J. Franklin Hyde, 96, chemist, inventor of silicone—the stuff of breast implants—and other silicon compounds, 11 October 1999.;

Henry W. Kendall, 72, physicist, cofounder of the Union of Concerned Scientists, winner of the Nobel Prize in physics in 1990, and professor of physics at MIT, 14 February 1999.;

Joseph C. R. Licklider, 75, psychologist, Internet visionary, and advocate of computer science programs; as Director of the Information Processing Techniques Office of the Pentagon he established the intellectual framework from which the Internet would develop, 7 August 1990.;

Linus Carl Pauling, 93, chemist, the only man in the world to have won two unshared Nobel Prizes, one in chemis try (1954) and one for peace (1962). Also considered the champion of Vitamin C and its curative powers, 19 August 1994.;

Carl Edward Sagan, 62, astronomer and author, whose lifelong passion was searching for intelligent life in the cosmos, 20 December 1996.;

Jonas Salk, 80, virologist, using killed virus discovered a vaccine for polio in the 1950s...