Summary
Overview
Michael Stevens and Hannah Fry explore the surprising science of water in this engaging episode, revealing that ice qualifies as a mineral and water is technically molten rock (lava). They delve into Earth's water distribution, showing that only a minuscule fraction is accessible freshwater, and discuss the origins of water on our planet, revealing that more than half predates our sun. The conversation touches on the physics of refrigeration and the remarkable nature of this essential substance.
Water as Lava: Redefining Ice and Water
Michael introduces a mind-bending concept that challenges our understanding of water: ice is actually a mineral, which makes water molten rock or lava. This classification is based on ice meeting all the criteria for a mineral - it's inorganic, solid, and has a definite crystal structure. The fluid dynamics of water and lava behave identically, further supporting this unconventional but scientifically valid perspective.
- Ice qualifies as a mineral because it's inorganic, solid, and has a definite crystal structure
- A cube of ice is a monomineralic rock, making melted ice molten rock or lava
- Ice won the Mineral Cup in 2015 when geologists voted on their favorite mineral
- The fluid dynamics of lava and water behave exactly the same way
" Ice is a rock. Sure. Because, well, hold on. Ice is a mineral because a mineral is just a inorganic material that is solid and has a definite crystal structure, which ice does. "
" So melted ice is molten rock, lava. So water is lava. "
Earth's Water Distribution: A Tiny Accessible Fraction
The hosts reveal the shocking reality of water availability on Earth. While our planet is known for being water-rich, only 2.5% of all water is fresh, and the amount actually accessible to humans as liquid surface water is an astonishingly small 0.0072% of Earth's total water. This discussion highlights how biased our perception is toward the tiny fraction of water we interact with daily, while most remains locked in oceans, ice, and underground reserves.
- Only 2.5% of Earth's water is fresh; the rest is too salty to drink
- Almost 70% of freshwater is frozen in glaciers and ice caps
- Another 30% of freshwater is groundwater, not on the surface
- Only 0.0072% of all Earth's water is accessible surface freshwater in rivers, lakes, and springs
- All human water use - drinking, showering, swimming pools - comes from just 0.0072% of Earth's water
" Only 0.0072% of all the water on earth... It is a tiny minuscule fraction of the 1% of the 2.5% that's not salt water. "
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