When we explore the cosmos, we come to believe and prove that we can solve problems that have never been solved. It brings out the best in us. Space exploration imbues everyone with an optimistic view of the future.

If you just take a single human and put him or her in the forest he or she might not do very well without some sort of education which he got or she got from some tribe.

America has had many other discoverers besides Columbus, but he seems to have made more satisfactory arrangements with the historians than any of the others.

Some of the most wonderful aspects and consequences of evolution have been discovered only recently. This is in stark contrast to creationism, which offers a static view of the world, one that cannot be challenged or tested with reason. And because it cannot make predictions, it cannot lead to new discoveries, new medicines, or new ways to feed all of us.

The strange thing about grinding that might surprise many people is that you can grind things and shape them using materials that are generally somewhat softer than the thing you're grinding and shaping.

If the Earth gets hit by an asteroid, it's game over. It's control-alt-delete for civilization.

The oncoming trouble I speak of is climate change. It's going to affect all of you in the same way the Second World War consumed people of my parent's generation.