Explain Quantum-Physics?
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According to quantum mechanics, an object exists for you only when you are aware of its existence. Otherwise it is a probablitly.\nI will give an example: If you look away from your computer to say a TV, then the computer object has ceased to exist and TV has started existing. But the you who is looking at TV is different from the previous you who was looking at the computer, because when the computer ceased to exist, so did you and so did the universe frame containing you, computer and the elements like light that made looking at computer possible. Now you, TV and the process of looking at TV is happening in a different universe.\nNow if you again turn your head to look towards computer, you will cease to exist with the TV universe and enter a third universe identical to the first universe. But how do you see the same computer if you are entering the new universe, then this is one of the less known uses of our memory, that is being used by the universe to make fools of us.
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Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity. The ultimate goal of some is a unified framework for all fundamental forces—a "theory of everything".\n\nclick here:http://en.wikipedia.org/wiki/Quantum_gravity#Overview
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Newtownian mechanics deals with behavior of macroscopic objects; quantum mechanics deals with the behavior of microscopic objects.  It’s called “quantum” because energy comes in discrete, tiny quantities (quanta) that radically affect the behavior of objects such as atoms or protons or electrons.  Instead of being able to describe reality as straightforward cause-and-effect (à la Newton), quantum mechanics ends up taking one down twisted roads of probability in terms of “wave functions,” which could be considered oscillations of a sort, but not exactly oscialltions like waves in a pond or even electric fields in light.\n\nEinstein made contributions to quantum mechanics (most notably his work regarding the quantization light into packets subsequently dubbed “photons,” for which he was awarded a Nobel Prize), but he never quite trusted its non-causal nature.\n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
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In quantum mechanics, particles are desribed by a quantum state that is characterised by a series of "quantum numbers". A closed system of particles obeys one of two sets of rules, depending on the sort of particle. Entanglement is actually easiest to understand for the class of particles called Fermions (particles like electrons and protons) rather than bosons (particles like photons).\n\nFermions obey a rule that says no two of them in a system can have exactly the same quantum state. Spin is a useful quantum number to use here, because it can have only one of two values for a particle - up or down.\n\nImagine creating a system in a very long box with just two electrons in it, one at either end, that are in their lowest possible energy state. They will be identical in all respects except that one will have spin up and the other spind down. There is no way of knowing which is which.\n\nNow imagine measuring the spin of the electron at one end of the box. Lets say its up. This *must* mean that the spin of the electron at the other end of the box is down. So we have "instantaneously" found out the spin of a remote particle, which relativity (which insists information cannot travel faster than light) says cannot happen. Einstein-Podolsky-Rosen argued that this created a paradox at the heart of quantum mechanics.\n\nThe paradox was resolved experimentally by showing that particles whose states are entangled in the way described above do indeed behave as quantum mechanics predicts. These experiments are often carried out with photons. In this case a single photon is broken down into tow or more photons whose quantum states must clearly add to give the state of the original photon (quantum numbers are preserved). \n\nSo say we split a photon into two new photons that differ in polarisation, and send them off in different directions to person a and person b. Person a measures the polarisation of theirs and instantly knows the polarisation of the one person b got. And this is precisely what happens.\n\nThis does not violate relativity because there is no way that person a can communicate to person b the result of their measurement faster than light, so no information can pass faster than the speed of light. This means if the two arrange to measure their photons as soon as they get them, each has exactly the same 50/50 probability of getting either polarisation.\n\nThis seems paradoxical because it is counter to classical intuitive feelings about how the world works. But classical and intuitive feelings are often unreliable, and experiment has shown that the paradox is not really a paradox but ironically a description of how the world really works.\n\nQuantum entanglement is being research for use in cryptography because it impossible to fiddle with. Lets say I split a load of photons and send half to a and half to b as keys to encrypt a message. When a makes his measurements on the photons he will know the results b will get and so can communicate with b securely. But if anyone tries to intercept the message to say b they will destroy the entanglement. They may get the key, but it is useless because they cannot communicate it to b - ie it will be obvious that there has been an interception.
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You mean quantum teleportation? I can point you to some layman's sites explaining how it works. . . Keep in mind, you are only teleporting the state of the "matter" (the experiments I am aware of only move photon states, though in principle you could apply them to electrons and protons), not the energy itself. Also, entangling macroscopic quantities of matter with some stream that could teleport its state (making a copy at the other end) is currently an intractable engineering problem.
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Quantum Physics would say "no". It was long supposed that once we got down to a certain level, everything would be predictable, but as you may already know, quantum physics doesn't tell us yes or no - it gives us several statistical maybes and such.
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For those who understand mathematics, and dare to imagine beyond the usual, quantum mechanics could easily be the most beautiful branch of physics.\n\nQuantum mechanics is a fundamental branch of theoretical physics that replaces Newtonian mechanics and classical electromagnetism at the atomic and subatomic levels. It is the underlying framework of many fields of physics and chemistry, including condensed matter physics, quantum chemistry, and particle physics. Along with general relativity, it is one of the pillars of modern physics.\n\nQuantum mechanics was developed in the first part of the 20th century and was highly successful in explaining the behavior of atoms, molecules and nuclei. Developed between 1900 and 1930 and later combined with the general and special theory of relativity, it revolutionized the concepts of physics. The new concepts, which were the particle properties of radiation, the wave properties of matter, quantization of physical properties and the idea that one can no longer know exactly where a single particle such as an electron is at any one instance were necessary to explain all of the new experimental evidence that was available at the time. For example, quantum mechanics explains the behavior of semiconductors which are used to make the myriad of devices we use every day.\n\nFollowing are the important contributors to the foundation of quantum mechanics and the principles they uncovered.\n\nYear  Researcher    Quantum Mechanics Concept\n1901  Planck        Blackbody radiation\n1905  Einstein      Photoelectric effect\n1913  Bohr          Quantum theory of spectra\n1922  Compton       Scattering of photons off electrons\n1924  Pauli         Exclusion principle\n1925  de Broglie    Matter waves\n1926  Schroedinger  Wave equation\n1927  Heisenberg    Uncertainty principle\n1927  Davison and Germer  Wave properties of electrons\n1927  Born          Interpretation of the wavefunction\n\n[The answer given by the first user (theswarm666x) is foolish. Although, one gives such examples in order to explain students of quantum mechanics what is actually meant by the terms like 'tunneling', you could not and should not use quantum mechanics in such a situation. Quantum mechanics talks about the wave aspect of objects (which is significant only for very small bodies) and waves can travel through walls.]
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Quantum mechanics is a mathematical theory that can describe the behavior of objects that are roughly 10,000,000,000 times smaller than a typical human being. Quantum particles move from one point to another as if they are waves. However, at a detector they always appear as discrete lumps of matter. There is no counterpart to this behavior in the world that we perceive with our own senses. One cannot rely on every-day experience to form some kind of "intuition" of how these objects move. The intuition or "understanding" formed by the study of basic elements of quantum mechanics is essential to grasp the behavior of more complicated quantum systems. \n\n\nPlease visit the below url for moe information
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Quantum Physics:\n\nThe science of manipulating the inner parts of atoms, to create worm holes, warp spacetime etc. the science attempts to get the atom dissected until you arrive at its smallest component, and then split that.
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http://www.joot.com/dave/writings/articles/entanglement/\n\nhttp://en.wikipedia.org/wiki/Quantum_entanglement\n\nim not sure about your level of expertise on the subject but some goods books are in search of Schodinger's cat by Gribbins and a basic level introduction introducing Quantum theory from the introduction series
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Quantum electrodymanics is the relativistic quantum theory of electromagnetism.  it was developed by Richard Feynman, Julian Schwinger, and Sin-Itiro Tomonaga in the 1940's and they shared a Nobel prize in 1965 for its development. It is, arguably, the most precisely verified scientific theory yet devised, making predictions (of atomic energy levels and of the magnetic moment of the electron - R. Van Dyck, Jr., P. Schwinberg, and H. Dehmelt, Phys Rev. Lett. 59, 26 (1987); P. Milonni, p. 108, The Quantum Vacuum\nAcademic Press, San Diego, CA, 1994) that have been experimentally validated to 1 part in 10^12!  \n\n1 part in 10^12 is about the ratio of the diameter of a large bacterial cell to the diameter of the Earth.
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reality in quantom physics is all probability.. there is a probability that a particle comes into existance... etc
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This might not be one sentence, but might help in understanding the concept easily. \n\nOk...now...in simpler terms..\nWe all are familiar with an atom. Atom is made up of core nucleus and electrons around the nucleus. If you look inside the Nucleus, you will find protons and neurtons. If you further look inside protons and neutrons, you will have quazars. We were stuck there until the string theory came along. Now...Sting theory suggests that quazars has something inside and that is nothing but a vibrating string of energy(light), which gives it the structure. \n\nSo in sense, its like saying..we have different atoms because deep inside, the string of engery is vibrating with different nodes. Difference in string vibrations is what gives difference in structure of atoms from inside, which is translated outside. Its an interesting concept. \nBoth scientists and philosophers are equally interested in this because string theory says that it all boils down to the vibrations of strings of energy in the subatomic level. So that is like saying....matter might look solid but deep inside, its just energy...more like an invisible light. \nHope this explanation helps. Ofcourse there is more to it than what i explained. There is tons of mathematical calculations and revolutionary ideas in quantum physics that goes with string theory. They are still working on it. Try watching "The elegant universe". It was originally aired in PBS, but i guess you can buy it in bookstores like Barnes&Nobels. Its fantastic. You can understand it easily since they show animations of it.
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A quantum computer is any device for computation that makes direct use of distinctively quantum mechanical phenomena, such as superposition and entanglement, to perform operations on data. In a classical (or conventional) computer, the amount of data is measured by bits; in a quantum computer, it is measured by qubits. The basic principle of quantum computation is that the quantum properties of particles can be used to represent and structure data, and that quantum mechanisms can be devised and built to perform operations with this data. Quantum computers use the principle of electron entanglement and use the 32 quantum states of the electron to perform calculations. If a successful quantum computer could be constructed, it would be millions of times more powerful than any computer today.\n\nQuantum information science concerns information science that depends on quantum effects in physics. It includes theoretical issues in computational models as well as more experimental topics in quantum physics including what can and cannot be done with quantum information. Quantum computing is a subfield of quantum information science
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The first website gives a good overview with no math, if you already understand light/waves/atoms skip to the part that I put in paranthesis.\nThe third site is a more advanced and goes more into the consequences.  In case we have different ideas of what laymen are.\nHere's a quick summary:\nquantum entanglement is when one photon of light is split into two equal photons of opposite polarity (direction of the wave disturbance) .  The two photons seem to be linked in a way that is currently innexplicable but demonstratable using interference patterns.  Which I hope you don't consider techno babble, but if you do, just ask what interference patterns are and I'll answer that, too.  That's a quick expanations of what's happening.\nUnless you mean why, the last site does a pretty good job of explaining that we don't really know, but we're trying pretty hard to figure it out.  There are many theories right now.  It'll go over a couple of them.(it's really an excellent paper.  I don't know what level of physics education you have, but it was perfect for me.I'm not a physicist, I'm a chemist.)
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A good book is called the new quantum universe.  You'll need to give yourself a bit of time to absorb all that information.  But it contains all the basic ideas, formulations and explanations to get started
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how about quantum information theory?  this encompasses some of the cool research that's going on currently, including quantum entanglement, teleportation and the 'quantum parallelism' that you get by using quantum bits in a superposition of states.  \n\nhttp://www.imaph.tu-bs.de/qi/concepts.html\nhttp://www.qubit.org/index.html\nhttp://plato.stanford.edu/entries/qt-entangle/\n\ngood luck!