You innovate in ways that stoke your economy. Because innovations in science and technology are the engines of 21st century economies.

And extracting one molecule's signature in spectral analysis from the rest of the signatures is hard work, sort of like picking out the sound of your toddler's voice in a roomful of screaming children during playtime. It's hard, but you can do it.

To achieve this density of a neutron star at home, just cram a herd of 50 million elephants into the volume of a thimble.

Kids are never the problem. They are born scientists. The problem is always the adults. They beat the curiosity out of kids. They outnumber kids. They vote. They wield resources. That's why my public focus is primarily adults.

The more I learn about the universe, the less convinced I am that there's any sort of benevolent force that has anything to do with it, at all.

If you are that person, you are more likely to believe that God cured you, this invisible force, creator of the universe, cured you, than that you had three idiotic doctors diagnose you. ... I taught physics to pre-med students who became doctors. Not all of them are smart, I assure you.

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.