Forty years ago today, “Cosmos: A Personal Journey” – a 13-art miniseries dealing with science, physics, the creation of the universe and the possibility of life among the stars – debuted on PBS. The writer and host was Cornell University astronomer and NASA consultant Carl Sagan, whose insight and ability to simplify complex scientific concepts made the show the most widely-watched PBS series until Ken Burns’ “The Civil War,” a decade later. Here’s a look at Sagan’s career: