First Observational Test of the ‘Multiverse’
The theory that our universe is contained inside a bubble, and that multiple alternative universes exist inside their own bubbles – making up the ‘multiverse’ – is, for the first time, being tested by physicists.

Image caption: The signatures of a bubble collision at various stages in the analysis pipeline. A collision (top left) induces a temperature modulation in the CMB temperature map (top right). The ‘blob’ associated with the collision is identified by a large needlet response (bottom left), and the presence of an edge is highlighted by a large response from the edge detection algorithm (bottom right). In parallel with the edge-detection step, we perform a Bayesian parameter estimation and model selection analysis.
Two research papers published in Physical Review Letters and Physical Review D are the first to detail how to search for signatures of other universes. Physicists are now searching for disk-like patterns in the cosmic microwave background (CMB) radiation – relic heat radiation left over from the Big Bang – which could provide tell-tale evidence of collisions between other universes and our own.
