The LIGO announcement

BBC News rapidly broke away from the 3.30 pm news conference back to the studio, where their own woefully ill-informed correspondent recycled the headlines. The press conference, aimed at lay people, was crammed full with awesome videos and clear explanation. So if you really want to know why this is such a big deal, here's the video - you may have to advance it a little to the start.

LIGO instruments measure gravitational waves at a time resolution of milliseconds. We were both intrigued that planned devices will be able to measure gravitational radiation with a cycle time of a billion years (!) - at 57 minutes 13 seconds.