It does no harm to the romance of the sunset to know a little bit about it.

It's perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential population growth. Jobs and wages depend on science and technology.

One of the great commandments of science is: 'Mistrust arguments from authority.'

I’m struck again by the irony that spaceflight-conceived in the cauldron of nationalist rivalries and hatreds-brings with it a stunning transnational vision. You spend even a little time contemplating the Earth from orbit and the most deeply engrained nationalisms begin to erode. They seem the squabbles of mites on a plum.

we make our world significant by the courage of our questions and the depth of our answers

How lucky we are to live in this time / the first moment in human history / when we are in fact visiting other worlds

We are the universe experiencing itself.