Earlier this year, a paper appeared in the journal Physical Review D, entitled “First observational tests of eternal inflation: Analysis methods and WMAP 7-year results” describing analysis of 7 year long survey of the Cosmic Microwave Background — which is the afterglow of the big bang — that attempted to identify signatures of a picture of the universe known as “the eternal inflation model” and to try and test the so-called “bubble-collision hypothesis”.

According to the BBCs reporting of the paper, this theory suggests that we live in a bubble. That our Universe is a bubble. One of many, many bubbles constantly popping into existence. And even colliding. In an ever expanding Universe.

Do you follow? No, neither did we.

So we asked Hiranya Peiris of University College London and Matt Johnson of the Perimeter Institute for Theoretical Physics, Canada, to come in an explain it to us.