Clair Patterson: The Caltech Scientist Who Exposed Lead Poisoning and Changed the World

[BootinUp]

excerpt

But in 1907, scientists developed the technique of radiometric dating, allowing scientists to compare the amount of uranium in rock with the amount of lead, the radioactive decay byproduct of uranium. If there was more lead in a rock, then there was less uranium, and thus the rock was determined to be older. Using this technique in 1913, British geologist Arthur Holmes put the Earth’s age at about 1.6 billion years, and in 1947, he pushed the age to about 3.4 billion years. Not bad. That was the (mostly) accepted figure when geochemist Clair Patterson arrived at the California Institute of Technology in Pasadena from the University of Chicago in 1952. (Radiometric dating remains today the predominant way geologists measure the age of rocks.)

By employing a much more precise methodology, and using samples from the Canyon Diablo meteorite, Patterson was able to place the creation of the solar system, and its planetary bodies such as the earth, at around 4.6 billion years. (It is assumed that the meteorite formed at the same time as the rest of the solar system, including Earth). Subsequent studies have confirmed this number and it remains the accepted age of our planet.

Patterson's discovery and the techniques he developed to extract and measure lead isotopes led one Caltech colleague to call his efforts "one of the most remarkable achievements in the whole field of geochemistry."

But Patterson was not done.

full article on substack https://open.substack.com/pub/californiacurated/p/clair-patterson-the-little-known