George Paget Thomson was born in Cambridge, England, on May 3, 1892. the only son of J. J. Thomson, a Nobel Prize-winning physicist, and Rose Paget, the daughter of Sir George Paget, a distinguished professor of medicine. Thomson's mother had met her husband while she was one of his students in the Cavendish Physical Laboratory. Not surprisingly, given the family tradition of learning, particularly in the physical sciences, Thomson showed an interest in science at a young age. His first recorded scientific inquiry is said to have concerned the twisting motion of a swing that hung in his nursery.

At Perse School, where he was sent in 1895, he demonstrated a talent for rugby, but, although he was physically agile, he never particularly enjoyed team sports. When the time came for Thomson's graduation, his headmaster advised him to study classics, but Thomson decided on a career in physics. In 1910, he entered...