July 12, 2024
Why does time flow in only one direction? Why do we grow older, not younger? Many physicists relate time’s arrow to “entropy” — a measure of disorder. But if that’s so, how did the universe seem to move towards more order with the formation of galaxies and planets? Physicist Paul Davies of Arizona State University answers those questions and more, with Logan Chipkin. The conversation covers the role of gravity in constructing time’s arrow, exemplified by black holes. They also cover the black hole information paradox — and Davies’ personal recollections of attending Stephen Hawking’s seminal lecture on the idea that black holes aren’t really so black, but slowly radiate energy. And they chat about the idea that information can be used as a fuel — a concept that is now being exploited to build better nano devices. But as Davies notes, nature got there first. And finally there’s a sociological turn: Could universities be improved — or not? This is the second part of FQXi's podcast series on "Irreversibility" — in this case writ large on the cosmic scale.