Richard Feynman (1918-1988) was a Nobel Prize-winning theoretical physicist who was one of the best-known scientists in the world during his lifetime. A pioneer in various scientific subcategories, Feynman is credited for contributions in quantum mechanics, quantum electrodynamics, quantum computing, and early conceptualization in nanotechnology. Feynman was one of the developers of the atomic bomb during World War II and a member of the Rogers Commission that investigated the Space Shuttle Challenger disaster of 1986.
"Scientific knowledge is an enabling power to do either good or bad — but it does not carry instructions on how to use it. Such power has evident value — even though the power may be negated by what one does with it."
Source: The Value of Science (1955), an address to the National Academy of Sciences [via Wikiquote]