She had studied the universe all her life, but had overlooked its clearest message: For small creatures such as we the vastness is bearable only through love.

The Apollo pictures of the whole Earth conveyed to multitudes something well known to astronomers: On the scale of the worlds - to say nothing of stars or galaxies - humans are inconsequential, a thin film of life on an obscure and solitary lump of rock and metal

One of the great commandments of science is, 'Mistrust arguments from authority'. (Scientists, being primates, and thus given to dominance hierarchies, of course do not always follow this commandment.)

All civilizations become either spacefaring or extinct.

Demon mean knowledge in Greek, especially about the material world. Science means knowledge in Latin. A jurisdictional dispute is exposed, even if we look no further

The cosmic calendar compresses the local history of the universe into a single year. If the universe began on January 1st it was not until May that the Milky Way formed. Other planetary systems may have appeared in June, July and August, but our Sun and Earth not until mid-September. Life arose soon after. We humans appear on the cosmic calendar so recently that our recorded history occupies only the last few seconds of the last minute of December 31st.

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.