Stephen Feeney at University College London and a few pals say they’ve found something in the echo of the Big Bang. These guys start with a different model of the universe called eternal inflation. In this way of thinking, the universe we see is merely a bubble in a much larger cosmos. This cosmos is filled with other bubbles, all of which are other universes where the laws of physics may be dramatically different to ours. These bubbles probably had a violent past, jostling together and leaving “cosmic bruises” where they touched. If so, these bruises ought to be visible today in the cosmic microwave background.