Saturday, August 26, 2017

Summer Air

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I just read Caesar’s Last Breath, in which author Sam Kean makes science writing as fun as anything else you’d bring to Limantour Beach for an enjoyable summer read, with the difference that he imparts thought-provoking information in addition to relaxing entertainment.

One of the chapters is about a gas we all take for granted, a component of the air all around us, called oxygen. It kind of jams my gears to imagine living in the vast span of human history before oxygen was discovered, before its true nature was precipitated out of the chaos of thousands of years of phlogiston and swirling human wonder. It’s thought-provoking to be reminded that oxygen was discovered less than 250 years ago, and it’s entertaining to read about the people and their experiments which led to the discovery. Imagine trying to discover oxygen yourself. How would you go about it?



Every schoolchild knows we need oxygen to breathe, to animate our lives so we can do things like walk to Sculptured Beach at Point Reyes and take pictures of weird rock formations. It’s a rote fact that we don’t even stop to think about, but around the late 1700s, as Kean writes, “[Antoine] Lavoisier had articulated the connections between fire, oxygen, and breathing, declaring that breathing was a sort of slow, controlled burning in our lungs. It remains one of the most important chemical discoveries ever….”

Having already discussed nitrogen, which preceded oxygen’s introduction to the Earth’s atmosphere, Kean continues farther down the page that, “Oxygen and nitrogen are neighbors on the periodic table…, [b]ut if the buildup of nitrogen a few billion years ago gave our planet its third and most benevolent atmosphere, the arrival of oxygen inaugurated a fourth and much more explosive regime. Whereas nitrogen is non-reactive to the point of being comatose, oxygen is volatile, manic, a madman in most every chemical reaction. It actually poisons many forms of life, and caused the greatest crisis that life on Earth ever faced, the so-called Oxygen Catastrophe of two billion years ago….”



Wikipedia refers to this “catastrophe” a little differently. On one hand oxygen’s arrival caused a mass extinction, but on the other hand, “the Great Oxygenation Event alone was directly responsible for more than 2,500 new minerals of the total of about 4,500 minerals found on Earth.”

I wonder which of the many minerals that make the geology of Point Reyes so interesting owe their existence to the formation of oxygen some 2.5 billion years ago.

In Caesar’s Last Breath, Kean writes that “oxygen destroyed early life because it detonates so easily inside cells; yet when life learned how to control oxygen, that reactivity became its greatest asset.” Continuing in a more arch vein, he continues, “And given how much havoc oxygen has wreaked throughout history, it’s fitting that this element destroyed every chemist who had a hand in its discovery. It’s the Hope Diamond of the periodic table.”

A science book written with a novelist’s flair: now that's a breath of fresh air.




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