When you're a hammer (as the saying goes), all your problems look like nails. If you're a meteorite expert pondering the sudden extinction of boatloads of species, you'll want to say an impact did it. If you're an igneous petrologist, volcanoes did it. If you're into spaceborne bioclouds, an interstellar virus did it. If you're a hypernova expert, gamma rays did it.

WhenIWasYourAge: It took a week to learn whether your photos came out okay.

There are as many atoms in each molecule of your DNA as there are stars in the typical galaxy. This is true for dogs, and bears, and every living thing. We are, each of us, a little universe.

Just before I said I wanted to be an astronomer I said I wanted to be a baseball player. I was quite athletic at the time, probably because I was bigger than other kids, and if you're bigger than other kids and you're 11 you win everything.

The greatest of people that have ever been in society, they were never versions of someone else. They were themselves.

We're quite happy with our Big Bang description of cosmic origins. But actually, the Big Bang accounts for what happened only after the beginning. The beginning itself, and especially what happened before, remains the biggest mystery of all.

Last I checked, Bill Gates was worth $50 billion. If the average employed adult, who is walking in a hurry, will pick up a quarter from the sidewalk, but not a dime, then the corresponding amount of money given their relative wealth that Bill Gates would ignore if he saw it lying on the street is $25,000.