Professor Jim Al Khalili from the University of Surrey delves into over 50 years of the BBC science archive to tell the story behind the emergence of one of the greatest theories of modern science, the Big Bang. The remarkable idea that our universe simply began from nothing has not always been accepted with the conviction it is today and, from fiercely disputed leftfield beginnings, took the best part of the 20th century to emerge as the triumphant explanation of how the universe began. Using curious horn-shaped antennas, U-2 spy planes, satellites and particle accelerators, scientists have slowly pieced together the cosmological jigsaw, and this documentary charts the overwhelming evidence for a universe created by a Big Bang.

Every cosmologist and astronomer agrees: our Universe is 13.7 billion years old. Using cutting-edge technology, scientists are now able to take a snapshot of the Universe a mere heartbeat after its birth. Armed with hypersensitive satellites, astronomers look back in time to the very moment of creation, when all the matter in the Universe exploded into existence. It is here that we uncover an unsolved mystery as old as time itself -- if the Universe was born, where did it come from? Meet the leading scientists who have now discovered what they believe to be the origin of our Universe, and a window into the time before time.