It is astonishing to realize that until Galileo performed his experiments on the acceleration of gravity in the early seventeenth century, nobody questioned Aristotle's falling balls. Nobody said, Show Me!

In astrophysics, we care about how matter, motion and energy manifest in objects and phenomenon in the universe. Stars are born. They live out their lives. They die. Some of the ones that die explode. Our sun will not be one of those, but it will die. And it'll take Earth with us. So we make sure we have other destinations in mind when that happens. And I've got it on my calendar.

The value of science is not simply what the next model of the iPod you will buy next week, but its real value comes about when it's time to distinguish reality from everything else. And to be scientifically literate is to be trained in what it is, to recognize your own frailty as a data-taking device.

So while you're getting ripped apart head to toe as you fall into a black hole, you will also extrude through the fabric of space and time, like toothpaste squeezed through a tube. To all the words in the English language that describe ways to die (e.g., homicide, suicide, electrocution, suffocation, starvation) we add the term spaghettification.

The greatest of people in society carve niches that represent the unique expression of their combinations of talents. If everyone had the luxury of expressing the unique combination of talents in this world, our society would be transofrmed over night.

In physics, opinions don't matter, only demonstrated experiments. The day the fellow succeeds, if ever, he won't need anybody else's opinion.

Kids are born curious about the world. What adults primarily do in the presence of kids is unwittingly thwart the curiosity of children.