Where does gold come from? - David Lunney

Summary

Medieval alchemists' dream of turning lead into gold is now possible through modern science, as gold originates from supernovae explosions in space. Earth's gold was likely delivered by such cosmic events and is found in veins formed by geothermal activity. Despite the possibility of creating gold in particle accelerators, it's currently unfeasible due to time and cost. The ocean contains vast amounts of gold, but its recovery is not economically viable. Future exploration may target extraterrestrial sources or benefit from cosmic events.

Takeaways

• 🧙‍♂️ Medieval alchemists sought to turn lead into gold, a process that was once thought impossible but is now achievable through modern science.
• 🌌 Gold is not native to Earth but was formed in space, specifically in supernovae, which are massive stellar explosions.
• 🔬 In stars, nuclear fusion converts hydrogen into heavier elements like helium, carbon, and oxygen, and eventually iron and nickel.
• 💥 Supernovae occur when a star's core collapses, creating extreme pressure that fuses protons and electrons into neutrons, leading to the formation of heavier elements like gold.
• ⚛️ The creation of heavy elements in a supernova happens rapidly, within seconds, contrasting the millions of years it takes for lighter elements to form.
• 🌐 Earth's gold was likely brought to our planet by supernova shockwaves that propelled elemental debris, which later condensed into new celestial bodies.
• 🏭 Gold is extracted from Earth through mining, a costly and labor-intensive process due to its rarity and the fact that all mined gold could fit into just three Olympic-size swimming pools.
• 🔬 Scientists can produce gold using particle accelerators by mimicking the nuclear reactions that occur in stars, but the process is currently too slow and expensive for practical use.
• 🌊 The world's oceans contain an estimated 20 million tons of gold, albeit at extremely low concentrations, making its extraction currently unfeasible.
• 🚀 Future exploration of other planets and celestial events, such as supernovae, might provide new sources of gold, though with potential risks to Earth's ecosystem.

Q & A

What were the alchemists in medieval times trying to achieve?

The alchemists in medieval times were trying to transform lead into gold, a process that was thought to be impossible at the time.

How is gold formed according to modern scientific understanding?

Gold is formed extraterrestrially, primarily during supernovae, where extreme pressures and conditions allow for the creation of heavy elements like gold.

What role do stars play in the creation of gold?

Stars play a pivotal role in the creation of gold by undergoing nuclear fusion, which eventually leads to supernovae where the conditions are right for the formation of gold and other heavy elements.

Why doesn't nuclear fusion in a star produce gold under normal circumstances?

Under normal circumstances, nuclear fusion in a star doesn't produce gold because the energy released isn't sufficient to force together protons and electrons to form neutrons, which is necessary for the creation of heavy elements like gold.

How does the process of creating gold in a supernova differ from the fusion of hydrogen to helium?

The creation of gold in a supernova is a rapid process that takes place in seconds, in contrast to the slow fusion of hydrogen to helium, which takes millions of years.

How does gold end up on Earth after a supernova explosion?

After a supernova explosion, the expanding shockwave propels elemental debris, including gold, through the interstellar medium, where it can become part of new star and planet formations, including Earth.

What is the significance of Earth's gold being kneaded into veins by geothermal activity?

The kneading of gold into veins by geothermal activity is significant because it concentrates the gold, making it easier to mine and extract for human use.

How much gold has been mined in all of human history, and how is this quantity visualized?

All the gold mined in human history could be visualized as filling just three Olympic-size swimming pools, highlighting the rarity and value of gold.

Can we produce gold using modern technology, and if so, how?

Yes, we can produce gold using particle accelerators that mimic the nuclear reactions occurring in stars, but the process is currently too slow and expensive to be practical.

Where else on Earth might there be significant amounts of gold, aside from within the Earth's crust?

The ocean is estimated to hold about 20 million tons of dissolved gold, although the concentrations are so low that it is currently not economically feasible to extract it.

What are some hypothetical future sources of gold that are mentioned in the script?

The script mentions the possibility of mining gold from other planets in our solar system and the potential for future supernovae to shower Earth with gold, although the latter also carries the risk of eradicating life.