Antony Valentini Antony Valentini is a theoretical physicist and a professor at Clemson University. He is known for his work on the foundations of quantum physics.[1] Education and career[edit] Valentini obtained an undergraduate degree from Cambridge University, then earned his Ph.D. in 1992[2] with Dennis Sciama at the International School for Advanced Studies (ISAS) in Trieste, Italy.[1][3] In 1999, after seven years in Italy, he took up a post-doc grant to work at the Imperial College with Lee Smolin and Christopher Isham.[1] He currently works at the Perimeter Institute for Theoretical Physics. Work[edit] Valentini has been working on an extension of the causal interpretation of quantum theory. Quantum equilibrium, locality and uncertainty[edit] In 1991, Valentini provided indications for deriving the quantum equilibrium hypothesis which states that in the frame work of the pilot wave theory. may be accounted for by a H-theorem constructed in analogy to the Boltzmann H-theorem of statistical mechanics.

Quantum spacetime In mathematical physics, the concept of quantum spacetime is a generalization of the usual concept of spacetime in which some variables that ordinarily commute are assumed not to commute and form a different Lie algebra. The choice of that algebra still varies from theory to theory. As a result of this change some variables that are usually continuous may become discrete. Often only such discrete variables are called "quantized"; usage varies. The idea of quantum spacetime was proposed in the early days of quantum theory by Heisenberg and Ivanenko as a way to eliminate infinities from quantum field theory. The germ of the idea passed from Heisenberg to Rudolf Peierls, who noted that electrons in a magnetic field can be regarded as moving in a quantum space-time, and to Robert Oppenheimer, who carried it to Hartland Snyder, who published the first concrete example.[1] Snyder's Lie algebra was made simple by C. The Lie algebra should be semisimple (Yang, I. for the spatial variables . .

Pilot wave In theoretical physics, the pilot wave theory was the first known example of a hidden variable theory, presented by Louis de Broglie in 1927. Its more modern version, the Bohm interpretation, remains a controversial attempt to interpret quantum mechanics as a deterministic theory, avoiding troublesome notions such as instantaneous wavefunction collapse and the paradox of Schrödinger's cat. The pilot wave theory[edit] The pilot wave theory is one of several interpretations of quantum mechanics. It uses the same mathematics as other interpretations of quantum mechanics; consequently, it is also supported by the current experimental evidence to the same extent as the other interpretations. Principles[edit] The pilot wave theory is a hidden variable theory. the theory has realism (meaning that its concepts exist independently of the observer);the theory has determinism. The positions and momenta of the particles are considered to be the hidden variables. Consequences[edit] where is known. . and .

Quantum geometry In theoretical physics, quantum geometry is the set of new mathematical concepts generalizing the concepts of geometry whose understanding is necessary to describe the physical phenomena at very short distance scales (comparable to Planck length). At these distances, quantum mechanics has a profound effect on physics. Quantum gravity[edit] In an alternative approach to quantum gravity called loop quantum gravity (LQG), the phrase "quantum geometry" usually refers to the formalism within LQG where the observables that capture the information about the geometry are now well defined operators on a Hilbert space. In particular, certain physical observables, such as the area, have a discrete spectrum. It has also been shown that the loop quantum geometry is non-commutative[citation needed]. It is possible (but considered unlikely) that this strictly quantized understanding of geometry will be consistent with the quantum picture of geometry arising from string theory. See also[edit]

Wave function collapse When the Copenhagen interpretation was first expressed, Niels Bohr postulated wave function collapse to cut the quantum world from the classical.[5] This tactical move allowed quantum theory to develop without distractions from interpretational worries. Mathematical description[edit] Mathematical background[edit] The quantum state of a physical system is described by a wave function (in turn – an element of a projective Hilbert space). The kets Where represents the Kronecker delta. An observable (i.e. measurable parameter of the system) is associated with each eigenbasis, with each quantum alternative having a specific value or eigenvalue, ei, of the observable. The coefficients c1, c2, c3... are the probability amplitudes corresponding to each basis . For simplicity in the following, all wave functions are assumed to be normalized; the total probability of measuring all possible states is unity: The process of collapse[edit] of that observable. , the wave function collapses from the full . .

Quantum entanglement Quantum entanglement is a physical phenomenon that occurs when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently – instead, a quantum state may be given for the system as a whole. Such phenomena were the subject of a 1935 paper by Albert Einstein, Boris Podolsky and Nathan Rosen,[1] describing what came to be known as the EPR paradox, and several papers by Erwin Schrödinger shortly thereafter.[2][3] Einstein and others considered such behavior to be impossible, as it violated the local realist view of causality (Einstein referred to it as "spooky action at a distance"),[4] and argued that the accepted formulation of quantum mechanics must therefore be incomplete. History[edit] However, they did not coin the word entanglement, nor did they generalize the special properties of the state they considered. Concept[edit] Meaning of entanglement[edit] Apparent paradox[edit] The hidden variables theory[edit]

Interpretations of quantum mechanics An interpretation of quantum mechanics is a set of statements which attempt to explain how quantum mechanics informs our understanding of nature. Although quantum mechanics has held up to rigorous and thorough experimental testing, many of these experiments are open to different interpretations. There exist a number of contending schools of thought, differing over whether quantum mechanics can be understood to be deterministic, which elements of quantum mechanics can be considered "real", and other matters. This question is of special interest to philosophers of physics, as physicists continue to show a strong interest in the subject. They usually consider an interpretation of quantum mechanics as an interpretation of the mathematical formalism of quantum mechanics, specifying the physical meaning of the mathematical entities of the theory. History of interpretations[edit] Main quantum mechanics interpreters Nature of interpretation[edit] Two qualities vary among interpretations:

Quantum Physics Revealed As Non-Mysterious This is one of several shortened indices into the Quantum Physics Sequence. Hello! You may have been directed to this page because you said something along the lines of "Quantum physics shows that reality doesn't exist apart from our observation of it," or "Science has disproved the idea of an objective reality," or even just "Quantum physics is one of the great mysteries of modern science; no one understands how it works." There was a time, roughly the first half-century after quantum physics was invented, when this was more or less true. Certainly, when quantum physics was just being discovered, scientists were very confused indeed! But time passed, and science moved on. The series of posts indexed below will show you - not just tell you - what's really going on down there. Some optional preliminaries you might want to read: Reductionism: We build models of the universe that have many different levels of description. And here's the main sequence:

Yves Couder In the first decades of the 20th century, physicists hotly debated how to make sense of the strange phenomena of quantum mechanics, such as the tendency of subatomic particles to behave like both particles and waves. One early theory, called pilot-wave theory, proposed that moving particles are borne along on some type of quantum wave, like driftwood on the tide. But this theory ultimately gave way to the so-called Copenhagen interpretation, which gets rid of the carrier wave, but with it the intuitive notion that a moving particle follows a definite path through space. Recently, Yves Couder, a physicist at Université Paris Diderot, has conducted a series of experiments in which millimeter-scale fluid droplets, bouncing up and down on a vibrated fluid bath, are guided by the waves that they themselves produce. The wave-particle duality is best illustrated by a canonical experiment in quantum mechanics that’s generally referred to as the two-slit, or two-hole, experiment. Scaling up

5 Thought-Provoking Quantum Experiments Showing That Reality Is an Illusion Anna LeMind, In5D GuestWaking Times No one in the world can fathom what quantum mechanics is, this is perhaps the most important thing you need to know about it. Granted, many physicists have learned to use its laws and even predict phenomena based on quantum calculations. 1. Today there are many interpretations of quantum mechanics with the Copenhagen interpretation being perhaps the most famous to-date. As stated by the Copenhagen interpretation, the state of the system and its position relative to other states can only be determined by an observation (the wave function is used only to help mathematically calculate the probability of the system being in one state or another). This approach has always had its opponents (remember for example Albert Einstein’s “God does not play dice“), but the accuracy of the calculations and predictions prevailed. Let us recap the nature of this experiment. 2. There is a source that emits a stream of electrons onto photosensitive screen. 3. 4. 5.

Derek Leinweber Centre for the Subatomic Structure of Matter (CSSM) and Department of Physics, University of Adelaide, 5005 Australia Copyright © 2003, 2004 This page provides a collection of the most recent visualizations of Quantum Chromodynamics (QCD), the underlying theory of the strong interactions. As a key component of the Standard Model of the Universe, QCD describes the interactions between quarks and gluons as they compose particles such as the proton or neutron. State of the art order a4-improved lattice operators are used in creating the animations, including the three-loop improved lattice gauge action and the five-loop improved lattice field strength tensor. The animaton at right was featured in Prof. Frank Wilczek's 2004 Nobel Prize Lecture. Contributions from Sundance Bilson-Thompson on improved operator construction and Ben Lasscock and James Zanotti on the vacuum response to static quarks, are gratefully acknowledged. For copyright information, please contact Derek Leinweber.

Guhr's research Quantum Chaos and Random Matrix Models Random matrices provide powerful models for a rich variety of complex systems. Here is a brief overview. A good example is the atomic nucleus shown to the right. In several different branches of physics, we study chaotically coupled systems or, equivalently, systems with symmetry breaking. Disordered systems are a wide field for applications of Random Matrix Models. local collaborator: Johan Grönqvist (PhD-student) external collaborators: Professor Achim Richter and his group at Technical University of Darmstadt, Professor Hans-Jürgen Stöckmann at University of Marburg. Study of SubAtomic Interactions through Lattice Quantum Chromo Dynamics on Mare Nostrum (SAIL) | Annual Report 2008 Abstract Quantum Chromodynamics (QCD) is the underlying theory governing the interaction between quarks and gluons, the strong force, and therefore, responsible for all the states of matter in the Universe. Analytical solutions of QCD in the low energy regime cannot be obtained due to the complexity of the quark-gluon dynamics. The only known non-perturbative method that systematically implements QCD from first principles is its formulation on a discretized space-time, lattice QCD. Results obtained The computing resources awarded to the project were invested to explore hadron-hadron scattering at different values of the light quark masses and at different lattice spacings. Images Needs of computation for different physics problems: mnad1_jpeg.jpg From quarks to stars. Publications or reports William Detmold, Martin J.

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