Dirac lecture 4 of 4 - Does 'G' vary? (Large Numbers Hypothesis) - very clean audio.

This is a video of Dirac's fourth lecture of four on quantum mechanics delivered in 1975 in Christchurch, New Zealand. The transcript of the lectures can be found in "Directions in physics : lectures delivered during a visit to Australia and New Zealand August/September 1975 / P. A. M. Dirac ; edited by H. Hora and J. R. Shepanski ; with a foreword by Sir Mark Oliphant" The video was taken from https://www.youtube.com/watch?v=P174LmmQYy4 and I used both https://podcast.adobe.com and Apple iMovie to enhance the audio considerably.