The Language of Quantum Physics is Strange | PHYSICS EXPLAINED
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- Опубликовано: 7 июл 2024
- This is how Quantum Physicists communicate their ideas
Hi guys, so I wanted to make a video explaining some of the notation used by quantum physicists to describe their ideas. There is a reason why things are written the way they are, and it is interesting to see these reasons, in my opinion.
In the video we will see bra and ket notation, originally invented by Paul Dirac, which is used describe the wave function of a quantum state - essentially all the mathematical information we know about our quantum system, which is the part of the universe we happen to be studying.
Bra-ket notation uses a ket to represent a quantum state, with the ket being distinct from, but mathematically related to, the bra. The ket representing a quantum state can also be written as a superposition of possible results to a measurement. For example if our system is an electron, and we measure its spin, then the electron's state BEFORE we measure its spin can be written as a superposition of the possible results of a spin measurement - spin up and spin down. This superposition is mathematically written by adding states together. The numbers in front of each state are directly related to the probability of us finding our system in that state, upon measuring.
AFTER we make a measurement, the system collapses into ONE of the possible measurement results - we never actually find it to be in a superposition. There are other subtle effects that tell us that a quantum system can exist in a superposition of states, but upon measurement the system probabilistically collapses into one of the possible measurement result states. This is called the Collapse of the Wave Function.
We also see that quantum states can be very nicely described by vectors in an abstract mathematical space known as a Hilbert Space. The quantum states display certain mathematical behaviours that are very similar to those displayed by vectors in real space. Additionally, we can use the Hilbert Space to represent the state of any quantum system, even one in a superposition of states, with one single vector. Pretty neat right?
Now guys I know that there's a lot of background noise in this video - I'm really sorry about this, but after all I live with my family and they have every right to speak in their own homes lol. Next time I'll try to find a time when there isn't as much going on in the background, to make a video.
Let me know what kind of videos you want to see from me next!
Follow me on Instagram @parthvlogs - I'm going to be posting a couple of IGTV vlogs on there towards the end of the year. Until the next video, see you soon!
Please don’t change anything regarding your content and style. Your explanations, for a truly complex topic, are easily digested for this simpleton. Much love & respect! 😁🙏🏼
That illustration of schrodigers cat at 3:00 is the best thing I've seen all day.
Wow, I actually understood everything!
Looks like my Linear Algebra university lessons weren't useless after all. (Matrixes are everywhere)...
You sir are an excellent teacher.
@@ParthGChannel yes I agree with Diver, you're quite good at teaching!
It helps me a lot,things which I studying made more clear....
One more thing if you shear your story how you get admission in UK,it will be helps Indian to get their, for a better opportunity for knowledge
I am not trying to be pedantic here, but Matrices are a "Representation" of a quantum state or operators. Furthermore, matrices can ONLY be used if we are dealing with a finite number of states e.g. the spin of the electron. If we have a system with Infinite states e.g. hydrogen atom or scattering of particle or even operators like the position operator, we cannot use the matrix representation, in such cases what we need is an abstract representation, which is the Bra-Ket notation. To push this to an extreme limit, no one really knows the dimensionality of the Hilbert space. We ASSUME it to be infinite (postulate of QM)
@@ParthGChannel please make a discord server wher we can discuss about physics
Completely agree. So glad I found this channel
seriously loved this! i now get the wave equation notation like never before!! I'm an electrical engineer by degree and I work for NASA JPL and I've studied quantum mechanics a bit for particle accelerator and plasma physics work that I do but the math for QM hadn't quite clicked for me until you just explained it in the 2d space similar to the unit circle for complex math! GREAT video! and i hadn't known about the ket and bra and bra-ket lol thanks! i really like all of your videos! please keep it up!
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This has been _extremely_ eye-opening. Thank you
Within the fist 2 seconds of the video beginning, I start smiling, and feel as if you have already conveyed the key point! transfer of knowledge at its beautiful best!
This is just awesome Parth! I was waiting ever since for this series to elaborately show up. I'm a freshman in physics and I'm already working in quantum computation this winter as a part of my internship. To be back from work and see this is really blissful and refreshing.
My dear Parth you are a blessing. Because you explain every little thing from the very basics. Not many are doing that with such clarity and eloquence as you do. Thanks
Parth, I know you made this some time ago sir, but you are excellent at explaining difficult subjects to curious novices! Thank you so much for taking the time to do so!
u just explain it as simple as possible which is amazing
keep it up my man
Thank you very, very much for what you're doing! This has been really helpful, and I hope you feel like your efforts are recognized and appreciated!
Excellent... I studied this 30 years ago as an undergrad and it brings it all back. Very clear and I agreed with the another persons comment that more of this stuff needs to be explained and taught to 16 to 18 year olds; this video helps make it accessible.
Your explanations are so clear and concise!
Please do more of these. They are extremely helpful for someone as myself who hasn't studied physics at university level (yet). I would personally love to see some more/a continuation on Schrödinger's equation, but of course also just whatever you feel motivated to make.
YOU'RE AWESOME! you keep reminding me the true zeal and reason due to which I chose science! I effing love it man!
Thanks Parth For all your Awesome and Knowledgeable Videos !
U really Explain in a Very Smooth way !
Love your content
Just the kind of level I am looking for. I'm a retired 69 year old just discovering quantum theory and love everyone of your videos. The comments section is also very entertaining, and at times controversial. But what would physics be without some challenges? Keep up the good work sir, you are an inspiration.
Absolutely amazing explanations!!! Just fabulous!
Teaching like yours are making all the difference🙌🙏🏻
Love your videos man!!
@4:29 Hey Parth your videos are great, and I really enjoy watching them. Just a small thing -- I psi > is not a wavefunction. Its a ket. Once you take an inner product of I psi > with either position < x I or momentum < p I basis it becomes a wavefunction. Further you cannot do these inner products with spin because it's an internal degree of freedom and has nothing to do with space or momentum, hence we only have the abstract notation of Kets no wavefunctions for spins.
It's probably the best lesson for me to understand quatum superposition! Thank you!
Good stuff as always! keep up the good work mate 👍🏻
This is the best channel that can explain the foundamental ideas of physics so well. Highly recommended.
Been studying qm for long..yet missed this simple representation in abstract space..now everything makes more sense. Thanks a lot , u are an awesome teacher and i can sense feynman technique in ur vids.
great explanation...loved it!!!
I love this series please continue it
:)
I think this is the best quantum mechanics video I've seen so far, keep up the good work :D
Absolutely fantastic material! Thank you!
This is just awesome! You are a brilliant teacher!
Really enjoy your videos, thanks! Keep them coming. Looking forward to the GR videos.
Why are your videos sooo good?? Great work..... You're the best Parth
Wow, I've never made a RUclips comment. I'm a fan after one video! Thank you for making understandable videos on a complex subject. Great work! Now I'll never get any sleep.....
This is such a great resource for me as a high school student. Please keep making these!
Great video. For such an abstract concept you made it tangible, especially with the illustrations. Keep it up!
I love this content!!
So good ! Well explained with little hand waving arguments. Keep it up
Thanks for adding a bit more to my understanding of this exciting field! Excellent work!!
Damn im studying applied mathematics and this video was truely brilliant , the way you described shrodinger equation was awsome keep up the good work
Wish u luck
I also love these video's and find them helpful ! Keep up the great work !
Brilliant and cogent primer for this topic! Your explanatory style is very crisp and precise. Thank you! You definitely inspired me to learn more in regards to this subject.
I'll be starting the Open University this Fall (BSc Physics). I foresee using your great content to buttress my formal studies.
Thanks again from New York!
Thanks Parth, u r sooooooo kind.
Excellent - thanks for your work, I really enjoyed it!!
You have the gift to make things stick in my head. Pleeease keep on explaining quantum physics. I am enjoing your videos so much!
Good
Excellent video. Very interesting and informative, and a must see for all beginning science students. We look forward to any sequel videos on this topic.
Sir you are far better than most of our nonsense proffesors who themselves dont know what are they teaching.
Thank you for all of these conceptuall stuff you are delivering ❤
Your way to teach is great!
you should start playlist and regular post related to same topic on particular day in a week.
I hope u keep your dedication to teach us how physics works ✌️
i love your way of teaching, its great and easy to understand.
"How to do higher studies in quantum physics and what is scope" please make a video about this 🙏
You have to do a PhD in physics and then decide to do some kind of research involving quantum mechanics
Essentially what Bob Ross said haha!
I am 38 now .... I still want to learn QM in depth. I realise that you could help me in suggesting the correct references in addition to watching your videos... you explain everything very nicely..excellent job...keep it up.
This is great, especially great because I'm not taking physics 2 at uni and I just watch these videos for fun. Some of your other videos really helped me out for my physics 1 course though.
Excellent! This is what is needed for us amateurs! Thank you....
You are just amazing, please keep showing these exceptional videos, I'm learning a lot from you.Thanks
Brilliant. It’s enjoyable leaning from you!
You are a great teacher, gifted
You are really great at demystifying ! 👍
Great work!
You are one of those no-nonsense youtuber :) Thanks for making this.
A great video, Parth! Thank you, I understood a lot more after watching. Hi from Australia! Look forward to viewing more :-)
Great , thank you parth , waiting for. Next one 😊
You have such a uniquely-natural and logical way of explaining these very supernatural, illogical phenomena. Keep it up. 👍
You just... can’t stop being helpful😊
I wish I could thank you, but it’s really much more than just 2 words with no real measure
Great video! Really enjoying the series.
Would love to see a series on Quantum Field Theory.
Great video, honestly the spirituality thing and Quantum mechanics are so realted, that's why 2 things can exist at the same time and at the same place.
Very well presented! Thanks!
Really great video!
Hey Parth! I can’t thank you enough for this... For once quantum physics started making sense to me .. I used to love physics until it all seemed getting so abstract and complicated , I lost it completely .. I have been a housewife for past 6 years and you make me think of getting back to studying physics. I watch your physics videos in my free time..
I have a request for you.. Is it possible to make a video on evolution of physics ? How different fields of physics came into being?
Excellent explanation.
You posted a video 3 days ago. 16000 views. Nice to see how far you've come
Amazing easy to understand, thanks for knowledge.
Really superbly clear. You explain it like you have really thought how to get a person over each hurdle (indeed, a person like your younger self )
Dude . You are amazing ! I have been learning QM for the last couple of months and I came to a situation where I have loads of doubts which are not quite reasonable to ask my professor. but I must say your videos are helping me alot . What are the important mathematical tools we should be thorough before learning QM ?? If you can put up a video on that ,it would be really helpful.
I'm 16 and writing an essay about the Dirac equation, thanks so much, your videos save my life!
Great video and easy to understand.
Thank you so much for this video.
I'm about to retire and allow myself some time to return to the Quantum Physics that I didn't get years ago. This is exactly what I need and I can't wait, thank you. With yourself and Sal Khan what more could we need.
many thanks for the very good explaining.
Very clarified video... I like it.. Cleared a lot of boubts👍🏻❤
Fantástic explication . Thanks and cumpliment.
Love you way of presenting!
Love your videos I'm watching all of them one by one :P
Please do a video on spin . I love it
Pretty helpful - especially where you get to the dreaded Hilbert spaces - thank you!
For the purposes of physics a Hilbert space behaves exactly like a finite dimensional linear vector space and nobody is asking you to deal with the actual mathematical complications.
Wow. This guy explains the basics in a way that NO ONE ELSE does. I used bra-ket notation for a year in grad school without knowing, really, what the hell I was doing. I just did it by following patterns which allowed me to pass tests. No book, professor, or classmate could explain it - they just used the very concepts in question in their explanations. This Parth guy boils it down to the fundamentals - a natural teacher and almost a mind reader.
Excellent!
First time here.
2 months ago was a 10k giveaway and now you are in 30k? that's impressive.
Nice channel, I'll stick around. Like and subed.
Man, Thank you very much! I was not bad at maths at all, but spent weeks trying to understand how spins are described with vectors. Even in basic quantum computing intros either book or youtube videos they start with electron beams bent toward North and South magnet pole, spin can be up and down, and suddenly they show vectors up and right(!?) (what the hell?).
North-south, up-right are (0,1)and(0,-1) why they use (1,0)(0,1) ??
Now it is much clearer ( at least to continue reading about :-) ). Thank you for your time putting together this video!
Yes! Yes! More of this! I'm finally understanding the math (I mean, also after reading Susskind's The Absolute Minimum) but YES! More! I'm finally getting it! I never understood quantum physics this well in university.
I love you brother. A brother from India. Do this as much as you can please.
thank you so much!!!!! really helpful and interesting!!! please do more quantum physics videos!!!
wow, an amazing video again ... greetings Parth G
Parth, very well explained..keep it up 👌
now, eventualy i understand it! thank you
Excellent! Please make a video about singularities
When you added that purple vector, something clicked in my head. I think I actually understand why it's called a wave now!
This type of video about Quantum physics was really necessary for me.....
Awesome!
Excellent
Thank you so much
Many thanks for an excellent explanation. The math is relatively easy, but the concepts and how they apply in a measurement is much more difficult as I find.
What's difficult about measurement? A measurement is simply an irreversible energy exchange.