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Physics (from the Greek, φύσις (phúsis), "nature" and φυσικός (phusikós), "natural"), the most fundamental physical science, is concerned with the basic principles of the Universe. Consequently, physics deals empirically with the dynamics of matter in the cosmos.
Introduction
Discoveries in physics find applications throughout the other natural sciences as they regard the fundamental constituents of the natural world. Some of the phenomena studied in physics, such as the phenomenon of conservation of energy, are common to all material systems. These are often referred to as laws of physics. Others, such as superconductivity, stem from these laws, but are not laws themselves because they only appear in some systems. Physics is often said to be the "fundamental science" (chemistry is sometimes included), because each of the other weaker sciences (biology, chemistry, geology, material science, engineering, medicine etc.) deals with particular types of material systems that obey the laws of physics. For example, chemistry is the science of matter (such as atoms and molecules) and the chemical substances that they form in the bulk. The structure, reactivity, and properties of a chemical compound are determined by the properties of the underlying molecules, which can be described by areas of physics such as quantum mechanics (called in this case quantum chemistry), thermodynamics, and electromagnetism.
Physics is closely related to mathematics, which provides the logical framework in which physical laws can be precisely formulated and their predictions quantified. Physical definitions, models and theories are invariably expressed using mathematical relations. A key difference between physics and mathematics is that because physics is ultimately concerned with descriptions of the material world, it tests its theories by observations (called experiments), whereas mathematics is concerned with abstract logical patterns not limited by those observed in the real world (because the real world is limited in the number of dimensions and in many other ways it does not have to correspond to richer mathematical structures). The distinction, however, is not always clear-cut. There is a large area of research intermediate between physics and mathematics, known as mathematical physics.
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Asymptotic behavior for logarithmic diffusion
F. Salvarani In this paper we prove, via the entropy dissipation method, that the solutions of the d-dimensional logarithmic diffusion equation, with nonhomogeneous Dirichlet boundary data, decay exponentially in time toward its own steady state. The result is valid not only in L-norm (as customary when applying ... [J. Math. Phys. 50, 113518 (2009)] published Fri Nov 20, 2009.
Markov property of Gaussian states of canonical commutation relation algebras
Denes Petz and Jozsef Pitrik The Markov property of Gaussian states of canonical commutation relation algebras is studied. The detailed description is given by the representing block matrix. The proof is short and allows infinite dimension. The relation to classical Gaussian Markov triplets is also described. The minimizer of r ... [J. Math. Phys. 50, 113517 (2009)] published Thu Nov 19, 2009.
On some properties of orthogonal Weingarten functions
Benoit Collins and Sho Matsumoto We give a Fourier-type formula for computing the orthogonal Weingarten formula. The Weingarten calculus was introduced as a systematic method to compute integrals of polynomials with respect to Haar measure over classical groups. Although a Fourier-type formula was known in the unitary case, the ort ... [J. Math. Phys. 50, 113516 (2009)] published Wed Nov 18, 2009.
physicsworld.com: news
Nanoparticles sink or swim in sewage
Fri, 20 Nov 2009 14:25:15 -0000
Neutron scattering could help make wastewater nanoparticle free
Binary systems share stardust
Thu, 19 Nov 2009 19:00:00 -0000
Rare glimpse of planet formation in binary star system
UK to pull out of Gemini Observatory
Thu, 19 Nov 2009 14:28:13 -0000
Funding is 'almost certain' to stop after 2012
Physics Today magazine
Materials in extreme environments
Sun, 01 Nov 2009 08:00:00 -0500
The study of materials under harsh conditions is essential to meet a range of energy challenges—from creating better turbines, reactors, and batteries to developing future energy systems in dense plasmas.
Human-generated sound and marine mammals
Sun, 01 Nov 2009 08:00:00 -0500
Loud anthropogenic noises can alter the behavior of whales and other marine mammals, sometimes with fatal consequences
Paul Dirac: Engineer, mathematician, philosopher, physicist
Sun, 01 Nov 2009 08:00:00 -0500
Dirac practiced theoretical physics for almost 60 years with a unique style: a sometimes baffling combination of intuition, imagination, rectilinear logic, and steam-hammer mathematical power.
Ask the Experts - Answers to physics questions at Scientific American.
Meta Description: [ Science questions and science expert answers in chemistry, physics, astronomy, mathematics, computers, environment, geology, medicine ]
Eric Weisstein's Treasure Trove of Physics - Online encyclopedia of physics terms and formulas. Full searchable, and also browsable alphabetically and by topic. Part of Eric's Treasure Troves of Science.
Meta Description: [ Eric Weisstein's World of Physics ]
Physics and Astronomy Classification Scheme (PACS) - Hierarchical numbering scheme, developed by the American Institute of Physics, used to identify fields and sub-fields of physics.
Physics Central - Find out how physics is part of your world. We answer your questions on how things work and keep you informed with daily updates on physics in the news. We describe the latest research and the people who are doing it and show you physics in action.
Meta Description: [ With Physics Central, we communicate the excitement and importance of physics to everyone. We invite you to visit our site every week to find out how physics is part of your world. We'll answer your questions on how things work and keep you informed with daily updates on physics in the news. We'l... ]
Physics Central - A page on modern physics, such as quantum mechanics and black holes, and some mathematics.
Meta Description: [ A page about theoretical physics. ]
Physics News Graphics - Diagrams (with captions) appearing in various AIP publications, sorted by category or by date.
Physics on MathPages - Articles, leaning towards a mathematical description, on a wide range of topics in physics.
Physics Post - A tutorial and article driven community. Votes, science news and a discussion forum.
Physics Today - The flagship publication of the American Institute of Physics (AIP). Provides feature articles, news stories, analyses, book and product reviews, a searchable job database, and obituaries.
Meta Description: [ Physics Today – Your daily physics news and research source ]
Physics.org - Searchable database of physics resources from the Institute of Physics which matches a person's question, age and knowledge profile to handpicked sites. Also includes the Physics Life animation.
Meta Description: [ A unique collection of physics resources for students, teachers and parents. It will help you find information based on your age and knowledge of science. ]
PhysicsWeb - Physics news, jobs, equipment buyer's guide, and events.
Meta Description: [ TBA ]
PhysLINK - Links to physics departments, physical societies, journals, job information, and other physics related information.
Meta Description: [ Physics, astronomy and science news, community, education and reference. Job board, directories, forums, chat, education reference, fun and more. ]
Physnet: The Physics Departments and Documents Network - Serves information from physics departments and institutes worldwide: departmental information, locally stored documents, authoring tools, free access journals, jobs, conferences and education material.
Meta Description: [ PhysNet is a portal to physics of the ISN and the EPS ]
PhysOrg.com - Physics news, semiconductor technology news, space news and a scientific forum.
Meta Description: [ PhysOrg news: latest science and technology news ]
Scientific American - Questions That Plague Physics - A conversation with Lawrence M. Krauss, chair of the physics department at Case Western Reserve University.
Meta Description: [ Science and Technology at Scientific American.com: Questions That Plague Physics: A Conversation with Lawrence M. Krauss -- [ COSMOLOGY ] -- Science and Technology from Scientific American: daily science news and technology news, science trivia, science experts, science newsletters, science shop... ]
The Net Advance of Physics - MIT resource providing discussions at various levels of sophistication that cover all areas of physics.
Meta Description: [ The Net Advance of Physics ]
Usenet Physics FAQ - sci.physics frequently asked questions with answers.
What You Want To Know About Physics - Summarizes in simple language, without advanced mathematics, the foundations of physics. The index gives direct access to selected topics.
Journal of Mathematical Physics - Journal of Mathematical Physics: All Topics
Physics Today magazine - The magazine for the physics community
PhysicsWeb News - PhysicsWeb News
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Simultaneity - Albert Einstein The Theory of Relativity:Imagine two observers, one seated in the center of a speeding train car, and another standing on the platform as the train races by. As the center of the car passes the observer on the platform, he sees two bolts of lightning strike the car - one on the front, and one on the rear. The flashes of light from each strike reach him at the same time, so he concludes that the bolts were simultaneous, since he knows that the light from both strikes traveled the same distance at the same speed, the speed of light. ... |
