Depending on how you define OXO, Tennis for Two was either the first or second video game. A paddle contest displayed on an oscilloscope, the game was created by physicist and pinball fan William Higinbotham, who debuted it in 1958 at the Brookhaven National Laboratory on Long Island. Oh, and Higinbotham also helped build the first atomic bomb and later became an outspoken opponent of nukes. From his 1994 New York Times obituary:

“William A. Higinbotham, a physicist who developed electronic components for the first atomic bomb and then became a leading advocate of controlling nuclear weapons, died on Thursday at his home in Gainesville, Ga. He was 84.

The cause was emphysema, his family said.

Mr. Higinbotham was a group leader in electronics at Los Alamos, N.M., where the first atomic bomb was developed during World War II. But he soon helped establish a group of scientists, the Federation of American Scientists, that warned about the risks posed by nuclear weapons unless they were tightly controlled.

Mr. Higinbotham has also been called the grandfather of modern video games. In 1958, as a senior physicist at Brookhaven National Laboratory on Long Island, he built for the laboratory’s annual public show what was very possibly the first video game — a tennis game that was displayed on a tiny cathode ray tube.”