By Kristin KalningGames editormsnbc.comupdated 9:13 a.m. ET Oct. 23, 2008 Kristin KalningGames editor• E-mailFifty years ago, before “Pong” and “Space Invaders,” a nuclear physicist created “Tennis for Two,” a 2-D tennis game that some say was the first video game ever.The game was never meant for commercial use. “Tennis for Two” was a science experiment, created by William Higinbotham for the annual visitor’s day at Brookhaven National Laboratory in Upton, N.Y. His aim wasn’t to kick off the multibillion-dollar game industry — he just wanted to “liven up the place” with his invention. And, as he wrote, “convey the message that our scientific endeavors have relevance for society.”