How to spot a multiverse

Published in Physics World, 4 October 2011

How can we tell if another universe has collided with our own? Physicists in Canada and the US believe they have the answer – it would leave “a unique and highly characteristic” imprint in the microwave background that pervades the cosmos. The physicists claim that the prediction can be tested using existing and future space telescopes, which contradicts a widespread view that the existence of a multiverse is untestable.

Chuck Bennett, an astrophysicist at Johns Hopkins University in Maryland, US, who was not involved with the study, believes the prediction helps bring multiverse theory into the realms of conventional, falsifiable science. “Science relies on being able to falsify ideas through experiment or observations of nature,” he says. “The fact that these potentialities exist enables us to call this ‘science’. That, to me, is a significant statement.” […]

The rest of this article is available here.