85 percent of the gravity of the universe has a point of origin about which we know nothing.

I try to keep this in mind when tied in to a rope 75 feet up in a tree... The history of ideas about our place in the universe has been a long series of let-downs for those who like to believe we are special.

Some morning while your eating breakfast and you need something new to think about, though, you might want to ponder the fact that you see your kids across the table not as they are but as they once were, about three nanoseconds ago.

Nothing is a thing: it's nothing. So I can imagine a place where there's not even nothing.

The word smart is not applied to all professions, even if you are smart in that profession. No one talks about smart lawyers. They may say a brilliant lawyer. They'll talk about a creative artist. Smart is saved for scientists. It just is. It's not even really applied to medical doctors. It applies to scientists in the lab figuring out what hadn't been figured out before.

Lots of people think, well, we're humans; we're the most intelligent and accomplished species; we're in charge. Bacteria may have a different outlook: more bacteria live and work in one linear centimeter of your lower colon than all the humans who have ever lived. That's what's going on in your digestive tract right now. Are we in charge, or are we simply hosts for bacteria? It all depends on your outlook.

Like no other science, astrophysics cross-pollinate s the expertise of chemists, biologists, geologists and physicists, all to discover the past, present, and future of the cosmos-and our humble place within it.