Sillett watched the motion of the redwoods in silence for a little while. "Despite the difficulty of doing science in these trees, there's always a moment during a climb when you can lose yourself," he went on. "You perceive time more clearly in redwoods. You see time's illusory qualities. When you get up into the crown of a redwood, you stop thinking about your life, you stop planning your future missions. You start feeling the limits of your perceptions of the world as a member of the human species. When you feel one of these trees moving, you get a sense of it as an individual."