The doctrine that the world is made up of objects whose existence is independent of human consciousness turns out to be in conflict with quantum mechanics and with facts established by experiment.”
Posts Tagged ‘Physics’
Tags: Nature, philosophy of science, Physics, Reality
Tags: computation, Physics, quantum computation
You’ve heard the hype a hundred times: Physicists hope to someday build a whiz-bang quantum computer that can solve problems that would overwhelm an ordinary computer. Now, four separate teams have taken a step toward achieving such “quantum speed-up” by demonstrating a simpler, more limited form of quantum computing that, if it can be improved, might soon give classical computers a run for their money. But don’t get your hopes up for a full-fledged quantum computer. The gizmos may not be good for much beyond one particular calculation. Even with the caveats, the challenge of quantum computing has proven so difficult that the new papers are gaining notice. “The question is, does this give you a first step to doing a hard calculation quantum mechanically, and it looks like it might,” says Scott Aaronson, a theoretical computer scientist at the Massachusetts Institute of Technology (MIT) in Cambridge and an author on one of the papers. (via New Form of Quantum Computation Promises Showdown With Ordinary Computers – ScienceNOW)
Tags: Physics, quantum foam, quantum gravity, Quantum Mechanics
Can we find evidence for quantum gravity? That’s a major puzzle in Physics. This might be possible using a simple table-top experiment, according to Jacob Bekenstein, at the Hebrew University of Jerusalem. Why should we take him seriously? Bekenstein is best known for studying the thermal properties of black holes, showing that entropy is proportional to the surface area of a black hole’s event horizon, recently announced an amazing proposal to use single photons for probing what is known as “quantum foam.” The quantum foam idea was introduced in 1955 by the American physicist John Archibald Wheeler, and is believed to exist on length scales so small that quantum fluctuations affect the very structure or texture of space–time. Bekenstein’s proposal is one of the the latest assaults in the quest to understand how quantum mechanics might be unified with Einstein’s General Theory of Relativity. Such a Unified Field Theory has escaped the grasp of physicists since they first began to understand the quantum and relativistic worlds in the early 20th century.
Why? A major challenge in coming up with a workable theory of quantum gravity is a complete lack of experimental evidence. The effects of quantum gravity are only expected to be measurable over extremely small distances. VERY VERY extremely small distances. But Bekenstein may have invented a clever loophole.