Matters of Scale - Reaction Times

Elapsed time between stimulus and involuntary human response (e.g., blink)
220 milliseconds

Between stimulus and voluntary response (e.g., braking to avoid obstacle)
384 milliseconds

Between emergency 911 call and arrival of fire department (Seattle, 2005)
4 minutes, 14 seconds

Between Japan's attack on Pearl Harbor and President Franklin Roosevelt's
declaration of war 22 hours, 37 minutes

Between the conception and birth of a human being
266 days

Between the reporting of the Antarctic ozone hole and the effective date of the Montreal Protocol
3 years, 7 months, 16 days

Between the Einstein/Szilard letter to Roosevelt warning of Nazi atomic weapon research and the first atomic blast ("Trinity" test) in New Mexico
5 years, 11 months, 14 days

Between President John F. Kennedy's speech calling for the United States to go to the moon and the Apollo 11 landing
8 years, 1 month, 27 days

Between NASA scientist James Hansen's August 1988 U.S. Senate testimony on the reality of global warming and a substantive U.S. federal response
17 years, 10 months +

Sources: Individual times: Robert J. Kosinski, Clemson University. Fire response: City of Seattle government. Roosevelt speech: History and Politics Out Loud (www.hpol.org/fdr/war). Human gestation: Gale Encyclopedia of Childhood and Adolescence. Einstein/Trinity: American Institute of Physics (www.aip.org/history/einstein), Wikipedia. Kennedy speech/Apollo 11: Wikipedia. Hansen testimony: J.N. Wilford, New York Times, August 23, 1988.