For MP4 (2.6GB)

    wget -qO- "https://hastebin.com/raw/amekevecum" | wget -nv --referer="https://www.feynmanlectures.caltech.edu/flptapes.html" --user-agent="Mozilla/5.0" --input-file -

For OGG:

    wget -qO- "https://hastebin.com/raw/esukabunew" | wget -nv --referer="https://www.feynmanlectures.caltech.edu/flptapes.html" --user-agent="Mozilla/5.0" --input-file -

Titles are here: https://www.feynmanlectures.caltech.edu/flpplaylist.js

The URL to the media file is easy to see in inspector, in firefox or chrome. it downloads happily with curl as long as you preserve the cookies.

The filenames follow a (mostly) predictable pattern, amenable to a simple for loop. After downloaded, I extracted the audio with ffmpeg.