William Thomson, Lord Kelvin, published his first scientific paper at sixteen, was appointed to a university chair at twenty-two, and dominated British physics for over fifty years. He laid the transatlantic telegraph cable, established the absolute temperature scale that bears his name, and formulated the second law of thermodynamics. He also declared heavier-than-air flight impossible and calculated the age of the Earth at a fraction of its actual value — spectacular errors from one of science’s most formidable minds.

This episode traces Kelvin from his Belfast childhood through the thermodynamic breakthroughs, the transatlantic cable triumph, and the famous wrong predictions that show even genius has limits.

• Thomson’s prodigious youth — university at ten, published at sixteen, professor at twenty-two
• The absolute temperature scale and the second law of thermodynamics
• The transatlantic telegraph cable and the engineering triumph that made him Lord Kelvin
• The wrong predictions — the age of the Earth, heavier-than-air flight, and the limits of Victorian physics