The idea that parallel universes exist has been the baseline of several science fiction films and series for decades, but this ideas has been a challenge for theoretical astrophysicists who try to explain the elusive nature that holds together subatomic particles, atoms and planets. Now a group of cosmologists who study the early universe believe they have found a way to find those signs that definitely prove the existence of other multiverses. Experts say that parallel universe basically inhabit the same physical space as our own and as they collide, they leave behind traces in the comic background which we can detect.
After looking at the background radiation-the microwave echo that comes from the beginning of the universe, researchers have found unusual gaps or "hot spots" that could be indicative of a disruption caused by the "friction" with other universes.
Writing for The Conversation, Dr Eugene Lim, a lecturer in theoretical particle physics and cosmology at King's College London, explained other universes would exist in the same physical space as our own.
He said: 'Indeed, they inevitably must collide, leaving possible signatures in the cosmic sky which we can try to search for.
'The exact details of the signatures depends intimately on the models – ranging from cold or hot spots in the cosmic microwave background to anomalous voids in the distribution of galaxies.
'Nevertheless, since collisions with other universes must occur in a particular direction, a general expectation is that any signatures will break the uniformity of our observable universe.'
Dr Lim emphasized that the idea of "multiverse" emerged as part of theories to unify quantum mechanics – the behavior of atoms and subatomic particles - and gravity.
Experts believe that the ‘hidden dimensions’ are curled or 'compactified' and are believed to be too small to be detectable, occurring in an almost infinite number of ways.
But ok… what happened after the Big Bang? Experts believe that the Big Bang was followed by a period of rapid expansion of the universe referred to as "cosmic inflation". But this widely accepted theory, requires that some parts of the universe are still accelerating.
'This means that the universe is, at least according to our current understanding, eternally inflating.
'Some parts can therefore end up becoming other universes, which could become other universes [and so on]. This mechanism generates an infinite number of universes.
'By combining this scenario with string theory, there is a possibility that each of these universes possesses a different compactification of the extra dimensions and hence has different physical laws.'
If scientists are able to identify specific signatures in the CMB (Cosmic Microwave Background) it would be then possible to obtain the answer to what form these universe would take.
Dr Lim added: These signatures are actively being pursued by scientists. Some are looking for it directly through imprints in the cosmic microwave background, the afterglow of the Big Bang. However, no such signatures are yet to be seen.
'Others are looking for indirect support such as gravitational waves, which are ripples in space-time as massive objects pass through.
'Such waves could directly prove the existence of inflation, which ultimately strengthens the support for the multiverse theory.
'Whether we will ever be able to prove their existence is hard to predict. But given the massive implications of such a finding it should definitely be worth the search.'
by Ivan; http://www.ewao.com/a/1-can-you-prove-the-existence-of-parallel-universes-scientists-believe-to-have-found-the-answer