2a) Daily Zen

 2a1) These are the tape recordings of Richard Feynman's 1961-64 Caltech Introductory Physics lectures, which form the basis of the book The Feynman Lectures on Physics. The original recordings were made on 1/4" reel-to-reel tapes, now preserved in Caltech's Archive. In 2010 the entire collection was digitized by media preservationist George Blood, at a sampling rate of 96 kHz with 24-bit samples, PCM-encoded in tiff files about 2 GB each in size. For this online publication we are serving more compact versions, downsampled to 48 kHz with 16-bit samples, reencoded as AAC-HE (mp4) and Opus (ogg) at a data rate of 48 kbps.

The Feynman Lectures on Physics Audio Collection at Caltech.edu