I look at my four boys, who are the colors of silt, loam, dust, and clay, an infinite palette for children of their own, and I understand that time erases whiteness altogether.

For if there is any single thing that everyone hopes for most dearly, it must be this: that the youngest outlive the oldest.

In the long run, most of us spend about fifteen minutes total in the entanglements of passion, and the rest of our days looking back on it, humming the tune.

There are always more questions. Science as a process is never complete. It is not a foot race, with a finish line.... People will always be waiting at a particular finish line: journalists with their cameras, impatient crowds eager to call the race, astounded to see the scientists approach, pass the mark, and keep running. It's a common misunderstanding, he said. They conclude there was no race. As long as we won't commit to knowing everything, the presumption is we know nothing.

The arrogance of the able-bodied is staggering. Yes, maybe we'd like to be able to get places quickly, and carry things in both hands but only because we have to keep up with the rest of you ... We would rather be just like us, and have that be all right.

The moth settled onto the curtain and sat still. It was an astonishing creature, with black and white wings patterned in geometric shapes, scarlet underwings, and a fat white body with black spots running down it like a snowman's coal buttons. No human eye had looked at this moth before; no one would see its friends. So much detail goes unnoticed in the world.

When the scope of the problem seems insuperable, isn't it time to call this one, give it up, and get on with life as we know it. I do know that answer to that one: that's called child abuse. When my teenager worries that her generation won't be able to fix this problem, I have to admit to her that it won't be up to her generation. It's up to mine. This is a now-or-never kind of project.