All votes in, a clear winner.
Thanks to entrants for many worthy clues.
Gold medal to jono@3 for his acrostic
Leader in physics (and primarily advanced mathematics) dabbled in relativity at Cambridge. Well done! I'd have voted for it.
Tie for silver between bacchanal@6's subbie and jono@23's backward clue; jono was on song in this PR!
Prizes:
Anecdotes (I have independently perpetrated the "it wasn't a question" 🤣):
https://www.youtube.com/watch?v=u3nWcaGgCXU
The man himself speaks:
https://www.youtube.com/watch?v=K8YMiRXy9GA
This excellent presentation by Dirac's biographer (I've read the book) is long. But if one hovers the cursor over the timeline, it's divided into sections which can be selectively viewed:
https://www.youtube.com/watch?v=jPwo1XsKKXg