The notion of multiple universes is one that cosmologists like to theorize about but generally don’t relish proving, mainly because doing so would be very difficult. But a team of researchers that showed a few years ago how matter might travel between our universe and others now think they ought to be able to observe this phenomenon in action using existing technology, lending credence to the multiverse theory. All they need is a neutron bottle, some neutrons, and a year.
Metamaterials can be used to create desktop black holes and simulate multiverses; now a physicist is using them to prove time travel can’t happen.
In a new paper, University of Maryland professor and metamaterial theorist Igor Smolyaninov says mapping light distribution in a metamaterial can serve as a model for the flow of time. The model shows that the forward direction of time is unrelenting; you cannot curve back on time and go back to where you started. You just have to build a desktop Big Bang to prove it.
Just when the search for exoplanets looked like the undisputed fashionable field of study for 2010, the cosmic microwave background (CMB) is stepping to the forefront of astronomy and cosmology. Last month, it was Oxford's Roger Penrose claiming that he'd found evidence of a cyclical universe in patterns of concentric circles in the CMB, suggesting our universe is just one of many that have come before it (and will come after it).
Man-made metamaterials could theoretically bend light to create invisibility cloaks, or alter electromagnetic waves in ways nature never intended. Now, a researcher at the University of Maryland in College Park thinks they could do much more than that, becoming man-made analogies to various cosmological theories of how the Universe works and helping researchers explain certain aspects of those universes.
First came dark matter, the gravitational source from within our galaxy that astronomers couldn't see. Then came dark energy, the undetectable force pushing the expansion of the universe. Now, NASA scientists believe they have confirmed a new player, dubbed "dark flow," that is dragging hundreds of galaxies along the same path. Even stranger, the researchers believe that dark flow is actually the gravitational pull from matter beyond the edge of the known universe.
For some time, physicists have theorized about the existence of alternate universes. In fact, some models of physics require multiple universes, to explain some rarely observed phenomena. But, other than obvious ones like The Man In The High Castle Universe where the Nazis won WWII, the Earth-295 Age of Apocalypse Universe, and the Terran Empire "Mirror Mirror" Universe, just how many alternate universes are there? Well, some Stanford University physicists have answered that question, and the magic number is: 10^10^16 other realities.
You're unique. Aren't you? One of the more creative hypotheses surrounding quantum mechanics posits the exact opposite. Though we can readily see only one world, quantum mechanics says that when we're not observing the particles that make up that world, those particles exist in multiple places at once. There are many theories that attempt to grasp what this means, but one of the most tantalizing is Hugh Everett's multiverse concept.
Physicists argue that studying multiverses and extra dimensions is just as scientific as understanding the observable
By Gregory MonePosted 03.18.2008 at 11:54 am 4 Comments
Is all this work on string theory and multiple dimensions and extra universes still science? Thats the question physicist Sean Carroll and writer John Horgan recently debated. Carroll, of the California Institute of Technology, also blogs regularly for Cosmic Variance, and he wrote out a detailed post explaining his position. Obviously, as a cosmologist who works full-time on these seemingly preposterous ideas, he is a bit biased. Hes not the guy youd expect to stop and say it isnt real science. But his piece on the subject does effectively explain why he and, one assumes, other theoretical physicists working on these problems think this way.