Lecture 9 | The Theoretical Minimum

(March 12, 2012) Leonard Susskind diverges from looking at the theory behind quantum mechanics and shifts the focus toward looking at more tangible examples.

Stanford University:

Stanford Continuing Studies:

Stanford University Channel on YouTube:

[JamesCarmichael]

I'm so glad and honoured to be able to subscribe to these videos and view them for free. I think Susskind is a fantastic physicist.

[astroboomboy]

Susskind is the man, such a laid back fellow!

[TheVivek]

38:28 So this is really just a bunch of 'psi-phi' ?

[petergreen]

❤Thank you very much publisher, Leonard and others including you the reader.

[patriciaheil]

ok i feel stupid do those equations come from the last 5 seconds of lecture 8 after a question and answer I couldn't hear?

[AndreasEhrencrona]

Something is missing here again no? I’m completely sure there was no discussion of the triplet state in the previous lectures.

[anklexpress]

Im suprised with all this talk about pop sci ideas of entaglement and wave functions that the students being up that Everett's many worlds interpretation never came up

[patriciaheil]

at 1 hour 35 I don't understand the right side of the equation. -i squared is i. that would cancel out with the i on the other side. h-bar squared would be just h-bar and the h-bar on the left would be cancelled out. so I missed why he didn't simplify.

[kigvader]

@1:05:05 I think there should be only 1 dx, no?

[zphuo]

@52:00 How the relationship between Lamda and k is being derived.

[superserkit]

Do the electrons know? Is the Principle of Least Action a result of following a path of stationary action, or could we also ascribe certain emissions and reductions in state-energy to characteristics of the particle, like laziness?

[georgekyriakou]

nice lecture
for the record, greeks call it Psi, p+s are both pronounced

[sleepy]

His whole 2 year series he refers to as 'the theoretically minimum'. So the name of this video series is a little annoying -- it is the theoretical minimum for quantum mechanics.

[harjinderooney]

Cookie monster...but he is an excellent teacher and physicist...i admirr him....

[andrewgoodings]

I do the same. I also ponder the reasons why he likes to eat all the time.

[davidwilkie]

Professor Susskind presents a careful explanation of "things as they are" in mathematical QM language, because, (if the implied question is what is this universe and where are we in it), a Big Bang beginning and total annihilation by dispersal in eternity, from which everything came due to the workings of a mathematical machine. The universe of time continuity is the same explanation "doubled up" by superimposed compaction over, and integrated with, the QM state.
And the rationale/reason for this is relativity, of a structure of constants/invariants confined by the principles that are the subject of the lectures. (?)

[РодионЧаускин]

Martin Laura Robinson Donald Brown Richard