Thursday, February 25 is officially “The Big Bang Theory Day,” as announced by the City of Pasadena at a celebration gathering over the weekend. And its only fitting, since the series has claimed Pasadena as its world since its September 24, 2007 debut. The gathering of series stars Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik, and Melissa Rauch, along with Executive Producers/Co-Creators Chuck Lorre and Bill Prady, as well as EP/Showrunner Steven Molaro made the