Do you ever wonder what would have happened if you had made a different choice, said a different thing, or turned a different corner? Would these decisions have affected your life, or even the world around you?
Do a myriad of different worlds exist where all of these possibilities play out? Where the meteor missed the earth millions of years ago leaving the dinosaurs to rule, or where Germany had won the World War?
A team of scientists from Griffiths University in Australia and the University of California suggest that these worlds could actually exist as part of a complex system of parallel universes which subtly interact with and influence one another.The new theory could help to explain some anomalies in quantum mechanics that have kept scientists guessing for centuries.
‘The idea of parallel universes in quantum mechanics has been around since 1957,’ said Howard Wiseman, a professor in Physics at Griffith University. ‘In the well-known ‘Many-Worlds Interpretation," each universe branches into a bunch of new universes every time a quantum measurement is made.
The "Many Worlds" theory was first proposed by Hugh Everett, based on evidence that quantum particles can occupy two states simultaneously, a fact that he explained by suggesting that both states co-existing in different universes.
Professor Wiseman and team subscribe to Everett’s theory, and believe that our version of the universe we experience is just one of an infinite number of other. Some could be very similar, whilst some could be vastly diverse in nature. To their inhabitants, each world is equally "real" with its own unique properties and characteristics.
"All possibilities are therefore realised – in some universes the dinosaur-killing asteroid missed Earth, said Prof.Wiseman. "In others, Australia was colonised by the Portuguese."
"But critics question the reality of these other universes, since they do not influence our universe at all," he added. "On this score, our ‘Many Interacting Worlds’ approach is completely different, as its name implies."
The researchers believe that there is a universal force of repulsion between closely existing worlds which tend to make them more dissimilar.
Dr Michael Hall from Griffith’s Centre for Quantum Dynamics added that the ‘Many-Interacting Worlds’ theory may even open up the potential to actually test to see if these worlds exist:
"The beauty of our approach is that if there is just one world, our theory reduces to Newtonian mechanics, while if there is a gigantic number of worlds it reproduces quantum mechanics," he explained."In between it predicts something new that is neither Newton’s theory nor quantum theory.
‘We also believe that, in providing a new mental picture of quantum effects, it will be useful in planning experiments to test and exploit quantum phenomena.’
"For us at least there is nothing inherently implausible in the idea," added Professor Wiseman."For fans of science fiction it makes those plots involving communication between parallel worlds not quite so far-fetched after all."