A video clip from 1973, where physicist and philosopher Richard Feynman talks with Fred Hoyle, the accomplished astronomer.
Feynman asks: “What, today, do we not consider part of physics, which may ultimately be part of physics?”
His answer (which should be cued up here at the 7:10 mark) is the initial conditions of the universe, as well as the possibility that the physical laws themselves evolve with time. (Conversation continues for a tiny bit in the followup video. Listen on to hear Feynman explain how he doesn’t like to speculate about things.)