The microwave oven was discovered accidentally by Percy Spencer, an engineer at Raytheon, while he was working on active radar sets. He noticed that a chocolate bar in his pocket had melted while he stood near a magnetron. Realizing that the microwave radiation was exciting the water molecules in the food, he tested popcorn and an egg, which exploded. Raytheon filed the first patent in 1945 and produced the 'Radarange,' which was as large as a refrigerator. Over the following decades, the technology was miniaturized and made affordable. The microwave oven revolutionized the modern kitchen by drastically reducing cooking times and enabling the 'TV dinner' and convenience food industries. It represents a classic case of military-funded research (radar) resulting in a transformative consumer product.