I love your videos so much. Thank you for doing them. I am a veterinary surgeon but I. Love. Physics. Please never stop making your brilliant videos. Looking Glass Universe for Nobel prize! Also spot on with your comment at 0.05s
"if no one can tell me what energy means " ..It is a very good question and what is needed. In my research - What we call mass is energy caught in a "standing wave / motion " as too with gravity and space time and the effect of dark energies and matter .. it is all energy . Ultimately , the universe and all its components can be broken down into energy . The energy dilutes into different forms (to maintain the fields) and is defined as the amount of disturbance of each field+ the energy to maintain the field . Each field is connected to other fields in specific ways , I suspect being evolved from an earlier , higher order field , giving us different forms ,identities such as particles , motion and gravity . What we call point particles are simply energy in our wave particle models but it appears that there are no real particles just relationships with fields which at some point resonate in quantum blocks and thus forming what we experience as stable particles . .. So I suspect it is all energy . So given energy is simply a disturbance can there be negative or out of phase energy on these fields ? It appears that dark matter and energy may give clues to these questions. When the big bang occurred how much energy was in the very dense state /form before expansion ? Why did the expansion conversion into time / space --gravity -- particles occur and could it have occurred differently (possibly in other kinds of universes ) ? The fundamental question of what is energy is a very very important one .. ty for the videos as always great work.
The Kaveman time and energy began together, if we froze all universe energy there will be no change in time. If we froze time no change can happen in energy.
As a Nuclear Energy Engineer who has only studied a small amount of quantum mechanics this interests me greatly... though QM in general does confuse me somewhat, it's not so much the probabilities like I imagine it is with a lot of people but how things even begin to interact with each other. xD Anyway enough blabbing about me, it's a great video :) the graphics and animations combined with your down to earth way of describing things really helps understand what seems like a really difficult concept! Please keep up the superb work. :)
Hi Erik, For six months last year I tried to teach concurrent causality to my CORE Group (Co-occurring drug addiction/mental illness), it's all equally important: Interdisciplinary studies. People want love and acceptance.
@@trustinjesus1119 I agree and I think causality is the most important thing to learn from QM. We receive in a general way, but not very general, what we send out, our realities are based upon our beliefs. When we are angry we find anger, Love finds love. It's funny I've been remembering lately what it was that really fueled my interest in the fundamental basis of the Universe. It was after I began my recovery from alchoholism that I first considered what I was thinking. I always thought, believed, whatever I was thinking was what I should be thinking about. I believed that my brain was my number one asset, I'm laughing as I remember. It turns out, I now believe, that my thoughts are automatically generated from how I relate current experiences to past experiences and I also believe that many thoughts are picked up from outside of ourselves based on our frequency/attitude. It seems to me that when I don't feel loved it's because I don't feel loving, I'm stuck in a different emotion under Fear but if I recognize this then I can make a conscious decision to think/imagine about things/times that I felt Love and then try to view my current "problem" through those eyes. Love is all inclusive, Fear is all exclusive even if it is for another. Love is the power of the Universe, Fear is the backdrop that allows us to see it. Love is the light that emerged from the darkness of loneliness. I think the Golden rule reflects the ultimate Truth of the Universe.
@@imaginaryuniverse632 Thank you for that, it's always fantastic to meet online a fellow traveler. Read here online a while back, "The Golden Rule, the sum of all knowledge & wisdom." I came across the Great Granddaughter of Lord Longford. About the smartest person in the world and the most gorgeous, you're really like her. You can find her on Google + and MeWe, Rachel Dupree. Stay blessed.
I watched this video in 2017, when I was in year 9 summer break, and I watched this video for some research I was thinking of doing on SE, as part of a project for year 10. I understood nothing, from the video (then), all I understood is just some bunch of physical explanations that you gave, and none of the mathematics made sense to me...linear combination, time evolution, I mean wth was that. 2 years later.... I picked up SE again for my year 12, mathematics research project and I learnt linear alegbra and now me watching this video seeing how linear combination relates to superposition, my eyes were filled with joy and excitement. When you understand the language.... the context simply follows through as smooth as water.
Perfect to the core.... This video ignited my mind to study quantum physics and I m today atleast in the state of not getting bored when discussion on this subject goes on.. Thanks a lot..
So I guessed right apparently, but I was sort of assuming it was gonna be something far more absurd, given quantum mechanics' track record. Like, maybe at each time interval it can pick up the momentum it would've had in other parts of the superposition or something... I don't know. QM is weird. I was pleasantly surprised that the logical reasonable conclusion was basically right. Also, glad you're back again!
I know right? When I finally understood what linearity meant, I realise it makes so much sense. But then it interacts with measurement sort of weird.. but more about that later I guess! How have you been going? You've been posting so regularly!
It's nice to know there's at least one island of coherence in the quantum world... Anyway, I've been great! Probably the most exciting news is that we had a chance to meet with Henry Reich from minutephysics at VidCon. He gave us a lot of great support and advice and he's even shared a couple of our videos, which is incredible. And on regular posting... Honestly I just know myself well enough to know that if I let myself start slipping I'm gonna completely lose track of it pretty quickly. I've seen it happen with too many of my projects, so I'm being really strict with my upload schedule this time around. Congrats and good luck on the PhD stuff, by the way! I've never been through the process myself but from what I hear it's grueling. I'm amazed you can find the time to put together videos at all!
Wow that's fantastic! How was VidCon? That's wonderful you went and Henry sounds like a top bloke! I think that's a great idea with the upload schedule. I've been thinking about doing that myself, cos otherwise.. well... you've seen how I upload. I don't really have the time for videos... I took 3 days off and the entire weekend to make this. It's not sustainable to try do it this way, but I don't know what I should do. I really love both. We'll see!
VidCon was great! If you get a chance, you should really check it out, it's an incredible opportunity to meet creators and get advice from some of the best in the business. I don't know where you're located, but they just expanded to do versions in Europe and Australia this year too. And yeah, Henry's amazing! On my schedule, the only reason it works is because I do have the time for all the work within my weekly schedule. Plus, the format I do is relatively quick to make compared to what I've heard from many other youtubers. It's still something like 10 hours per video, but at least it's not like 30-40. But maybe it'd be worth trying a longer-scale schedule, like monthly or something, with internal deadlines to keep things on track? I don't know, I suck at internal deadlines personally, but I hear from more organized people that they supposedly help.
"I hear from more organized people that they supposedly help." This made me laugh! Sorry this reply is late- it's so easy for notifications on RUclips to get lost. I heard about Vidcon expanding! I used to live in Aus so I was really upset that I'd miss that vidcon. But I'm in England now so I'm thinking of going to the Amsterdam one! You were in Florida (?) for it?
I won't pretend to fully understand, but after one viewing, at least I'm getting a grasp of what I'm not understanding. (I have NO maths, chemistry or physics; so, well done! I'm subscribing.)
When you measure, nature "chooses" one of the possibilities in the superposition. To me that suggests that it was doing that all along, we just didn't know it yet. So what we have is a mathematical model to describe imprecision. Measurement reduces the imprecision, so of course it changes our mathematical model. This imprecision is just in our knowledge, not in reality.
Ahaha! I don't think I'd have time to since I've got a tonne more QM videos to make... But would it help if I said it's basically conservation of energy? Or have you heard that before?
is there a difference between exp(-i Ht/hbar) and exp( i Ht/hbar)? because exp( i Ht/hbar) is a incorrect way, maybe related to the left or right propagation.
I'm wondering how entanglement comes into this? Now that I think about it I'm sure I understand every part of the continues process let alone how a time evolution would be applied. We always kinda talk about the endpoints: "let's say the particles are entangled", some stuff happens, "we measure and see the results", but seems like the middle parts are interesting here in how they conserve linearity and connect to the unentangled state.
Hey! Sorry for the late reply! Good to see you here though. AH! Lovely question. Ok, let's think about this entangled state: We have a photon that can be in state A or B and an electron that can be in state 0 or 1. If the photon starts in state A and meets the electron in state 0, it doesn't change. But if the electron is in state 1, say the photon now goes to state B. So what if the electron was in a superposition 0+1? Originally we are in a superposition 0A+1A (before the photon meets the electron). Then we go into state 0A+1B, an entangled state. Now this is where linearity comes into it. the 0A part and 1B part evolve independently of each other. Does this help?
Nice to see you too as well. So many videos seem like lots of effort so hope balancing the passions of physics and physics videos (also life, seems good sometimes) is going well ;D Ahhh, so we look at both particles as one system from the beginning and evolve each part accordingly! That makes a lot of sense. So when they say that the particles are inseparable when entangled it means that evolving them separately the whole time isn't the same as evolving the whole system, as it was before they interacted, because just looking at the photon, we can't explain the sudden change of state (also maybe wouldn't be linear?). In this light entanglement doesn't seem too complicated and mysterious, pretty much a normal evolution of the wave function, or maybe I'm missing something. P.S. Thought of a question while writing the comment, heh. Could the particles become unentangled by simple time evolution? Seems to me that it's impossible since entanglement follows an interaction and those are kinda bound by the arrow of time :p
Haha! I'm really struggling with the balance. Instead I just put my research (and life...) on hold for a week to work on these videos.. Yes indeed, if you ignored one part of an entangled system, the rest does look nonlinear! In fact, this fact is what lead people to propose that this explains measurement. Good question! Yes, they can become unentangled- in the previous example, say if the electron is in state 1, then it always flips the state of the photon (from A to B and vis versa). Now say they interacted twice. You'd be back to the same unentangled state! The reason this is rare though is because the particles would have to come back into Contact for this.
Oh, so the electron is always in state 1? But that doesn't seem like entanglement to me because if we measure the state of the electron at any point it won't have an influence the photon.
Oh no, that was bad wording on my part! I meant, suppose the electron has this sort of interaction: If it's in state 0, do nothing to the photon. If it's in state 1, flip the state of the photon. Ie, if the photon is in state A, make it B, or vise versa. If it's in a superposition, do a superposition of both. For example, if I had 0+1 originally and if the photon was B, I'd end up with: 0B+1A which is entangled. But if they were brought back together to interact again then the 0B part becomes 0B, and the 1A part becomes 1B, so overall you end up with 0B+1A=(1+2)B, which isn't entangled.
The time evolution part can be derived by separating variables and solving the time part of the equation. This equation will be a separable differential equation which will give the exponential seen in this video once solved.
Isn't linearity a pretty terrible assumption? Time doesn't play very nice with velocity or distance (which involves apparent velocity) unless you jump through a lot of hoops in your definition of time.
I wish everyone who studies math at a higher level was exposed to it, it’s such an elegant way of representing cons. of energy in a differential equation
'time evolution is a linear.' is this a quantum mechanical fact or a special case of schroedinger eq? or something else? definition of linear is "L of sums is the sum of L's" to me, this linearity came from the fact that we wanted only the special case, when PSI(x,t) = F(t) G(x), a function of time alone times a function of x alone. because this may be the only one that we can solve analyatically.
I understand your confusion about Energy, but from the opposing view. I just can't wrap my mind around Mass. The closer we look at things the more we realize they're made mostly of empty space. To me, this makes the wave feel very natural and the particle very unnatural.
The coefficients were wickedly confusing in this video - it looked like alpha and beta originally represented momentum (3:16) but later distinctly represented position and momentum (3:52) - took me a migraine to figure out that the first representation was just a generic example and didn't inform the later representation
Looking Glass Universe Sorry for taking so long to answer. About math, I started engineering classes this year and I finished calculus 1 this semester, I know the derivatives, integrals and all those things. I want to learn the basics, the theory of QM and then I can go deeper with it. (sorry for my grammar, english is not my first language)
How deep does it go? I'm starting introductory PDEs, real analysis. I'm done with one semester of linear algebra and differential equations (along with the whole calculus series done) but I'm not sure what else I should study before going on.
ozfizzy It sounds like you both have what you need. Linear algebra is good to have, but you can pick up what you need as you go. I would recommend Griffiths just for some basics and Sakurai for more understanding of QM. Some bits of Sakurai do need Linear algebra, but you can skip them if you want.
It may be said that the Schroedinger equation is almost pathologically linear, or just a bit too linear for its own good. It leads to awkward predictions which Schroedinger himself parodied in his description of a cat which could be killed by the outcome of a quantum mechanical event. So where does nonlinearity come from? In lead position as a possibility is Roger Penrose's idea about gravity, which is a known source of nonlinearity. At least for objects heavier than the Planck mass there is enough gravity around to make at least one graviton, and this is a destroyer of linearity. Following this, I advocate the triple interaction of matter, the electromagnetic field and alleged tachyonic Brownian motion as a source of nonlinearity, though I am not ruling out gravity as well. I have to come up with ideas to pursue my interest in computer simulations of quantum mechanical behaviour. With numerical methods available I don't have any issues with dealing with nonlinear behaviour and just need to specify exactly what sort of nonlinear behaviour I am expecting to see. I think that the interaction between an alpha particle and two molecules of ammonia is always going to be a unitarity-preserving interaction. However the interaction between an alpha particle and two molecules of nitrogen tri-iodide can involve a destruction of unitarity. The agent of this destruction is tachyonic Brownian motion on the Planck scale. In the first round TBM is orthogonal to the wave function so it is apparently useless as an idea, but when we add in the electromagnetic field it is a different story.
Dude, the linearity of the equation stems from statistical independence. It has absolutely NOTHING to do with physical linearity. Let me give you some more attention, though. Your basement is very cold. ;-)
i remember that in high school, i used to amaze people by deriving the Schrödinger equation using simply the de Broglie equation, expressing it in terms of 'k'(wave number) and putting it into the mass spring equation (had to explain how second order diff eqtns also worked to them) to derive the TISE. Not sure if this is rigorous in any way but since i came up with it, I'll always have a special place for it in my heart ;) Most fans of science cower away from it's math part but i get attracted to it and I'm obsessed with it. The only reason i don't hate math is physics XD
+Looking Glass Universe First ever I heard of dr Broglie was on your channel. His video got me real excited. Are you still as enamoured with Pilot-Wave as before?
No. They don't interfere with each other at all; they pass right through each other without affecting each other. If they did affect each other, then the interference pattern would be destroyed as soon as the waves first met. The interference is in the medium (water for water waves, etc.).
But in the double slit experiment you actually do get an interference patern. If I am right then the time dependent waves do interfere and the time independent waves do not interfere. So if you look at 1:17 the wave at the left side can interfere with other time dependent waves, where the wave at the right side can not. But I have to say that I don't know that much about quantum mechanics so maybe I am wrong :-)
Coco Yes, there is an interference pattern, but the waves do not interfere with each other. I am trying to point out that 'interfere', like most words, has multiple meanings, and that you should not confuse or conflate those meanings. Specifically, just because there is an interference pattern does not mean that the waves interfere with each other (in the sense of affecting each other).
Michael Sommers Ah, so the waves in the linear combination doesn't affect each other, but they do cause an interference pattern in the wavefunction, which is described by the linear combination of these waves.
Michael Sommers Well, I understand what you are trying to say. However, the message of this video was, that both wave functions do develop as if the other functions do not exist. Meaning: As if practically only one slit exists and therefore only one wave function. If that were the case, then there should be no interference pattern at all (in my understanding). However, there is, because both waves are necessary to calculate the probabilities of where the particle can land on the screen. They deeply affect each other. Don't you think so? You can't just imagine that the other wave function does not exist, because it would lead to (probably) a nearly gaussian distribution on the screen, wouldn't it?
I have a Crazy Idea, can energy and time relate to each other.? A particle with no change in energy can not travel in space no matter how much time we give it. A particle with infinite energy can not travel in space if we measure it at a single Time.
"A particle with no change in energy can not travel in space no matter how much time we give it." I don't see how that could be true. Say, for instance, I threw a ball in deep space. Since there is (practically) no friction in deep space, the ball will continue to fly (this is known from Newton's 1st Law of Motion; an object at rest or moving at a particular speed will remain at rest or moving at that speed will continue that way unless acted upon by an external force). Thus, even though Im not adding any new energy to the ball after its been thrown (i.e. its energy doesn't change) and it doesn't lose any energy (no friction in space), it is still travelling in space
She takes her sweet time to tell us that she doesn't know why the equation is linear. It's linear because the individual systems in the quantum mechanical ensemble that the equation describes are statistically independent. If they were not independent, then there would be a non-linear (bi-linear) term in the equation that would correct for the statistical correlations. People! Please stop teaching physics on the internet if you don't know enough physics!
Don't be sorry for giving us free insight into complicated things less frequently than a hypothetical other version of you with fewer other things to do would. Thank you so much for everything you have uploaded! =3
A Good Boy If a tree falls in a forest and no one is there to hear it, does it make a sound? You've probably heard that one before, and were inclined to say yes. But have you heard this variant: if an electron does what it does and there is no measurement, does it retain its properties of position and velocity and such? This really isn't all that different a question.
1) You'll need to be introduced to the wave function prior to the video. 2) Pause at 0:57 for reference. We're dealing with a particle and describing mathematically how it changes over time. 2a) *initial state* : This is just an initial position and initial velocity. 2b) *time evolver* : Pick a number of seconds (or hours w/e) to elapse. This little function of time will then manipulate the initial state, sending your particle to a new position with a new velocity. 2c) *final state* : That new position with that new velocity. 2d) intuition: Start with an apple held high up, call its initial position x=0 and its velocity v=0. Release the apple and start your watch. Pause everything (like really, pause the universe) after 3 seconds. Call this the new position and however fast it was going the new velocity. Newton found a working time evolver that could act (essentially multiply) on (0, 0) and spit out our new position and new velocity. Try watching the video again, it's an excellent video. Let me know if this helps.
I love your videos so much. Thank you for doing them. I am a veterinary surgeon but I. Love. Physics. Please never stop making your brilliant videos. Looking Glass Universe for Nobel prize! Also spot on with your comment at 0.05s
I should stop watching these before I go to bed! Schrodinger Dreams!
Where you are simultaneously dreaming and not dreaming.
Tom Percival uk
yep just about bed time for me
"if no one can tell me what energy means " ..It is a very good question and what is needed. In my research - What we call mass is energy caught in a "standing wave / motion " as too with gravity and space time and the effect of dark energies and matter .. it is all energy . Ultimately , the universe and all its components can be broken down into energy . The energy dilutes into different forms (to maintain the fields) and is defined as the amount of disturbance of each field+ the energy to maintain the field . Each field is connected to other fields in specific ways , I suspect being evolved from an earlier , higher order field , giving us different forms ,identities such as particles , motion and gravity . What we call point particles are simply energy in our wave particle models but it appears that there are no real particles just relationships with fields which at some point resonate in quantum blocks and thus forming what we experience as stable particles . .. So I suspect it is all energy . So given energy is simply a disturbance can there be negative or out of phase energy on these fields ? It appears that dark matter and energy may give clues to these questions. When the big bang occurred how much energy was in the very dense state /form before expansion ? Why did the expansion conversion into time / space --gravity -- particles occur and could it have occurred differently (possibly in other kinds of universes ) ? The fundamental question of what is energy is a very very important one .. ty for the videos as always great work.
The Kaveman time and energy began together, if we froze all universe energy there will be no change in time. If we froze time no change can happen in energy.
If observing quantum particles changes them, does atoms in our brains have anything to do with this?
As a Nuclear Energy Engineer who has only studied a small amount of quantum mechanics this interests me greatly... though QM in general does confuse me somewhat, it's not so much the probabilities like I imagine it is with a lot of people but how things even begin to interact with each other. xD
Anyway enough blabbing about me, it's a great video :) the graphics and animations combined with your down to earth way of describing things really helps understand what seems like a really difficult concept! Please keep up the superb work. :)
I'm really happy to hear that you keep up your interest in quantum mechanics! That's fantastic.
Thank you very much :)
Hey! I am going to college RN for Nuclear Engineering!! :D
This reminds me that I should get back to QM and read less neurology/psychology and related stuff. Thanks for the inspiration.
Ha! Yes, pulled you back in :P
Hi Erik, For six months last year I tried to teach concurrent causality to my CORE Group (Co-occurring drug addiction/mental illness), it's all equally important: Interdisciplinary studies. People want love and acceptance.
@@trustinjesus1119 I agree and I think causality is the most important thing to learn from QM. We receive in a general way, but not very general, what we send out, our realities are based upon our beliefs. When we are angry we find anger, Love finds love. It's funny I've been remembering lately what it was that really fueled my interest in the fundamental basis of the Universe. It was after I began my recovery from alchoholism that I first considered what I was thinking. I always thought, believed, whatever I was thinking was what I should be thinking about. I believed that my brain was my number one asset, I'm laughing as I remember. It turns out, I now believe, that my thoughts are automatically generated from how I relate current experiences to past experiences and I also believe that many thoughts are picked up from outside of ourselves based on our frequency/attitude. It seems to me that when I don't feel loved it's because I don't feel loving, I'm stuck in a different emotion under Fear but if I recognize this then I can make a conscious decision to think/imagine about things/times that I felt Love and then try to view my current "problem" through those eyes. Love is all inclusive, Fear is all exclusive even if it is for another. Love is the power of the Universe, Fear is the backdrop that allows us to see it. Love is the light that emerged from the darkness of loneliness. I think the Golden rule reflects the ultimate Truth of the Universe.
@@imaginaryuniverse632 Thank you for that, it's always fantastic to meet online a fellow traveler. Read here online a while back, "The Golden Rule, the sum of all knowledge & wisdom." I came across the Great Granddaughter of Lord Longford. About the smartest person in the world and the most gorgeous, you're really like her. You can find her on Google + and MeWe, Rachel Dupree. Stay blessed.
these videos are literally so good ima go show off to my science teacher now byeee
I watched this video in 2017, when I was in year 9 summer break, and I watched this video for some research I was thinking of doing on SE, as part of a project for year 10. I understood nothing, from the video (then), all I understood is just some bunch of physical explanations that you gave, and none of the mathematics made sense to me...linear combination, time evolution, I mean wth was that. 2 years later.... I picked up SE again for my year 12, mathematics research project and I learnt linear alegbra and now me watching this video seeing how linear combination relates to superposition, my eyes were filled with joy and excitement. When you understand the language.... the context simply follows through as smooth as water.
Perfect to the core.... This video ignited my mind to study quantum physics and I m today atleast in the state of not getting bored when discussion on this subject goes on.. Thanks a lot..
Wow. Double upload!
Awesome way to start the week.
I thought we could use some positives :)
So I guessed right apparently, but I was sort of assuming it was gonna be something far more absurd, given quantum mechanics' track record. Like, maybe at each time interval it can pick up the momentum it would've had in other parts of the superposition or something... I don't know. QM is weird. I was pleasantly surprised that the logical reasonable conclusion was basically right. Also, glad you're back again!
I know right? When I finally understood what linearity meant, I realise it makes so much sense. But then it interacts with measurement sort of weird.. but more about that later I guess!
How have you been going? You've been posting so regularly!
It's nice to know there's at least one island of coherence in the quantum world...
Anyway, I've been great! Probably the most exciting news is that we had a chance to meet with Henry Reich from minutephysics at VidCon. He gave us a lot of great support and advice and he's even shared a couple of our videos, which is incredible. And on regular posting... Honestly I just know myself well enough to know that if I let myself start slipping I'm gonna completely lose track of it pretty quickly. I've seen it happen with too many of my projects, so I'm being really strict with my upload schedule this time around.
Congrats and good luck on the PhD stuff, by the way! I've never been through the process myself but from what I hear it's grueling. I'm amazed you can find the time to put together videos at all!
Wow that's fantastic! How was VidCon? That's wonderful you went and Henry sounds like a top bloke!
I think that's a great idea with the upload schedule. I've been thinking about doing that myself, cos otherwise.. well... you've seen how I upload.
I don't really have the time for videos... I took 3 days off and the entire weekend to make this. It's not sustainable to try do it this way, but I don't know what I should do. I really love both. We'll see!
VidCon was great! If you get a chance, you should really check it out, it's an incredible opportunity to meet creators and get advice from some of the best in the business. I don't know where you're located, but they just expanded to do versions in Europe and Australia this year too. And yeah, Henry's amazing!
On my schedule, the only reason it works is because I do have the time for all the work within my weekly schedule. Plus, the format I do is relatively quick to make compared to what I've heard from many other youtubers. It's still something like 10 hours per video, but at least it's not like 30-40. But maybe it'd be worth trying a longer-scale schedule, like monthly or something, with internal deadlines to keep things on track? I don't know, I suck at internal deadlines personally, but I hear from more organized people that they supposedly help.
"I hear from more organized people that they supposedly help." This made me laugh!
Sorry this reply is late- it's so easy for notifications on RUclips to get lost.
I heard about Vidcon expanding! I used to live in Aus so I was really upset that I'd miss that vidcon. But I'm in England now so I'm thinking of going to the Amsterdam one! You were in Florida (?) for it?
Your videos are great. I'm a big fan! Wish you success.
Thank you so much :)
Thank god for youtube & smart people like this.
Best, cutest and most pleasantly voiced video on RUclips.
I won't pretend to fully understand, but after one viewing, at least I'm getting a grasp of what I'm not understanding. (I have NO maths, chemistry or physics; so, well done! I'm subscribing.)
Your videos are astounding! I'm truly grateful to have been able to stumble upon your channel. Thank you soooo much and I wish you luck!
Awww, thank you!!
When you measure, nature "chooses" one of the possibilities in the superposition. To me that suggests that it was doing that all along, we just didn't know it yet. So what we have is a mathematical model to describe imprecision. Measurement reduces the imprecision, so of course it changes our mathematical model. This imprecision is just in our knowledge, not in reality.
Which software or methods you use to make your videos
@2:24 I’m hooked. Lead the way!
When the components of the superpositions interact with each other, does that mean that it's not linearly independent anymore?
It'd be nice if you explain the Bernoulli equation ❤️😍
Ahaha! I don't think I'd have time to since I've got a tonne more QM videos to make... But would it help if I said it's basically conservation of energy? Or have you heard that before?
Check out The Efficient Engineer's video on it. He deals a lot with Fluid Mechanics and Mechanical Engineering.
is there a difference between exp(-i Ht/hbar) and exp( i Ht/hbar)?
because exp( i Ht/hbar) is a incorrect way, maybe related to the left or right propagation.
The quantum eraser experiment shows time to not be linear. It(the quantum eraser) shows retrocausation.
smokey 336 No it doesn't. It just looks like it does, but you still cannot change the past.
Johan 't Hart tell that to the photons that changed their path. 😉😀
I think I made a video on that 100 years ago... not sure if it's any good, but I explain why there isn't retrocausality in QM
As u said schrodinger equation plays same role as newtons 2nd law is there a thing called net external superposition ?
Bet these videos take ages to make, you're awesome, keep it up
SO SO SO LONG. Thank you for appreciating it :D
I'm wondering how entanglement comes into this? Now that I think about it I'm sure I understand every part of the continues process let alone how a time evolution would be applied. We always kinda talk about the endpoints: "let's say the particles are entangled", some stuff happens, "we measure and see the results", but seems like the middle parts are interesting here in how they conserve linearity and connect to the unentangled state.
Hey! Sorry for the late reply! Good to see you here though.
AH! Lovely question. Ok, let's think about this entangled state: We have a photon that can be in state A or B and an electron that can be in state 0 or 1. If the photon starts in state A and meets the electron in state 0, it doesn't change. But if the electron is in state 1, say the photon now goes to state B. So what if the electron was in a superposition 0+1? Originally we are in a superposition 0A+1A (before the photon meets the electron). Then we go into state 0A+1B, an entangled state. Now this is where linearity comes into it. the 0A part and 1B part evolve independently of each other.
Does this help?
Nice to see you too as well. So many videos seem like lots of effort so hope balancing the passions of physics and physics videos (also life, seems good sometimes) is going well ;D
Ahhh, so we look at both particles as one system from the beginning and evolve each part accordingly! That makes a lot of sense. So when they say that the particles are inseparable when entangled it means that evolving them separately the whole time isn't the same as evolving the whole system, as it was before they interacted, because just looking at the photon, we can't explain the sudden change of state (also maybe wouldn't be linear?). In this light entanglement doesn't seem too complicated and mysterious, pretty much a normal evolution of the wave function, or maybe I'm missing something.
P.S. Thought of a question while writing the comment, heh. Could the particles become unentangled by simple time evolution? Seems to me that it's impossible since entanglement follows an interaction and those are kinda bound by the arrow of time :p
Haha! I'm really struggling with the balance. Instead I just put my research (and life...) on hold for a week to work on these videos..
Yes indeed, if you ignored one part of an entangled system, the rest does look nonlinear! In fact, this fact is what lead people to propose that this explains measurement.
Good question! Yes, they can become unentangled- in the previous example, say if the electron is in state 1, then it always flips the state of the photon (from A to B and vis versa). Now say they interacted twice. You'd be back to the same unentangled state! The reason this is rare though is because the particles would have to come back into Contact for this.
Oh, so the electron is always in state 1? But that doesn't seem like entanglement to me because if we measure the state of the electron at any point it won't have an influence the photon.
Oh no, that was bad wording on my part! I meant, suppose the electron has this sort of interaction:
If it's in state 0, do nothing to the photon.
If it's in state 1, flip the state of the photon. Ie, if the photon is in state A, make it B, or vise versa.
If it's in a superposition, do a superposition of both. For example, if I had 0+1 originally and if the photon was B, I'd end up with: 0B+1A which is entangled. But if they were brought back together to interact again then the 0B part becomes 0B, and the 1A part becomes 1B, so overall you end up with 0B+1A=(1+2)B, which isn't entangled.
You appearance is more uncertain than the uncertainty principal
HA! Thank you.
I have never seen that form of Schrödinger's Equation! Is there anywhere I can find more information on it
There's a nice bit about it in Sakurai (modern QM). But otherwise look up the time evolution operator :)
The time evolution part can be derived by separating variables and solving the time part of the equation. This equation will be a separable differential equation which will give the exponential seen in this video once solved.
Isn't linearity a pretty terrible assumption? Time doesn't play very nice with velocity or distance (which involves apparent velocity) unless you jump through a lot of hoops in your definition of time.
I hoped this video would explain "superposition of states"
Finally you're back!
I know... I'm ashamed of myself :P
Can someone please explain what she means when she says "superposition"? I know the english term but I do not understand it in this context.
I wish everyone who studies math at a higher level was exposed to it, it’s such an elegant way of representing cons. of energy in a differential equation
I really enjoy your videos. Thank you for the great work :)
When did you start with QM?
Hello
Can you please let me know
Is the video made on white board?
It's not! But my most recent one is :)
Did you do it on paper?
'time evolution is a linear.' is this a quantum mechanical fact or a special case of schroedinger eq? or something else?
definition of linear is "L of sums is the sum of L's"
to me, this linearity came from the fact that we wanted only the special case, when PSI(x,t) = F(t) G(x), a function of time alone times a function of x alone. because this may be the only one that we can solve analyatically.
I understand your confusion about Energy, but from the opposing view. I just can't wrap my mind around Mass. The closer we look at things the more we realize they're made mostly of empty space. To me, this makes the wave feel very natural and the particle very unnatural.
Yeah, I guess it's all a bit confusing when you examine it closely!
Thanks for your Homework session :)
The coefficients were wickedly confusing in this video - it looked like alpha and beta originally represented momentum (3:16) but later distinctly represented position and momentum (3:52) - took me a migraine to figure out that the first representation was just a generic example and didn't inform the later representation
You are incredibly intelligent
This video is so great! Thank you :)
Could you tell us more about the measurement problem?
Yes absolutely!! I am very excited to get to that actually!
0:04 its that time of the decade again
Your video helped a lot in my understanding. Thanks. The apple makes me feel safe I think.
Hey how are you doing? The apple makes me feel safe too :P Thank you!
Thank you very much!
I want to learn QM but I don't know where I can get things to study it. Can you help me?
Yes! What's your math background? And what level of depth do you want?
Looking Glass Universe Sorry for taking so long to answer. About math, I started engineering classes this year and I finished calculus 1 this semester, I know the derivatives, integrals and all those things. I want to learn the basics, the theory of QM and then I can go deeper with it. (sorry for my grammar, english is not my first language)
How deep does it go? I'm starting introductory PDEs, real analysis. I'm done with one semester of linear algebra and differential equations (along with the whole calculus series done) but I'm not sure what else I should study before going on.
ozfizzy It sounds like you both have what you need. Linear algebra is good to have, but you can pick up what you need as you go. I would recommend Griffiths just for some basics and Sakurai for more understanding of QM. Some bits of Sakurai do need Linear algebra, but you can skip them if you want.
Looking Glass Universe Nice, thanks for your help. On this vacation, I will apply all my time on QM.
how do you solve the second question?
It may be said that the Schroedinger equation is almost pathologically linear, or just a bit too linear for its own good. It leads to awkward predictions which Schroedinger himself parodied in his description of a cat which could be killed by the outcome of a quantum mechanical event. So where does nonlinearity come from?
In lead position as a possibility is Roger Penrose's idea about gravity, which is a known source of nonlinearity. At least for objects heavier than the Planck mass there is enough gravity around to make at least one graviton, and this is a destroyer of linearity. Following this, I advocate the triple interaction of matter, the electromagnetic field and alleged tachyonic Brownian motion as a source of nonlinearity, though I am not ruling out gravity as well. I have to come up with ideas to pursue my interest in computer simulations of quantum mechanical behaviour. With numerical methods available I don't have any issues with dealing with nonlinear behaviour and just need to specify exactly what sort of nonlinear behaviour I am expecting to see.
I think that the interaction between an alpha particle and two molecules of ammonia is always going to be a unitarity-preserving interaction. However the interaction between an alpha particle and two molecules of nitrogen tri-iodide can involve a destruction of unitarity. The agent of this destruction is tachyonic Brownian motion on the Planck scale. In the first round TBM is orthogonal to the wave function so it is apparently useless as an idea, but when we add in the electromagnetic field it is a different story.
Dude, the linearity of the equation stems from statistical independence. It has absolutely NOTHING to do with physical linearity. Let me give you some more attention, though. Your basement is very cold. ;-)
@@lepidoptera9337 In view of your use of obscene language in other comments, this comment will be ignored.
@@david_porthouse Whatever language I use is irrelevant to the validity of my statements. You need to get a grip.
i remember that in high school, i used to amaze people by deriving the Schrödinger equation using simply the de Broglie equation, expressing it in terms of 'k'(wave number) and putting it into the mass spring equation (had to explain how second order diff eqtns also worked to them) to derive the TISE.
Not sure if this is rigorous in any way but since i came up with it, I'll always have a special place for it in my heart ;)
Most fans of science cower away from it's math part but i get attracted to it and I'm obsessed with it. The only reason i don't hate math is physics XD
Can u provide me a link (or, if there is no link, an actual post) showing how to derive the Schrodinger equation from the de Broglie equation?
Saeed Baig
I once uploaded a ppt to slideshare but it's been a while 😅
I'll let you know
The uniform tablet has the
Equation
Thank you.
You're very welcome!
did you see the Veretasium episode on pilot wave?
I read the script for him and we discussed it. Yes, I'm bragging. But seriously, Derek is so kind and generous.
+Looking Glass Universe First ever I heard of dr Broglie was on your channel.
His video got me real excited. Are you still as enamoured with Pilot-Wave as before?
I'm still really interested in it! But I'm starting to see the issue with how it relates to GR. Still- I think it's really important to discuss.
So much fun!
so its measuring time in relation to potential perception of placement...? weird stuff mate
Welcome back...
:D
Isn't the double slit experiment the perfect example that they *ARE* aware of each other? They interfere with each other if they are not measured.
No. They don't interfere with each other at all; they pass right through each other without affecting each other. If they did affect each other, then the interference pattern would be destroyed as soon as the waves first met. The interference is in the medium (water for water waves, etc.).
But in the double slit experiment you actually do get an interference patern. If I am right then the time dependent waves do interfere and the time independent waves do not interfere. So if you look at 1:17 the wave at the left side can interfere with other time dependent waves, where the wave at the right side can not. But I have to say that I don't know that much about quantum mechanics so maybe I am wrong :-)
Coco
Yes, there is an interference pattern, but the waves do not interfere with each other. I am trying to point out that 'interfere', like most words, has multiple meanings, and that you should not confuse or conflate those meanings. Specifically, just because there is an interference pattern does not mean that the waves interfere with each other (in the sense of affecting each other).
Michael Sommers Ah, so the waves in the linear combination doesn't affect each other, but they do cause an interference pattern in the wavefunction, which is described by the linear combination of these waves.
Michael Sommers Well, I understand what you are trying to say. However, the message of this video was, that both wave functions do develop as if the other functions do not exist. Meaning: As if practically only one slit exists and therefore only one wave function. If that were the case, then there should be no interference pattern at all (in my understanding). However, there is, because both waves are necessary to calculate the probabilities of where the particle can land on the screen. They deeply affect each other. Don't you think so? You can't just imagine that the other wave function does not exist, because it would lead to (probably) a nearly gaussian distribution on the screen, wouldn't it?
"Baba yaga." *creepy ambient whispers*
More videos pls
I have a Crazy Idea, can energy and time relate to each other.? A particle with no change in energy can not travel in space no matter how much time we give it. A particle with infinite energy can not travel in space if we measure it at a single Time.
"A particle with no change in energy can not travel in space no matter how much time we give it."
I don't see how that could be true.
Say, for instance, I threw a ball in deep space. Since there is (practically) no friction in deep space, the ball will continue to fly (this is known from Newton's 1st Law of Motion; an object at rest or moving at a particular speed will remain at rest or moving at that speed will continue that way unless acted upon by an external force).
Thus, even though Im not adding any new energy to the ball after its been thrown (i.e. its energy doesn't change) and it doesn't lose any energy (no friction in space), it is still travelling in space
Out of the whole video the most confusing part of this video was how an apple was in a superposition of saying "ladida" and not saying "ladida"
She takes her sweet time to tell us that she doesn't know why the equation is linear. It's linear because the individual systems in the quantum mechanical ensemble that the equation describes are statistically independent. If they were not independent, then there would be a non-linear (bi-linear) term in the equation that would correct for the statistical correlations.
People! Please stop teaching physics on the internet if you don't know enough physics!
Madam.....
I need answers to some questions
Hi. Aaaaaaand.... you introduce the notion of a wave function out of a thin air :D :D D: :D :D Cheers :3
Nah, this is part of a series! ruclips.net/p/PLg-OiIIbfPj1ZYpBuheqR0RFLusldquqf
Looking Glass Universe Hi. Oh, I see! Put the series link in description! Keep it up!!!!!!!! Cheers
I should! Sorry :P
Looking Glass Universe
Hey you're back :)
Yes! I'm sorry I keep disappearing :'(
But you keep coming back, too! I'll take quality over quantity and I'm sure many of your other viewers do too
Don't be sorry for giving us free insight into complicated things less frequently than a hypothetical other version of you with fewer other things to do would. Thank you so much for everything you have uploaded! =3
your videos are awesome :)
Thank you :D
I lost at 2:31 can someone kindly enough explain it to me please🙏
Why do you insist on superpositions when there is ultimately only one real number in the measurement?
Holobrine that's only when you measure it
A Good Boy If a tree falls in a forest and no one is there to hear it, does it make a sound? You've probably heard that one before, and were inclined to say yes. But have you heard this variant: if an electron does what it does and there is no measurement, does it retain its properties of position and velocity and such? This really isn't all that different a question.
Seems like you tried hard to control your laugh while recording.
Btw nice vdo.
👍
Where are my pilot-wave people at?
c:
Made simple?
Bad. Did not discuss S eq but went into other things
Sorry, you lost me at "| >". Why would you use that obtuse notation, and not explain it, for something "made simple"?
ഒന്നും മനസിലായില്ല ❗️❗️😄
I enjoyed learning about the quantum world so much that I wrote a fiction novel called Quantum Bob:
www.amazon.com/dp/B01MA5I4OT
That's fantastic :D Good work!
If you really like it, I suggest you to learn real physics instead of those "metaphysics"
Damn i graduated 4 years ago why does maths and physics stil turns me on
Any class 9 Indian students here 😅
Holy God, the comments section of this video is like the table next to the garbage can back in High School.
Didn't make any sense.
1) You'll need to be introduced to the wave function prior to the video.
2) Pause at 0:57 for reference. We're dealing with a particle and describing mathematically how it changes over time.
2a) *initial state* : This is just an initial position and initial velocity.
2b) *time evolver* : Pick a number of seconds (or hours w/e) to elapse. This little function of time will then manipulate the initial state, sending your particle to a new position with a new velocity.
2c) *final state* : That new position with that new velocity.
2d) intuition: Start with an apple held high up, call its initial position x=0 and its velocity v=0. Release the apple and start your watch. Pause everything (like really, pause the universe) after 3 seconds. Call this the new position and however fast it was going the new velocity. Newton found a working time evolver that could act (essentially multiply) on (0, 0) and spit out our new position and new velocity.
Try watching the video again, it's an excellent video. Let me know if this helps.
haa I didn't understood ,even though my iq is 135
Bad ripoff of MinutePhysics.
Couldn't agree more!