I read that this is why the electron don't fall in the nucleus. Could you please make a video about it, I can't find a good intuitive answer to that question. Thanks and great vid as always.
It derives from Energy-time uncertainty. The amazing consequence is that if you know the count (energy) of photons, then the E and B values (phases) are undefined. So a single photon has no definite E and B (but a large number of possible ones) and to model a classical Maxwell field like an EM wave you need huge numbers of photons. See number-phase uncertainty in wikipedia’s page on ‘coherent states'.(number-phase uncertainty also sheds light on whether things are waves or particles, there is a built in uncertainty)
this is off subject but you should find it interesting. Sometime in the 1980s, Richard Feynman came to the University of Alaska Fairbanks to give public and departmental lectures. In the departmental lecture he chose to solve a well-known problem in a different way: he put no constraints on probability. Probabilities could be greater than1 or less than 0. The terms on the right side of the equation consisted of multiple probability terms. He solved the equation by showing that all the meaningless terms (P1) cancelled out, giving a real answer. I would love to see this demonstrated in one of your videos.
I couldn't get such easy concepts even after my graduation in physics.. and you made it actually as simple as this concept is... Thankyou❤️ for being what you are !!!
intro for newbies on parths channel:"subscribe for fun physics content" intro for OG's: "i post fun physics content like this, but i dont have to try very hard because physics is already fun" OG intro>>>>>new one
GREAT Explanation! It would be nice if you explain in a similar way how this field of science, quantum mechanics, developed, evolved, what had been the thought process of the people who contributed to this field, why it didn't go another way around so on. Specifically, going through the thought process of developing theories about reality.
have you studied the Hamilton-Jacobi equations of classical mechanics, and also the role of the Poisson bracket? If not, the origins of QM will not be quantitative.
There is some good background in a book called "The Thirty Years That Shook Physics", which is a secondhand account of this entire experience. Of course an entire book is a bit longer and more costly than a video, but if you're really itching for some info it's in there :)
Great video, thanks. I saw another video (I think Veritasium) mentioning the squeezed light at LIGO, and it never mentioned what was actually going on. When you talk about that, can you mention HOW one squeezes the light? For example, my understanding with regular laser light going through a spatial filter (a small hole in a thin opaque membrane) is that we know the position of the light as it went through the hole very well, and so we are limited in our knowledge of the momentum, but since c is a constant (I think), then the uncertainty in momentum shows up in the direction of travel. Thus a spatial filter causes light to diffract. Is there a corresponding physical explanation for how one would actually do the amplitude / phase squeezing? Also, I saw a 3blue1brown video on the uncertainty principle, and Grant was stating that the uncertainty principle is not a quantum property per se, but more that it's a mathematical inevitability of any system that involves measurements. As such, it might not be that the uncertainty principle is a property of OUR universe, but a property of ANY universe in which measurements can happen.
Well Parth, a completely different message comes from the Schrodinger equation that is the base of the quantum wave. I know that you express what is the general weird interpretation, but think it this way. What it represents is that those variables are OUT OF PHASE between them. Using the complex coordinates, you can appreciate that the x is at the real axis while the momentum is at the imaginary axis; the same happens to energy and time. The phase difference contains some of the action "h"; that is the reason why Heisenberg's point that there will always exist a difference when measuring these variables, and this difference contains h. The difference is an exact situation, there is no diffuse about them, just out of phase an h is involved because the system can never show both simultaneously! That is what uncertainty is... you can read more in a short amazon book "Space, main actor of quantum and relativistic theories" hope it will inspire and see the quantum world less wierd.
I am new to this field and I have a v basic doubt....what happens to the output side after squeezing....I maybe wrong but what I know is that two photons are created from the vacuum state with the help of Squeezed operator(what it means physically I don't know...maybe some kind of non linear medium which produces two photons). And here comes my doubt(s) what are the relationship between states of two photons which were produced(I know that they are squeezed in one domain say amplitude squeezed) but how are they related to each other? And I don't understand the reason why we need to two photons in the first place, what is the argument behind?
If I understand correctly, "solid" objects don't go through each other (eg. an apple on a desk) because of electrons and the Uncertainty Principle? Is that right? I'm imagining electrons in the atoms along the touching edges of each object being forced together, to be shared between atoms of each object; an electron from the bottom of the apple joining an atom from the top of the desk, filling its inner-most shell perhaps. And this would mean the electrons in that shell would need to be different in at least one way, otherwise the Uncertainty Principle would prevent the electron from joining that shell? Or perhaps it would pop into a higher shell, but still be shared between apple and desk. I feel a bit like I'm spewing nonsense here, but this is the best that I can guess at the interaction right now. :) I'm wondering where the force that prevents apple from falling through desk makes its appearance though. I feel like electrons could always find at least one shell where there were no existing electrons with a matching profile. Or they could be stripped off their atoms and roam free, where they presumably don't need to worry about the Uncertainty Principle. As you can see, I grasp a few of these concepts but not enough to understand why an apple doesn't fall through a desk. So I wonder if that might be an interesting video topic?
Very clear explanation. TY. Why isn't momentum conjugate with time? instead of momentum conjugate with position. Why isn't energy conjugate with position? instead of energy & time. Is it coincidence that time translation symmetry = conservation of energy?
see Feynman's derivation of Noether's theorem by giving a small 'kick' to the action.. the extra action is zero only when the kick is the conjugate variable.. another route is to think of them as fourier pairs frequency(energy) vs time, position vs momentum..
@@nemuritai Feynman is terrible at explaining things. I was watching Feynman try to explain it last night at 46:47 of the vid 'Feynman's Lectures on Physics - Symmetry in Physical Law' He drew this sort of shape _ | | | | |_| If we throw a ball upwards & it takes 0.5 s to reach the ceiling. Let's say the left verticle line is the Parth of the ball. then we move 10 mm to the right & throw the ball, the situation is exactly the same, it takes 0.5 s to reach the ceiling. Let's say the right verticle line is the ball's trajectory on the 2nd throw Because we see exactly the same thing: 0.5 s both times, there's a kind of symmetry - it's like how we look in the mirror & see the (almost) exactly the same thing The bottom horizontal line is a movement of the ball 10 mm to the right. Feynman says the top horizontal line is the complete opposite. Then he repeats this claim over & over again. Then the audience applause for no reason. Sean Carroll also tried to explain the rectangle at 55:23 of the YT vid 'The Biggest Ideas in the Universe | 14. Symmetry' He calls the movement right: S(AC) He calls the movement left: S(BD) He says they're opposite. He says therefore there is a conserved quantity. I literally had no the slightest idea wtf he was on about Definitely Parth G could explain this better than both of them. There are also some videos on Noether's theorem by NoahExplainPhysics which are indecipherable hieroglyphics. You say: _"see Feynman's derivation of Noether's theorem by giving a small 'kick' to the action"_ I've been watching DrPhysicsA explain nicely & quite clearly the Lagrangian, Principle of Least Action & Hamiltonian in the YT vid 'Analytical Mechanics' He says the Lagrangian = KE - PE & the 'action' is like the sum of the Lagrangians along a ball's trajectory. Now you say the movement right is a kick to the action. It isn't clear what you mean but maybe you mean the horizontal line right is something to do with adding some energy to the trajectory of the ball. Then you say for no reason _" the extra action is zero only when the kick is the conjugate variable"_ Why do you say this? I really have no idea wtf you're talking about. Have you ever thought about trying to explain what you mean clearly? It might help. Your comment about Fourier reminds me of a terrible YT video I once saw. I guess I'll just watch that shit again.
@@DrDeuteron Yes her theory says energy is conserved = time translation symmetry = you can do your experiment at breakfast time or lunchtime & the results are the same. So why energy is conjugate with time in QM & she says similar? Coincidence?
Also check out Landau & Lifshitz' book 'mechanics', section 43(pg 138 in my copy). Uses simple classical 'Action' to show in one paragraph the proof that momentum is the derivative in position, q, whereas energy is the derivative in time, t. Of course if the action is constant then the derivatives are also constant so the corresponding value is conserved - momentum for position, energy for time. That is enough but to understand feynman's diagram go to wikipedia's version of feynmans proof. The shift or kick in q ie. position corresponds to an action that sums to zero (action is an integral over time) the picture shows it is momentum. Similsr for a shift up in time and then integrating over time.
Helo parth this is saurav ......i wanna ask u something..... I hv heard about time crystals,which changes its shape with respect to time......i thought that the crystal must be a living crystal......it is true or false...... And can human being can said time sapiens becz we also take many changes with respect to time??
I though Heisenberg's uncertainty principle tells us that concepts like position, momentum and particle when applied to nature at the atomic scale of uncertain usefulness.
Long story short, due to the uncertainty principle.. In fact momentum(light or electron microscope etc) can be thought of as not only the invariant quntity to position translation but also as the uncertainty in position. (recall as well inverse relationship of momentum and wavelength) See Rayleigh Criterion or wikipedia for 'angular resolution' for details.
Parth why there is uncertainty which is causing it or it is fundamental nature of universe or God doing that.there must be some rational logic behind this phenomenon We performed experiments and came to conclusions that there exists uncertainty and mathematically proved but that spark or feel or satisfaction is not there always feel there is some reason or explanation is missing.thank you superb explanation
I am reminded of Einstein's definition of insanity, which is: "Doing the same thing over and over and expecting different results." It seems, though, that the universe is insane - it does the same thing over and over (such as producing light waves) and creates different results.
I think that quote was shown not to be from Einstein (But I can't 100% confirm or deny), however, if I am recalling my quantum mechanics professor correctly, Einstein was not a fan of quantum mechanics, disliking the probabilistic nature of the interpretation. He famously said "God does not play dice" in response to this. I hope this serves as a little fun fact for ya :)
@@IronAsclepius he didn't believe the idea of a non-deterministic universe was possible. Not that it was determinable, but deterministic rather than probabilistic.
the collapse of the wave f. does not tell us an exact property of a quantum system (for example position or momentum). applying an quantum operator doesn't transform probability amplitudes i.e. wave f. into probability densities with sigmas equal to zero . so stop spreading the "exact measurement" myth and start using the term "quasi" or get rid of the "exact". the rest of the info contained in the vid is on point though :)
I don't know why your photo takes half the screen size while you are not the subject of focus ?? I suggest that you don't show your face to give subject more space for vivid explanation
Thank you for the great comments everyone! As always, let me know what other topics to cover in future videos :)
Hi sir 😊
Why is it that light can't go through an aperture smaller than the wavelength of the light?
I read that this is why the electron don't fall in the nucleus. Could you please make a video about it, I can't find a good intuitive answer to that question. Thanks and great vid as always.
Time crystal sir
Hi Parth G! Can I know where do physicist work and where are you working...
Wow! Today my 4 favorite channels parth g , kurzgesagt , learn engineering and eugene khutoryansky uploaded.😁🤘.
It derives from Energy-time uncertainty. The amazing consequence is that if you know the count (energy) of photons, then the E and B values (phases) are undefined. So a single photon has no definite E and B (but a large number of possible ones) and to model a classical Maxwell field like an EM wave you need huge numbers of photons. See number-phase uncertainty in wikipedia’s page on ‘coherent states'.(number-phase uncertainty also sheds light on whether things are waves or particles, there is a built in uncertainty)
thanks bro.we need more people like you
Great as always!
Thank you!
Thak you for uploading this videos man, the make difficult topics easy to digest.
Being an Indian and a physics student , I feel very proud to see your channel is growing exponentially. With lots of love from India 💓💓💕❤️
@nazerawiyonathan7980 yeah I was thinking that too
this is off subject but you should find it interesting. Sometime in the 1980s, Richard Feynman came to the University of Alaska Fairbanks to give public and departmental lectures. In the departmental lecture he chose to solve a well-known problem in a different way: he put no constraints on probability. Probabilities could be greater than1 or less than 0. The terms on the right side of the equation consisted of multiple probability terms. He solved the equation by showing that all the meaningless terms (P1) cancelled out, giving a real answer. I would love to see this demonstrated in one of your videos.
Wow! Your videos are really great! Love from Bangladesh ❣️
I couldn't get such easy concepts even after my graduation in physics.. and you made it actually as simple as this concept is... Thankyou❤️ for being what you are !!!
intro for newbies on parths channel:"subscribe for fun physics content"
intro for OG's: "i post fun physics content like this, but i dont have to try very hard because physics is already fun"
OG intro>>>>>new one
Your explanation is very clear
Please do a video on Fresnel's zones! Also, one on Fresnel and Fraunhoffer diffraction!
Learn basic diffraction rest are just modified version of it
GREAT Explanation! It would be nice if you explain in a similar way how this field of science, quantum mechanics, developed, evolved, what had been the thought process of the people who contributed to this field, why it didn't go another way around so on. Specifically, going through the thought process of developing theories about reality.
have you studied the Hamilton-Jacobi equations of classical mechanics, and also the role of the Poisson bracket? If not, the origins of QM will not be quantitative.
There is some good background in a book called "The Thirty Years That Shook Physics", which is a secondhand account of this entire experience. Of course an entire book is a bit longer and more costly than a video, but if you're really itching for some info it's in there :)
@@IronAsclepius Thanks for the information.
Great video, thanks. I saw another video (I think Veritasium) mentioning the squeezed light at LIGO, and it never mentioned what was actually going on. When you talk about that, can you mention HOW one squeezes the light? For example, my understanding with regular laser light going through a spatial filter (a small hole in a thin opaque membrane) is that we know the position of the light as it went through the hole very well, and so we are limited in our knowledge of the momentum, but since c is a constant (I think), then the uncertainty in momentum shows up in the direction of travel. Thus a spatial filter causes light to diffract. Is there a corresponding physical explanation for how one would actually do the amplitude / phase squeezing?
Also, I saw a 3blue1brown video on the uncertainty principle, and Grant was stating that the uncertainty principle is not a quantum property per se, but more that it's a mathematical inevitability of any system that involves measurements. As such, it might not be that the uncertainty principle is a property of OUR universe, but a property of ANY universe in which measurements can happen.
Simply excellent!
Awesome. Thank you
Well Parth, a completely different message comes from the Schrodinger equation that is the base of the quantum wave. I know that you express what is the general weird interpretation, but think it this way. What it represents is that those variables are OUT OF PHASE between them. Using the complex coordinates, you can appreciate that the x is at the real axis while the momentum is at the imaginary axis; the same happens to energy and time. The phase difference contains some of the action "h"; that is the reason why Heisenberg's point that there will always exist a difference when measuring these variables, and this difference contains h. The difference is an exact situation, there is no diffuse about them, just out of phase an h is involved because the system can never show both simultaneously! That is what uncertainty is... you can read more in a short amazon book "Space, main actor of quantum and relativistic theories" hope it will inspire and see the quantum world less wierd.
Very good explanation! thank you.
Do a video on interaction terms in the free lagrangians
Can you explain why the >= (greater or equal) sign can be changed into just the = (equal) sign? How does the "squeezing" work in the former? Thanks.
Hi sir thanks for giving video on one of my favourite 😊 topics
HEY CAN YOU MAKE A VIDEO ABOUT LARGE HADRON COLLIDER.
I am new to this field and I have a v basic doubt....what happens to the output side after squeezing....I maybe wrong but what I know is that two photons are created from the vacuum state with the help of Squeezed operator(what it means physically I don't know...maybe some kind of non linear medium which produces two photons). And here comes my doubt(s) what are the relationship between states of two photons which were produced(I know that they are squeezed in one domain say amplitude squeezed) but how are they related to each other? And I don't understand the reason why we need to two photons in the first place, what is the argument behind?
Thank you for the video bhaiya... can you please make a video on ultraviolet catastrophe...
If I understand correctly, "solid" objects don't go through each other (eg. an apple on a desk) because of electrons and the Uncertainty Principle? Is that right?
I'm imagining electrons in the atoms along the touching edges of each object being forced together, to be shared between atoms of each object; an electron from the bottom of the apple joining an atom from the top of the desk, filling its inner-most shell perhaps. And this would mean the electrons in that shell would need to be different in at least one way, otherwise the Uncertainty Principle would prevent the electron from joining that shell? Or perhaps it would pop into a higher shell, but still be shared between apple and desk.
I feel a bit like I'm spewing nonsense here, but this is the best that I can guess at the interaction right now. :)
I'm wondering where the force that prevents apple from falling through desk makes its appearance though. I feel like electrons could always find at least one shell where there were no existing electrons with a matching profile. Or they could be stripped off their atoms and roam free, where they presumably don't need to worry about the Uncertainty Principle.
As you can see, I grasp a few of these concepts but not enough to understand why an apple doesn't fall through a desk. So I wonder if that might be an interesting video topic?
5:00 What if we can't measure phases and amplitudes at all ?
Hi Parth G! Can I know where do physicist work and where are you working...
Very clear explanation. TY. Why isn't momentum conjugate with time? instead of momentum conjugate with position. Why isn't energy conjugate with position? instead of energy & time.
Is it coincidence that time translation symmetry = conservation of energy?
Noether's theorem.
see Feynman's derivation of Noether's theorem by giving a small 'kick' to the action.. the extra action is zero only when the kick is the conjugate variable.. another route is to think of them as fourier pairs frequency(energy) vs time, position vs momentum..
@@nemuritai Feynman is terrible at explaining things. I was watching Feynman try to explain it last night at 46:47 of the vid 'Feynman's Lectures on Physics - Symmetry in Physical Law'
He drew this sort of shape
_
| |
| |
|_|
If we throw a ball upwards & it takes 0.5 s to reach the ceiling. Let's say the left verticle line is the Parth of the ball.
then we move 10 mm to the right & throw the ball, the situation is exactly the same, it takes 0.5 s to reach the ceiling. Let's say the right verticle line is the ball's trajectory on the 2nd throw
Because we see exactly the same thing: 0.5 s both times, there's a kind of symmetry - it's like how we look in the mirror & see the (almost) exactly the same thing
The bottom horizontal line is a movement of the ball 10 mm to the right. Feynman says the top horizontal line is the complete opposite. Then he repeats this claim over & over again. Then the audience applause for no reason.
Sean Carroll also tried to explain the rectangle at 55:23 of the YT vid 'The Biggest Ideas in the Universe | 14. Symmetry'
He calls the movement right: S(AC)
He calls the movement left: S(BD)
He says they're opposite.
He says therefore there is a conserved quantity.
I literally had no the slightest idea wtf he was on about
Definitely Parth G could explain this better than both of them.
There are also some videos on Noether's theorem by NoahExplainPhysics which are indecipherable hieroglyphics.
You say: _"see Feynman's derivation of Noether's theorem by giving a small 'kick' to the action"_
I've been watching DrPhysicsA explain nicely & quite clearly the Lagrangian, Principle of Least Action & Hamiltonian in the YT vid 'Analytical Mechanics'
He says the Lagrangian = KE - PE & the 'action' is like the sum of the Lagrangians along a ball's trajectory. Now you say the movement right is a kick to the action. It isn't clear what you mean but maybe you mean the horizontal line right is something to do with adding some energy to the trajectory of the ball. Then you say for no reason _" the extra action is zero only when the kick is the conjugate variable"_ Why do you say this? I really have no idea wtf you're talking about. Have you ever thought about trying to explain what you mean clearly? It might help. Your comment about Fourier reminds me of a terrible YT video I once saw. I guess I'll just watch that shit again.
@@DrDeuteron Yes her theory says energy is conserved = time translation symmetry = you can do your experiment at breakfast time or lunchtime & the results are the same. So why energy is conjugate with time in QM & she says similar? Coincidence?
Also check out Landau & Lifshitz' book 'mechanics', section 43(pg 138 in my copy). Uses simple classical 'Action' to show in one paragraph the proof that momentum is the derivative in position, q, whereas energy is the derivative in time, t. Of course if the action is constant then the derivatives are also constant so the corresponding value is conserved - momentum for position, energy for time. That is enough but to understand feynman's diagram go to wikipedia's version of feynmans proof. The shift or kick in q ie. position corresponds to an action that sums to zero (action is an integral over time) the picture shows it is momentum. Similsr for a shift up in time and then integrating over time.
Sir make a video on minimum uncertainty principle
Do a video on explanation of gyroscopic effect ,
Pls make a Quantum Mechanics course
Helo parth this is saurav ......i wanna ask u something.....
I hv heard about time crystals,which changes its shape with respect to time......i thought that the crystal must be a living crystal......it is true or false......
And can human being can said time sapiens becz we also take many changes with respect to time??
I though Heisenberg's uncertainty principle tells us that concepts like position, momentum and particle when applied to nature at the atomic scale of uncertain usefulness.
Make a video on noethers theorem
Why is it that you can't see an object with light who's wavelength is larger than the size of the object?
Long story short, due to the uncertainty principle.. In fact momentum(light or electron microscope etc) can be thought of as not only the invariant quntity to position translation but also as the uncertainty in position. (recall as well inverse relationship of momentum and wavelength) See Rayleigh Criterion or wikipedia for 'angular resolution' for details.
But are we really squeezing light or is it that it's just in our calculations
Parth why there is uncertainty which is causing it or it is fundamental nature of universe or God doing that.there must be some rational logic behind this phenomenon
We performed experiments and came to conclusions that there exists uncertainty and mathematically proved but that spark or feel or satisfaction is not there always feel there is some reason or explanation is missing.thank you superb explanation
Hi
Help me, parth g
I'm confused ✋
I am reminded of Einstein's definition of insanity, which is: "Doing the same thing over and over and expecting different results." It seems, though, that the universe is insane - it does the same thing over and over (such as producing light waves) and creates different results.
He never said that
I think that quote was shown not to be from Einstein (But I can't 100% confirm or deny), however, if I am recalling my quantum mechanics professor correctly, Einstein was not a fan of quantum mechanics, disliking the probabilistic nature of the interpretation. He famously said "God does not play dice" in response to this. I hope this serves as a little fun fact for ya :)
@@IronAsclepius he didn't believe the idea of a non-deterministic universe was possible. Not that it was determinable, but deterministic rather than probabilistic.
@@AfricanLionBat Who said it is not important
@@laurendoe168 I'm not trying to detract from your original point. I was just pointing out he didn't say it which is important.
the collapse of the wave f. does not tell us an exact property of a quantum system (for example position or momentum). applying an quantum operator doesn't transform probability amplitudes i.e. wave f. into probability densities with sigmas equal to zero . so stop spreading the "exact measurement" myth and start using the term "quasi" or get rid of the "exact".
the rest of the info contained in the vid is on point though :)
Eigen energy values and angular momenta are exact enough. What are you on about?
Claim your under an hour ticket here
bad sound quality
I don't know why your photo takes half the screen size while you are not the subject of focus ?? I suggest that you don't show your face to give subject more space for vivid explanation
Hi