Since life on Earth is, so far, the only known example of life in the universe, our dilemma may simply be that we have no other examples to compare us with. If we did, then the life/non-life transition might look downright simple to us.

The theory of evolution, like the theory of gravity, is a scientific fact.

I'm a fan of the planets in any combination. When I was born, Mercury, Venus, Jupiter, Saturn, Uranus, Neptune, Pluto, the Sun, and the Moon were all in the sky.

Einstein's theory, we know that it fails. In advance, we know it fails. So that a deeper understanding of nature is awaiting us.

Countless women are alive today because of ideas stimulated by a design flaw in the Hubble Space Telescope.

I as an astrophysicist, see the universe, feel the universe, smell the universe every day. Every day. And for people to say, I'm cool, I'm right here, it's all I need.

Trillions of years into the future, when all stars are gone...all parts of the cosmos will cool to the same temperature as the ever-cooling background. At that time, space travel will no longer provide refuge because even Hell will have frozen over. We may then declare that the universe has died-not with a bang, but with a whimper.