Golden Stardust

When you think of gold (Photo 1), what comes to your mind? To some, gold mining is an environmental threat. To others, gold is a store of wealth that keeps its value over time. A thin layer of gold is added to the surface of some religious symbols or as a topping of sparkles on a chocolate treat. Gold is worn as jewellery. Gold is used in medicine. If you are reading this note on a computer or cell phone, the electronic components in that device contain gold. Gold is important.

Photo 1: A spectacular sample of gold, entwined with the white mineral called quartz. The sample comes from the Croesus Mine, Munro Township, Ontario. The sample is on long-term loan to the Royal Ontario Museum, from the Ontario Geological Survey. Photographed by Andy Fyon, Oct 23/13. [note added in humour: on the label for this sample, under the heading quality, is the descriptive text "killer". I assume that means this is a pretty good sample. ]

Where did that gold come from?

  • A bank; true, but before the bank?

  • A mine; true, but before the mine?

  • Rocks deep in the Earth; true, but before the Earth?

  • Hummm, stars?

Yes! All the gold on Earth came from stars. Exploding stars, to be more precise.

Stars are nuclear reactors. Hydrogen atoms in the star combine through a process called fusion. Atoms of new elements are a by-product, created over millions of years. But not all elements are created this way: just elements having an atomic mass up to iron. The fusion energy is not energetic enough to create heavier elements like gold.

So, how do stars produce elements heavier than iron? Two other processes are accepted. As a star ages, it eventually collapses onto itself to create a supernova explosion. The powerful energy associated with that supernova explosion creates the heavier elements like gold - in seconds! Another source of the heavy elements, like gold, was actually detected on August 17, 2017. That is a kilonova explosion created when two neutron stars collide. It is one of the most powerful stellar explosions. The creation of gold and all other elements heavier than iron by these two processes have something in common: a super powerful nuclear reaction that goes bang!

My head hurts. Let me simplify. All elements, including gold, are star dust.

How did those elements get into the Earth? When a star explodes, all the elements are blasted into space. That space debris ultimately forms new stars and planets! Planets like Earth. And that, grossly simplified, is how Earth obtained all its gold.

We are hoarding, wearing, eating, and using stardust and that is cool!

Feb 12/22; Facebook: Feb 12/22