Recent content by VRT

Here're my favorite lectures on the subject - "Group Theory, Robert de Mello Koch" - very intense. I wish quality of the video would be better, though...

I think by "what this mean" OP asked about the link between math and physics. Why particles can be described by those math groups? Why "there are 8 but not 9 gluons" followed from "there are 8 generators of SU(3)"? Why math rules (8 generators) took over physics logic (3 gluons and 3 anti-gluons...

Beautiful! That's what I didn't know before you said it. Susskind's description is completely different. According to him the theorem states "flows in phase space are incompressible (volume preserved)", what also "means div(H)=0" (see...

Thank you for help with terminology. ##\rho \mathbf{v}## is what I considered as "flow" (and insisted that its div = 0), not just ##\mathbf{v}##. Switch to ##\mathbf{v}## from ##\rho \mathbf{v}## doesn't go easy on me (imagine somebody proposed to use speed in places of momentum in mechanics)...

I appreciate you time, mikeph. Just to prevent going in circles I'll make a step back. There are 3 statements here: if (1) div = 0 then (2) flow is imcompressible and (3) volume is preserved. I understand that (2) and (3) are equivalent to each other. I do not understand how (2) and (3)...

Number of elements of the flow entering the volume is the same as number of elements of the flow leaving the volume - that make div = 0, doesn't it?

I see what you all are saying - it probably comes to the terminology. Maybe he said "incompressible" but not "uncompressible" - most likely I've changed it - sorry for the confusion. Susskind proved that div=0 and therefore concluded that volume is preserved (I think I didn't said it this way in...

Challenging Susskind's "uncompressible flow" in Liouville’s Theorem It’s in Susskind’s 7th lection on the classical mechanics when he’s approaching Liouville’s Theorem he’s using "uncompressible flow" term to express the idea that divergence of flow in phase space is 0 – as much of flow is...

Just in case, here's a short version of the book - "Leonard Susskind on The Black Hole Wars"

Thank you for replies, The whole picture is understood (and even confirmed). What is missing is why the part of the game after host opens a door is not an independand game? How it's different from the game where you wouldn't have to make 1st pick (1st pick was totally random anyway)? Just 3...

Hi everyone, 2 goats and the car are from . The monkey is for you to remove from my back – it’s killing me! The problem also was in “21” movie. The setup is you are on a game show, there are 3 closed doors with 2 goats and a car behind the doors, you do not know what is behind which...

I'll approach the issue from the usability stand point. "A function is a map" means you can use and reuse it for different input parameters (as a function in computer library) and get results from it. For example, f(x)=3x^2+6. You can feed it with many real numbes from some interval (-10.0 to...

Also it considers relativity: quantum mechanics + special relativity = quantum field theory.

Usually it's one of "PF Patrons" I who reminds others that you cannot apply every day analogy to quantum mechanics :). Nothing is really wrong with "packet" (until you try to open it and you can't - it's a photon). I guess, it's commonly used in this context. WannabeNewton's also made a comment...

I'm somewhat uncomfortable using words "packet" and "quantum" interchangeably. "Packet" implies internal structure while a "quantum" is unbreakable.