Of all the pundits and bloggers looking down their noses at Marco Rubio for not knowing the age of the Earth, how many have any clue how the age was calculated, or how the Earth formed, or how scientists figured out how it formed?
I thought the answer to those questions would make a good topic for a story, and in my research I came across this column in USA Today by Dan Vergano. The column gives due credit to Clair Patterson - one of the most underappreciated scientists of the 20th century and one most often wrongly referred to as a she. Vergano’s column is one of the smartest pieces of writing to emerge from Rubio/age of the Earth fray.
Here’s the meat of the science:
In 1955, Patterson published a study in the journal Geochimica et Cosmochimica Acta, that reported lead ratios found in one of the Canyon Diablo meteorites. These iron meteorites are the leftover pieces of a big one that created Meteor Crater in Arizona about 50,000 years ago. Most important, they were also leftovers from the formation of the solar system, which before the publication of his papers was known only to be billions of years ago. As Patterson explained in an interview in the year that he died, the Canyon Diablo meteorites didn't contain any uranium, a metal that radioactively decays into lead at well-established rates taking hundreds of millions of years. Other rocks contained both lead and uranium, screwing up earlier age estimates.
So, by reporting the ratio of lead types found in these pristine meteorites and comparing them to lead ratios found in the other rocks on the Earth and other meteorites, Patterson could calculate the age of the solar system, when the Earth formed, to be 4.55 billion years old, give or take 70 million years. "Except for a few minor disagreements, this paper is probably a concrete expression of the attitudes of most investigators in the field," Patterson noted in the study.
The column also goes into Patterson’s other underappreciated claim to fame – getting the lead out of gasoline. This has all been told before by Bill Bryson, who wrote a beautiful version of the Clair Patterson story for his book, “A Short History of Nearly Everything.” But it’s a story worth retelling and Vergano was smart to do it while the age of the Earth is in the news.