Lecture 4 | Quantum Entanglements, Part 1 (Stanford)
Lecture 4 of Leonard Susskind’s course concentrating on Quantum Entanglements (Part 1, Fall 2006). Recorded October 16, 2006 at Stanford University. This Stanford Continuing Studies course is the first of a three-quarter sequence of classes exploring the “quantum entanglements” in modern theoretical physics. Leonard Susskind is the Felix Bloch Professor of Physics at Stanford University. Complete playlist for the course: www.youtube.com Stanford Continuing Studies: continuingstudies.stanford.edu About Leonard Susskind: www.stanford.edu Stanford University channel on YouTube: www.youtube.com
Video Rating: 4 / 5
@geoffreyah A complex number is in the form a+bi. a and b are constants and i is the square root of -1. The complex conjugate of a number is a-bi, so for a real number it’s just the number itself.
What is a complex conjegate? What kind of math does one need to know to understand this math? I had beginning and intermediate algrebra
@andrew11235 The sigma are operators which operate on spinors, the two-dimensional equivalents of tensors.
Estimado puebloperuano me dirijo a ustedes no para prometerlesel eloro y el moro, sino para darles planes de gobierno concretos de como podemos sacar adelante al peru, directo al grano, mi plan de gobierno no es politiquero ni tiene ningun tinte de demagogia, se basa en el conocimiento y el saber en todos los ambitos de la ciencia y la tecnologia, e aquiun gran dicho: el pueblo perece por falta de conocimiento.
that bottle could be perrier or vine and first two lecture could be vodka or cofee in the cup. u cnnot know the ingredients unless u try to taste. its a quantum thing hahahaha. and the result can ALTER your grade state LOL. GREAT PROFESSOR!!!
3 for one electron in the ‘n’ direction. 3 for the other electron in the ‘m’ direction.
It’s supposed to represent the spin of an electron
So sigma is a 3rd-order tensor, right? It has components sigma 1, sigma 2 and sigma 3, all of which are matrices.
spin is a 3 dimensional physical quantity. however, unlike momentum or position, you can only measure spin along one direction. Along that direction, your spin is either up or down, i.e. your measurement yields one of two possible results, making the state space of spin 2D, thus why your sigmas are 2-dimensional. These matrices are really nothing but the operator (spin component along a direction) expressed in terms of the Eigenstates of some operator (usaully Sz).
nevertheless has some issues with susskind. I don’t know what it is, but it’s probably because susskind is a non-believer. Youtube videos with susskind are full of haters.
“”TO ALL PEOPLE WHO ARE READING THIS : DOSE THE ELECTRICITY OF BRAIN CAN BE HACKED VIA SOME TECHNOLOGY? Can ANY Microwaves or ELF Waves Manipulate the Electricity of the brain?
My Clear Question : Do some people Reading OUR MINDS And manipulating our subconscious regions of mind-brain via having the electricity of our brain in thier computers?
I hope for search, curiosity.
The sigmas are two dimensional because they operate on the representational space of the spin vectors which, as APoudy points out, is two dimensional. You need three to generate the physical space of the spinning particle.
The point is that the dimention of sigma matrices has to do with the uantity of eigenvectors only. Up and down are the two distinct eigenvectors of observable, they’re orthogonal, two distinct output of any measurements, and the way to express it in quantum theory is to have 2×2 Hermitian operators.
If the sigma matrices are applied to spin in three dimensional space, why aren’t they 3×3 matrices?
nice he lectures with a bottle of champagne, he’s a baller
what? really??????
He cant tell a left from a right handed system and blames his shoulder for that.
Incredible, coming from a string theorist !
or should I say, its totally apt that he does string theory – with no clue about reality.
why do you comment the same thing a week apart?
His coordinate system at 2:07 is not right handed !!!
oops, I just saw someone corrected it at 2:35 !
what a GREAT teacher. The fact that such a cutting-edge scientist as Mr. Susskind should recognize the importance of taking the risk and time of teaching speaks wonders about his intentions regarding the search for the truth. And that’s not the impression I used to get from him before seeing these lectures. A great mind.
I don’t get it, why would it take 6 independent real variable to characterize a pair of electron?
Hello grandpa,you’re so funny.
Pooppepper, before being concerned about peoples sexuality, although it is irrelevant and no business of yours,grammar class might be a good start. Btw, since you act it, are you homophobic? Maybe you are gay and don’t know it yet, hence your stage name. Oh, yes, I’m straight fyi.
I notice, in returning to this video, that I have received three “thumbs down” for pointing out that I am being impersonated.
To be sure, one can get only so exercised over the tarnished reputation of a faceless screen name on Youtube; but the “thumbs down” still strike me as curious.
well this could make quantum entanglements lectures an even higher intelectual experience