In 1945, Raytheon engineer Percy Spencer noticed a candy bar melting in his pocket while he worked near a radar magnetron. Instead of dismissing the accident, he tested the same energy on popcorn and eggs, then developed the technology that became the microwave oven—and ultimately transformed how the world cooks.

In 1945, Raytheon engineer Percy Spencer noticed a candy bar melting in his pocket while he worked near a radar magnetron. Instead of dismissing the accident, he tested the same energy on popcorn and eggs, then developed the technology that became the microwave oven—and ultimately transformed how the world cooks.

The melted snack supplied a clue, but a patent, a team of engineers and two decades of miniaturisation turned microwave heating into an everyday appliance.