The idea that the universe we in habit is just one of many has been floating around scientific circles for years now. The idea, called a multiverse, posits that there are multiple universes out there, likely with different laws of physics. So another universe could look much like our own, or be totally different. Some might be stable, while others may not.
It is also thought that, if these universes touch each other, there would be some kind of evidence left over and, likely, they only evidence we’re likely to find. That’s because, if multiple universes exist, they must be so far apart in space that light traveling between the would carry very little useful information.
But according to Caltech cosmologist Ranga-Ram Chary, we might have traces of one such collision between our universe and a neighbor. The European Space Agency’s Planck telescope inadvertently uncovered a patch of bright light that seems out of place.
The thinking goes that this patch of light is from another universe colliding with ours shortly after the Big Bang, something like a few hundred thousand years after, which is quite short by cosmological standards. That light we’re seeing, which is part of the Planck’s map of the cosmic microwave background, would be left over from that other universe. The brightness may be explained by the other universe having more protons and electrons, per capita so to speak, than does our universe. This might explain why this patch of light is 4,500 times brighter than it should be.
More evidence won’t be easy to gather though, and there isn’t a lot to go on with this one paper. But NASA is working on a new project that might help. The Primordial Inflation Explorer, or PIXIE, is being designed by scientists at Goddard Space Flight Center. PIXIE needs funding, which is unlikely to come along before the end of 2016, but it will contain instruments capable of more accurately observing the light Chary found.