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Loschmidt's Paradox
Loschmidt's paradox, also known as the reversibility paradox, irreversibility paradox or ', is the objection that it should not be possible to deduce an irreversible process from time-symmetric dynamics. This puts the time reversal symmetry of (almost) all known low-level fundamental physical processes at odds with any attempt to infer from them the second law of thermodynamics which describes the behaviour of macroscopic systems. Both of these are well-accepted principles in physics, with sound observational and theoretical support, yet they seem to be in conflict, hence the paradox. Origin Josef Loschmidt's criticism was provoked by the H-theorem of Boltzmann, which employed kinetic theory to explain the increase of entropy in an ideal gas from a non-equilibrium state, when the molecules of the gas are allowed to collide. In 1876, Loschmidt pointed out that if there is a motion of a system from time ''t''0 to time ''t''1 to time ''t''2 that leads to a steady decrease of ''H'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Journal Of Theoretical Physics
The ''International Journal of Theoretical Physics'' is a peer-reviewed scientific journal of physics published by Springer Science+Business Media since 1968. According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 1.708 and publishes both original research and review articles. The editor-in-chief is Heinrich Saller (Max Planck Institute for Physics). Scope and indexing The journal covers the following areas: general relativity, quantum theory with relativistic quantum field theory, quantum measurement theory, quantum geometry and quantum logic. Services abstracting and indexing this journal include Chemical Abstracts Service, Mathematical Reviews, Science Citation Index, Scopus, and Zentralblatt MATH zbMATH Open, formerly Zentralblatt MATH, is a major reviewing service providing reviews and abstracts for articles in pure and applied mathematics, produced by the Berlin office of FIZ Karlsruhe – Leibniz Institute for Information Infrastructur . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CPT Symmetry
Charge, parity, and time reversal symmetry is a fundamental symmetry of physical laws under the simultaneous transformations of charge conjugation (C), parity transformation (P), and time reversal (T). CPT is the only combination of C, P, and T that is observed to be an exact symmetry of nature at the fundamental level. The CPT theorem says that CPT symmetry holds for all physical phenomena, or more precisely, that any Lorentz invariant local quantum field theory with a Hermitian Hamiltonian must have CPT symmetry. History The CPT theorem appeared for the first time, implicitly, in the work of Julian Schwinger in 1951 to prove the connection between spin and statistics. In 1954, Gerhart Lüders and Wolfgang Pauli derived more explicit proofs, so this theorem is sometimes known as the Lüders–Pauli theorem. At about the same time, and independently, this theorem was also proved by John Stewart Bell. These proofs are based on the principle of Lorentz invariance and the princ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian National University
The Australian National University (ANU) is a public research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and institutes. ANU is regarded as one of the world's leading universities, and is ranked as the number one university in Australia and the Southern Hemisphere by the 2022 QS World University Rankings and second in Australia in the ''Times Higher Education'' rankings. Compared to other universities in the world, it is ranked 27th by the 2022 QS World University Rankings, and equal 54th by the 2022 ''Times Higher Education''. In 2021, ANU is ranked 20th (1st in Australia) by the Global Employability University Ranking and Survey (GEURS). Established in 1946, ANU is the only university to have been created by the Parliament of Australia. It traces its origins to Canberra University College, which was established in 1929 and was integrated into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Causation
Universal causation is the proposition that everything in the universe has a cause and is thus an effect of that cause. This means that if a given event occurs, then this is the result of a previous, related event. If an object is in a certain state, then it is in that state as a result of another object interacting with it previously. The idea of universal causation is formulated in western philosophy similarly for ages, however the formulations contain some profound differences in methodology and philosophical assumptions. Examples: In contrast, Bertrand Russell argued (in 1912) that the law of causation as usually stated by philosophers is false and is not used in sciences (maybe with exception of their infancy). However his position on universal causation evolved and "was not as naive as it may have appeared". In 1927 Russell writes that the notion of universal causation marks the beginnings of science and philosophy. Philosophers who do believe in exception-less, universal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debra Searles
Debra Bernhardt (née Searles) (born 1965) is an Australian theoretical chemist. She is best known for her contributions towards understanding the fluctuation theorem. This theorem shows the second law of thermodynamics and the zeroth law of thermodynamics can be derived mathematically rather than postulated as laws of nature. Personal profile Bernhardt has previously worked as an associate professor in the Faculty of Science at Griffith University. During her time at Griffith University, she became the founding director of the Queensland Micro- and Nanotechnology Centre. She received her PhD from the University of Newcastle for her work on quantum chemistry. In 2012, Bernhardt joined the University of Queensland as a professor in a joint appointment between the School of Chemistry and Molecular Biosciences and the Australian Institute of Bioengineering and Nanotechnology. In 2019 Bernhardt was elected to a Fellowship of the Australian Academy of Science. She is also a Fellow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denis Evans
Denis James Evans , (born 19 April 1951, Sydney) is an Australian scientist who is an Emeritus Professor at the Australian National University and Honorary Professor at The University of Queensland. He is widely recognised for his contributions to nonequilibrium thermodynamics and nonequilibrium statistical mechanics and the simulation of nonequilibrium fluids. Career Evans graduated with a BSc (Hons 1) in Physics from the University of Sydney in 1972 and a PhD from the Australian National University in 1975. He was a CSIRO Postdoctoral Fellow at the University of Oxford from 1976 to 1977, a Research Fellow at Cornell University from 1977 to 1978 and a Fulbright Fellow at the National Bureau of Standards (Boulder, Colorado, USA) during 1979 and 1980. Evans was appointed as Research Fellow in the Ion Diffusion Unit of the ANU Research School of Physics at the Australian National University in 1979 and joined the ANU Research School of Chemistry in 1982. He was Academic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluctuation Theorem
The fluctuation theorem (FT), which originated from statistical mechanics, deals with the relative probability that the entropy of a system which is currently away from thermodynamic equilibrium (i.e., maximum entropy) will increase or decrease over a given amount of time. While the second law of thermodynamics predicts that the entropy of an isolated system should tend to increase until it reaches equilibrium, it became apparent after the discovery of statistical mechanics that the second law is only a statistical one, suggesting that there should always be some nonzero probability that the entropy of an isolated system might spontaneously ''decrease''; the fluctuation theorem precisely quantifies this probability. Statement Roughly, the fluctuation theorem relates to the probability distribution of the time-averaged irreversible entropy production, denoted \overline_t. The theorem states that, in systems away from equilibrium over a finite time ''t'', the ratio between the probab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ergodic Theory
Ergodic theory (Greek: ' "work", ' "way") is a branch of mathematics that studies statistical properties of deterministic dynamical systems; it is the study of ergodicity. In this context, statistical properties means properties which are expressed through the behavior of time averages of various functions along trajectories of dynamical systems. The notion of deterministic dynamical systems assumes that the equations determining the dynamics do not contain any random perturbations, noise, etc. Thus, the statistics with which we are concerned are properties of the dynamics. Ergodic theory, like probability theory, is based on general notions of measure theory. Its initial development was motivated by problems of statistical physics. A central concern of ergodic theory is the behavior of a dynamical system when it is allowed to run for a long time. The first result in this direction is the Poincaré recurrence theorem, which claims that almost all points in any subset of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wandering Set
In dynamical systems and ergodic theory, the concept of a wandering set formalizes a certain idea of movement and mixing. When a dynamical system has a wandering set of non-zero measure, then the system is a dissipative system. This is the opposite of a conservative system, to which the Poincaré recurrence theorem applies. Intuitively, the connection between wandering sets and dissipation is easily understood: if a portion of the phase space "wanders away" during normal time-evolution of the system, and is never visited again, then the system is dissipative. The language of wandering sets can be used to give a precise, mathematical definition to the concept of a dissipative system. The notion of wandering sets in phase space was introduced by Birkhoff in 1927. Wandering points A common, discrete-time definition of wandering sets starts with a map f:X\to X of a topological space ''X''. A point x\in X is said to be a wandering point if there is a neighbourhood ''U'' of ''x'' and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixing (mathematics)
In mathematics, mixing is an abstract concept originating from physics: the attempt to describe the irreversible thermodynamic process of mixing in the everyday world: mixing paint, mixing drinks, industrial mixing, ''etc''. The concept appears in ergodic theory—the study of stochastic processes and measure-preserving dynamical systems. Several different definitions for mixing exist, including ''strong mixing'', ''weak mixing'' and ''topological mixing'', with the last not requiring a measure to be defined. Some of the different definitions of mixing can be arranged in a hierarchical order; thus, strong mixing implies weak mixing. Furthermore, weak mixing (and thus also strong mixing) implies ergodicity: that is, every system that is weakly mixing is also ergodic (and so one says that mixing is a "stronger" notion than ergodicity). Informal explanation The mathematical definition of mixing aims to capture the ordinary every-day process of mixing, such as mixing paints, drinks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissipative System
A dissipative system is a thermodynamically open system which is operating out of, and often far from, thermodynamic equilibrium in an environment with which it exchanges energy and matter. A tornado may be thought of as a dissipative system. Dissipative systems stand in contrast to conservative systems. A dissipative structure is a dissipative system that has a dynamical regime that is in some sense in a reproducible steady state. This reproducible steady state may be reached by natural evolution of the system, by artifice, or by a combination of these two. Overview A dissipative structure is characterized by the spontaneous appearance of symmetry breaking (anisotropy) and the formation of complex, sometimes chaotic, structures where interacting particles exhibit long range correlations. Examples in everyday life include convection, turbulent flow, cyclones, hurricanes and living organisms. Less common examples include lasers, Bénard cells, droplet cluster, and the Belousovâ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transfer Operator
Transfer may refer to: Arts and media * ''Transfer'' (2010 film), a German science-fiction movie directed by Damir Lukacevic and starring Zana Marjanović * ''Transfer'' (1966 film), a short film * ''Transfer'' (journal), in management studies * "The Transfer" (''Smash''), a television episode *''The Transfer'', a novel by Silvano Ceccherini Finance * Transfer payment, a redistribution of income and wealth by means of the government making a payment * Balance transfer, transfer of the balance (either of money or credit) in an account to another account * Money transfer (other) ** Wire transfer, an international expedited bank-to-bank funds transfer Science and technology Learning and psychology * Transfer (propaganda), a method of psychological manipulation * Knowledge transfer, within organizations * Language transfer, in which native-language grammar and pronunciation influence the learning and use of a second language * Transfer of learning, in education Mathematic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
