as n=2. For n=5 we have double rotation speeds, and the objects are related to ordinary tensors, which may be somewhat familiar.
To emphasize, spinors are geometrical objects because their components change upon rotation, but they behave differently from vectors. We say that spin is 'intrinsic' to particles, by which we mean that we don't directly see it, and cannot describe it in terms of positions of things ('parts of the particle' going around in a circle). But spin DOES relate to space, unlike intrinsic properties like electric charge, which (as far as we know now) have nothing to do with space.
WHY don't we experience these weird objects like spinors in our daily lives? Because of the Pauli principle, or more precisely the theorem of spin and statistics. When combining Special Relativity and Quantum Mechanics, we are forced into Quantum Field Theory. It is impossible to construct a sensible QFT in which spin 1/2 fields can be excited with more than a single quantum in any given state. Therefore spin 1/2 fields cannot be excited into the domain where they manifest as classical fields. The excitations of spin 1/2 fields manifest as isolated objects. This is contrary to spin 1, i.e. a vector field such as the photon field, which can be excited with many quanta so as to manifest as a classical electromagnetic field. We cannot directly experience the electron field like we can experience the electromagnetic field, e.g. in optics while playing with polarizers.
But what about indirect observations? Special Relativity puts severe limits on the mathematical form that physical theories can have. This aspect is not so well-known among laymen, but absolutely crucial in modern physics. Quantum Mechanics requires the existence of quantum amplitudes, and leads to a formulation in terms of a Lagrangian, which is where all modeling of fundamental interactions starts. The combination of SR and QM allows only terms of certain forms in the Lagrangian, and the spins always combine in such a way that some of their weirdness (but not all) remains hidden from direct observation.
The graph just shows how to measure it. Most of the Quantum Mechanics is based upon the idea of waves-particle duality that's why unit circles are used a lot
As far as I understand it, the term spin was used, because scientist back then thought that magnetic field produced by an electron was due to it's spinning (angular movement). Only when it was calculated, that outer layer would have to rotate with many time the speed of light it was changed. Now there is quantum spin, and angular momentum that each particle have. Two separate, not related (?) characteristics of the particle.
Please do a video on Turing machines and computability! I loved this, as always
We are very thankful to you
Thanks.
THESE PEOPLE ARE HELPING RAISE THE GLOBAL IQ BRAVO!!!!
Hello, please Eughene would it be possible to make video on spinors ? Something simple and short , like introduction. F.e. notation, basic operation, what do they represent , or relation to weyl and dirac spinors ? Thanks , greetings from Slovakia
Spinors are on my list of topics for future videos. Thanks.
Is there a video that shows what spin quantum numbers mean? Like, what is spin 1/2? What is spin 2? What is spin 1?
Yes , from 5 years later!
th-cam.com/video/pYeRS5a3HbE/w-d-xo.htmlsi=TLqECgkCH3b9-j-a
We have to discover a physical basis of spin. Mathematical representation is not enough.
The problem is that spin is an intrinsic property and is not akin to the same physical models of angular momentum and spin that classical physics apply to
+Mr Jasonekos
Yes, we get that. That's why he said *discover* a physical basis of Spin. As in, find a model / basis *we don't know yet*. So, instead of knowing what it is *not* like, we are saying we would like to know what it *is* like.
...and the first step forward in this direction is by altogether ditching the misnomer "spin" and adopting a new, more accurate name.
Perhaps smt like Intrinsic Magnetic Moment or simply, Quantum Moment might sound more accurate
excellent point about physical basis....little did i know but magnetic moments are quantized as well....have to find the text book from which i got this information
Bad news. We will never discover the physical basis of spin. It is inherently not intelligable.
As a lay person amateur scientist what we are observing is free fall matter i.e. the electron with spin.
without a fixed reference point we are unable to determine the true components of the spin hence when the measurement is against another electron it forces a pseudo reference point which allows you to measure spin relative to the other however without a fixed reference point we are unable to determine the true essence of the spin trajectory.
My observations of the universe is that all matter is in free fall with some initial spin trajectory at conception