About observables in physics the use of the term observable in control theory Observability Cleanup date July 2010 No footnotes date May 2009 In physics , particularly in quantum physics , a system observable is a property of the Quantum state system state that can be determined by some sequence of physical operational definition operations . For example, these operations might involve submitting the system to various electromagnetic field s and eventually reading a value off some gauge. In systems governed by classical mechanics , any experiment ally observable value can be shown to be given by a real ... between system state and the value of an observable requires some basic linear algebra for its description ... meaningful observable. For the case of a system of Elementary particle particle s, the space V .... For example, suppose math a rangle math is an eigenket eigenvector of the observable math mathbf ... of the observable math scriptstyle mathbf A math is made while the system of interest is in the state .... To be more precise, the dynamical variable observable is a not necessarily bounded Hermitian operator .... In an infinite dimensional Hilbert space, the observable is represented by a Symmetric operator ... of an observable represents a real physical quantity for that particular dynamical variable, then we must conclude that there is no largest eigenvalue for the position observable in this uncountably ... Hilbert space, the role of an observable in quantum mechanics is to assign real numbers to outcomes of particular measurements this means that only certain measurements can determine the value of an observable ... to determine the value of an observable. Incompatibility of observables in quantum mechanics A crucial ... corresponding to non commutative operators are called incompatible . See also Observable universe ... Hilbert space. , www.am473.ca, 10 26 08 refend Category Quantum mechanics ca Observable cs Pozorovateln veli ina de Observable es Observable eo Videbla fiziko fr Observable it Osservabile hu Megfigyelhet ... more details
In mathematics , in the representation theory of algebraic group s, an observable subgroup is an algebraic subgroup of a linear algebraic group whose every finite dimensional rational representation arises as the restriction to the subgroup of a finite dimensional rational representation of the whole group. An equivalent formulation, in case the base field is closed, is that K is an observable subgroup of G if and only if the quotient variety G K is a quasi affine variety . Some basic facts about observable subgroups Every normal subgroup normal algebraic subgroup of an algebraic group is observable. Every observable subgroup of an observable subgroup is observable. External links http www.jstor.org cgi bin jstor printpage 00029327 di994362 99p00143 Extensions of Representations of algebraic linear groups Category Representation theory of algebraic groups ... more details
Multiple issues wikify April 2012 orphan April 2012 restructure October 2011 unreferenced October 2011 A Partially Observable system is one in which the entire state of the system is not fully visible to an external sensor. In a partially observable system the observer may utilise a memory system in order to add information to the observer s understanding to the system. An example of a Partially Observable system would be a card game in which some of the cards are discarded into a pile face down. In this case the observer is only able to view their own cards and potentially those of the dealer. They are not able to view the face down used cards, and nor are they able to view the cards which will be dealt at some stage in the future. A memory system can be used to remember the previously dealt cards that are now on the used pile. This adds to the total sum of knowledge that the observer can use to make decisions. In contrast, a fully observable system would be that of chess. In chess apart from the who is moving next state the full state of the system is observable at any point in time. Partially Observable is a term used in a variety of mathematical settings, including that of Artificial Intelligence and Partially observable Markov decision process es. Category Systems science ... more details
In statistics , observable variables or manifest variables , as opposed to latent variable s, are those Variable mathematics variables that can be observed and directly measured. ref Dodge, Y. 2003 The Oxford Dictionary of Statistical Terms , OUP. ISBN 0 19 920613 9 ref See also Observables in physics Observability in control theory Latent variable model References references Category Social sciences Category Econometrics Category Statistical terminology Econometrics stub statistics stub ... more details
For a general discussion of the universe Universe File Observable Universe with Measurements 01.png thumb right 350px Visualization of the 93 billion light year or 28 billion parsec three dimensional observable ... small to be seen in the image. cosmology In Big Bang cosmology , the observable universe consists ... to the edge of the observable universe is roughly the same in every direction that is, the observable ... of the universe as a whole. Every location in the universe has its own observable universe which may or may not overlap with the one centered on the Earth. The word observable used in this sense ... is made between the visible universe, which includes only signals emitted since recombination, and the observable ... light years , while the comoving distance to the edge of the observable universe is calculated to be 14.3 ... of the observable universe is estimated to be about 28 billion parsecs 93 billion light year s , ref ... Springer isbn 978 0 387 77637 8 pages 27 ref putting the edge of the observable universe at about 46 ... publisher Scientific American accessdate 2008 11 06 ref The universe versus the observable universe ... would currently lie outside the observable universe. In the future the light from distant galaxies will have had more time to travel, so some regions not currently observable will become observable ... to accelerate, there is a future visibility limit beyond which objects will never enter our observable ... to redshift, as discussed in the following paragraph is only larger than the number currently observable ... years , whereas the current comoving radius of the observable universe is calculated on p. 7 to be 3.38 ... to the cube of the radius, so as shown on p. 8 the ratio between the number of galaxies observable in the future visibility limit to the number of galaxies observable today would be 4.50 3.38 sup 3 sup 2.36. ref Though in principle more galaxies will become observable in the future, in practice ... the observable universe if we can receive signals emitted by the galaxy at any age in its past history ... more details
The no observable adverse effect level NOAEL denotes the level of exposure of an organism , found by experiment or observation , at which there is no biologically or statistically statistical significance significant e.g. alteration of morphology biology morphology , functional capacity, Human development biology growth , development or life span increase in the frequency or severity of any adverse effects in the exposed population when compared to its appropriate control. ref http www.setonresourcecenter.com cfr 40CFR P132 003.htm Seton Resource Center ref ref http en.academic.ru dic.nsf enwiki 3597129 Definition of NOAEL ref In toxicology it is specifically the highest tested dose or concentration of a substance i.e. a drug or chemical or agent e.g. radiation , at which no such adverse effect is found in exposed test organisms where higher doses or concentrations resulted in an adverse effect. ref name Faustman Faustman, E.M., Omenn, G.S. Risk assessment. 2001 In C. D. Klaassen ed. Casarett & Doull s Toxicology, 6. ed., McGraw Hill, New York, pp. 92 94. ISBN 0 07 134721 6. ref ref http www.fsra.net glossary.html Food Safety and Risk Assessment website at Glasgow Caledonian University ref This level may be used in the process of establishing a dose response relationship , a fundamental step in most risk assessment methodologies. In drug development, NOAEL of a new drug is assessed in laboratory animals drugs prior to initiation of clinical trials to establish a safe clinical starting dose in human trials. The United States Environmental Protection Agency US EPA defines NOAEL as an exposure level at which there are no statistically or biologically significant increases in the frequency or severity of adverse effects between the exposed population and its appropriate control some effects may be produced at this level, but they are not considered as adverse, or as precursors ... level References references Category Toxicology de NOAEL fr Dose sans effet toxique observable it NOAEL ... more details
A Partially Observable Markov Decision Process POMDP is a generalization of a Markov Decision Process . A POMDP models an agent decision process in which it is assumed that the system dynamics are determined by an MDP, but the agent cannot directly observe the underlying state. Instead, it must maintain a probability distribution over the set of possible states, based on a set of observations and observation probabilities, and the underlying MDP. The POMDP framework is general enough to model a variety of real world sequential decision processes. Applications include robot navigation problems, machine maintenance, and planning under uncertainty in general. The framework originated in the Operations Research community, and was later taken over by the Artificial Intelligence and Automated planning Automated Planning communities. An exact solution to a POMDP yields the optimal action for each possible belief over the world states. The optimal action maximizes or minimizes the expected reward or cost of the agent over a possibly infinite horizon. The sequence of optimal actions is known as the optimal policy of the agent for interacting with its environment. Definition Formal definition A discrete time POMDP models the relationship between an agent and its environment. Formally, a POMDP ... and acting in partially observable stochastic domains journal Artificial Intelligence Journal volume ... control of partially observable Markov processes last Sondik first E.J. year 1971 publisher Stanford ... control of partially observable Markov decision processes over a finite horizon journal Operations ... title The optimal control of partially observable Markov processes over the infinite horizon discounted ... Persons with Dementia during Handwashing Using a Partially Observable Markov Decision Process author ... Using Video and a Partially Observable Markov Decision Process author Jesse Hoey, Pascal ... control fr Processus de d cision markovien partiellement observable zh ... more details
Context date September 2009 Representation validity is concerned about how well the constructs or abstraction s translate into observable measures. There are two primary questions to be answered Do the sub constructs properly define the construct if you break up the main abstractions into smaller abstractions or definitions ? Do the observation s properly interpret, measure, or test the constructs? One way to argue positively, albeit a very weak argument, is to claim face validity for the construct observable relationship. Basically this is making the following claim on the face of it, it seems like a good translation. The weakness of this argument can be strengthened by a consensus of experts. Another way to argue positively is to claim content validity for the construct observable relationship. To do this one must check the operationalization against the relevant content domain for the construct to extent to which the tests i.e., the observable measures measure the content of the subject being tested i.e., that all the important content areas are covered adequately. Category Validity statistics psychology stub sociology stub statistics stub ... more details
The Minor Planet Electronic Circulars MPECs are published by the Minor Planet Center . They generally contain Astrometry positional observations and Kepler orbit orbits of unusual minor planet s and all comet s. Monthly lists of observable unusual objects, observable distant objects, observable comets and the critical list of numbered minor planets also appear on these circulars. Daily Orbit Update MPECs, issued every day, contain new identifications and orbits of minor planets, obtained over the previous 24 hours. External links http www.minorplanetcenter.net iau services MPCServices.html MPC Publications http www.minorplanetcenter.net mpec RecentMPECs.html Recent MPECs See also Minor Planet Circular IAU Circular Electronic Telegram of the Central Bureau for Astronomical Telegrams sci mag stub Category Astronomy data and publications Category Science and technology magazines ... more details
Unreferenced stub auto yes date December 2009 A hydrological phenomenon , or hydrologic phenomenon , is an observable movement of water within the water cycle . Hydrological phenomena are studied within the field of hydrology , and include precipitation meteorology precipitation , including rain and snow flood s drought s DEFAULTSORT Hydrological Phenomenon Category Hydrology Category Soil physics geomorph stub Hydrology stub ... more details
The Observability Gramian is a Gramian used in optimal control theory to determine whether or not a linear system is observable. For a linear system described by math dot x A x B u math math y C x D u , math The observability Gramian is given by math W o t int limits 0 t e A T tau C T C e A tau d tau math If and only if the matrix math W o math is nonsingular for every math t 0 math , the pair math A,C math is observable. See also Controllability Gramian Gramian matrix References unreferenced date July 2008 Category Control theory math stub ... more details
Dynamic psychiatry is that which is based on the study of emotional processes , their origins, and the mental mechanisms underlying them, rather than observable behavioral phenomena, in contrast with descriptive psychiatry which is based on the study of observable symptoms and behavioral phenomena rather than underlying psychodynamic processes. Most modern psychiatrists believe that it is most helpful to combine the two complementary approaches in a biopsychosocial model . ref name isbn0 415 25670 4 cite book author Williams, Gavin De Kadt, Emanuel Jehuda title Sociology and development publisher Routledge location New York year 2001 pages 152 isbn 0 415 25670 4 ref References reflist Category Psychiatric models psych stub ... more details
Cosmic mass may mean mass of the cosmos , see Mass of the observable universe Cosmic mass distribution , see Cosmic microwave background radiation and Large scale structure of the cosmos Cosmic mass density , see Shape of the Universe Cosmic mass field , see Metric expansion of space Cosmic mass function , see Friedmann equations Techno Cosmic Mass , a religious and musical event, promoted by Matthew Fox priest Techno Cosmic Masses Matthew Fox dab ... more details
In mathematics , in the representation theory of algebraic group algebraic Group mathematics groups , a Grosshans subgroup , named after Frank Grosshans , is an algebraic subgroup of an algebraic group that is an observable subgroup for which the ring mathematics ring of functions on the quotient algebraic variety variety is finitely generated . External links http www.staff.uni mainz.de pommeren Artikel invar.pdf Invariants of Unipotent subgroups http www.math.lsa.umich.edu idolga invbook.pdf Lectures on Invariant Theory Category Representation theory of algebraic groups algebra stub ... more details
MMG may refer to Mechanomyogram or mechanomyography , measuring the mechanical signal observable from the surface of a muscle when the muscle is contracted Medium machine gun , a category of firearm Minerals and Metals Group , an Australia based mining company Mosley Music Group , a record label created by Timbaland Motor City Machine Guns , a professional wrestling tag team often abbreviated MMG Maybach Music Group , record label founded by Rick Ro Rick Ross disambig de MMG it MMG ja MMG ru ... more details
Mergeto Pulsar date April 2010 Timing noise is the name for rotational irregularities observed in all pulsars . This timing noise is observable as random wandering in the pulse frequency or phase. ref http www.saao.ac.za wgssa as4 urama.html African Skies 4 Radio Pulsar Glitch Studies Bot generated title ref It is unknown whether timing noise is related to pulsar Glitch astronomy glitches . References references var star stub physics stub Category Pulsars ... more details
Business event can refer to A phenomenon , any observable occurrence, or an extraordinary occurrence, that has significance to a business. A type of gathering A convention meeting , for example, a sales convention A Users group meeting In technology Event computing , a software message indicating that something has happened, such as a keystroke or mouse click Event UML , in Unified Modeling Language, a notable occurrence at a particular point in time Complex event processing where events that have significance to the business may be deemed Business Events. disambiguation ... more details
learning , and can be solved with value iteration and related methods. Partially observable Markov decision process A POMDP partially observable Markov decision process POMDP is a Markov decision ... more details
In quantum mechanics , a complete set of commuting observables CSCO is a set of commutative commuting operator mathematics operator s whose eigenvalue s completely specify the quantum state state of a system harv Gasiorowicz 1974 p 119 . For example, in the case of the hydrogen atom , the Hamiltonian quantum mechanics Hamiltonian H , the angular momentum L and its projection mathematics projection L sub z sub along any arbitrary z axis form a CSCO if one ignores the spin physics spin of the proton and of the electron as well as the movement of the center of mass . Since each pair of observables in the set commutes, the observables are all compatible so that the measurement of one observable has no effect on the result of measuring another observable in the set. It is therefore not necessary to specify the order in which the different observables are measured. Measurement of the complete set of observables constitutes a complete measurement, in the sense that it projects the quantum state of the system onto a unique and known vector in the basis defined by the set of operators. This specifies the conditions for the preparation of a well defined quantum state. Also, the states which form the basis of the CSCO are completely defined by specifying the eigenvalues math lambda 1 math , math lambda 2 math , ..., associated with each observable math O 1 math , math O 2 math , ... of the CSCO. In the above example of the hydrogen atom, the basis states are defined by the quantum numbers math n,l,m rangle math , and it is not necessary to include the wave function or the atomic orbital . References Citation last1 Gasiorowicz first1 Stephen title Quantum Physics publisher John Wiley & Sons location New York isbn 978 0 471 29281 4 year 1974 . Category Quantum mechanics quantum stub cs pln mno ina pozorovateln ch de Vollst ndiger Satz kommutierender Observablen fr Ensemble complet d observables qui commutent nl Complete verzameling van commuterende observabelen ru ... more details
Multiple issues orphan February 2009 primarysources September 2010 expert Quantum Field Theory date March 2011 A qubit field theory is a quantum field theory in which the canonical commutation relation s involved in the quantisation of pairs of observables are relaxed. Specifically it is a quantum field theory in which, unlike most other quantum field theories, the pair of observables is not required to always Commutative property commute . Theory In many ordinary quantum field theories, constraining one observable to a fixed value results in the uncertainty of the other observable being infinite c.f. uncertainty principle , and as a consequence there is potentially an infinite amount of information involved. In the situation of the standard position momentum commutation where the uncertainty principle is most commonly cited , this implies that a fixed, finite, volume of space has an infinite capacity to store information. However, Bekenstein bound Bekenstein s bound hints that the information storage capacity ought to be finite. Qubit field theory seeks to resolve this issue by removing the commutation restriction, allowing the capacity to store information to be finite hence the name qubit , which derives from quantum bit or quantised bit. David Deutsch has presented a group of qubit field theories which, despite not requiring commutation of certain observables, still presents the same observable results as ordinary quantum field theory. ref Cite web url http arxiv.org abs quant ph 0401024 title Qubit Field Theory author David Deutsch authorlink David Deutsch date 6 January 2004 accessdate 27 February 2012 ref References Reflist External links http arxiv.org abs quant ph 0401024 Qubit Field Theory by David Deutsch DEFAULTSORT Qubit Field Theory Category Quantum field theory quantum stub ... more details
Descriptive psychiatry is based on the study of observable symptoms and behavioral phenomena rather than underlying psychodynamic processes. In descriptive psychiatry, the clinical psychiatrist focuses on empirically observable behaviors and conditions, such as words spoken or actions taken. Modern works sometimes refer to it as biological psychiatry . ref name isbn0 415 11972 3 cite book author Evans, F. J. title Harry Stack Sullivan interpersonal theory and psychotherapy publisher Routledge location New York year 1996 pages 56 isbn 0 415 11972 3 ref It was championed by Emil Kraepelin in the early 20th century and is sometimes called Kraepelinian psychiatry. ref name isbn0 415 11972 3 One major work of descriptive psychiatry is the Diagnostic and Statistical Manual of Mental Disorders . ref name isbn0 415 11972 3 Its focus on observable symptoms contrasts with dynamic psychiatry s emphasis on emotional processes and the mental mechanisms underlying them. The relative popularity of these two basic approaches to psychiatry changes over time. ref name titleAnnals of Medicine The Dictionary of Disorder The New Yorker cite web url http www.newyorker.com archive 2005 01 03 050103fa fact?currentPage 2 title Annals of Medicine The Dictionary of Disorder The New Yorker accessdate 2008 03 23 ref Descriptive psychiatry was seen at its low points as narrow, bloodless, and without real significance. ref name titleAnnals of Medicine The Dictionary of Disorder The New Yorker At its high points, it is considered orderly, systematic, and scientific. Most modern psychiatrists believe that it is most helpful to combine the two complementary approaches in a biopsychosocial model . ref name isbn0 415 25670 4 cite book author Williams, Gavin De Kadt, Emanuel Jehuda title Sociology and development publisher Routledge location New York year 2001 pages 152 isbn 0 415 25670 4 ref References reflist Category Psychopathology Category Psychiatric classification systems psychology stub ... more details
To help compare different orders of magnitude , this page lists distance s greater than 100 yottametre Ym 10 sup 26 sup metre m or 11,000 million light year s . At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshift s, which depends on the physical cosmology cosmological models used. 1 E 25 m Distances shorter than 100 Ym 130 Ym redshift 6.41 13,000 million light years Distance measures cosmology Types of distance measures Light travel distance LTD to the quasar List of quasars SDSS J1148 5251 130 Ym redshift 1000 13,700 million light years Distance LTD to the source of the cosmic microwave background radiation radius of the observable universe measured as a LTD 260 Ym 27,400 million light years Diameter of the observable universe double LTD 440 Ym 46,000 million light years Radius of the universe measured as a comoving distance . 590 Ym 62,000 million light years Cosmological event horizon the largest comoving distance from which light will ever reach us the observer at any time in the future 1,000 Ym 1 kYm Non SI unit prefixes Metric prefixes that were obsoleted or withdrawn from the SI standard in older usage Size of universe beyond the observable universe cosmic light horizon , depending on its curvature if it is zero i.e. the universe is spatially flat , the value is infinity Infinity in cosmology infinite see shape of the Universe This series on orders of magnitude does not have a range of longer distances. See also Orders of magnitude length Associations Orders of magnitude length wide External links http www.astro.ucla.edu 7Ewright CosmoCalc.html Ned Wright s Javascript Cosmology Calculator http www.astro.princeton.edu mjuric universe Logarithmic Maps of the Universe Category Orders of magnitude length 26 it 1 E26 m sh 1 E26 m measurement stub ... more details
A black hole cosmology also called Schwarzschild cosmology or black hole cosmological model is a cosmological model in which the observable universe is the interior of a black hole . Such models were originally proposed by theoretical physicist Raj Pathria , ref name pathria cite journal author Pathria, R. K. authorlink Raj Pathria year 1972 title The Universe as a Black Hole journal Nature journal Nature volume 240 pages 298 299 doi 10.1038 240298a0 issue 5379 bibcode 1972Natur.240..298P ref and concurrently by mathematician I. J. Good . ref cite journal author Good, I. J. authorlink I. J. Good title Chinese universes journal Physics Today volume 25 issue 7 page 15 date July 1972 doi 10.1063 1.3070923 ref Any such model requires that the Hubble radius of the observable universe is equal to its Schwarzschild radius , that is, the product of its mass and the Schwarzschild radius Formula for the Schwarzschild radius Schwarzschild proportionality constant . This is indeed known to be nearly the case however, most cosmologists consider this close match a coincidence. ref cite journal author Landsberg, P. T. title Mass Scales and the Cosmological Coincidences journal Annalen der Physik volume 496 issue 2 pages 88 92 date 1984 doi 10.1002 andp.19844960203 bibcode 1984AnP...496...88L ref In the version as originally proposed by Pathria and Good, and studied more recently by, among others, Nikodem Pop awski , ref cite journal author Poplawski, N. J. authorlink Nikodem Pop awski year 2010 title Radial motion into an Einstein Rosen bridge journal Physics Letters B volume 687 pages 110 113 doi 10.1016 j.physletb.2010.03.029 bibcode 2010PhLB..687..110P ref the observable universe is a black hole existing as one of possibly many inside a larger universe, or multiverse . References reflist physics stub Category Black holes Category Physical cosmology ... more details
about the use of this term in Hinduism and Buddhism Trail kya the Maoist concept Three Worlds Theory the 1877 religious book Three Worlds book Artwork image file Three Worlds.jpg title Three Worlds artist M. C. Escher year 1955 type Lithography lithograph height metric 36.2 width metric 24.7 metric unit cm Three Worlds is a Lithography lithograph print by the Netherlands Dutch artist M. C. Escher which was first printed in December, 1955. Three Worlds depicts a large pool or lake during the autumn or winter months, the title referring to the three visible perspectives in the picture the surface of the water on which leaf leaves Bouyancy float , the world above the surface, observable by the water s mirror reflection of a forest , and the world below the surface, observable in the large fish swimming just below the water s surface. Escher also created a picture named Two Worlds . See also Puddle M. C. Escher Puddle Printmaking Sources Locher, J.L. 2000 . The Magic of M. C. Escher . Harry N. Abrams, Inc. ISBN 0 8109 6720 0. External links http home.comcast.net eschermc Gallery of Eschers images M. C. Escher Category Works by M. C. Escher Category 1955 paintings printmaking stub ... more details
Phantom energy is a hypothetical form of dark energy with Equation of State Cosmology equation of state math w 1 math Clarify date September 2010 . If it exists, it could cause the expansion of the universe to accelerating universe accelerate so quickly that the Big Rip would occur. If this is true, the expansion of the universe reaches an infinite degree in finite time, causing expansion to accelerate without bounds. This acceleration will pass the speed of light since it involves lengthening of distance, not particles moving , causing the observable universe to shrink. As the observable universe contracts objects will be unable to interact with each other via fundamental forces, and eventually the expansion will prevent any action of forces between any particles, even within atoms, ripping apart the universe. This will happen to all of the universe in an event known as the Big Rip. One application of phantom energy in 2007 was to a cyclic model of the universe. External links Robert R. Caldwell et al. http arxiv.org abs astro ph 0302506v1 Phantom Energy and Cosmic Doomsday Cite journal author Lauris Baum and Paul Frampton title Turnaround In Cyclic Cosmology journal Phys. Rev. Lett. volume 98 year 2007 pages 071301 doi 10.1103 PhysRevLett.98.071301 pmid 17359014 issue 7 bibcode 2007PhRvL..98g1301B arxiv hep th 0610213 DEFAULTSORT Phantom Energy Category Physical cosmology physics stub es Energ a fantasma fr nergie fant me it Energia fantasma ta ... more details
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