Ultimate fate of the universe out a theory that has since come to be called the Big Bang theory of the origin of the universe. In 1948, Fred Hoyle set out his opposing Steady State theory in which the universe continually expanded but remained statistically unchanged as new matter is constantly created. These two theories were active contenders until the 1965 discovery, by Arno Penzias and Robert Wilson, of the cosmic microwave background radiation, a fact that is a straightforward prediction of the Big Bang theory, and one that the original Steady State theory could not account for. As a result, the Big Bang theory
The Big Bang Theory (season 9) The Big Bang Theory (season 9) The ninth season of the American sitcom "The Big Bang Theory" started airing on CBS on Monday, September 21, 2015. It returned to its regular Thursday time slot on November 5, 2015 for the season's seventh episode. It concluded on May 12, 2016. On March 12, 2014, "The Big Bang Theory" was renewed for an additional three years, extending it through the 2016–17 season for a total of ten seasons. Laura Spencer was upgraded to the main cast during the season as Dr. Emily Sweeney, after being a recurring cast member for two seasons.