SPECIAL: This one-hour PBS special isn’t easy to describe. Well, it’s an hour – that’s the easy part. And it’s by Eric Idle of Monty Python’s Flying Circus fame, who returns to the realm of absurdist, eccentric and intelligent TV, to explain the universe, through musical numbers, with help from presenter Brian Cox and a small group of singing co-conspirators. These include Warwick Davis, of Life’s Too Short and the Harry Potter movies, as the Big Bang. F