There are more than one universe. Is this theory is calculative or just a hypothetical Concept . LET US SEE WHAT MICHIO KAKU SAYS IN HIS BOOK "PARALLEL WORLDS". To understand what parallel universes might look like, we must first understand the symmetries of the strong, weak,and electromagnetic interactions. The strong force, for example, is based on three quarks (sub -particles ) which scientists label by giving them a ficttious “color” (for example, red, white, and blue). We want the equations to remain the same if we interchange these three colored quarks. We say that the equations have SU(3) symmetry, that is, when we reshuffle the three quarks, the equations remain the same. Scientists believe that a theory with SU(3) symmetry forms the most accurate description of the strong interactions (called Quantum Chromodynamics :- a new theory of nuclear forces). If we had a gigantic supercomputer, starting with just the masses of the quarks and the strength of their interac tions, we could, in theory, calculate all the properties of the proton and neutron and all the characteristics of nuclear physics. Similarly, let’s say we have two leptons, the electron and the neutrino. If we interchange them in an equation, we have SU(2) symmetry. We can also throw in light, which has the symmetry group U(1). (This symmetry group shuffles the various components or po- larizations of light among each other.) Thus, the symmetry group of the weak and electromagnetic interactions is SU(2) × U(1). If we simply glue these three theories together, not surprisingly we have the symmetry SU(3) × SU(2) × U(1), in other words, the sym- metry that separately mixes three quarks among themselves and two leptons among themselves (but does not mix quarks with leptons). The resulting theory is the Standard model ( unifying the three natural forces excluding gravity ) , which, as we saw ear- lier, is perhaps one of the most successful theories of all time. As Gordon Kane of the University of Michigan says, “Everything that happens in our world (except for the effects of gravity) results from Standard Model particle interactions.” Some of its predictions have been tested in the laboratory to hold within one part in a hundred million. (In fact, twenty Nobel Prizes have been awarded to physi- cists who have pieced together parts of the Standard Model.) Finally, one might construct a theory that combines the strong, weak, and electromagnetic interaction into a single symmetry. The simplest GUT theory that can do this interchanges all five particles (three quarks and two leptons) into each other simultaneously. Unlike the Standard Model symmetry, the GUT symmetry can mix quarks and leptons together (which means that protons can decay into electrons). In other words, GUT theories contain SU(5) symme- try (reshuffling all five particles—three quarks and two leptons— among themselves). Over the years, many other symmetry groups have been analyzed, but SU(5) is perhaps the minimal group that fits the data. When spontaneous breaking occurs, the original GUT symmetry can break in several ways. In one way, the GUT symmetry breaks down to SU(3) × SU(2) × U(1) with precisely 19 free parameters that we need to describe our universe. This gives us the known universe. However, there are actually many ways in which to break GUT sym- metry. Other universes would most likely have a completely dif- ferent residual symmetry. At the very minimum, these parallel universes might have different values of these 19 parameters. In other words, the strengths of the various forces would be different in different universes, leading to vast changes in the structure of the universe. By weakening the strength of the nuclear force, for exam- ple, one might prevent the formation of stars, leaving the universe in perpetual darkness, making life impossible. If the nuclear force is strengthened too much, stars could burn their nuclear fuel so fast that life would not have enough time to form. The symmetry group may also be changed, creating an entirely different universe of particles. In some of these universes, the pro- ton might not be stable and would rapidly decay into antielectrons. Such universes cannot have life as we know it, but would rapidly dis- integrate into a lifeless mist of electrons and neutrinos. Other uni- verses could break the GUT symmetry in yet another way, so there would be more stable particles, like protons. In such a universe, a huge variety of strange new chemical elements could exist. Life in those universes could be more complex than our own, with more chemical elements out of which to create DNA-like chemicals. We can also break the original GUT symmetry so that we have more than one U(1) symmetry, so there is more than one form of light. This would be a strange universe, indeed, in which beings might “see” using not just one kind of force but several. In such a universe, the eyes of any living being could have a large variety of receptors to detect various forms of light-like radiation. Not surprisingly, there are hundreds, perhaps even an infinite number of ways to break these symmetries. Each of these solutions, in turn, might correspond to an entirely separate universe.
Posted on: Fri, 21 Jun 2013 21:10:38 +0000
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