I’m looking at my gold wedding band.
Glittering gold created in a supernova explosion billions of years ago.
How did it get to my finger?
We are stardust,
We are golden
We are billion year old carbon
– Joni Mitchell
But what about my gold wedding ring? We know that all the heavy elements in the universe are created exclusively in the massive explosions of very large stars, called supernovas. So rare are these that an average galaxy of 100 billion stars only sees a supernova about every hundred years. For a few days, those supernovas may outshine the entire galaxy as they spray atoms of all the elements on the periodic table into interstellar space.
These rare supernovas are the only place in the universe where gold is created.
Over billions of years, the atoms become part of vast galactic clouds and nebula. In more time, a passing gravity wave, perhaps from the violent merger of two black holes, may precipitate a wave of star formation, like water molecules suddenly condensing into drops of liquid water to make clouds.
The nuclei of the forming stars pull in more and more dust, harvesting and concentrating angular momentum, creating spinning eddies around the central star-to-be – thermodynamic engines resisting the inexorable pull of gravity. These spinning clouds condense into planets, not at random, but following the Constructal Law physics of all matter and energy flows.
Billions of years later, we humans come on to the scene. Our planet is 90% molten iron and magma hotter than 1000 degrees C. On the surface floats a thin crust, 70% covered in water. On the remaining 25%, we evolve opposable thumbs to better poke around amongst the planetary detritus.
One might think that gold atoms would be diffused throughout the mass of the earth and its rocks, virtually undetectable in its rarity. But this is not the case.
Instead, we find it in lumps and in very specific places. How did all those diffuse gold atoms from the primordial solar system find each other once on earth? How did they decide to get together and make nuggets that we could find and make into wedding bands?
This question is unanswerable until you begin to comprehend that the crust of the earth is a giant evolving refinery, churning, folding, scraping, compressing and melting, creating trillions of Constructal flows, each creating more access to flows of a specific element or compound until much of the gold (and many other elements) on the earth is concentrated in a few specific locations.
The very fact that I exist to wear a gold wedding band is testimony to billions of years of evolution of the inanimate physical universe and more billions of years of biological evolution, all of it following the same immutable Constructal Law of physics.
We are stardust,
My ring is golden,
We are billions of years of cosmic evolution
See The Physics of Life for more information about the Constructal Law