Ask courageous questions. Do not be satisfied with superficial answers.

If you want to make a [rhubarb] pie from scratch, first you have to create the universe.

Extinction is the rule. Survival is the exception.

Before we invented civilization our ancestors lived mainly in the open out under the sky. Before we devised artificial lights and atmospheric pollution and modern forms of nocturnal entertainment we watched the stars. There were practical calendar reasons of course but there was more to it than that. Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.

Humans are very good at dreaming, although you'd never know it from your television.

If the greenhouse effect is a blanket in which we wrap ourselves to keep warm, nuclear winter kicks the blanket off.

When we look up at night and view the stars, everything we see is shinning because of distant nuclear fusion.