Wednesday, July 10, 2013

It’s elementary


Oliver Sacks, neurologist/psychologist/best-selling author, had an essay in the New York Times the other day about turning 80. He had a bit to say about age and elements of the same atomic number. At 79, he is gold. At 80, he will be mercury. He's looking forward to it, he says. Being 80, that is. Sounds like a slippery slope to me.

I looked to see what element's atomic number was my age, 76. Osmium. No gold or mercury for me. Just boring old osmium that no one has ever heard of. The name osmium comes from the Greek for "smell," because of the smoky aroma of one of its oxides. A bit of irony, since I have no sense of smell. Osmium also has the dubious distinction of being the densest naturally-occurring element. Dense and stinky. It is also the rarest element in the Earth's crust, presumably because it mostly sank towards the core when the Earth was molten. Dense and stinky and hard-to-find.

Anyway, I have only a few more weeks with osmium. Then I turn iridium. Another rare metal of even less distinction than osmium. No, wait! We have heard of iridium. Iridium is rare in the Earth's crust (it is the second densest element), but it is more common in meteorites. And it is also more common in the thin layer of global sediment that marks the boundary between rocks of Cretaceous age and rocks of Tertiary age. Which happens to be when the dinosaurs became extinct. Bam! Big meteorite hits Earth, kicking up a worldwide cloud on iridium-rich dust. Now that's a story I can live with for a year.

From then on it's up-hill element-wise –- platinum, gold, scintillating mercury –- but downhill age-wise, Oliver Sack's optimism notwithstanding.