Built on recycled dinosaur breath
Sunday, June 18, 2017
“The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.”
― Carl Sagan, Cosmos
And, as Sagan might have added, we are built of dinosaur breath, because the universe recycles.
Atoms on Earth tend to stay on Earth, looping through people and progress and places. Leonardo daVinci, then, is just a little part of all of us, and so is Caesar. Because the universe constantly reuses the starstuff atoms, and the Earth reuses its starstuff atoms, we are each a little bit of everything good and everything bad around us.
Atoms — of nitrogen, calcium and the rest — do not come about easily. Only in the unimaginable furnace of the core of a star, where temperatures exceed 18 million degrees, can the ultimate alchemy grow hydrogens, the original atoms, into other elements. This fusion is so blistering that the normally strict separation of hydrogen protons fails, allowing them to approach each other and pair up into larger elements.
So here on Earth, the stuff we started with when the planet formed is all we’ve got, give or take a little meteorite dust. For all the new lava firing out of volcanoes and fresh rain puddling on the lea, fertilizers sparking life from death, and tender greens sprouting free, it has all been here before.
The Earth blasts out mass and gas with every eruption, but that terrestrial heartburn is just a regurgitation of ocean floor once swallowed up in deep trenches, where it slides down into the molten mantle, melting and smelting back into volcano magma. The continent cycle, in which one smudge of volcano vomit is tracked from tuff to trench and back, takes perhaps 400 million years.
The air also recycles. Nitrogen comes and goes, piggybacking and forthing into soil and air and proteins in bacteria and cells. Nitrogen, which dominates the air, is aloof as gases go, rarely interacting and dampening the tendency of the more excitable oxygen to blow things up.
Oxygen visits all of the natural cycles, tied to rocks, tied to plants and animals, tied to water, tied to air.
Oxygen is an electron thief. Left in the company of most other elements, it ties itself to their electrons, creating all sorts of molecules. Oxygen is like a mousetrap: as it approaches an electron belonging to something else, the trap springs shut on a vulnerable electron and, bazinga, a new oxygen compound has formed.
When later the oxygen is hoisted away and the stolen electrons retaken, the mousetrap is reset, ready to steal again. Over and over, in metabolism and lithification and respiration and other processes, the traps are reset and reused.
My folks recycled, too, on a humbler but more discernible scale. An old mattress with plenty of residual flatness morphed into a sofa: Mom sewed it a gracious green upholstery cover, Dad built wooden legs and arms for it, and the mattress body lives on in the living room.
Likewise, their original washing machine still had a few working parts when it was eclipsed by a washer-dryer set. Dad rebuilt it into a lawn mower with a spin cycle that clipped weed and reed and centipede.
Oxygen in the atmosphere is freed by plants, resetting the oxygens by pairing them with other oxygens. Animals scoop them up, bonding them back onto hydrogens and carbons and keeping the energy snap for their own use. But oxygen also clamps onto the silicon and iron and other elements in rocks and dirt — it is a voracious electron snapper — and so ties in with the rock cycle, and the carbon cycle, and the occasional popsicle.
Some of it locks onto the ocean bottom, disappearing for 200 million years underground. Some of it returns to the air, where it may blow completely around the earth in a week, or from pole to pole in a month. Follow a single breath of air drawn by dinosaur or daVinci, and within days it might have spread around the the world, possibly been metabolized by some other creature, maybe hitched a ride with calcite or cloud or cauliflower or creamsicle — by now it could be anywhere on or in the Earth.
Some has come and gone and come again a million times since then, coughing and swallowing and blowing and bonding through multiple configurations on multiple continents in the interim. And since one breath contains over 12 sextillion particles (a 12 with seven comma sets), chances are that at least one of them that rattled through a dinosaur on its blowby through Earth’s systems is now in each of us.
Joy Moses-Hall teaches physics and astronomy at Pitt Community College. She has a doctorate in oceanography and is the author of the novel Wretched Refuge.