California is a western state in the United States. Penny, Leonard, Sheldon and Raj moved to Pasadena to begin their careers in science or acting.
Howard, Amy and Bernadette were either born or at least grew up in California.
California is the most populous state and home to the second and fifth largest metro areas, Los Angeles and San Francisco. First settled by Native Americans, the state was developed by the Spanish and then became part of Mexico. After won by the U.S. in the Mexican War, California has become a diverse multi-cultural state which has a large fruit and vegetable industry, entertainment industry and technology industry. It also contains the highest and lowest points in the United States and has the third longest coastline.
"The Big Bang Theory" was filmed in Los Angeles in the movie making capital of the world, Hollywood.