2023-09-23 21:08:36 UTC
can watch/listen to them while doing household chores, and one also
learns the correct English pronunciation of the technical terms.
So I listened to some videos of QFT lectures by Prof. Susskind.
However, after about three videos so far, I am rather disappointed.
I have the impression that Susskind deliberately wants to
counteract all too flowery gobbledygook with a "don't talk, but
calculate" approach. I have always found such an approach absurd
in physics, but especially devastating in teaching. He does some
math, "We put this in here, and then we get this," "I'm not going
to say why, I'm just going to do it this way," and then he says,
"And this is the simplest example of a quantum field." (these are
all not literal quotations). He doesn't explain what a "quantum
field" is supposed to be. This doesn't seem very educational to me.
As an example of an approach that I like (at least according to the
few pages I have read so far), I would like to mention "Quantum Field
Theory" by Mark Srednicki (which is a written text, not a video).
He first explains that it is about combining quantum mechanics and
relativity. In order to do this, space and time must be treated
"on an equal footing at the outset". In quantum theory, time is a
label (parameter), location is an operator. So to treat them equally,
one can either treat location as a label, or one can treat time as
an operator, says Srednicki. Since the second is a bit complicated
(Srednicki says it would lead to string theory), Srednicki follows
the way to make the location a label. Each location x is associated
with an operator phi(x). And this is a quantum field.
So Srednicki first explains what requirements a quantum field
should satisfy and why, and then he shows how these requirements
can be satisfied, so that one can grasp the concepts. Susskind
lacks such an explanation (though I have not seen all the
videos in the series, so I may be missing something).
[[Mod. note -- It would be useful to have references to the specific
videos and books under discussion. -- jt]]