I cannot stress often enough that what science is all about is not proving things to be true but proving them to be false.

A universe without purpose should neither depress us nor suggest that our lives are purposeless. Through an awe-inspiring cosmic history we find ourselves on this remote planet in a remote corner of the universe, endowed with intelligence and self-awareness. We should not despair, but should humbly rejoice in making the most of these gifts, and celebrate our brief moment in the sun.

I hope that every [person] at one point in their life has the opportunity to have something that is at the heart of their being, something so central to their being that if they lose it they won't feel they're human anymore, to be proved wrong because that's the liberation that science provides. The realization that to assume the truth, to assume the answer before you ask the questions leads you nowhere.

[The writers of the holy books] did not even know the earth revolves around the sun. Why are we listening?

90% of the mass in your body comes from empty space.

The amazing thing is that every atom in your body came from a star that exploded.

You couldn't be here if stars hadn't exploded, because the elements - the carbon, nitrogen, oxygen, iron, all the things that matter for evolution - weren't created at the beginning of time. They were created in the nuclear furnaces of stars, and the only way they could get into your body is if the stars were kind enough to explode. So, forget Jesus. The stars died so that you could be here today.