If we ruin the earth, there is no place else to go.
We are like butterflies who flutter for a day and think it is forever.
You are made of a hundred trillion cells. We are, each of us, a multitude.
In order to make an apple pie from scratch, you must first create the universe.
When we look up at night and view the stars, everything we see is shinning because of distant nuclear fusion.
By looking far out into space we are also looking far back into time, back toward the horizon of the universe, back toward the epoch of the Big Bang.
Knowing a great deal is not the same as being smart; intelligence is not information alone but also judgement, the manner in which information is coordinated and used.
If I finish a book a week, I will read only a few thousand books in my lifetime, about a tenth of a percent of the contents of the greatest libraries of our time. The trick is to know which books to read.
We are fortunate: we are alive; we are powerful; the welfare of our civilization and our species is in our hands. If we do not speak for Earth, who will? If we are not committed to our own survival, who will be?
The lifetime of a human being is measured by decades, the lifetime of the Sun is a hundred million times longer. Compared to a star, we are like mayflies, fleeting ephemeral creatures who live out their lives in the course of a single day.