Main content

Trail: The Mystery of Dark Energy

At the heart of astronomy is a mystery 鈥� what is causing the Universe鈥檚 expansion to speed up? Is it a new force 鈥� Dark Energy? Or is our understanding of how gravity works wrong?

2 minutes

This clip is from

Horizon2016, The Mystery of Dark Energy

More clips from Horizon

See all clips from Horizon (469)