This stuff is so trippy to think about.
Now Stephen Feeney at University College London and a few pals say they’ve found tentative evidence of this bruising in the form of circular patterns in cosmic microwave background. In fact, they’ve found four bruises, implying that our universe must have smashed into other bubbles at least four times in the past.
Again, this is an extraordinary result: the first evidence of universes beyond our own.
So, what to make of these discoveries. First, these effects could easily be a trick of the eye. As Feeney and co acknowledge: “it is rather easy to fifind all sorts of statistically unlikely properties in a large dataset like the CMB.” That’s for sure!