Uploaded 10 years ago? I find this now? Thats crazy. The way you are showing ACTUAL experiment results leading to every new fact about reality is great and unparalleled.
I have watched the first 15 videos, some more than once. I promise I will do so again, after I finish them all. Thank you for all the effort you put into these videos. I love how you explain the wave equations.
What mass are we using when we try to calculate the velocity rotational velocity of an electron? Are we using the rest mass of the electron? Is the mass of the electron not dependent on the velocity with which it is traveling? So when at relativistic speeds would the inertial mass of the electron not be significantly larger than the rest mass of the electron?
4:30 Had to think about this for a minute. Silver and Hydrogen have an outer electron that is in an s orbital (5s for silver, 1s for hydrogen). Because the s orbital has no angular momentum, any magnetic dipole moment seen in the experiment has to come from the electron itself.
So to hazard sounding dense: Electron appear to/have a magnetic dipole, which -could- be explained by rotation of the particle, but since such rotation can't be accounted for by a classical understanding the electron instead has some kind of "snazziness" that intrinsically grants it the aforementioned dipole. And this snazziness only appears to have a magnitude of 1/2 or -1/2 for any electron?
snazziness does only occur in ±½ for the "electron" ◘ the electron is neither a point nor a wave it is a resonance - the choice of half as name is somewhat arbitrary ○○○ Stern-Gerlach only shows the response is quantifiable i.e. in definite or discrete values not smeared all over a non-definite; I have no idea what magnetic monopole is
So there is 'something' that acts kind of like momentum that is generated by 'something' that we call "spin" which is not the product of anything "actually" spinning. Got it, for a second there I was confused :)
This is just speculation and I'm not that qualified enough at all to dwell in these matters, but I'll try to dig up what is done on the matter. Also, in your last video (Spin II), I find it curious that the Higgs Boson is the only elementary particle to have no spin (or having a "0" spin qualifies as having a spin?) - I'll post this question on that video also
I have heard that atomic clocks are based on electrons switching spin states and use microwaves as a standard (or something along those line). Can you please describe to me in more detail how spin states are related to atomic clocks?
literally saving my life right now, decided to try and derive Dirac's equation even though I've never covered spin, angular momentum, Schrodinger's equation or the uncertainty principle or anything. These videos are really getting me through 💯
If there is a Higgs Field that provides mass to particles that interact with it, could it be that another similar field is providing the unique spin based on another unique property of the particle?
Classical angular momentum (moons, baseballs, and insects) is totally different from quantum angular momentum (magnets, superposition, quantum encryption). They call the quantum one the same name because the math looks the same, but like the video says, an electron would have to spin thousands of times the speed of light, which we believe cannot happen. And these 2 different concepts with the same name (again happened with "colors" in quantum chromodynamics or QCD) is a huge failing in making science concepts easy to understand and work with.
Very nice video! I have a remark. The electron could be a pointy charge travelling at the speed of light on a circular trajectory (plus the motion of its centre) with a radius of 193[fm]. It would match what the Dirac equation says.
It’s ironic that Michelson and Morley discovered the null result for the ether drift experiment revealing the observer-independence of the speed of light c, and the “fine structure” of the 656-nm hydrogen line revealing the existence of electron spin. Quantum information theorists have actually linked these two results en route to a “principle” understanding of what’s going on with spin. We explain this in our book, "Einstein's Entanglement: Bell Inequalities, Relativity, and the Qubit" Oxford UP (2024) and I’ll summarize it here. According to Einstein, special relativity (SR) is a "principle theory," i.e., a theory whose formalism follows from an empirically discovered fact. For SR that empirically discovered fact is the light postulate - everyone measures the same value for the speed of light c, regardless of their relative motions. Since c is a constant of Nature according to Maxwell's electromagnetism, the relativity principle (the laws of physics are the same in all inertial reference frames) says it must be the same in all inertial reference frames. And, since inertial reference frames are related by uniform relative motions (boosts), the relativity principle tells us the light postulate must obtain, whence the Lorentz transformations of SR. Likewise, quantum information theorists have rendered QM a principle theory and its empirically discovered fact is called Information Invariance & Continuity (Brukner & Zeilinger, 2009). In more physical terms, Information Invariance & Continuity entails that everyone measures the same value for Planck's constant h, regardless of their relative spatial orientations or locations (let me call that the "Planck postulate"). Since h is a constant of Nature according to Planck's radiation law, the relativity principle says it must be the same in all inertial reference frames. And, since inertial reference frames are related by relative orientations or locations in space (rotations or translations), the relativity principle tells us the Planck postulate must obtain, whence the finite-dimensional Hilbert space of QM. Quantum superposition is one consequence of the Planck postulate and here is how it makes perfect sense using spin as shown in this video. Suppose you send a vertical spin up electron to Stern-Gerlach (SG) magnets oriented at 60 deg relative to the vertical. Since spin is a form of angular momentum, classical mechanics says the amount of the vertical +1 angular momentum that you should measure at 60 deg is +1*cos(60) = 1/2 (in units of hbar/2). But the SG measurement of electron spin constitutes a measurement of h (Weinberg, 2017), so everyone has to get the same +/- 1 for a spin measurement in any SG spatial orientation, which means you can't get what you expect from common sense classical mechanics. Instead, QM says the measurement of a vertical spin up electron at 60 deg will produce +1 with a probability of 0.75 and it will produce -1 with a probability of 0.25, so the average is (+1 + 1 + 1 - 1)/4 = 1/2. In other words, QM says you get the common sense classical result on 'average only' because of the observer-independence of h. Give up your dynamical bias for QM (just as is done for SR) and the physics of spin makes perfect sense. And if you explore the Bell states for spin-entangled pairs using this approach, you find it solves the mystery of entanglement without violating locality (as in Bohm’s pilot wave), statistical independence (as in superdeterminism or retrocausality), intersubjective agreement (as in QBism), or the uniqueness of experimental outcomes (as in Many Worlds).
So I am to understand that there are entities that have 'angular momentum' in the same sense as any macroscopic object has angular momentum -but- the existence of this momentum cannot be attributed to any mechanic we understand in our day-to-day lives as being able to "grant" angular momentum?
Many are not available without access to an online library subscription. Other than that Googling the title with the additional flag filetype:pdf will turn them up online.
Just a crazy idea, but I wonder if some of the "quantum weirdness" around spin could be explained by redefining the electric charge to be a vector quantity (having direction) at extremely small scales (size of the electron)?
intrinsic angular momentum is not due to spinning on its own axis. is this a relative angular momentum just as in the case of photons which have momentum which is not equal to mass into velocity but it exists with some other physical expression??
Revising for my Atomic Physics exam in summer. Spin is probably one of the hardest things for me to visualise… I guess that's because there is no visualisation?
Yes. It's genuine quantum weirdness. An "intrinsic angular momentum" that cannot be increased or decreased. A magnetic moment that cannot be explained by the motion of charge.
Sancarn That's a very interesting question. Theoretically a proton is comprised of two up quarks and one down quark and has net spin 1/2. Two up quarks and one down quark in a system with net spin 3/2 comprise a so-called delta plus particle (or "resonance") which is very short lived. The way in which the proton's spin arises from its constituent parts is actually not well understood (the so-called Proton Spin Crisis). Some interesting recent work is described in phys.org/news/2013-04-quarks-dictate-proton.html
viascience Interesting… So spin has something to do with where the quarks are… I guess this can't really be visualised either… Otherwise you could say "If the spin is this when in this orientation and this in this other orientation what happens when they are in between?" Or am I missing something here?
Is the orbital angular momentum s=sqroot of s(s+1)hbar or s= sproot of 3 over 2 hbar also is this the energy that an electron has from the spin angular momentum?
Actually, there is quantity, which acts akin to angular momentum. Scientists figured out angular momentum within Newtonian physics and address this similar quantity by the same name, when found.
Not to invoke Kaluza-Klein early - but in the context of their theory, isn't it as though each particle spins (or does not spin) in a 5th dimension? To restate - it's like these are uncountable 5d spinning tops, stacked on top of each other - and because they are 5d and only rotating across their 4th and 5th dimensions, they can bounce back and forth in 3d as harmonic oscillators - the way tops balanced one above the other would bounce above the one below, and also jostle the one above - while the set moves en masse across the 4d plane in which they're partially spinning. Or like canon shot of uncountable 5d particles, traveling through 4d spacetime, and we can only interact with those with a ratio spin to ours.
That's interesting that higher quantum numbers -> classical mechanics, and that the electron orbitals become more like classical orbits - somehow I missed that at school. We solved the first orbital for Hydrogen numerically, but it would have been interesting to plug in larger numbers also and see them becoming more circular. Anyway, thanks for the video - on to part b...
It doesn't make sense to me that the horizontally-orientated dipole in the experiment would not turn itself due to the (stronger) North pole above it simultaneously attracting its south rear end and repelling its north front end, which would then re-orientate it vertically with the south end up, and therefore it would curve upwards... in that sense, no orientation of any dipole could be expected to stay on the straight middle path, but create the duality as was seen...
Can someone explain me, how the photons all spin at the same rate, when they have different amounts of energy? E_f=h*f It's quite a paradox to me, since the different amounts of energy must occupy less or more space depending on the energy levels. But if they have different size, how can they rotate around themselves at the same speed?
Spin is a misnomer; Nothing is spinning; Stern-Gerlach it seemed handy way to say it so the idea has propagated into dynamical ideas that are fluid and change the Original Steens Molasses just to confuse the Bunnies; Energies do not occupy space maybe they create them????
What is Spin ? I think the answer is phase shift (= shift in coordinate). 1. I think the de Broglie waves of multiple particles in one quantum state are connected in series, and the each wave shift msλ at the connecting point. (ms:spin quantum number, λ:wave length)Let us consider a case in which two electrons are in one quantum state [n,l,ml,ms=+1/2]. The de Broglie wave of 1st electron shifts +λ/2 in coordinate. And the de Broglie wave of 2nd electron shifts +λ/2+λ/2 in coordinate. Accordingly the two waves destructively interfere. [the Pauli exclusion principle] 2. Suppose that two electrons are moving in a single orbit, and suppose that the de Broglie wave of one electron shifts +λ/2 in coordinate and the de Broglie wave of another electron shifts -λ/2 in coordinate. The two waves have the shift of exactly one wavelength, which leads to a constructive interference of the wave, making it possible for the two particles to move in the same orbit. [the 4th quantum number] 3. The variable of wave function Φ{φez･(r ×p)} in φ direction has angular momentum r ×p. Accordingly, the shift in coordinate msλ change the angular momentum as follows: ml(h/2π)→ ml(h/2π)+ms(h/2π). I'm sorry that I'm not good at English.
It's electron toroid. Doughnut🍩 shape. Not a sphere. El ecto tron. Greek and from Latin trutina, from Greek trutanē balance, set of scales. The behavior of the electron particles is based on this spring balance type action.
To me the number 2 has a different and very special significance, we see it in simple equations llike mv^2/2 and 2mc^2 etc., it appears because we are only seeing half the picture. I have reason to believe that the proton and electron are the two halves of the same wave, and that all our classical and quantum definitions are only half the picture. By taking the view that the proton and the electron are a Dirac particle pair, the description of our world becomes simpler, without compromising the result. I describe my ideas in more detail here: groundpotential.org
Uploaded 10 years ago? I find this now? Thats crazy. The way you are showing ACTUAL experiment results leading to every new fact about reality is great and unparalleled.
I have watched the first 15 videos, some more than once. I promise I will do so again, after I finish them all. Thank you for all the effort you put into these videos. I love how you explain the wave equations.
You are most welcome. I am always happy to hear when someone finds these videos useful.
What mass are we using when we try to calculate the velocity rotational velocity of an electron? Are we using the rest mass of the electron?
Is the mass of the electron not dependent on the velocity with which it is traveling? So when at relativistic speeds would the inertial mass of the electron not be significantly larger than the rest mass of the electron?
I've just discovered your videos, great job!!
Thanks again, I download these and watch them a couple of times so the sink in. Thanks for all the hard work.
Spin is one of those "nobody understands it" things. The math works out, but it means exactly is a bit mysterious.
Sounds pretty anti-realist in comparison to earlier videos in this series lol
It's like the infield fly rule in baseball, it exists but nobody understands it.
It's easy to understand when you can see it's the same spin as that which exists in classical politics.
4:30 Had to think about this for a minute. Silver and Hydrogen have an outer electron that is in an s orbital (5s for silver, 1s for hydrogen). Because the s orbital has no angular momentum, any magnetic dipole moment seen in the experiment has to come from the electron itself.
Thanks for making these...loved ur way of telling in short and unique way..❤️
So to hazard sounding dense: Electron appear to/have a magnetic dipole, which -could- be explained by rotation of the particle, but since such rotation can't be accounted for by a classical understanding the electron instead has some kind of "snazziness" that intrinsically grants it the aforementioned dipole. And this snazziness only appears to have a magnitude of 1/2 or -1/2 for any electron?
snazziness does only occur in ±½ for the "electron" ◘ the electron is neither a point nor a wave it is a resonance - the choice of half as name is somewhat arbitrary ○○○ Stern-Gerlach only shows the response is quantifiable i.e. in definite or discrete values not smeared all over a non-definite; I have no idea what magnetic monopole is
So there is 'something' that acts kind of like momentum that is generated by 'something' that we call "spin" which is not the product of anything "actually" spinning. Got it, for a second there I was confused :)
You are most welcome.
Will do, thanks.
This is just speculation and I'm not that qualified enough at all to dwell in these matters, but I'll try to dig up what is done on the matter.
Also, in your last video (Spin II), I find it curious that the Higgs Boson is the only elementary particle to have no spin (or having a "0" spin qualifies as having a spin?) - I'll post this question on that video also
You are welcome.
I love your videos. I am a budding young* theoretical physics enthusiasts... and am learning much... thank you very much.
+Joshua crosby Glad to hear it.
Can't wait for the next part! Thanks for the vid!
great video, keep them coming!
I have heard that atomic clocks are based on electrons switching spin states and use microwaves as a standard (or something along those line). Can you please describe to me in more detail how spin states are related to atomic clocks?
literally saving my life right now, decided to try and derive Dirac's equation even though I've never covered spin, angular momentum, Schrodinger's equation or the uncertainty principle or anything. These videos are really getting me through 💯
If there is a Higgs Field that provides mass to particles that interact with it, could it be that another similar field is providing the unique spin based on another unique property of the particle?
"snazziness" is as good a term as I've ever heard for whatever the hell it is that's going on in there! ;-)
So why do moons/stars spin backwards creating an angular problem?
Classical angular momentum (moons, baseballs, and insects) is totally different from quantum angular momentum (magnets, superposition, quantum encryption). They call the quantum one the same name because the math looks the same, but like the video says, an electron would have to spin thousands of times the speed of light, which we believe cannot happen. And these 2 different concepts with the same name (again happened with "colors" in quantum chromodynamics or QCD) is a huge failing in making science concepts easy to understand and work with.
is it any caption or subtitle for the video I can get? need it since my english is limited. thank you
+Danny Rachmat I have uploaded a transcript.
+viascience where can I get the transcript? sorry it looks like I dont know too much about technology nowadays
+Danny Rachmat Click on the CC button and it will display while the video is playing.
That's an interesting idea. I don't know of any work along those lines.
Very nice video!
I have a remark. The electron could be a pointy charge travelling at the speed of light on a circular trajectory (plus the motion of its centre) with a radius of 193[fm]. It would match what the Dirac equation says.
Yes, Michelson was know for being a fanatic about accuracy. An experimentalist of the highest order.
That was freaking awesome 👌
It’s ironic that Michelson and Morley discovered the null result for the ether drift experiment revealing the observer-independence of the speed of light c, and the “fine structure” of the 656-nm hydrogen line revealing the existence of electron spin. Quantum information theorists have actually linked these two results en route to a “principle” understanding of what’s going on with spin. We explain this in our book, "Einstein's Entanglement: Bell Inequalities, Relativity, and the Qubit" Oxford UP (2024) and I’ll summarize it here.
According to Einstein, special relativity (SR) is a "principle theory," i.e., a theory whose formalism follows from an empirically discovered fact. For SR that empirically discovered fact is the light postulate - everyone measures the same value for the speed of light c, regardless of their relative motions. Since c is a constant of Nature according to Maxwell's electromagnetism, the relativity principle (the laws of physics are the same in all inertial reference frames) says it must be the same in all inertial reference frames. And, since inertial reference frames are related by uniform relative motions (boosts), the relativity principle tells us the light postulate must obtain, whence the Lorentz transformations of SR.
Likewise, quantum information theorists have rendered QM a principle theory and its empirically discovered fact is called Information Invariance & Continuity (Brukner & Zeilinger, 2009). In more physical terms, Information Invariance & Continuity entails that everyone measures the same value for Planck's constant h, regardless of their relative spatial orientations or locations (let me call that the "Planck postulate"). Since h is a constant of Nature according to Planck's radiation law, the relativity principle says it must be the same in all inertial reference frames. And, since inertial reference frames are related by relative orientations or locations in space (rotations or translations), the relativity principle tells us the Planck postulate must obtain, whence the finite-dimensional Hilbert space of QM.
Quantum superposition is one consequence of the Planck postulate and here is how it makes perfect sense using spin as shown in this video.
Suppose you send a vertical spin up electron to Stern-Gerlach (SG) magnets oriented at 60 deg relative to the vertical. Since spin is a form of angular momentum, classical mechanics says the amount of the vertical +1 angular momentum that you should measure at 60 deg is +1*cos(60) = 1/2 (in units of hbar/2). But the SG measurement of electron spin constitutes a measurement of h (Weinberg, 2017), so everyone has to get the same +/- 1 for a spin measurement in any SG spatial orientation, which means you can't get what you expect from common sense classical mechanics. Instead, QM says the measurement of a vertical spin up electron at 60 deg will produce +1 with a probability of 0.75 and it will produce -1 with a probability of 0.25, so the average is (+1 + 1 + 1 - 1)/4 = 1/2. In other words, QM says you get the common sense classical result on 'average only' because of the observer-independence of h.
Give up your dynamical bias for QM (just as is done for SR) and the physics of spin makes perfect sense. And if you explore the Bell states for spin-entangled pairs using this approach, you find it solves the mystery of entanglement without violating locality (as in Bohm’s pilot wave), statistical independence (as in superdeterminism or retrocausality), intersubjective agreement (as in QBism), or the uniqueness of experimental outcomes (as in Many Worlds).
You should explain electron spin as a 2D Complex Vector.
So I am to understand that there are entities that have 'angular momentum' in the same sense as any macroscopic object has angular momentum -but- the existence of this momentum cannot be attributed to any mechanic we understand in our day-to-day lives as being able to "grant" angular momentum?
doesn't h bar imply a rigid circular orbit of an electron not necessarily consistent with their location according to Schrodinger's wave function?
Thank you! Bravo
Preatty accurate explanation about QM -> spin
It would be better if the link to relevant research papers are attached in description.
Good going :)
Many are not available without access to an online library subscription. Other than that Googling the title with the additional flag filetype:pdf will turn them up online.
This made my head spin.
Just a crazy idea, but I wonder if some of the "quantum weirdness" around spin could be explained by redefining the electric charge to be a vector quantity (having direction) at extremely small scales (size of the electron)?
Good idea and worth it to try;
intrinsic angular momentum is not due to spinning on its own axis.
is this a relative angular momentum just as in the case of photons which have momentum which is not equal to mass into velocity but it exists with some other physical expression??
Revising for my Atomic Physics exam in summer. Spin is probably one of the hardest things for me to visualise… I guess that's because there is no visualisation?
Yes. It's genuine quantum weirdness. An "intrinsic angular momentum" that cannot be increased or decreased. A magnetic moment that cannot be explained by the motion of charge.
It is really, very strange. Do you know what happens if you actually spin a proton? Does anything weird happen? Or can you just not spin the proton?
Sancarn That's a very interesting question. Theoretically a proton is comprised of two up quarks and one down quark and has net spin 1/2. Two up quarks and one down quark in a system with net spin 3/2 comprise a so-called delta plus particle (or "resonance") which is very short lived. The way in which the proton's spin arises from its constituent parts is actually not well understood (the so-called Proton Spin Crisis). Some interesting recent work is described in
phys.org/news/2013-04-quarks-dictate-proton.html
viascience Interesting… So spin has something to do with where the quarks are… I guess this can't really be visualised either… Otherwise you could say
"If the spin is this when in this orientation and this in this other orientation what happens when they are in between?"
Or am I missing something here?
Is the orbital angular momentum s=sqroot of s(s+1)hbar or s= sproot of 3 over 2 hbar also is this the energy that an electron has from the spin angular momentum?
Actually, there is quantity, which acts akin to angular momentum. Scientists figured out angular momentum within Newtonian physics and address this similar quantity by the same name, when found.
Maksim Banin he is talking about spin, ( spin =/= angular momentum)its slight different
Not to invoke Kaluza-Klein early - but in the context of their theory, isn't it as though each particle spins (or does not spin) in a 5th dimension? To restate - it's like these are uncountable 5d spinning tops, stacked on top of each other - and because they are 5d and only rotating across their 4th and 5th dimensions, they can bounce back and forth in 3d as harmonic oscillators - the way tops balanced one above the other would bounce above the one below, and also jostle the one above - while the set moves en masse across the 4d plane in which they're partially spinning.
Or like canon shot of uncountable 5d particles, traveling through 4d spacetime, and we can only interact with those with a ratio spin to ours.
That's interesting that higher quantum numbers -> classical mechanics, and that the electron orbitals become more like classical orbits - somehow I missed that at school. We solved the first orbital for Hydrogen numerically, but it would have been interesting to plug in larger numbers also and see them becoming more circular. Anyway, thanks for the video - on to part b...
Thankyou.
It doesn't make sense to me that the horizontally-orientated dipole in the experiment would not turn itself due to the (stronger) North pole above it simultaneously attracting its south rear end and repelling its north front end, which would then re-orientate it vertically with the south end up, and therefore it would curve upwards... in that sense, no orientation of any dipole could be expected to stay on the straight middle path, but create the duality as was seen...
Can someone explain me, how the photons all spin at the same rate, when they have different amounts of energy? E_f=h*f
It's quite a paradox to me, since the different amounts of energy must occupy less or more space depending on the energy levels. But if they have different size, how can they rotate around themselves at the same speed?
Spin is a misnomer; Nothing is spinning; Stern-Gerlach it seemed handy way to say it so the idea has propagated into dynamical ideas that are fluid and change the Original Steens Molasses just to confuse the Bunnies; Energies do not occupy space maybe they create them????
You're welcome.
What is Spin ? I think the answer is phase shift (= shift in coordinate).
1. I think the de Broglie waves of multiple particles in one quantum state are connected in series, and the each wave shift msλ at the connecting point. (ms:spin quantum number, λ:wave length)Let us consider a case in which two electrons are in one quantum state [n,l,ml,ms=+1/2].
The de Broglie wave of 1st electron shifts +λ/2 in coordinate. And the de Broglie wave of 2nd electron shifts +λ/2+λ/2 in coordinate. Accordingly the two waves destructively interfere.
[the Pauli exclusion principle]
2. Suppose that two electrons are moving in a single orbit, and suppose that the de Broglie wave of one electron shifts +λ/2 in coordinate and the de Broglie wave of another electron shifts -λ/2 in coordinate.
The two waves have the shift of exactly one wavelength, which leads to a constructive interference of the wave, making it possible for the two particles to move in the same orbit.
[the 4th quantum number]
3. The variable of wave function Φ{φez･(r ×p)} in φ direction has angular momentum r ×p.
Accordingly, the shift in coordinate msλ change the angular momentum as follows: ml(h/2π)→ ml(h/2π)+ms(h/2π).
I'm sorry that I'm not good at English.
fuck yea your videos are so awesome
Muchas gracias.
It's electron toroid. Doughnut🍩 shape. Not a sphere. El ecto tron. Greek and from Latin trutina, from Greek trutanē balance, set of scales. The behavior of the electron particles is based on this spring balance type action.
To me the number 2 has a different and very special significance, we see it in simple equations llike mv^2/2 and 2mc^2 etc., it appears because we are only seeing half the picture. I have reason to believe that the proton and electron are the two halves of the same wave, and that all our classical and quantum definitions are only half the picture. By taking the view that the proton and the electron are a Dirac particle pair, the description of our world becomes simpler, without compromising the result. I describe my ideas in more detail here: groundpotential.org
*lines
XD!
First!