I like that he isn’t afraid to show the math and look at how it works. Seeing the actual equations feels better than someone just telling me that math tells us these things
David Walker lol because the probability waves are measurable and the formulas match with measured experiments. Basically how all science works. The universe existed and worked mathematically long before there was anything that tried to comprehend it.
I am a chemistry graduate, and every time I see a new physics video of yours I feel like reuniting with an old friend I haven't heard for a long time. I already left a comment under a post you wrote a couple of weeks back, but I just wanted to make sure that you read this: your work here on TH-cam is deeply appreciated, keep it up!
Finally, a channel that isn't afraid to delve into the math! Excited for the next video, but not as excited as I am for you to finish up Maxwells equations! Keep up the good work 🙂
For someone like me who is really into quantum mechanics but could never afford the university fees to indulge my curiosity. Thanks Parth. To share knowledge freely is one of the things still holding us back. you have inspired a generation buddy. Please keep it up! Your financial situation should have no bearing on learning. and im learning tons here. so Thanks again Parth. your the main man on my laptop now. lol.
"im in shock" DONT BE you are providing very good content and its your ability to explain stuff simply. I thank you. PS love the joys of Wave Functions.
I really love the fact that you used actual equations to show what you're describing. Most videos on these subjects just try to make analogies and animations so that they are more easily understandable, but your explanation is the best in my opinion.
This channel is the only one that I watch that has videos I have to pause and rewind to understand everything. It is challenging and interesting at once.
The coefficient term with its complex conjugate (squared) is the probability, but this is important to note; it is *not* the "probability of finding the system in that state" as you mentioned. The language here is important, so more precisely it is the probability of the system being in that state after a measurement (and/or interaction with some part of the environment) is made on the system.
Thank you very much! I've been circling around this topic for a long time. Not having a background in math, progress is slow, but this video really furthered my understanding quite a bit. I especially liked the fact that you first described the general principle of entanglement and only went into the Bell state after that. The books/videos I've encountered before all skipped straight to the Bell state without identifying it as a special case. To me, the route you took is much clearer. I'd say you nailed it as far as bridging the gap is concerned. And no need to apologise for talking to long, it was very well paced. Please keep up the good work!
Perfectly clear... ..More Over.. the result is 💯 percent same..if we talk or anylise two really Entangled souls.. (Of two persons..) Simply.. No coincidence!
I love finding old videos of people where they were shocked and grateful at their subscribers being a certain amount then look at their subscribers count abd it's, double triple or quadrthe amount now. Was at 20,000 now you're at 104k. Life is wild, but I'm happy for you.
Hi, since minute 10:40 more or less, the chart of equivalences between the parameters and the letters contains a mistake. d=beta x delta, and not beta x gamma. Thanks for your videos, you're fantastic!
Wow!. I have very basic quadratic equations and probability knowledge but this explanation was crystal clear to me how quantum entanglement works. Amazing!! Thanks for making it simple. ☺️👍
Great explanation, for those who are not in a physics major ( I took an engendering master's degree ) i can recommend 2 excellent books that cover pretty much everything regarding modern physics (On a superficial level, of course, but they are not bed reading books either): - Revolutions in Twentieth-Century Physics - by Griffiths - Quantum Physics: A First Encounter - by Scarani These will give you valuable insights on what is going on with physics for the past 100 years.
I actually understood way more from your graphics and explanations than from other videos - sure I don't get most of it since I stuggle with common physics but still, your video is a very good help even for non native speakers.
What's the problem ? The 2 electrons keep the opposite orientation "spin" as long as no perturbation will impact them changing their spin, even if sent far away , because they were in opposite spin from the beginning i.e. around the atom nucleus, why should be weird?
I was really interested in physics during school but after school in college i lost touch gradually but really your content got me back into it a bit and this was really the best explanation I've seen for quantum entanglement by far.
Thank you for this video. Most of the videos talking about quantum entanglement, only say when the first quantum is measured spin up, the other quantum is always measure spin down (or up, and hence part of my confusion), and I could not comprehend what's the big deal about about that at all. After watching this video, my understanding is that the mentioned scenario is just a special case among others (not sure if this understanding is right or not). Your work helped me further pursue the quantum world. Thank you again.
I have a few questions. When you say system of two electrons, what do you mean exactly? How do you get a system of two electrons experimentally ? How do you actually say that they are entangled in reality ? What if three particles are entangled and measured what wud be the result? How can you measure the spin of an electron/ photon, what exactly do you do in actuality ? If you mean by spin, the axis of rotation and suppose if electron is spherical isn't it both anticlockwise and clockwise based on how you view it ? in that case how can you distinguish between spins of both entangled particles as opposing ? After measuring the spin of the particle A , how long will you take to measure the spin of the entangled particle B ? Will the result stay same after a long time ? Or is it spontaneous and almost immediate ? The vague jargon here in this video gives rise to many actual questions and those are the ones which confuse a person and not the actual math.
I’d love for you to explain how electrons get entangled, how to maintain entanglement, AND, most importantly, how can you tell if they are still entangled?
Hi Parth, i have been scourging for resources and videos that would help me understand this concept of entanglement better and this video was precisely what I needed, with just enough (and simple) mathematical representations. Thanks a bunch!
Are you taking video requests? Here's my list. Thanks. 1) Spooky action at a distance with real world experiments. Does the communication travel at more than the speed of light? 2) Quantum tunneling and total internal reflection. UpAndAtom referred to this but she didn't really explain it. 3) How does a tunneling diode work and why does it work etc.
Seems like you could think about the superposition of states as a car tire rolling down the road. It could be turned in every orientation, but when you take a picture of the tire, the photo will be of the tire in one orientation.
We need the two combined to describe situations like when large masses are on the quantum scale, such as black hole singularities and the Big Bang and stuff like that.
Why we need it is easier than what it would look like. I would say the most interesting reason why we need it is that it might help answer the question: How small was the universe at time t=0? People like Hawking and Penrose used GR to predict that the universe must have started as a singularity, i.e. its volume would have been zero at time t=0 (though t=0 might have been an infinity long time ago because of time dilation). But a QM+GR combination might say that there is some minimum volume and the "singularities" of both Black Holes and the entire universe can't be smaller than that volume. If that was true it might lead to an "everything from nothing" theory for the beginning of time (the idea that the universe started as a quantum fluctuation with near zero energy and that it still has near zero energy today). I'm just a layman, and this comment is probably going to get ripped apart by someone who knows more than me. Suggest you wait for other comments before taking me seriously!
K Tell that is a pretty food explanation, although one thing I will say is that we don’t need QM+GR to know that the initial singularity had to have a finite volume. But it will help us find what that volume is, as you said
I love the way you present the math in all of your videos! And you calling it high school math is a very accurate depiction! I love it thank you so much you make it incredibly easy to follow along
I graduated Mechanical Engineering in 2006, and swopped to management consulting in 2008...Damn, i miss this stuff! Need to brush up the math, but i largely followed all the way. Tx
Thanks you for your professional effort! Quick question , have you heard about a state called "quantum entanglement with the earth's magnetic grids" ? , ( it comes from the theory of migrating birds capables of watching this lines to get oriented while traveling)
Hey, great video! However, there's something I didn't quite understand. It seems like the separable state at 11:09 and the entangled state at 13:49 are exactly the same but only with different coefficients ? For example, if you take the entangled state (13:49) and choose all coefficients equal to 1/2, you can factorize it in the exact same way as the separable state (11:14) by taking the coefficients equal to 1/sqrt(2).
Amazing ! perfect for licence degree and now my master to keep having the big picture of all the stuff we are then adding when you go further in quantum physics
You certainly made a great effort & it was bold of you to attempt to use maths as an aid to understanding. Unfortuneately the maths alone is challenging especially delivered at the speed at which you speak. I found it difficult to absorb each "step" whilst keeping track of what came next. The result is I am just as lacking in understanding as I was at the beginning of your talk . another problem: where the heck are the two "particles" (or waveforms). How do you isolate an electron to measure it's spin, how do you actually prove that " b" is the same before & after measurement of "a" at the instant of measurement? Finally why refer to system when you are addressing only 2 electrons & what about instantaneous action, light speed less or more?
Question: what is the difference between 1. saying particles are in a superposition of different states, and 2. just saying we have uncertainty about which state they're in, and expect them to be in each state with a given probability?
Ever make a simulation of two tiny bar magnets, aligned (in three dimensions) opposite, travelling in opposing directions? Make two thresholding detectors, on opposite sides, that attempt to measure the alignment (spin), on three axes, and add the appropriate amount of noise on each axis. Try adding Gaussian noise of different levels, and only real, and then complex.
I’d recommend watching the double slit experiment to understand a little more about this; its crazy to think that what is most rudimentary to us, is the most perplexing
In classical thermodynamics, two (or more) particles in phase space (generally) move independently (statistically) of each other. This means that you can isolate any one of them and study its behavior without fear of compromising your analysis. In other words, the particles in phase space are "separable" - due to that statistical independence. However, that is not necessarily true in quantum mechanics - where observables often depend on each other (are correlated) in ways that you don't generally find in the phase spaces of classical physics.. In other words, particles in QM are often statistically dependent - a condition that physics calls entanglement. (That term is often reserved for cases of maximum entanglement, such as in the EPR experiment.) Students of classical physics usually find this to be weird, and don't really know what to make of it at first. But any high school math student who has studied basic conditional probability knows about this idea and can give you many examples of statistical dependence in real life. I'm wondering if it would take the scariness away if entanglement in QM were simply taught as statistical dependence from the start. Complex issues could be addressed afterwards. Whadaya think?
I see that someone else mentioned a typo at 8:22. I actually saw the typo first at 8:01. I was following your explanation perfectly until I became incongruent with what you were saying and what I was seeing. The spin is written incorrectly on particle B in the second part of your equation. The arrow is red but you have drawn it as a down arrow.
This is a great video and you are pretty clear, the only thing i was thinking about is how fast you are speaking making it a bit hard to follow along, i was able to understand everything and u did a great job explaining, well done!
I was thnking that perhaps when you explain ket up and down it may perhaps be easier for someone watching to think of up and down as one being in relation to the circular spin as being wider or ket up; or the height direction of travel coming down in elevation in relation to observation as down ket or vice versa. I'm not sure if I misinterpreted your connotation please feel free to let me know. Other than that very informational and well put together
Hey, I am really very glad to be a part of your journey and learn something that I will too learn while pursuing majors in Astrophysics and Astronomy. But currently I am in IB board. My only request to you is that can you give me some tips about how and what do cambridge interviewers want to see in their candidates? Pls
question: ¿can you affect the quantum state of an entangled particles, if you somehow manipulate the spin of one of them, or, you just know in which state the other one will be in that particular time?...thanks...
Two questions about entanglement: 1) you say that measurement on Particle A _changes_ the math for the probability distribution for Particle B. But how? What's the physical mechanism for this? 2) How long does the system stay entangled? If Particle A and Particle B are flying in opposite directions in a particle accelerator, and you measure Particle A's spin, you know _at that instant_ that the spin of Particle B is the opposite. But how long does it stay this way? What kinds of interaction, if any, would affect the entangled state of the system, and why? If Particle B interacts with a magnetic field that deflects its path according to its spin, does that count as a measurement? Will Particle B go back to being independent of Particle A thereafter?
You guys should check out E8 next. Is E8 the state of particles not being observed, meaning, E8 is the living energy holding ALL POSSIBILITIES before it is collapsed/observed?
PG your math is flawless and it's a good thing I knew the outcome before you got to it. But from a purely physics point of view, if the electrons are 10 light years apart does measuring spin on A still dictate spin on B and if so what is the time involved?
Very well done. But The issue I have with your explanation is that it’s not weird at all. It’s completely consistent with a classical view of the world. Ie: electron A had spin down and electron B had spin up. You just don’t know it. So it’s a 50/50 guess on electron A but once you know it, then you know electron B. It’s not weird at all and perfectly at peace with classical physics
No, that's not it. Merely not knowing a state does not give the correct results in quantum mechanics. One has to understand that there is no state before the measurement. This is no different from rolling dice, by the way. Moving dice also don't have a state (in the set of possible outcome states) before they come to rest.
Sounds like I've heard it while watching about Quantum Computing.. Can you make a video on that too please..!! By the Way, love your videos and the way you explain things..!!
Just interested in the topic what if i measure particle A to be in the spin up state which means that certainly practical B is in the spin down 100% now what happens if i go an measure particle B even though i know it's state shouldn't that affect it's state as i measure it and now it may go into spin up causing particle A to switch it's spin state. Another thing could you shed some light on quantum communication and if it is true or a youtube myth as i heard Chinese have achieved something like that.
Quick typo: at 10:20 d should be equal to beta * delta :) also thanks for this video. Currently doing my senior thesis on quantum entanglement of photons and i've been trying to wrap my head around entanglement and this gave a pretty clear mathematical explanation for entanglement. I think you should have covered though the more physical aspects. Like WHAT actually causes entanglement. What physical setups in the lab can you make that will create particles to be in these entangled states etc! new video idea? :P
I'm a bit of a duffer with this 'measuring spin' malarkey so I did a bit of Googling, and it seems the best analogy is cricket, (in fact a Googly). So very (very) basically it seems you fire your electron at a magnet and see what direction it heads off. This is analagous to a bowler delivering a ball with spin i.e. how the ball reacts to the batsman's stroke will tell you whether the bowler was spinning to oneside or the other. Owzat?
Good God, dude. Quantum physics and Schröedinger's Cat almost kind of delves into philosophy as well. ("If a tree falls in the woods and there's no one present to hear it, does it make a sound?") I just watched a video on the explanation of the Klein Bottle concept, and if that wasn't confusing enough, I then found myself watching a video about the Banach-Tarski Paradox, and that literally twisted my brain into a pretzel. Now I'm here, getting more confused.
5 ปีที่แล้ว +3
Very cool! I always felt bad that there are only two kinds of material to understand things like these: the "popular science" kind, with well ... "silly" examples and trying to save people from ANY math very-very carefully. And the other kind: "ok, this is far more too much for me" (eg lectures in universities etc) . But nothing between :( I don't even mind complex numbers, calculus etc either, but still even with these knowledge on math I have (which I suppose is still more than the 'average' people have, but surely far-far more less what experts have), I find myself in the "middle group" where there is hard to find any suitable material. Sorry for my bad English, hopefully I could express my thoughts in an understandable way at least.
LGB Gábor Lénárt I agree with you, but my problem is (this is just a me problem, he is very good at explaining) I get distracted extremely easily, and I'm only in 9th grade, but I am a nerd lol, and I was curious about quantum entanglement and all that stuff, because I heard my dad (also a nerd) mention it once, so I thought I'd do some research, anywho, my point is, is that he is very good at explaining but his voice is so calm I get distracted easily and when I click back in I have to rewind the video to understand what's going on, also probably doesn't help that I'm only in 9th grade and even though I love math and I'm in geometry, I can't exactly understand calculus and all that yet, maybe I'll research that next!
Hi Parth, at 6:41, can you give a concrete example of how a classical state is separable in to the product of two independent terms? Just randomly I've thought about two classical spinning tops, but maybe you have a more instructive scenario in mind. In particular can you go in to why (mathematically) is it that when we can factor them in to separate terms, that the probability of one isn't affected by the other? Thanks.
Some other questions, where exactly in space are electrons A and B? I'm assuming they exist simultaneously in time. are they firing photons at each other a la QED? how soon after you measure the spin of A do you see the probability of measuring the spin of B deviate from its original? I'm assuming it won't be immediate correct? You have to wait for exactly the time that light takes to travel their distance apart? so you have this lag in time after measuring A wherein B retains its original probability until the information gets to it at the speed of light whereupon the probability changes. if this were true, then it's not weird anymore. A's just telling B (via a photon) "hey i got measured in such and such a state, now change your probability accordingly"
What if your detector is more like a fish bowl which detects that which "sinks" or that which "floats" relative to the water in the fishbowl itself? And quantum entanglement infallibly causes one unentangled particle to be "that which will inevitably sink" and the other to be "that which will inevitably float" in a fishbowl that has glass on on all sides and on the bottom but not at the top? But one doesn't always know if the fishbowl one is using is upright, and one doesn't even know that the sinking or floating itself is relative to the water in the fishbowl. Because both the glass of the fishbowl and the water of the fishbowl is still entirely unknown to us. I mean what if it all makes perfect, perfect sense, but it is something more like that? The "sinking" or "floating" is relative to the water in the fishbowl. It's not like a clock with hands that are clearly moving either clockwise or counterclockwise with respect to the clockface itself - whether that clock is filmed or not.
Thanks for the informative info Mr Parth. I would like to ask, What do you think about the theoretical connection between consciousness and quantum entanglement?
Hey there's a mistake at 10:19. The fourth restrictive equation should be: d= βδ. It's amazing how the internet didn't point it out yet! The logic still stands, of course. This is more of a typo, or inconsistency, than an actual mistake. Amazing video, nevertheless. Keep it up! :D
Loving the videos. Clear explanation and can (just about) follow the maths. One small request - could you make your figure "2" a little less 'loopy'? I keep thinking it's some sort of Greek letter rather than a square or square-root signifier.
I love these quantum mechanics videos. They’re really interesting and tie into my physical chem 2 class right now. Not trying to call you out Parth but I did find that you had a small math typo around 10:45 the last d=βγ should have said d=βδ I know it’s such a small correction but I wanted to bring it up. I really like how you bring up the math. You’ve really solidified my understanding on the notation and the wave function so thank you very much! Cheers
I am in a superposition to understand and NOT understand this at the same time... Cannot wait to collapse into the state of understanding this.
Try watching this while high! I understand perfectly.
I see what you did there.
Yes, but its 50/50 and you won't know until prof does measurement when he gives test.
@@joeboxter3635 😂😂
😂😂
I like that he isn’t afraid to show the math and look at how it works. Seeing the actual equations feels better than someone just telling me that math tells us these things
This in a way is really funny cause that’s so true
Mathematics are the language of physics, that's why
And it made it easier for me to understand than other people using weird objects spinning.
How can you form mathamatical formula's for something that is beyond our comprehension
David Walker lol because the probability waves are measurable and the formulas match with measured experiments. Basically how all science works. The universe existed and worked mathematically long before there was anything that tried to comprehend it.
I am a chemistry graduate, and every time I see a new physics video of yours I feel like reuniting with an old friend I haven't heard for a long time. I already left a comment under a post you wrote a couple of weeks back, but I just wanted to make sure that you read this: your work here on TH-cam is deeply appreciated, keep it up!
Finally, a channel that isn't afraid to delve into the math!
Excited for the next video, but not as excited as I am for you to finish up Maxwells equations!
Keep up the good work 🙂
If you like the math, I highly recommend the channel viascience
For someone like me who is really into quantum mechanics but could never afford the university fees to indulge my curiosity. Thanks Parth. To share knowledge freely is one of the things still holding us back. you have inspired a generation buddy.
Please keep it up!
Your financial situation should have no bearing on learning.
and im learning tons here.
so Thanks again Parth. your the main man on my laptop now. lol.
"im in shock" DONT BE you are providing very good content and its your ability to explain stuff simply. I thank you. PS love the joys of Wave Functions.
Thank you so much! :D
I'll have to watch this several times but... yeah!
I really love the fact that you used actual equations to show what you're describing. Most videos on these subjects just try to make analogies and animations so that they are more easily understandable, but your explanation is the best in my opinion.
This channel is the only one that I watch that has videos I have to pause and rewind to understand everything. It is challenging and interesting at once.
The coefficient term with its complex conjugate (squared) is the probability, but this is important to note; it is *not* the "probability of finding the system in that state" as you mentioned. The language here is important, so more precisely it is the probability of the system being in that state after a measurement (and/or interaction with some part of the environment) is made on the system.
the characters "I and > "is called a KET , like bracket and there is a bracket called BRA for other quantum equations to.
Quantum state is a metaphor for the fact that you have all options available until you pick one. #Freewill #choosewisely
This is what brought me to this video
Thank you very much! I've been circling around this topic for a long time. Not having a background in math, progress is slow, but this video really furthered my understanding quite a bit. I especially liked the fact that you first described the general principle of entanglement and only went into the Bell state after that. The books/videos I've encountered before all skipped straight to the Bell state without identifying it as a special case. To me, the route you took is much clearer. I'd say you nailed it as far as bridging the gap is concerned. And no need to apologise for talking to long, it was very well paced. Please keep up the good work!
Perfectly clear...
..More
Over.. the result is 💯 percent same..if we talk or anylise two really
Entangled souls..
(Of two persons..)
Simply..
No coincidence!
I love finding old videos of people where they were shocked and grateful at their subscribers being a certain amount then look at their subscribers count abd it's, double triple or quadrthe amount now. Was at 20,000 now you're at 104k. Life is wild, but I'm happy for you.
i am here to understand how Jonas is still alive in his world.
Same here 😁
Same here
thought i was alone hehe
😑😑🙃🙃🙃😑😑😂😂😂😂😂😂😂
Hi, since minute 10:40 more or less, the chart of equivalences between the parameters and the letters contains a mistake. d=beta x delta, and not beta x gamma. Thanks for your videos, you're fantastic!
When Parth goes blurry it's not because his camera has lost focus, it's because his phase is changing. Or maybe it's just because you've lost focus.
Wow!. I have very basic quadratic equations and probability knowledge but this explanation was crystal clear to me how quantum entanglement works. Amazing!! Thanks for making it simple. ☺️👍
Me 5 minutes into the video:
Ight imma head out. You win this round youtube
LOL. Can I follow you? I think Ill always know I'm intellectually not alone. :-)
Physicist here, but have not done any QM for 40 years. A better explanation that in any of my classes. I did remember the bra-ket notation though.
Great explanation, for those who are not in a physics major ( I took an engendering master's degree ) i can recommend 2 excellent books that cover pretty much everything regarding modern physics (On a superficial level, of course, but they are not bed reading books either):
- Revolutions in Twentieth-Century Physics - by Griffiths
- Quantum Physics: A First Encounter - by Scarani
These will give you valuable insights on what is going on with physics for the past 100 years.
I actually understood way more from your graphics and explanations than from other videos - sure I don't get most of it since I stuggle with common physics but still, your video is a very good help even for non native speakers.
What's the problem ? The 2 electrons keep the opposite orientation "spin" as long as no perturbation will impact them changing their spin, even if sent far away , because they were in opposite spin from the beginning i.e. around the atom nucleus, why should be weird?
Great, I like the way you clearly explain things for the layman. You have a new subsriber
He really does it
But he wanted a subscriber
I was really interested in physics during school but after school in college i lost touch gradually but really your content got me back into it a bit and this was really the best explanation I've seen for quantum entanglement by far.
Thank you for this video. Most of the videos talking about quantum entanglement, only say when the first quantum is measured spin up, the other quantum is always measure spin down (or up, and hence part of my confusion), and I could not comprehend what's the big deal about about that at all. After watching this video, my understanding is that the mentioned scenario is just a special case among others (not sure if this understanding is right or not). Your work helped me further pursue the quantum world. Thank you again.
Can you create a video on how exactly a quantum computer works?
I have a few questions. When you say system of two electrons, what do you mean exactly? How do you get a system of two electrons experimentally ? How do you actually say that they are entangled in reality ? What if three particles are entangled and measured what wud be the result? How can you measure the spin of an electron/ photon, what exactly do you do in actuality ? If you mean by spin, the axis of rotation and suppose if electron is spherical isn't it both anticlockwise and clockwise based on how you view it ? in that case how can you distinguish between spins of both entangled particles as opposing ? After measuring the spin of the particle A , how long will you take to measure the spin of the entangled particle B ? Will the result stay same after a long time ? Or is it spontaneous and almost immediate ? The vague jargon here in this video gives rise to many actual questions and those are the ones which confuse a person and not the actual math.
Good lighting! Oh, and great presentation style. Sorry, no questions about entanglement. I like how you made the math simple to follow.
I’d love for you to explain how electrons get entangled, how to maintain entanglement, AND, most importantly, how can you tell if they are still entangled?
This is the kind of physical and practical information you never hear anyone talk about at all.
Hi Parth, i have been scourging for resources and videos that would help me understand this concept of entanglement better and this video was precisely what I needed, with just enough (and simple) mathematical representations. Thanks a bunch!
Great video! Would love a follow-up on how two particles can become entangled in the first place
If they are in a state of well defined total angular momentum. For instance
very well explained. Thank you for keeping the Maths, because entanglement can never be really understood without understanding the Maths behind it
very few videos on youtube take the time to explain this. it's refreshing to see your videos!
Are you taking video requests? Here's my list. Thanks. 1) Spooky action at a distance with real world experiments. Does the communication travel at more than the speed of light? 2) Quantum tunneling and total internal reflection. UpAndAtom referred to this but she didn't really explain it. 3) How does a tunneling diode work and why does it work etc.
thanks for putting this up. I understood this video more than what Feynman tried to explain.
Om Vedant Chimmalgi that’s a bold claim
Ploop Ploopploopboop you clearly don’t know who freynman is then? Try research before you comment
Seems like you could think about the superposition of states as a car tire rolling down the road. It could be turned in every orientation, but when you take a picture of the tire, the photo will be of the tire in one orientation.
Please make a video on why we need to combine quantum mechanics and general relatively and how will the combination look like ?
We need the two combined to describe situations like when large masses are on the quantum scale, such as black hole singularities and the Big Bang and stuff like that.
Why we need it is easier than what it would look like. I would say the most interesting reason why we need it is that it might help answer the question: How small was the universe at time t=0?
People like Hawking and Penrose used GR to predict that the universe must have started as a singularity, i.e. its volume would have been zero at time t=0 (though t=0 might have been an infinity long time ago because of time dilation).
But a QM+GR combination might say that there is some minimum volume and the "singularities" of both Black Holes and the entire universe can't be smaller than that volume. If that was true it might lead to an "everything from nothing" theory for the beginning of time (the idea that the universe started as a quantum fluctuation with near zero energy and that it still has near zero energy today).
I'm just a layman, and this comment is probably going to get ripped apart by someone who knows more than me. Suggest you wait for other comments before taking me seriously!
K Tell that is a pretty food explanation, although one thing I will say is that we don’t need QM+GR to know that the initial singularity had to have a finite volume. But it will help us find what that volume is, as you said
According to me this was probably his best video till date
I love the way you present the math in all of your videos! And you calling it high school math is a very accurate depiction! I love it thank you so much you make it incredibly easy to follow along
I graduated Mechanical Engineering in 2006, and swopped to management consulting in 2008...Damn, i miss this stuff!
Need to brush up the math, but i largely followed all the way. Tx
Thanks you for your professional effort! Quick question , have you heard about a state called "quantum entanglement with the earth's magnetic grids" ? , ( it comes from the theory of migrating birds capables of watching this lines to get oriented while traveling)
Hey, great video!
However, there's something I didn't quite understand. It seems like the separable state at 11:09 and the entangled state at 13:49 are exactly the same but only with different coefficients ?
For example, if you take the entangled state (13:49) and choose all coefficients equal to 1/2, you can factorize it in the exact same way as the separable state (11:14) by taking the coefficients equal to 1/sqrt(2).
Entanglement is a refinement of the wave function. Meaning spin up and spin down are separated in the wave
I love all of your videos, thank you for sharing. Could you please make one about quantum zeno effect thay would be great.
Amazing ! perfect for licence degree and now my master to keep having the big picture of all the stuff we are then adding when you go further in quantum physics
Parth you are just awesome... you explained to be clearly what entanglement is.. it is just a mathematical construct :)
You certainly made a great effort & it was bold of you to attempt to use maths as an aid to understanding. Unfortuneately the maths alone is challenging especially delivered at the speed at which you speak. I found it difficult to absorb each "step" whilst keeping track of what came next. The result is I am just as lacking in understanding as I was at the beginning of your talk . another problem: where the heck are the two "particles" (or waveforms). How do you isolate an electron to measure it's spin, how do you actually prove that " b" is the same before & after measurement of "a" at the instant of measurement? Finally why refer to system when you are addressing only 2 electrons & what about instantaneous action, light speed less or more?
Quantum soup/foam = Aether field.
e->~
Question: what is the difference between 1. saying particles are in a superposition of different states, and 2. just saying we have uncertainty about which state they're in, and expect them to be in each state with a given probability?
Ever make a simulation of two tiny bar magnets, aligned (in three dimensions) opposite, travelling in opposing directions? Make two thresholding detectors, on opposite sides, that attempt to measure the alignment (spin), on three axes, and add the appropriate amount of noise on each axis. Try adding Gaussian noise of different levels, and only real, and then complex.
I can‘t follow from 12:19 on: can you show the steps how you calculated this probability?
Thank you very much
Paul
Amazing video! Truly incredible content you are making here!
I’d recommend watching the double slit experiment to understand a little more about this; its crazy to think that what is most rudimentary to us, is the most perplexing
In classical thermodynamics, two (or more) particles in phase space (generally) move independently (statistically) of each other. This means that you can isolate any one of them and study its behavior without fear of compromising your analysis. In other words, the particles in phase space are "separable" - due to that statistical independence. However, that is not necessarily true in quantum mechanics - where observables often depend on each other (are correlated) in ways that you don't generally find in the phase spaces of classical physics.. In other words, particles in QM are often statistically dependent - a condition that physics calls entanglement. (That term is often reserved for cases of maximum entanglement, such as in the EPR experiment.) Students of classical physics usually find this to be weird, and don't really know what to make of it at first. But any high school math student who has studied basic conditional probability knows about this idea and can give you many examples of statistical dependence in real life. I'm wondering if it would take the scariness away if entanglement in QM were simply taught as statistical dependence from the start. Complex issues could be addressed afterwards. Whadaya think?
I have a question, what make or what is the cause of two electron (or the system if you want to generalize it) entangled?
Samaj nhi aya , par sunkar acha laga😊
Love from भारत🚩🕉️
Quantum Entanglement and Made Easy really makes about as much sense in a sentence as quantum entanglement
Question: Bell states at 8:00: why isn't it: 1/(sqrt2) |up_A> |down_B> + 1/(sqrt2) |down_A> |up_B> as well?
and also at 8:24?
I see that someone else mentioned a typo at 8:22. I actually saw the typo first at 8:01. I was following your explanation perfectly until I became incongruent with what you were saying and what I was seeing. The spin is written incorrectly on particle B in the second part of your equation. The arrow is red but you have drawn it as a down arrow.
This is a great video and you are pretty clear, the only thing i was thinking about is how fast you are speaking making it a bit hard to follow along, i was able to understand everything and u did a great job explaining, well done!
I was thnking that perhaps when you explain ket up and down it may perhaps be easier for someone watching to think of up and down as one being in relation to the circular spin as being wider or ket up; or the height direction of travel coming down in elevation in relation to observation as down ket or vice versa. I'm not sure if I misinterpreted your connotation please feel free to let me know. Other than that very informational and well put together
The video is more way easier than reading the book
Thank you
your voice is so soothing
You’ve genuinely made my life better
Hey, I am really very glad to be a part of your journey and learn something that I will too learn while pursuing majors in Astrophysics and Astronomy. But currently I am in IB board. My only request to you is that can you give me some tips about how and what do cambridge interviewers want to see in their candidates? Pls
question: ¿can you affect the quantum state of an entangled particles, if you somehow manipulate the spin of one of them, or, you just know in which state the other one will be in that particular time?...thanks...
If you manipulate their spin, you collapse the system
Two questions about entanglement:
1) you say that measurement on Particle A _changes_ the math for the probability distribution for Particle B. But how? What's the physical mechanism for this?
2) How long does the system stay entangled? If Particle A and Particle B are flying in opposite directions in a particle accelerator, and you measure Particle A's spin, you know _at that instant_ that the spin of Particle B is the opposite. But how long does it stay this way? What kinds of interaction, if any, would affect the entangled state of the system, and why? If Particle B interacts with a magnetic field that deflects its path according to its spin, does that count as a measurement? Will Particle B go back to being independent of Particle A thereafter?
1) it is a mystery. maybe ER = EPR
2) until something interacts with A or B.
You guys should check out E8 next. Is E8 the state of particles not being observed, meaning, E8 is the living energy holding ALL POSSIBILITIES before it is collapsed/observed?
@8:40, is the last statement correct? First of all, is the entangled state considered right for the explanation that follows after @8:40
Appreciate the excellent video. By doing the math, you are showing us theoretical physics, which then makes experimental physics more understandable.
PG your math is flawless and it's a good thing I knew the outcome before you got to it. But from a purely physics point of view, if the electrons are 10 light years apart does measuring spin on A still dictate spin on B and if so what is the time involved?
At 8:01 I think you made a mistake on the Bell State the spin for B should be up on the right hand side
That's what I think too. Admitting he made an error is not easy, it seems.
Fantastic explanation of complex topic with simple maths
This is not for.the mortals like me...Parth G you are the king..respect...
Very well done. But The issue I have with your explanation is that it’s not weird at all. It’s completely consistent with a classical view of the world. Ie: electron A had spin down and electron B had spin up. You just don’t know it. So it’s a 50/50 guess on electron A but once you know it, then you know electron B. It’s not weird at all and perfectly at peace with classical physics
No, that's not it. Merely not knowing a state does not give the correct results in quantum mechanics. One has to understand that there is no state before the measurement. This is no different from rolling dice, by the way. Moving dice also don't have a state (in the set of possible outcome states) before they come to rest.
Sounds like I've heard it while watching about Quantum Computing.. Can you make a video on that too please..!!
By the Way, love your videos and the way you explain things..!!
Just interested in the topic what if i measure particle A to be in the spin up state which means that certainly practical B is in the spin down 100% now what happens if i go an measure particle B even though i know it's state shouldn't that affect it's state as i measure it and now it may go into spin up causing particle A to switch it's spin state.
Another thing could you shed some light on quantum communication and if it is true or a youtube myth as i heard Chinese have achieved something like that.
Quick typo: at 10:20 d should be equal to beta * delta :) also thanks for this video. Currently doing my senior thesis on quantum entanglement of photons and i've been trying to wrap my head around entanglement and this gave a pretty clear mathematical explanation for entanglement. I think you should have covered though the more physical aspects. Like WHAT actually causes entanglement. What physical setups in the lab can you make that will create particles to be in these entangled states etc! new video idea? :P
I'm a bit of a duffer with this 'measuring spin' malarkey so I did a bit of Googling, and it seems the best analogy is cricket, (in fact a Googly). So very (very) basically it seems you fire your electron at a magnet and see what direction it heads off. This is analagous to a bowler delivering a ball with spin i.e. how the ball reacts to the batsman's stroke will tell you whether the bowler was spinning to oneside or the other. Owzat?
That's a pretty great analogy, especially since I love me some cricket :D
Good God, dude. Quantum physics and Schröedinger's Cat almost kind of delves into philosophy as well. ("If a tree falls in the woods and there's no one present to hear it, does it make a sound?") I just watched a video on the explanation of the Klein Bottle concept, and if that wasn't confusing enough, I then found myself watching a video about the Banach-Tarski Paradox, and that literally twisted my brain into a pretzel. Now I'm here, getting more confused.
Very cool! I always felt bad that there are only two kinds of material to understand things like these: the "popular science" kind, with well ... "silly" examples and trying to save people from ANY math very-very carefully. And the other kind: "ok, this is far more too much for me" (eg lectures in universities etc) . But nothing between :( I don't even mind complex numbers, calculus etc either, but still even with these knowledge on math I have (which I suppose is still more than the 'average' people have, but surely far-far more less what experts have), I find myself in the "middle group" where there is hard to find any suitable material. Sorry for my bad English, hopefully I could express my thoughts in an understandable way at least.
LGB Gábor Lénárt I agree with you, but my problem is (this is just a me problem, he is very good at explaining) I get distracted extremely easily, and I'm only in 9th grade, but I am a nerd lol, and I was curious about quantum entanglement and all that stuff, because I heard my dad (also a nerd) mention it once, so I thought I'd do some research, anywho, my point is, is that he is very good at explaining but his voice is so calm I get distracted easily and when I click back in I have to rewind the video to understand what's going on, also probably doesn't help that I'm only in 9th grade and even though I love math and I'm in geometry, I can't exactly understand calculus and all that yet, maybe I'll research that next!
Can u propose any formula unit for energy. Ex.(grígori{★});swift, (lámpsi{★});flash
Hi Parth, at 6:41, can you give a concrete example of how a classical state is separable in to the product of two independent terms? Just randomly I've thought about two classical spinning tops, but maybe you have a more instructive scenario in mind. In particular can you go in to why (mathematically) is it that when we can factor them in to separate terms, that the probability of one isn't affected by the other? Thanks.
Some other questions, where exactly in space are electrons A and B? I'm assuming they exist simultaneously in time. are they firing photons at each other a la QED? how soon after you measure the spin of A do you see the probability of measuring the spin of B deviate from its original? I'm assuming it won't be immediate correct? You have to wait for exactly the time that light takes to travel their distance apart? so you have this lag in time after measuring A wherein B retains its original probability until the information gets to it at the speed of light whereupon the probability changes. if this were true, then it's not weird anymore. A's just telling B (via a photon) "hey i got measured in such and such a state, now change your probability accordingly"
Mathematical explanations are very welcome. Thank you for this magnificent video.
Intelligent, handsome, and amazing elocution ... the last few seconds made me chuckle too 😆🤭
What if your detector is more like a fish bowl which detects that which "sinks" or that which "floats" relative to the water in the fishbowl itself? And quantum entanglement infallibly causes one unentangled particle to be "that which will inevitably sink" and the other to be "that which will inevitably float" in a fishbowl that has glass on on all sides and on the bottom but not at the top? But one doesn't always know if the fishbowl one is using is upright, and one doesn't even know that the sinking or floating itself is relative to the water in the fishbowl. Because both the glass of the fishbowl and the water of the fishbowl is still entirely unknown to us. I mean what if it all makes perfect, perfect sense, but it is something more like that? The "sinking" or "floating" is relative to the water in the fishbowl. It's not like a clock with hands that are clearly moving either clockwise or counterclockwise with respect to the clockface itself - whether that clock is filmed or not.
Excellent video and very well narrated. Great work.
Thanks for the informative info Mr Parth. I would like to ask, What do you think about the theoretical connection between consciousness and quantum entanglement?
Question: does the direction of the spin of let us say particle A changes every time the direction is measured? Thx
What is the latest scientific explanation regarding instant communication between pair of quantum entangled particles (March 7, 2021) ?
Good deep dive into entanglement; however does entanglement manifest with other properties than spin, e.g. charge, mass?
Whenever you have a symmetry you can have entanglement.
Hey there's a mistake at 10:19. The fourth restrictive equation should be: d= βδ. It's amazing how the internet didn't point it out yet!
The logic still stands, of course. This is more of a typo, or inconsistency, than an actual mistake.
Amazing video, nevertheless. Keep it up! :D
Loving the videos. Clear explanation and can (just about) follow the maths. One small request - could you make your figure "2" a little less 'loopy'? I keep thinking it's some sort of Greek letter rather than a square or square-root signifier.
I love these quantum mechanics videos. They’re really interesting and tie into my physical chem 2 class right now. Not trying to call you out Parth but I did find that you had a small math typo around 10:45 the last d=βγ should have said d=βδ I know it’s such a small correction but I wanted to bring it up. I really like how you bring up the math. You’ve really solidified my understanding on the notation and the wave function so thank you very much! Cheers
Dont be shocked.. Man you deserve this! :-)
Understood it finally . The best lecture . Feeling enlightened
THIS IS TOOOO GOOOD WAS SEARCHING FOR SOMETHING FOR SOOO LONG TYSM.