Documentary: Why is the universe speeding up?

The Universe is expanding but why is it accelerating? For thousands of years we've believed that the entire universe unfolded from its light. However the real truth about the cosmos lies not in what meets the eye but in the darkness. A mysterious new reality is emerging. A strange dark matter somehow binds stars and galaxies. And an even more enigmatic dark energy is causing the expansion of the universe to speed up. This is the story of a brilliant group of scientist whose are the next big step in untangling the enigma.