Science isn't just about solving this or that puzzle. It's about understanding how the world works: the whole world from the vastness of the cosmos to the particularity of an individual human life. It's worth thinking about how all the different ways we have to talk about the world manage to fit together.

A full understanding of what happens in our everyday lives needs to take into account what happened at the Big Bang. And not only is that intrinsically interesting and just kind of cool to think about, but it's also a mystery that is not given much attention by working scientists; it's a little bit underappreciated.

The idea that time is an illusion is an old one, predating any Times Square ball drop or champagne celebrations. It reaches back to the days of Heraclitus and Parmenides, pre-Socratic thinkers who are staples of introductory philosophy courses.

If time travel were possible, you still wouldn't be able to change the past - it's already happened!

Doing physics is a lot of fun if you like it.

Bioethics is a very, very important field. As we get more and more in the arena of understanding science and getting better opportunities, the fact that you can do things with biological sciences that have an impact on a human being means you must have ethical standards.

The dilemma felt by science fiction writers will be perceived in other creative endeavors.

I understand that space travel and expansion is just as much about altering ourselves, our attitudes, our social structures, our very biology, as it is about altering the places we choose to live.