Lecture 2 | New Revolutions in Particle Physics: Basic Concepts

[zomgthisisawesomelol]

Interested in going to Stanford?

Pros: Susskind

Cons: Fellow students

[bundawartini]

Good, I like that you share this video, I wish success always Leonard Susskind gives the second lecture of a three-quarter sequence of courses that will explore the new revolutions in particle physics.

[bbsonjohn]

41:43 Any other cookies?

[Denkom1]

Any other cookieees?

[grunder20]

Formulas can be confusing.

[adelle0001]

nice one!

[agapitoflores001]

I'm a Physics advocate! hahah.. I want this kind of video.

[monstermoonshine]

The i in [x, P_x]=ih is the square root of -1.

[4kx]

in 1:15:49 he is telling one thing: [ x, Px ] = i *h

What is "i" in there ? What does it mean?

[mssodin28]

@4kx its a vector quantity. With i, j,k being respect to x, y, z plane.

[4kx]

0:41:43 - any other cookies.. yyy, any other question :DD

[1isaacmusic]

LMAO @ 22:25, I can tell he hates that guy, it's the same guy that's in all the lectures. He better be careful, I heard when Len was in the Special Forces he learned how to kill a man with a cookie. A single cookie.

[djwafroking]

41:42

[tomczyce]

about the question about the meter... ok seriuosly...stanford students ask these kinds of questions??...wow.....silly spoiled rich parent kidss...

[SpeakingSerpent]

@tomczyce , Gosh tom, i wish we could all be as smart as poor people.

[tomczyce]

@SpeakingSerpent haha your sarcasm... the prof himself cant help but to answer the question without bringing it into the context of a joke ( for obviuos reasons)

PS interesting how it's the so called poorer people in history, the researchers, the people who start off from scratch and must work hard to make it who commonly achieve great things. Which is only bringing me back to my point in my original post, thats all im saying...

[Tild06]

@tomczyce Hey, I believe these are not "stanford kids" yet stanford continued learning students. He explains this in other lectures. Real physics courses involve MUCH more mathematics and calculation. The students here are actually probably 40 years old and older. They are there to ask those questions, otherwise they'd watch the lectures for free online.

[wizardofmadness]

@tomczyce Americans (not only kids) are still into 1/4 "mile" in less than 10 seconds. That's why. They don't really know that's around 400 meters.

[Heyga4Huk]

any other fcookies?

i'm sorry, any other questions?

hahaha

[cakeplus8psycho]

im attending his string theory lectures at stanford presently. he is one of the great minds of our day. holographic theory is a brilliant theory and a beautiful one.

[xxIFNTxx]

a^- and a^+ are not observables so you cant say that they can't be measured simultaneously...

[bhigr]

Hmm, but the real solution for the harmonical oscillator is E=hw(n+1/2). He dropped the ground state energy E=hw/2!

[fermista]

@bhigr He did say at 1:22:15 that we are defining the zero-point energy in this example to be equal to zero.

[bhigr]

@fermista But, the lowest energy is not equal to zero and this has real world consequences.

[fermista]

@bhigr True, he probably should've put down the energy which included the zero-point energy. But in the context of creation and annihilation operators, only the differences between energy levels are important, which is uneffected by setting the ZPE to zero.

[bhigr]

That's a funny way of introducing periodic boundary conditions. The supposed motivation is computability...

[bhigr]

This is weird. He expects people to have a good knowledge of quantum mechanics and special relativity, but he doesn't expect them to know exp(i*x)=cos(x)+i*sin(x)?

[yawdvgt]

@bhigr he expects pre-knowledge from his other lectures, i think he explains mathematics all along his lectures when is needed

[jjstankowicz]

I'm not the only one watching these who says aloud things like "You shouldn't use the letter L twice!" or "You're missing a factor of 2!" to my computer monitor, right?

[TheBobathon]

The properties of the quantum harmonic oscillator were introduced in detail in the 10th lecture in the Quantum Mechanics series:

watch?v=JIuU3xnOx7g

[HigherPlanes]

I saw Professor Susskind on TV on a show about astronomy on the history channel. Pretty cool. I think it was that show called through the wormhole.

[TheCommiesUK]

Ah little Physics jokes...@ 1:18

[nanobot81]

this are great lectures. im debating between stanford and mit.

[luzzie9]

Welcome back, Professor, i can't wait for Dirac to make an appearance.

[Entropy3ko]

Well h/2pi is also called the Dirac constant :P