Once the cells in a biological machine stop working, it can never be started again. It goes into a cascade of decay, falling toward disorder and randomness. Except in the case of viruses. They can turn off and go dead. Then, if they come in contact with a living system, they switch on and multiply. (194)

Time has a different quality in a forest, a different kind of flow. Time moves in circles, and events are linked, even if it's not obvious that they are linked. Events in a forest occur with precision in the flow of tree time, like the motions of an endless dance. (p. 12)

It showed a kind of obscenity you see only in nature, an obscenity so extreme that it dissolves imperceptibly into beauty.

During climbs into taller trees, I was occasionally able to look down on the backs of birds, which shine with reflected sunlight as they move through the green depths of the canopy, like schools of fish.

He liked the loneliness of inner space, the sense of being forgotten by the world.

When people asked him why he didn't work with those viruses, he replied, I don't particularly feel like dying.

If equations are trains threading the landscape of numbers, then no train stops at pi.