The idea that our universe is not alone — that it might be one among many universes, like a froth of soap bubbles — is not new. For instance, some cosmologists have proposed the theory of the multiverse, the idea that there may exist an infinite number of other universes besides our own; parallel worlds that may even be ruled by radical, bizarre laws of physics.
But while these theories excite the imagination, many scientists believe they are better fodder for science fiction than actual science. That's because most conceptions of parallel universes entail that they are fundamentally undetectable. A parallel universe is, by definition, separate from our own universe, and since we can only observe things inside our universe, these parallel universes must be forever unobservable. In the language of science, if something is unobservable, it may as well not exist.
A recent study by one scientist from the California Institute of Technology could change everything, however. Dr. Ranga-Ram Chary believes he may have found evidence that parallel universes have been bumping up against ours, like bubbles floating in a foam, and that these bumps have caused "bruises" that can be observed, reports New Scientist.
Chary looked for signs of these cosmic bumps in the Planck map of the cosmic microwave background (CMB), a map of the radiation leftover from the first few moments of our forming universe. It's a map that would look the same no matter where you're viewing it from in the universe; a blueprint, if you will, of the structure of the cosmos.
Is there anybody out there? NASA’s Kepler Mission has been on the hunt for possible life-supporting planets since 2009 — and though we don’t have the answer yet, we have a lot of possibilities. This is Kepler-10b, but it probably won’t work — daytime temps are around 2,500 degrees Fahrenheit. But maybe one of these other Kepler-discovered planets is like Earth? (Photo: NASA/Kepler Mission/Dana Berry)
What Chary found was extraordinary: mysterious glowing regions that are consistent with the idea of a bump from a parallel world, a place where matter from another universe may even have briefly leaked into ours.
Extraordinary claims require extraordinary evidence, however, and even Chary admits that there could be an alternative explanation for these bright spots. Rather than be fleeting kisses from a neighboring universe, they might just represent a big patch of hot dust — hardly romantic.
“I suspect that it would be worth looking into alternative possibilities,” suggested Princeton University’s David Spergel. “The dust properties are more complicated than we have been assuming, and I think that this is a more plausible explanation.”
Others are even more skeptical. Joseph Silk of Johns Hopkins University in Baltimore, Maryland, called Chary's parallel universe theory "completely implausible."
“My view is that [the glowing regions] are almost certainly due to foregrounds,” he added.
Obviously more research will be needed to sift through all the possible explanations. In many ways, this puts us right back where we began with the multiverse theory, with it being untestable. If Chary's bright spots are not enough to rule out alternative theories, then they may simply remain mysterious, and the multiverse theory reserved to mere speculation.
On the other hand, these bright spots also offer multiverse enthusiasts something they were previously missing: something observable. And if it's possible that parallel universes can be observed, even indirectly, from the insides of our universe, then perhaps they can be scientifically investigated after all. It's a possibility that can't be so easily ignored, at the very least.