Perhaps the depth of love can be calibrated by the number of different selves that are actively involved in a given relationship.

We are star stuff which has taken its destiny into its own hands. The loom of time and space works the most astonishing transformations of matter.

There are many hypotheses in physics of almost comparable brillance and elegance that have been rejected because they did not survive such a confrontation with experiment. In my view, the human condition would be greatly improved if such confrontations and willingness to reject hypotheses were a regular part of our social, political, economic, religious and cultural lives.

The cosmos is within us. We are made of star stuff

Whatever the reason you're on Mars, I'm glad you're there, and I wish I was with you.

If our long-term survival is at stake, we have a basic responsibility to our species to venture to other worlds. Sailors on a becalmed sea, we sense the stirring of a breeze.

The universe forces those who live in it to understand it.