Lecture 1: Classical Field Theories and Principle of Locality
ฝัง
- เผยแพร่เมื่อ 11 ก.พ. 2024
- MIT 8.323 Relativistic Quantum Field Theory I, Spring 2023
Instructor: Hong Liu
View the complete course: ocw.mit.edu/courses/8-323-rel...
TH-cam Playlist: • MIT 8.323 Relativistic...
Principle of locality, concept of classical fields, different types of fields, action principle, classical equations of motion, examples of classical field theories
License: Creative Commons BY-NC-SA
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To say this is beyond my field of expertise would be an understatement, but it's great that this is freely available for everyone to watch. Sometimes the internet isn't so bad.
Hoped in my country this was more of a thing
This course is beyond my current knowledge, but something was said during the very helpful intro. Hong talked about the importance of doing all problem sets to gain intuition of the subject, and that intuition will help learn and understand as the course progresses. In my current classes, I've been trying to read, take notes, and look at other sources for explanations on topics. But what he said made me realize that I am not doing the most important actions that will help me learn and master the subjects and courses I'm taking. So I thank him for that
Thanks for highlighting this.
Most excellent recap I have seen on these concepts! It is a long time since my classes at U. Also followed prof. Zweibach QM courses on MIT OCW some years ago, I highly recommend those as well. MIT OCW is a great resource!
Will follow the rest of this series.
I remember last year I missed lectures of quantum field theory and here it is now !
Thnx MIT !
I want to say that Hong’s explanation is quite soulful. it is detailed, also helpful to understand. He delivers not only that knowledge but the way to understand it. God bless MIT and Dr. Hong Liu.
Thoroughly enjoyed this. Dr. Liu clearly has empathy for his students as well as an intimate grasp on this difficult yet beautiful subject.
Thank you for sharing your expertise.
I'm excited to learn from this series and Dr. Hong Liu. I think you can use quantum field theory to understand human behavior and dynamics too. Any system which exhibits quantum behaviors, traits and interactions.
oh, thank you, so much, for wonderful lectures, dear Professor.
what i'm thinking recently is i'm going through an era in which i have to rethink if everything's correct or not, on my side...hope everyone is well...🥰
MIT, thank you for this refreshing lecture.
Finally !!! I hope we also get the second and third part in a few months. OCW is the best
The whole course is available now.
@@cycklist I was talking about second and third courses in this series, QFT 2 and QFT 3 , their lecture notes and problem sets are on OCW but not lectures yet
@@dw96969Relativistic Quantum Field Theory 3 is available.
@@kw7807 where ? also videos ?
Could you share the link please ?
sorry clicked by mistake while being high, this is dope
Haram
That's why we tell kids to stay away from light drugs - they inevitably lead to heavy ones. First, you try weed, and then you do not notice how you went into the quantum field theory.
Thank you so much for this
Mit lectures are treat to watch
Lecture begins at 14:58
Thx🎉
Great lecture. Thanks.
i waited so long for this , thanks MIT ❤ god bless you
Holy shit. Thank you so much!
Thank you so much
Please also upload QFT II and QFT III in the next semesters
Please also record the lectures of the course on QFT II as well.
It seems that Professor Sunil Mukhi is also developing something about field theory. The language he used was quite similar to Professor Hong Liu.
Thank you.
Thanks! ❤
Finally it’s time for relativistic qft!!
Post Covid people came to realized about true powers of open source, actually people knew it way earlier but people have now started to harness the powers of true open source, open source is not just idea, or concept, it is the real soul of development.
Thank s. Need more cours
Good. Thank for your video from korea
starts @14:40, you' re welcome
This is beyond my comprehension but beautiful nonetheless. Really cool to be able to see lectures from the World’s great Universities.
thanks for the videos!
any chance at getting a quantum field theory 2 and 3 uploaded?
When the Phi looks like a marshmellow on a stick, you are in the realms of physics.
I have trouble balancing my check book but I will listen to this course (and not understand anything :)
magnificent❤
Danke!!!!
Good profesor thanks from egypt
oi, wish this was available literally 5 years ago lol.
My man Hong went from walking pace to warp in less than a Planck unit of time.
language of the gods
Niiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiice
43:33 can someone please elucidate the difference between labels and dynamical variable.
How to invest Real Estate: Location... Term, Condition, Price ? Bacccarat Strategy...
A lecture like this is why I gave up on Physics after one semester at University
I can't believe man hong liu the god is here🎉
La ilaha ilallah (There is no God, but the One ☝️ God).
❤
"Education is only way of live a peaceful life"
-anonymous
cope
That was simple 😅!
So if I add MSG, I can theoretically taste it later if I lick the space within its propagation window? I think I am pick'n up what you are put'n down.
Hi MIT please upload undegrad physics core ❤
10:09
👏👏👏💯🔝
The only thing I can understand is that he is speaking English.
Does anybody know if prof. Liu teaches the second course on QFT?, and if so, are there plans to publish that second course on youtube?
Here's what we have by Prof. Liu: ocw.mit.edu/search/?q=Prof.+Hong+Liu. Best wishes on your studies!
@@mitocw Thank you very much MIT
大家認為微積分的符號以及意義有瑕疵嗎?
Sorry I didn't get that, can you start again slowly.
*0.25x speed youtubers enter the chat*
0:10
Only here to see how he wrote on the top of the board
One day I’m going to be able to use all this stuff I learn 😂 either that or I’ll end up begging for money “will practice theoretical physics for food”
1:05:06 What does the \partial ^ \mu mean?
\partial^\mu (superscript \mu) is standard notation for the contraction of the spacetime derivatives \partial_
u with the inverse g^{\mu
u} of the spacetime metric. In more words: \partial_
u (subscript
u) are just the derivatives with respect to the (usually 4) spacetime coordinates, i.e. \frac{\partial}{\partial x^
u}. Concretely, \partial_0 is the time derivative, \partial_1, _2, _3 are the spatial derivatives. To get the upper index, you need to contract with the inverse of the metric: \partial^\mu = g^{\mu
u} \partial_
u. As QFT is usually done in the context of special relativity in flat spacetime, the metric (and its inverse) are just diagonal matrices with either (−1, +1, +1, +1) or (+1, −1, −1, −1) on the diagonal, depending on the conventions you use. So in the end \partial^\mu is just +/− \partial_\mu, where it depends on the conventions whether the time-derivative or the spatial-derivatives get the minus sign.
@@EdwinSteiner Thank you very much!
Square viewless..rate..🤔
General thought view..not check..
Why c equal to one?
Because the numerical values of dimensionful constants like c and h-bar depend on the units of measurement you choose. Since units of measurement are arbitrary conventions, anyway, you simply pick your units of measurement such that c = 1 (and usually also h-bar = 1) in those units. This way you get much simpler formulae.
but lagrangian and Hamiltonians are in economics
Elon I know your lurking here good day to you sir.
Nah, he's too busy X-crementing.
Very beautiful sweet sir ❤❤❤❤❤
Is this the thing about the cat in the box?
No! it's the theoretical physicist sitting in a box and thinking
No, it's the thing about infinitely many cats in infinitely many boxes.
中央量子場小組需要台端
What happened to
L = T - V
H = T + V
??????
Simply the Lagrangian and Hamiltonian mechanics my friend. I think you should first catch up on classical mechanics and then quantum mechanics before taking this class.
In general, L and H do not follow the form you provided
sad to say but, US top universities especially in stem sector, are dominated by chinese and indian, immigrant or not
Hong seemed to only read from his notes. 😢
😂but am sure it you're asked to read the same 😂😂😂😂you may get stuck
Locality implies continuity as subjectively experienced on the surface of the earth at 12 noon in the Astrodome on a Spring morning.
General Relativity is a local theory of surfaces (a black hole is a perfect, non-radiating sphere, where all radii of curvature meet at from opposite points at the center. But vectors do not have a common origin by Fermat's Last Principle for n=2
c = a + b
c^n = (a+b)^n = a^n + b^n+ f(a,b,n)
c^n = a^n + b^n iff f(a,b,n) = 0
f(a,b,n) 0
c^n a^n + b^n QED
(This was actually proved by a math "C" student within two weeks after Fermat's expression was published, but then the men in white coats took him away,m never to be heard from again)
Note that for n=2, Pythagorean theorem is wrong (and thus, vectors, which are affine - have no common origin - i.e., are in principle not local) Each vector has its own coordinate system ( which is why the trace of the relativistic field tensor is zero, meaning nothing exists, as in the Pauli matrices - the foundation of SU(2). Note that SU(2) is a group that only has one operator - mutiplication, but that two elements must exist (by addition) in order for multiplication to take place at all (Russell's Paradox means 1^2 1).
There is much, much more to this story, but I don't have the space-time to write it here. I've been kicked off most of the classical websites, but I am on physics.org with links to pdf's.
"There is Me and Thee, but I'm not altogether certain about Thee...."
and, finally,
"Just because you're schizophrenic doesn't mean that the Universe isn't a figment of your imagination"
Equations to follow only if you send beer and pizza. "Drink your Beer and Eat your Pizza" - Zen Koan from south Chicago....
Ngl i thought he Said he was Hung xD😅😂
ehh I'll just stick to pure math
The original state prior to existence forming is the state known as 'Being'. Logically, it simply has to 'Be' in order for everything else to then 'Be Able To Come Into Being'. But, who's 'Being' is it? That is the intelligent question. And the answer to that question is, 'It Is My Being'. The 'Being' part of the 'Human Being' now reading these words. You know, the 'Being' part of every 'Human Being' that coincidentally always gets ignored. Our 'One Common Ground'. Best wishes.
Allahu Akbar!
@@sovereigncitizen3633 Yes. That original 'Unmoving State' that some call 'God'. Best wishes 🙏
@@NowisEvollovetion The Original existence that has no beginning and no end. The necessary existence that all contingent existences depend upon to exist in the first place.
That necessary existence is Allah(The God). The Creator, the designer, The sustainer of all existences.
None has the right to be worshipped besides this necessary existence Allah SWT. Allah is the only One ☝️ with the right to legislate for Allah’s creation.
Allahu Akbar!!!
@@sovereigncitizen3633 And yet. In that state prior to existence forming there is 'No Existence'. There is 'Absolutely Nothing' the 'Source Of Everything'. Best wishes.
@@NowisEvollovetion How can something come from nothing? How can existence come from non-existence?
If all you're introducing is the derivative, then nothing exists. (An element can't change if there is no element)
The traces of the relativistic Field Tensor and the Pauli matrices are all zero, which means nothing exists locally.
There are no negative numbers: -c = a-b, b>a iff a = b-c, a+0 = a, a-a = 0
If there are no negative numbers, there are no imaginary numbers.
del X B = 0, means the coordinate change dB from
B = 0 to B = B means that B = 0 for any coordinate system.
So instructors are still using chalkboards today, and not powerpoints!? Or at least interactive whiteboards?
Teacher can not write without paper😂😂😂