Lecture 19, 18.376, Thu Apr 20, 2023.
Summary
%
Do  #020; moving sources and wave generation.
Cover the "Moving point sources" section in the "Lecture Topics"
notes posted on the web page (Lecture topics for 18376).

Note on #021. This was mostly done using the Average Lagrangian
approach, so I will skip most of it. Exception: #021b. You SHOULD READ
THE REST and try to "fill-in" the blanks. Check the "Lecture Topics"
notes posted on the web page. Below I mark the parts I will cover next,
read the rest on your own.

In section 4: Modulation Theory.
4.1.3 The Fourier Transform approach.
      WILL BE COVERED.
4.2.2 Example: the classical limit of Quantum Mechanics
      WAS COVERED [using other notes].
4.3   Average Lagrangian.
      WAS COVERED [using other notes].

In section 5: Loose topics related to modulation theory
      I plan to cover a bit of this.

In section 6: Energy for Dispersive Systems.
      I have covered this from a different perspective.
%
% ==========================================================================
NOTE: Here #nnn	are references to the Lecture Points file.
      [PSQ] means Problem Set Question.
 The "lecture summaries and points" are NOT intended as study materials.
 The points purpose is explained in the "lecture points" file.
 The summaries are brief descriptions each lecture, used by the instructor
 to keep track of the material covered. They ARE *NOT* "lecture notes" to
 be used to study and/or replace attending the lectures, etc. They are
 provided for your convenience, as a help to organize your own notes.
% ==========================================================================
% EOF