Lecture 3: The Wave Function

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MIT OpenCourseWare

MIT OpenCourseWare

10 жыл бұрын

MIT 8.04 Quantum Physics I, Spring 2013
View the complete course: ocw.mit.edu/8-04S13
Instructor: Allan Adams
In this lecture, Prof. Adams introduces wave functions as the fundamental quantity in describing quantum systems. Basic properties of wavefunctions are covered. Uncertainty and superposition are reiterated in the language of wavefunctions.
License: Creative Commons BY-NC-SA
More information at ocw.mit.edu/terms
More courses at ocw.mit.edu

Пікірлер: 768
@anthonybrakus5280
@anthonybrakus5280 4 ай бұрын
Big up to MIT for offering these OCW lectures. I have learned Calculus, Classic Physics, Linear and Abstract Algebra, and Quantum Physics and I didn't even have to pay late library book fees. 👍🏾 Thanks MIT, for being conscientious and gracious! 🎉💥🪅🎇🤸🏽‍♂️🕺🏿💃🏼🎆🎊🙏🏾
@priscillacharlot8188
@priscillacharlot8188 4 ай бұрын
Amazing !
@mahinvasavada2992
@mahinvasavada2992 3 ай бұрын
A class that ends with an applause. That is how all classes should be.
@mishvanzant
@mishvanzant Ай бұрын
I love watching him lecture! He's so excited to show everyone "here's everything we've figured out so far, come help us figure out more!"
@AlexTrusk91
@AlexTrusk91 8 жыл бұрын
i think this kind of high quality content makes the world a better place for seekers.
@stauffap
@stauffap 7 жыл бұрын
First you need to find it though. If you haven't figured out the value of science and scientific institutions yet you might end up "learning" "quantum mechanics" from "what the bleep" or Deepak Chopra, instead of learning it from MIT. The truth seems to be, that for many people it's hard to get on the right track without some type of guidance. They'll get sidetracked by conspiracy theories, fraudulent claims and various pseudo-sciences. And that may be understandable, since we haven't evolved to perceive or understand reality accurately. Furthermore our success (as a species) seems to be largely based on an accumulation of knowledge i.e. learning from other people and building upon that. So it's understandable that people can not see the value of the scientific method or scientific institutions. Scientific thinking isn't something, that has come naturally to us. It's not something that people just come up with themselves. So for most people it requires a person, who introduces them to science, leads them into the right direction, makes them ask the right questions etc. If you lack that you might not be very likely to end up here.
@jacobvandijk6525
@jacobvandijk6525 4 жыл бұрын
You obviously missed this: 53:13. Think about it.
@AlexTrusk91
@AlexTrusk91 3 жыл бұрын
@@stauffap 4 years after my comment I'm not really any further with this lecture series. But started multiple other lectures on different topics like Human Behavioural Biology from Stanford. I'm also thinking of finally trythe problem sets, but I guess I maybe would be hit by a wall then. So I probably gonna try it anyways.
@stauffap
@stauffap 3 жыл бұрын
@@AlexTrusk91 You should definately try problem sets. You never fully understand physics if you can't do the math (you might just have the illusion that you understand it). I meet people all the time, who think that they understand a certain topic in physics, because they have developped a more or less accurate intuition, but they fail when confronted with having to calculate something and often fail as well with their intution. The ultimate test to whether or not you understand a certain topic in physics is always doing problem sets that involve math (and preferably understanding the derivations).
@Abhi-mt4dn
@Abhi-mt4dn 3 жыл бұрын
@@stauffap And can you help me abt problem sets like from where and how i should start to solve them like pre requisites and everything , i would really appreciate it
@willcatch
@willcatch 3 жыл бұрын
Whoever filmed this did a great job. Panning and framing. Spot on.
@scowell
@scowell 2 жыл бұрын
Would have been nice to see his laptop screen as direct instead of through the projector... still, a wonderful job as you said.
@Darthvanger
@Darthvanger 2 жыл бұрын
@@scowell wow wow, we're not talking about THAT much advanced technology here.
@ashlynparrott7130
@ashlynparrott7130 Жыл бұрын
Fell asleep watching a ghost hunting video, woke up and this was on my TV thanks to autoplay. I didn't even feel groggy waking up because I was so alarmed by how good of a teacher this guy is. I'm more of a molecular biology person but I think I'll continue watching these!
@whelan4545
@whelan4545 8 жыл бұрын
love this guys passion
@r58302
@r58302 4 ай бұрын
An absolutely perfect lecturer
@aussiedog5221
@aussiedog5221 Жыл бұрын
Six years ago, after I retired, I went through these lectures and the second semester with Dr. Zwiebach. Simply outstanding. I am back for a bit of review. Thanks Dr. Adams and Dr. Zwiebach.
@josephhall5681
@josephhall5681 11 ай бұрын
;Touch and hold a clip to pin it. Unpinned clips will be deleted after 1 hour.😢hh O❤ ❤❤❤
@annehinrichs22
@annehinrichs22 3 жыл бұрын
Oh my goood, how can this be so much better than at my university?? The whole structure and order in which this is taught are just so clear!!
@Ne012
@Ne012 3 жыл бұрын
MIT is a very prestigious university. Very low acceptance rate because they take the cream of the crop in student's. If they do that for their students you can only imagine how they select their professors.
@patinho5589
@patinho5589 3 жыл бұрын
@@Ne012 yeah but : I went to Cambridge.. very selective on students.. terrible lecturing and teaching in general in the subject I studied which was economics.
@justindamirgian5977
@justindamirgian5977 Жыл бұрын
They put him in camera for a reason. I imagine they have good and bad professors also
@lukelively4732
@lukelively4732 6 жыл бұрын
I wish I took school more seriously as a kid so I could go to this school. This professor is amazing and I love his passion.
@bogdantokarski2798
@bogdantokarski2798 2 жыл бұрын
So do I.
@softwareminimalist
@softwareminimalist 2 жыл бұрын
Yeah, you can learn now.
@Darthvanger
@Darthvanger 2 жыл бұрын
I've seen a few other lectures from the other teachers and I didn't like them as much as these ones. I think this is a gem, and we should appreciate we can watch the best of the best for free. It's not limited to the 100 of the smartest hardworking kids anymore and it's awesome!
@mississippijohnfahey7175
@mississippijohnfahey7175 2 жыл бұрын
This is better though. All the learning with none of the crippling loans, egotistical teachers, or crushing deadlines! Einstein figured out SR while working as a patent clerk (though he did have a decent undergrad education)
@RaidenShogun1145
@RaidenShogun1145 Жыл бұрын
You can always work harder now.
@weechinghwa8440
@weechinghwa8440 4 жыл бұрын
Teaching in MIT is like a superstar singing on stage. Everyone claps for the good performance.. Holy moly
@Tikorous
@Tikorous 3 жыл бұрын
People get excited when I stop speaking too, probably for a different reason
@josephflynn9560
@josephflynn9560 6 жыл бұрын
I love this so much. Trying to decide on Electrical Engineering or Physics. Did a long stint with the Marines and now using G.I. bill at a wonderful community college for freshman year. I have not been in school for a long time lol. MIT is still a dream and it feels SO good to be able to just listen. Watching these videos let's me know that I AM smart enough to sit here, even if life may not allow it right now. To be able to touch my mind to something I have wanted since I was a child is a gift and I wanted to say thank you to MIT and Prof Adams for doing this. One day, even if I am retired, I will take a degree at MIT , so stay awesome!!!!
@yorichixX
@yorichixX 2 жыл бұрын
i did bachelors in electrical engineering now i am going to switch to masters in physics!
@maxwellpineiro
@maxwellpineiro 11 ай бұрын
How is it all going ?
@2Worlds_and_InBetween
@2Worlds_and_InBetween 6 ай бұрын
I was the kid at school who said I wanted to be a Physicist when I grow up... (... grow up.... something I might get round to one day ;-) and got told, "there's no point we already know everything" by the _teacher_ I went on to do mechanical and computer engineering with Physics /QM as the stuff I do for fun. but its more just a love of learning stuff do what you enjoy
@jorgecastro5834
@jorgecastro5834 2 жыл бұрын
I love the way the teacher brings those abstract postulates to live. In so doing he makes quantum mechanics crystal clear. He does it so well that one can not help feeling that there can't be a better way to put it (and I have thought about it several times). This work is invaluable! Just brilliant.
@poopoostinky1064
@poopoostinky1064 3 жыл бұрын
I wish I could get into MIT. These lectures have me hooked in a way I’ve never been hooked before. I’m trying my hardest to understand and I think I’m getting there
@michellewest6929
@michellewest6929 3 жыл бұрын
You’ll make it there! I wish you all the best! You deserve to be there.
@olekbeluga314
@olekbeluga314 2 жыл бұрын
I don't think that matters here. What he's saying doesn't apply to MIT.
@FreshBeatles
@FreshBeatles 5 жыл бұрын
Great lecture. Can't wait for the free pizza at 5!
@Andrewtmcb
@Andrewtmcb 5 жыл бұрын
LMAO!!! xD
@NovaWarrior77
@NovaWarrior77 4 жыл бұрын
Dang. I missed it by 3 years...
@putzak
@putzak 3 жыл бұрын
The pizza is an imaginary component probably
@josef596
@josef596 2 жыл бұрын
@@NovaWarrior77 - I missed it by 4.
@bzboii
@bzboii 2 жыл бұрын
Wait it said free pizza at 5, not at 120…?
@paulboro5278
@paulboro5278 3 жыл бұрын
You are my favorite teacher. I watched these lectures for the first time about four years ago. Because of these lectures, I have a very good understanding of basic quantum mechanics. I just completed my post-graduation from IIT Guwahati recently. These lectures were very helpful during the last four years.
@IndrajitSen_TxState
@IndrajitSen_TxState 2 жыл бұрын
Truth be told, your IIT professors must learn pedagogy from these professors.
@paulboro5278
@paulboro5278 2 жыл бұрын
@itchy armpits I majored in physics.
@theawantikamishra
@theawantikamishra Жыл бұрын
Engineering Physics?
@MadScientist267
@MadScientist267 6 ай бұрын
I'm never going to directly use any of this but that hasn't kept me from trying to just understand it for my own curiosity. Never know when something will appear at the edges of something else and come in handy. This dude has come the closest so far to getting me there 🤣
@ams1749
@ams1749 2 жыл бұрын
I have my class 11 English language exam tomorrow, and here I am at 10 pm learning about wave functions,(this lecture is amazing and addictive though).
@nc-broadcast
@nc-broadcast 5 жыл бұрын
Absolutely in awe at what Dr. Adams can do with just whiteboard and chalk. In another life perhaps I'd be in that classroom, or better yet in another world, following the Many Worlds interpretation of this beautiful subject.
@marcostala
@marcostala 8 жыл бұрын
I studied Telecommunications engineering. And now I realized that I was not that far to be studying formulas to be applied to Quantum mechanics. I mean, all these mathematical functions of waves are almost the same. Of course it helps that I was reading and watching lots of videos about the "double slit experiment" and such, to know what are you talking about. But I never expected I would understand so much about Mathematics of the Quantum Mechanics. It is all about Waves.... This concept of uncertainty (given by waves) is driving me crazy (in a good way) This is the first Quantum Mechanics Lesson that I can "somehow" follow! Thank You!! Amazing Professor!!!
@victorfergn
@victorfergn 6 жыл бұрын
Physicists always try to use the same math, it was the kind of math especially designed for them.
@ginnyjollykidd
@ginnyjollykidd 5 жыл бұрын
The concepts are easier to understand when you know the language, like psi and B*B
@olekbeluga314
@olekbeluga314 2 жыл бұрын
These lectures were very helpful in turning my room into a physics laboratory as I attempt to re-create the Hitachi experiment using homebrewed CRTs. It was not, however, all that helpful in subsiding my extreme existential terror. I'm going to be seeing things that go through neither both holes, nor one of the holes, nor none of the holes in my nightmares now. Thanks a lot, guys.
@schmetterling4477
@schmetterling4477 2 жыл бұрын
Here, kid, have a cookie. :-)
@jesse2450
@jesse2450 2 жыл бұрын
I wish there was a KZfaq channel with instructors who are obviously super interested in the topic they are teaching regardless of the subject
@nickb4302
@nickb4302 7 жыл бұрын
It's amazing how accurate certain aspects of quantum mechanics can be calculated. They're basically just determining odds and they still get the right answer based on experiment. Weird.
@dadestor
@dadestor 3 жыл бұрын
Let me sound smart and say that is empirical knowledge 😌
@dooterino
@dooterino 8 жыл бұрын
9:32 When he realizes how long we've been working on quantum theory he looks like a father proud of his son's progress. If I weren't dedicated to applying physics in the more esoteric corners of computer engineering that moment alone would have pushed me into pure physics.
@brandonklein1
@brandonklein1 6 жыл бұрын
High school senior here, I'm actually fascinated with that EXACT field!
@mohammadkhalili3247
@mohammadkhalili3247 Жыл бұрын
your lecture is captivating, dear Allan! especially about superposition concept, i always just notice to math rule, but it has interesting physical meaning.
@sandipchakraborty184
@sandipchakraborty184 4 жыл бұрын
MIT is the only great source of quality education which is accessible to all.Thanks really i am greatly thankful to mit for giving the world a opportunity to become capable.
@santiagoarce5672
@santiagoarce5672 3 жыл бұрын
Man, I love this lecturer! He's so enthusiastic!
@Mohamedkassr
@Mohamedkassr 9 жыл бұрын
Prof.John Admis, I couldn't express my thanks for your awesome lecture. Wave fns / Fourier series and transform notes. Also you're ready to any questions. Thanks :) for all things
@Ztingjammer
@Ztingjammer 4 жыл бұрын
Came to his first lecture thanks to 3B1B, and here I am intending to go through as much as I can from Allan Adams ❣
@learning4951
@learning4951 2 жыл бұрын
In which video did he refer to allan?
@christofchaos
@christofchaos 5 жыл бұрын
@1:00:12 Localized particles have less localized momentum because the momenta of the composite waves are cancelling and interfering with each other. Likewise, applying energy to the particles packet of waves causes the particle to move, albeit with some uncertain probability as to the direction/speed of movement. This movement reduces the coherence of the particle, and we become less certain as to where it is located. What is being described is the movement of a particle through space, but only if the particle is a secondary reaction created by the interfering waves. Try to imagine the amount of waves (EM or otherwise) passing through us at any second. Now imagine these waves all form the standing particles that make us up. They are highly localized, and their individual momenta are uncertain. But when we apply a macro-force to the system, the momenta of all these particles becomes more certain, and they become less coherent in the static, localized positions they were in before. As the waves re-settle, they regroup, becoming coherent again with all the particles being reformed in a different place and once again, localized.
@Ne012
@Ne012 3 жыл бұрын
So thankful now of all the hard work I put into Fourier series and transforms and convolution that I can do these problem sets.
@tanvec
@tanvec 3 жыл бұрын
11:54 "Happy electrons" this guy is the Bob Ross of Quantum
@occhams1
@occhams1 7 жыл бұрын
I liked the StrongBad reference at 40:02 :) very subtle.
@edwardhayes1314
@edwardhayes1314 9 ай бұрын
The teacher and course lecture is awesome, very professional. excellent job
@MrMachi95
@MrMachi95 8 жыл бұрын
play ride of the Valkyrie when he asks for it, fits beautifully.
@nkeny1307
@nkeny1307 8 жыл бұрын
Watching these for fun. What a great professor!
@alexbillingham9593
@alexbillingham9593 7 жыл бұрын
same. its completely irrelevant to my school work but its just so damn interesting
@financewithsom485
@financewithsom485 6 жыл бұрын
Watching before 1 day of exams
@ismaelmelendez2710
@ismaelmelendez2710 4 жыл бұрын
SOMMAN EDU did you pass? Are you now a quantum theorist
@roku6194
@roku6194 2 жыл бұрын
@@financewithsom485 how did they go
@financewithsom485
@financewithsom485 2 жыл бұрын
@@roku6194i am a software engineer now studied mechanical engineering that time this comment is 4 years back 😂
@JohnVKaravitis
@JohnVKaravitis 5 жыл бұрын
58:54 VERY slick teachable moment here. THIS shows that this guy knows his shit and gives a damn that the students can see how things connect.
@zevikan8638
@zevikan8638 8 жыл бұрын
proved to be a major help in understanding the uncertainty principle : )
@kehaarable
@kehaarable 2 жыл бұрын
but how can you be sure?
@isaacmchugh6384
@isaacmchugh6384 5 жыл бұрын
This is the best TV show I've ever watched
@shijiechai9780
@shijiechai9780 8 жыл бұрын
Thank you very much for such excellent demonstration!!
@user-vv9yd1jp6q
@user-vv9yd1jp6q 11 ай бұрын
This is the one subject that still holds my attention.
@MrsBreeFree
@MrsBreeFree 7 жыл бұрын
Really cool lecture! I am from germany and go to University here, but your Profs seems really excited to teach and he makes fun jokes, its so easy to listen to him :)
@AJ5
@AJ5 3 жыл бұрын
I study at a Fachhochschule and yet I'm here watching these videos instead
@tanyadeeedmondson-wl7vi
@tanyadeeedmondson-wl7vi 4 ай бұрын
Thank you all so very much.
@maurocruz1824
@maurocruz1824 7 жыл бұрын
{X,P}= complete knowledge. Postulate 1: Wave function. Postulate 2: The wave function is a kind of 'generator function' of the probability that the particle actually be in certain x position. 26:30 Postulate 3: The states of the system are closed under linear combinations. Mathematica package. Fourier transform.
@artistpw
@artistpw 10 ай бұрын
Really love the content available on youtube.
@cbk41
@cbk41 9 жыл бұрын
Dr. Benedict Gross from Harvard stated in his Abstract Algebra lectures that you could never know enough linear algebra. Seems like the big point of the decomposition of wave functions into their linear combinations and superposition helps to illustrate both of their points.
@jaje69
@jaje69 2 жыл бұрын
I paused the video and started Ride of the Valkyries for the III postulate. Definitely added something to it.
@drzecelectric4302
@drzecelectric4302 4 жыл бұрын
Just what I need right now. Thank you!!
@0xaugustus
@0xaugustus 7 жыл бұрын
Are the recitation videos available? Thanks
@CHistrue
@CHistrue 9 жыл бұрын
Some favorites: "Schrodinger's Cat, Wanted Dead And Alive" "Heisenberg Might Have Slept Here." And my own awful addition: "Mathematicians consider it risque when infinities cancel. Physicists are more tolerant. They do not mind if it happens during energy jumps as long as it is discrete!" Thumb this up if it is not completely horrible. My humor might have to be renormalized!
@nachik09
@nachik09 9 жыл бұрын
This is awesome!
@CHistrue
@CHistrue 9 жыл бұрын
Nachiketa Ramesh Here is one not directly related to quantum physics, but reasonably funny none the less: "Entropy---It may not be the first bad law to keep a good man down but it is definitely the Second!"
@nachik09
@nachik09 9 жыл бұрын
CHistrue I didn't get this one. Second law of thermodynamics right? What man? How did it keep him down X(
@CHistrue
@CHistrue 9 жыл бұрын
Nachiketa Ramesh Well, you know, it ruins the perfect closed system. No perpetual motion machines. I guess if I have to explain it, the humor misses. Should I try again?
@nachik09
@nachik09 9 жыл бұрын
CHistrue Yes please!!
@nanoprehistoric
@nanoprehistoric 5 жыл бұрын
17:30 the moment i realized that he wrote his own name as a wave function! Hahaha
@nemethma
@nemethma 11 ай бұрын
20 years ago I had these same types of classes. No clue what was going on at the time. Now I get it. Maybe can go get that A I was looking for!
@back81192
@back81192 4 жыл бұрын
This course is just fantastic!!!
@Dwaynefries1
@Dwaynefries1 6 жыл бұрын
I was taking a calculus class and trying to figure a way to handle an integral of an infinite slope. I felt I had an explaination, and it turns out that my description was correct, though I did not know a technical definition, which turned out to be a kronical delta. To that end, the first stupid function descriped, it appears to me that it can be simply remapped through a manifold, more clearly straightening the function in away that multiple values are not taken. In that way, it reverts back to what I would call a kronical delta again, and there is once again a 1 to 1 function created, removing the stupidity. This is my opinion though. Anyone have thoughts or am I way off base?
@timothylovecock4332
@timothylovecock4332 8 жыл бұрын
The lecturer is fantastic.
@xazau-
@xazau- 2 ай бұрын
This guy is good! A lot better than any of the physics classes I took!
@IliaToli
@IliaToli 7 жыл бұрын
You guys are too awesome. I finally start understanding quantum mechanics. I am a mathematician, chemist and aerospace engineer, but not a physicist. It is particularly hard to explain quantum mechanics to me, but you are outstanding. Will write my PhD thesis in quantum chemistry, which means that I can't have enough of quantum mechanics.
@JimBob1937
@JimBob1937 6 жыл бұрын
Ken, that's an odd statement. Obviously, in context, he is stating that a level of comprehension has personally been reached by him with enough confidence to state he is 'understanding' the current level of knowledge we hold. Obviously he isn't stating he's reached a mastery level of understanding that entirely exceeds that of all humankind to date... that would be a large assertion indeed.
@ginnyjollykidd
@ginnyjollykidd 5 жыл бұрын
Quantum chemistry sounds awesome!
@NazriB
@NazriB 2 жыл бұрын
Lies again? WTF WOF
@lukelyon5917
@lukelyon5917 9 жыл бұрын
I'm a little confused around 28 minutes or so (dealing with the probability when psi(x) is a simple sinusoid). If |psi(x)|^2 equals some constant value for all x, then the improper integral from negative infinity to infinity can't possibly be equal to 1, right? If the limit as x->infinity of the probability function doesn't equal zero, then the integral must diverge. Does this just mean that Psi(x) can't possibly be of the form e^ikx?
@therealrictuar
@therealrictuar 7 жыл бұрын
52:40 dont the cross terms have different signs because the norm squared is complex conjugate*function? so we end up with e^(i(b-a))+e^(i(a-b)), which is actually the sum of cosins? so we get cos(b-a)+cos(a-b)? so one might expect something that looks like big small small repeating?
@starwarsjk99
@starwarsjk99 8 жыл бұрын
Given two possible configs of a quantum system, corresponding to two distinct wave functions ψ1(χ) and ψ2(x), the system can also be in a superposition of ψ1(χ) and ψ2(x). Ψ(χ)=αψ1(χ)+βψ2(x). If ψ1(χ) and ψ2(x) are e^ikx waves they can satisfy the schrodinger equation assuming a constant potential everywhere. But the resulting wave function Ψ(χ) wouldn't appear to satisfy the schrodinger equation. Does the superposition wavefunction have to follow the shrodinger equation or is it only the wave forms that are collapsed that have this property.
@adiagramonsnorkel
@adiagramonsnorkel 7 жыл бұрын
If ψ1(χ) and ψ2(x) both satisfy the Schrodinger equation. Which means that they are a solution to Schrodinger equation then their linear superposition is also a solution to Schrodinger equation. It is a property of differential equations.
@jandejongh
@jandejongh 2 жыл бұрын
Thanks Prof. Adams; absolutely brilliant intro into QM (not that I would know, I'm EE :-)). But just in case viewers need a perhaps equally well-taught lecture series on Fourier: There's an excellent treatment on this topic by Brad Osgood from Stanford available on YT. Highly recommendend!
@jwomqha
@jwomqha 7 жыл бұрын
What a great teacher
@edgarvardanyan2581
@edgarvardanyan2581 8 жыл бұрын
How possibly can I know more about 1 over sqrt(2pi) coeficient in Fourier equation?
@tempestvideos9834
@tempestvideos9834 9 ай бұрын
In his mind the epic depth of what he is teaching is the objective gospel. Flight of the Valkyries... Passionate dude.
@daveconerly1450
@daveconerly1450 3 жыл бұрын
This was one of my professors at MIT a while back. The class was exremely hard. He was a genius of course. . He talked pretty fast when teaching. . If for any reason you got behind , it was almost impossible to catch up.
@karabomothupi9759
@karabomothupi9759 3 жыл бұрын
Did you graduate?
@developercm
@developercm 8 жыл бұрын
Does Quantum Field Theory replace traditional Quantum Mechanics (e.g the methods therein) or does it just extend Quantum Mechanics? In other words, if you only had Quantum Field Theory, would it be sufficient to derive the same theoretical outcomes (e.g. predictions) that traditional Quantum Mechanics does, but using different methodologies?
@vinitchauhan973
@vinitchauhan973 5 жыл бұрын
To some extent it does replace classical quantum theory for example the wave particle duality is thought as well, a duality, in terms of a classical quantum theory while a quantum field theory treats it as local excitations in the respective fields, it extends quantum theory by providing a relationship between quantum theory and special relativity such that some quantum systems can be described completely in the sense that they can also be described in terms of special relativity.
@sameertomar5099
@sameertomar5099 3 жыл бұрын
One of the best Professors
@WowUrFcknHxC
@WowUrFcknHxC 6 ай бұрын
I've never had a college professor that is so good at teaching they get applause at the end of a lecture...
@arrabalimaz622
@arrabalimaz622 4 жыл бұрын
I understand here in sir here till the 2019 and I had seen there 1 million subscription now it's 2.5 approx I'm quite happy
@xrisku
@xrisku 6 жыл бұрын
great lecture series. thanks!
@frede1905
@frede1905 4 жыл бұрын
There's something I don't understand: I've learned that quantum wave functions can be described as a "ket vector" in an abstract vector space called Hilbert space. The position wave function, for example, used to express the probability of finding the particle at a point, can be described as a vector in an infinite dimensional Hilbert space. But we also have the wave function used to describe spin ("spinor"), and this wave function exists in a 2-dimensional Hilbert space. So my question is, what is the relationship between these two different wave functions? I've also heard that the wave function contains everything that there is to know about the particle, but I'm like, "which wave function 😭😧?" I would be really thankful if someone could help!
@paulryan94
@paulryan94 3 жыл бұрын
The spatial wave function in the Schrodinger picture, psi, is not the same as a ket vector, | psi >. psi is the projection of |psi> onto the position basis: psi = < x | psi > | psi > holds all the information of the general quantum state and can be projected onto different basis's. That's why it's so useful. For example the momentum wave function can be arrived at by projecting | psi > onto the momentum basis: psi = < p | psi > But if you had just psi, the 'wave function', you still have a full picture of the quantum state because you can go to the ket | psi > from it.
@frede1905
@frede1905 3 жыл бұрын
@@paulryan94 Thank you for your answer, but the question I asked above was answered on physics stack exchange right after I made my comment. So it's no longer something that confuses me :). Here's the link to the question and answer on the site, if you're interested: physics.stackexchange.com/questions/560132/wave-function-as-a-ket-vector-in-a-hilbert-space
@ogradus
@ogradus 3 жыл бұрын
1:17:00 I think the Geiger counter messed with the camera and microphone for a second based off the angle of that plate while you were reading it. Cool!
@Peace-ey5hn
@Peace-ey5hn 6 жыл бұрын
IMO, a "quantum vibrational wave/ripple" is set off at the point where the electron is fired. A quantum aerodynamics of sorts. The wave precedes the electron. It is this wave that is responsible for the distribution pattern as each electron, even though fired 1 at a time, is carried on it. It explains the "probability" of where each would land. When you try to measure the electron, it is not the "conscious" act of doing it that causes the electrons to behave as particles, but it's because you break the wave. Thus, as there is no wave for the electron to ride on, it will come through the slit as an independent particle.
@jagergaming2281
@jagergaming2281 5 жыл бұрын
when the wavefunction is your signature
@user-vv9yd1jp6q
@user-vv9yd1jp6q 11 ай бұрын
41:33 both sides of the equation are superposition in gravitational contraction
@LeonardGimson-zf7ry
@LeonardGimson-zf7ry 7 ай бұрын
Very great professor, very interesting way to teach
@yanemailg
@yanemailg 8 жыл бұрын
58'56.. Good question : Why prof says probability between x1 and x2... I'd say either x1 or x2 and that would reduce the incertainty. Why would it be wrong ?
@SuperMnunez
@SuperMnunez 8 жыл бұрын
I think he says is the average between the two, which this is what the expectation vale is.
@accidentalelectrolytic216
@accidentalelectrolytic216 Жыл бұрын
how would these equations change if we wanted to incorporate three dimensions of time instead of just one dimension (aka point in time, now.)?
@biohazard5702
@biohazard5702 Жыл бұрын
At 9:30 he just realized how crazy this science is at what he is teaching and the enormous exponential Research and knowledge we gain and how fast we went from X to y in such a small space of time
@biohazard5702
@biohazard5702 Жыл бұрын
I think he has add or ADHD cause I am the same when I look and notice what's Ian saying " I'am like dude whaooooo are your even realizing what you're saying"
@BandhanGoyal
@BandhanGoyal 5 жыл бұрын
At 59:53 - there need not be a wavelength for a momentum (unless we are presuming it a wave beforehand). E.g. A cyclist riding a bike has a momentum but no wavelength. Please clarify.
@selvakumar3k
@selvakumar3k 2 жыл бұрын
In 22.54 minutes, How can we generalize the dimension of psi is [sqrt(L)]^-1. What about if the particle moves in three dimension, where three quantities like dxdydz will appear in the integral. So in that case the dimension of psi becomes [L]^-(3/2). Please clarify if i am wrong.
@Jamony1
@Jamony1 7 жыл бұрын
Wow, a passionate physics lecturer :o
@hasanshirazi9535
@hasanshirazi9535 5 жыл бұрын
When the Prof. rubs the chalk off the black board, doesn't it go into his open coffee bottle?
@grandpaobvious
@grandpaobvious 4 жыл бұрын
Chalk is nontoxic when consumed in moderation.
@hasanshirazi9535
@hasanshirazi9535 4 жыл бұрын
@@grandpaobvious Yes, may be Calcium in it is even beneficial for the bones!
@shivam1996able
@shivam1996able 4 жыл бұрын
if youre paying attention...the chalk is already in the coffee bottle, and also not in the coffee bottle
@abderrahimbenmoussa4359
@abderrahimbenmoussa4359 3 жыл бұрын
There is.probably a function to assess that
@mohammadbinmahbub9160
@mohammadbinmahbub9160 4 жыл бұрын
41:14 Does discreteness (quantum-ness) exist anymore as a consequence of superposition?
@cademosley4886
@cademosley4886 Жыл бұрын
Now that KZfaq provides an overlay graph of the most watched parts of the videos when you hover the mouse over the timeline, I find it pleasing that that graph has two peaks, a smaller peak at 6:25 and a larger peak at 36:37. Remind you of anything? =)
@Baked_Noodle
@Baked_Noodle Жыл бұрын
This lecture is love.
@gattac900
@gattac900 7 жыл бұрын
Please make more videos with Allen Adams! other Physics classes?
@seeker313
@seeker313 7 жыл бұрын
What does it mean that the wave associated with a particle is the interference of many different waves? I mean what is the significance of each wave? I think it means that the particle's wave can have any wavelength among those many waves with different probabilities. So it's nothing but the Uncertainty Principle.
@user-km2tp5lo7e
@user-km2tp5lo7e 2 ай бұрын
Thanks for the insight
@ankeunruh7364
@ankeunruh7364 3 жыл бұрын
What is the underlying idea of transforming units by that 2pi-thing (like ω and ħ instead of h and ν)? Does it come from something like "thinking in terms of the complex plane" or from classical mechanics (like harmonic oscillators) - or has it some special meaning in QM?
@ankeunruh7364
@ankeunruh7364 3 жыл бұрын
@Dirk Knight Thank you - I think I got it. Since we can use the idea of the unit circle (and so sin and cos) for almost all oscillations in nature, it's useful to get rid of 2π in many of the formula...
@deveshverma9125
@deveshverma9125 4 жыл бұрын
The professor is amazing
@ericgrey4744
@ericgrey4744 2 жыл бұрын
Can someone explain why the norm squared of e^(ia) is 1?
@krishsrivastava3123
@krishsrivastava3123 3 жыл бұрын
hey if anyone has solved the problem set then kindly tell me why they have neglected columb's constant in their calculation of columbian force in question 1 because of that all my answers are coming different.
@corcovado1047
@corcovado1047 3 жыл бұрын
Why isn't the imaginary wave function drawn as a vector like we do in the electronics for current and voltage?
@emanuellandeholm5657
@emanuellandeholm5657 3 жыл бұрын
Love this series! One question, why is the professor writing integrals like Int (the infinitesimal) (the function)?
@jackgude3969
@jackgude3969 9 ай бұрын
1:17:08 - I love how happy he is as he says "It's got uranium in it!"
@RohanRajadhyaksha
@RohanRajadhyaksha 4 жыл бұрын
I am a confused about what he does around 31:00. As far as I understand, de Broglie's hypothesis that relates E and P to λ applies to physical waves. Are we then justified in applying that to the "abstract" wave function Ψ? Can someone help to explain why that is okay?
@ankeunruh7364
@ankeunruh7364 3 жыл бұрын
I take this step as a try: calculate with it, make predictions, and if they can be confirmed by observation or experiment, use it. As said in the Copenhagen Interpretation of QM, we can't avoid classical terms.
@Stylax32
@Stylax32 8 жыл бұрын
great lecture,,,
@adosar7261
@adosar7261 5 жыл бұрын
so can we say that it hasnt postion but a location where we will find it ?
@WonderersWondering
@WonderersWondering Жыл бұрын
amazing lecture
@sricharanbattu4502
@sricharanbattu4502 6 жыл бұрын
At 49:36,psi 1 squared is probability, isn't it? I mean alpha squared psi squared should be alpha squared probability. Iam confused. Please help.
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