Few questions grip the mind more forcefully than those about the creation of the universe, and since the discoveries of the 1920s it has been a primary goal of physicists to trace the history of the universe back to "where it all came from" the moment of creation in the Big Bang. This is the up-to-date story of the enormous growth in knowledge of the early universe and the important discoveries about that titanic explosion that took place 15 billion years ago.