Understanding Gender Differences in Reproduction: "Males can pass on their genes by mating with lots of females, whereas with a female, mating with lots of males doesn't benefit her."

The Universe Crawling with Life: "If we found life on Mars or Enceladus or anywhere in the solar system, then you do your bayesian statistics and you immediately say, right, that means life is, the universe is crawling with life."

The Rarity of Life in the Universe: "If you want to believe that we're the only life form in the universe, then that immediately commits you to the belief that the origin of life on this planet was a quite stupendously improbable event, because the sheer number of available planets in which life could have started is so huge."

Memetic Replication vs. DNA Replication: "The one example I use is the reverse baseball cap, which spread as an epidemic of memes, because people think it looks cool, so they turn their cap backwards, and so that the act of imitation is analogous to DNA replication, but it's memetic replication, not DNA replication."

The Concept of Memeplexes: "A cooperative of memes might be something like the Roman Catholic Church, where a whole lot of different replicating ideas survive in each other's presence and therefore could be regarded as a meme complex or memeplex."

The Darwinian Multiverse: "The Smolin spin on that refinement of that helps, because instead of just saying we've got billions of universes, and some of them just happen to be conducive to producing the world as we see it and live in it. Because he postulates a kind of darwinian selection of universes and the qualities that make for fecundity, that make for reproductive success of a universe good at making baby universes, those very same qualities are the qualities that eventually make for chemistry and life."

The Shifting Moral Zeitgeist: "It's palpable, manifest that the moral zeitgeist shifts as the decades go by."

Balancing Science Communication: "I try to do both, I think, insofar as it's possible, and I think it probably isn't possible in physics, or is much harder in physics to. To write for colleagues and for the general public at the same time, because physics is so difficult, modern physics is so difficult."

Public Engagement in Science: "I think that communication to the public should not just be left to professional journalists who do a good job of actually reading up the science and then translating it into lay terms."

Cosmic Legacy: "It would be nice to think that something of our culture would be at least slight possibility of being discovered by other civilizations so we wouldn't be totally forgotten."