I've always thought that one of the the great thing about physics is that you can add more digits to any number and see what happens and nobody can stop you.

What people don't appreciate, when they picture Terminator-style automatons striding triumphantly across a mountain of human skulls, is how hard it is to keep your footing on something as unstable as a mountain of human skulls. Most humans probably couldn't manage it, and they've had a lifetime of practice at walking without falling over.

I think the comic that's gotten me the most feedback is actually the one about the stoplights. Noticing when the stoplights are in sync, or calculating the length of your strides between floor tiles - normal people notice that kind of stuff, but a certain kind of person will do some calculations.

There are so many adventures that you miss because you're waiting to think of a plan. To find them, look for tiny interesting choices. And remember that you are always making up the future as you go.

Sometimes I mistake this for a universe that cares.

Things are rarely just crazy enough to work, but they're frequently just crazy enough to fail hilariously.

Space is about 100 kilometers away. That’s far away—I wouldn’t want to climb a ladder to get there—but it isn’t that far away. If you’re in Sacramento, Seattle, Canberra, Kolkata, Hyderabad, Phnom Penh, Cairo, Beijing, central Japan, central Sri Lanka, or Portland, space is closer than the sea.