History Channel ® : In 1954, a young Princeton university doctoral candidate named Hugh Everett III came up with a radical idea: That there exist parallel universes, exactly like our universe. These universes are all related to ours; indeed, they branch off from ours, and our universe is branched off of others. Within these parallel universes, our wars have had diferent outcomes than the ones we know. Species that are extinct in our universe have evolved and adapted in others. In other universes, we humans may have become extinct.
This thought boggles the mind and yet, it is still comprehensible. Notions of parallel universes or dimensions that resemble our own have appeared in works of science fiction and have been used as explanations for metaphysics.
With his Many Worlds theory, Everett was attempting to answer a rather sticky question related to quantum physics: why does quantum matter behave erratically? The quantum level is the smallest one science has detected so far. The study of quantum physics began in 1900, when the physicist Max Planck first introduced the concept to the scientific world. Planck’s study of radiation yielded some unusual findings that contradicted classical physical laws. These findings suggested that there are other laws at work in the universe, operating on a deeper level than the one we know.
Parallel Universes: Split or String?
The Many-Worlds theory and the Copenhagen interpretation aren’t the only competitors trying to explain the basic level of the universe. In fact, quantum mechanics isn’t even the only field within physics searching for such an explanation.
Following his famous Theory of Relativity, Einstein spent the rest of his life looking for the one final level that would answer all physical questions. Physicists refer to this phantom theory as the Theory of Everything. Quantum physicists believe that they are on the trail of finding that final theory. But another field of physics believes that the quantum level is not the smallest level, so it therefore could not provide the Theory of Everything.
These physicists turn instead to a theoretical subquantum level called string theory for the answers to all of life. String theory was originated by the physicist Michio Kaku. His theory says that the essential building blocks of all matter as well as all of the physical forces in the universe — like gravity — exist on a subquantum level. These building block resemble tiny rubber bands – or strings – that make up quarks – quantum particles -, and in turn electrons, and atoms, and cells and so on. Exactly what kind of matter is created by the strings and how that matter behaves depends on the vibration of these strings. It is in this manner that our entire universe is composed. And according to string theory, this composition takes place across 11 separate dimensions. According to the theory, our own universe is like a bubble that exists alongside similar parallel universes. Unlike the Many Worlds theory, String theory supposes that these universes can come into contact with one another. Gravity can flow between these parallel universes. When these universes interact, a Big Bang like the one that created our universe occurs.
Einstein didn’t live long enough to see his quest for the Theory of Everything taken up by others. Then again, if Many Worlds is correct, Einstein is still alive in a parallel universe. Perhaps in that universe, physicists have already found the Theory of Everything.