Advanced Search Filters
Filter search results by source, date, and more with our premium search tools.
" "The many sorrows of our recent history suggest that we humans have a learning disability.
Carl Edward Sagan (9 November 1934 – 20 December 1996) was an American astronomer, planetary scientist, cosmologist, astrophysicist, astrobiologist, author, and science communicator. His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation. Sagan assembled the first physical messages sent into space, the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan argued the hypothesis, accepted since, that the high surface temperatures of Venus can be attributed to, and calculated using, the greenhouse effect. He testified to the US Congress in 1985 that the greenhouse effect will change the earth's climate system.
Biography information from Wikiquote
Filter search results by source, date, and more with our premium search tools.
Related quotes. More quotes will automatically load as you scroll down, or you can use the load more buttons.
From the surface of the Earth the Sun would have seemed to be flickering, as in a time-lapse movie. So there was a time when sunlight first broke through the dust pall, when the Sun, Moon and stars could first be noticed had there been anyone there to see them. There was a first sunrise and a first nightfall.
Enjoy ad-free browsing, unlimited collections, and advanced search features with Premium.
Let's go back to the solar nebula... with the temperature declining the farther we get from the Sun. ...at different distances from the Sun, different materials will condense out, because they have different vapor pressures or different melting points. ...water condenses out roughly at the vicinity of the Earth, whereas silicates condense out closer to the Sun... you have to go out to somewhere near the present distance of Saturn before methane condenses.