The First Video Game
There is a lot of controversy over who created the first "video game". The basis of this argument seems to be directly a result of how "video game" is defined. Is it a blanket term for all interactive electronic games? Or is it more strictly refer to games played on a television set?
The earliest game seems to be a missile simulator created by Thomas T. Goldsmith Jr. and Estle Ray Mann in 1947. This was made for s cathode-ray tube but was built with analog circuitry. After this was "Nought and Crosses" (Tic-Tac-Toe) by A.S. Douglas in 1953. And "Tennis for Two" by William Higinbotham in 1958. One displayed on a primitive CTR screen, the other on an oscilloscope. In 1961 students from MIT built "Spacewar!" the precursor to Asteroids. Spacewar! seems to have been the first fully realized video game although it used a vector graphics system for its display. All these games where predecessors to what would become video games that we could play either in an arcade or at home. A problem, though, with these games is that they all ran on huge computer systems that were only found in laboratories and universities.
Enter Ralph Baer. In 1951, Baer a TV engineer presented a novel concept to his employers at Loral. The idea was to create a computer system that would allow people to play games on their TV. This is probably the first time the full concept of video games was realized. To create a portable gaming system pitted for mass consumption. Unfortunately, Baer's idea was not giving to go ahead in 1952 and it took him until 1966 to begin building prototypes for his idea. In 1971 MagnovoxBaer which resulted in the Odyssey, the first home video game. This opened the door for Atari, Coleco, Magnavox and later Nitendo, Sony and Xbox. .
If you define video games as using a video signal, Ralph Baer seems to be the winner. Also, if you are crediting the first fully conceptualized video game system, Ralph Baer seems to still hold sway. But if your crediting the first video game to the first game written for a computer then the simple game created by Goldsmith and Mann would have to take the crown. It is hard to give full credit to anyone though, the argument is riddled with criteria of what defines a "video game".