You know you've reached middle age...
When you're cautioned to slow down by your doctor, instead of by the police.
Clair Cameron PattersonBorn 2 Jun 1922; died 5 Dec 1995 at age 73.U.S. geochemist who in 1953 made the first precise measurement of the Earth's age, 4.55 billion years. He pioneered in three major areas of geochemical research. (1) He provided the first reliable ages of the earth and meteorites (1962), using analysis of the isotopic compositions and concentrations of lead in terrestrial materials and meteorites. This has been a benchmark for researchers. (2) He established the patterns of isotopic evolution of lead on earth, by analysis of critical rocks, sediments and waters of the planet. Thus he created a powerful tool for identifying, tracing and evaluating the nature of the major geochemical reservoirs in the crust, mantle, and oceans. (3) He studied environmental lead pollution. |
