Researchers at the Perimeter Institute for Theoretical Physics are working to bring the multiverse hypothesis — we are living in one universe of many — into the realm of testable science.
Perimeter Associate Faculty member Matthew Johnson and his team are looking for clues for the existence of multiverses (a.ka. parallel universes) in the cosmic microwave background data, assumed to be left over from the Big Bang.
To do that, “we simulate the whole universe,” he says. “We start with a multiverse that has two bubbles in it, we collide the bubbles on a computer to figure out what happens, and then we stick a virtual observer in various places and ask what that observer would see from there.”
For example, if another universe had collided with ours in the early universe, it would have left evidence in the form of a “a disk on the sky,” creating a “bruise” in the pattern, he says. That the search for such a disk has so far come up empty makes certain collision-filled models less likely.