The Rest Is Science Polymetalic Nodules Are Weird
May 13, 2026
A strange metallic rock from the deep ocean sparks a tale of Cold War recoveries and secretive salvage stunts. Listeners travel through how metal nodules form and act like natural batteries and weigh the environmental cost of mining the seafloor for battery metals. The conversation also jumps to handedness and ambidexterity, lightning risks for tall animals, and why damp cold feels colder.
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Glomar Explorer Was A CIA Cover Story
- Hannah Fry recounts the Cold War CIA operation using the Glomar Explorer and Howard Hughes as a cover to attempt to recover a sunken Soviet submarine.
- The 'mining worthless rocks' cover story successfully hid a classified deep-sea salvage operation.
Hannah's Polymetallic Nodule Gift
- Hannah Fry was gifted a polymetallic nodule recovered from the Atlantic and keeps it as a prized possession in her Cambridge office.
- She describes its look, texture, and the missing letter that purportedly documented its exact recovery location, making the object feel personally mysterious.
Ocean Pearls Grow Millimeters Per Million Years
- Polymetallic nodules form by hydrogenous precipitation, layering metals like manganese, nickel, and cobalt around a tiny seed over tens of millions of years.
- They grow at roughly one millimeter per million years and reach potato- to grapefruit-size, meaning many formed around the time of the dinosaurs.