Babies are born bluegray – the color of predawn sky. For the first time, atmospheric oxygen diffuses across the membranes of their lungs and into their bloodstream, where it is picked up and carried by molecules of hemoglobin.
Hemoglobin changes its shape when bound with oxygen. Light hits it differently, reflecting the redness of the iron in the core. As this soft rust travels, wavelike, under the skin, the baby takes on a ruddy glow. We see – in a moment – sunrise.
Meanwhile stars, to do their shining, are converting hydrogen into oxygen, carbon, and iron, releasing these, and other elements, along with light and heat. At the same time, the atoms of our bodies are constantly replaced by others in the surrounding environment. Like a funnel of water above an open drain, we are eddies in a flow of atoms. We are, literally, stardust.