On March 17th, physicists with the BICEP2 experiment announced they had detected the remnant of gravitational waves in the cosmic microwave background, the light left over from the big bang. Although still needing confirmation, the discovery lends weight to the idea that the early universe underwent rapid expansion.
Video credits - writer/host: Sophie Bushwick, production assistant: Geoffrey Giller, editor: Kathryn Free, producer: Eric R. Olson