Carl Sagan - The Varieties of Scientific Experience - A Personal View of the Search for God

Figure 36.Cretaceous-Tertiary Impact

Don Davis, one of the greatest painters of science-based art, takes us to the panicky last second of the age of the dinosaurs. An asteroid or comet some 10 kilometers in diameter plunged through the shallow ocean near what is now Yucatan in Mexico, igniting global wildfires and producing a dense cloud of smoke and dust that darkened and froze the surface of the Earth.

[1]The Lorentz transformations specify how time slows down and length contracts in any frame of reference depending on its relative speed. Einstein's theory of special relativity derived the Lorentz transformation by assuming a constant speed of light for all observers.

[2]There is something anthropocentric without a doubt in talking about liquid water, but let's grant them that. It's curious in these arguments to find organisms who are made largely of liquid water saying that liquid water is central to the universe. But put that aside.

[3]In July 2006, NASA announced that the Cassini space probe in the Saturn system observed evidence for numerous great lakes of liquid hydrocarbons on Titan.

[4]In 2006 the Planetary Society and Harvard University inaugurated the SETI Optical Telescope, the first-ever optical observatory dedicated to the search for intelligent extraterrestrial signals. For the history of the Planetary Society and SETI, see www.planetary.org, and for the thrill of actually participating in the search, go to www.setiathome.ssl.berkeley.edu/.

[5]In 1998 two international teams of astronomers independently reported unexpected evidence that the expansion of the universe is accelerating. These findings suggest that the universe is not oscillating but will continue to expand forever.

[6]Earth-based telescopes provided the answer in 1998. See previous note.

[7]By 2006 the world nuclear arsenals had been reduced to about twenty thousand weapons-still roughly ten times what would be necessary to destory our our global civilization. The principal reductions since 1985 were due to the 1993 Start II Treaty between the United States and the Soviet Union.

[8]In 1988 the Vatican allowed samples of the original shroud material to be dated by the radiocarbon method. Three laboratories (in Arizona, Oxford, and Zurich) independently determined that the fabric dates from the period A.D. 1260 to 1590.