We already know the limits of Einstein's theories. From the centers of black holes at the very beginning of the universe - we call these singularities - Einstein's equations fail. In fact, people have joked that's where God is dividing by zero.

When you are a hammer, all of your problems will look like nails to you.

It'd be a shame to talk about the universe and not show some images of it, because we have some of the more stunning representations of our field relative to any of the sciences. But I don't use the imagery as a substitute for the insights and wisdom I can convey so that when you leave you say to yourself, "Wow, I'm a little more deeply connected to the universe, and I want to learn more."

Seventy percent of Earth's surface is water and over 99 percent is uninhabited, so you would expect nearly all impactors to hit either the ocean or desolate regions on Earth's surface. So why do movie meteors have such good aim?

Enjoying science shouldn't be rocket science.

With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.

I know that the molecules in my body are traceable to phenomena in the cosmos. That makes me want to grab people on the street and say: ‘Have you HEARD THIS?