Bernard H. Lavenda | |
---|---|
Born | New York City, U.S. | 18 September 1945
Nationality | Italian |
Awards | Telesio-Galilei Academy Award in 2009 |
Scientific career | |
Fields | Physics |
Bernard Howard Lavenda (born September 18, 1945) is a retired professor of chemical physics at the University of Camerino and expert on irreversible thermodynamics. He has contributed to many areas of physics, including that of Brownian motion, and in the establishment of the statistical basis of thermodynamics, and non-Euclidean geometrical theories of relativity. He was the scientific coordinator of the "European Thermodynamics Network" in the European Commission Program of Human Capital and Mobility. He was also a proponent for the establishment of, and scientific director of, a National (Italian) Centre for Thermodynamics, and has acted as scientific consultant to companies such as the ENI Group, where he helped to found TEMA, a consulting firm for SNAM Progetti, ENEA (Italian National Agency for New Technologies, Energy and the Environment), and the Solar Energy Research Institute in Golden, Colorado. He has had over 130 scientific papers published in international journals, some critical of the new fashions and modes in theoretical physics.
Professor Lavenda currently lives in Trevignano Romano near Rome, is married with two adult children and two grandchildren, for whom his textbook "A New Perspective on Thermodynamics" is dedicated.
Bernard H. Lavenda was born in New York City. After completing secondary school in North Adams, Massachusetts, he attended Clark University where he graduated cum laude in 1966 with a B.Sc in chemistry. Having passed the entrance examination for the doctoral program at the Weizmann Institute of Science, he began experimental work on enzymes under the direction of Ephraim Katzir, who was later to become the President of Israel. Realizing that he was not made out for experimental work, he came under the influence of Ephraim's brother, Aaron, after reading his book Nonequilibrium Thermodynamics in Biophysics, coauthored with Peter Curran.
After the Six Days War, Aaron Katchalsky helped him secure a studentship for a doctoral degree in Ilya Prigogine's group in Brussels.
His doctoral thesis, "Kinetic analysis and thermodynamic interpretation of nonequilibrium unstable transitions in open systems", showed that when homogeneous nonlinear chemical reactions far from equilibrium on the thermodynamic branch, which is an extension of the law of mass action at equilibrium, become unstable they make transitions to kinetic branches with lower entropy production than the thermodynamic branch.
This result was initially contested by Prigogine who reasoned from hydrodynamic instabilities, like the Rayleigh-Benard instability, which show a larger entropy production beyond the critical point in order to maintain spatial structures. Prigogine later considered these spatial structures to be produced by unstable chemically diffusing systems, based on Alan Turing's morphological models, calling them 'dissipative structures' and for which Prigogine received the Nobel Prize in Chemistry in 1977.
Prigogine later acknowledged that such transitions to lower states of entropy reduction were possible since no spatial structural changes were involved, and later incorporated Lavenda's work into a chapter of his new book Thermodynamic Theory of Structure, Stability, and Fluctuations, co-authored with Paul Glansdorff. After receiving his doctorate from the Universite Libre de Bruxelles, with la plus grande distinction, he returned to Israel in 1970 to work as a post-doctoral student in the Physical Chemistry Department of the Hebrew University. During that period he published a short note in the Italian physics journal, Lettere Al Nuovo Cimento [3 (1972) 385-390] criticizing the Glansdorff-Prigogine universal criteria of evolution which attributes an inequality to a potential which is a function only of intensive variables, the forces. He pointed out that no such thermodynamic potential could exist for it would be devoid of all information regarding how large the system is, or how many particles it contains. The inequality would be a criterion of stability, but, on account of the assumption of local (stable) equilibrium of the components that the system is broken up into, the sum of stable components can hardly become unstable. The note would probably have gone unnoticed were it not for Peter Landsberg's citation of it in his Nature review of the Glansdorff-Prigogine book [P. T. Landsberg, "The fourth law of thermodynamics" [1] ], where he predicted "the occasional lack of lucidity in the book which may give rise to some discussion within the next few years".
After the murder of Aharon Katzir in Lod Airport massacre in May 1972, Lavenda accepted a position of consultant at Nuovo Pignone in Florence Italy together with a teaching position at the University of Pisa. Through the vice President of Nuovo Pignone, he came into contact with Vicenzo Gervasio who was later to become President of ENI Data, and the idea crystallized of setting up a company dedicated to the analysis and dynamic modeling of fouling processes in refineries and reactors. He established relations between ENI and Northwest Research, Boeing, and SERI (Solar Energy Research Institute). He helped form a new company within the ENI group, TEMA, which was supported by SNAM Progetti. While retaining an unpaid lectureship in Thermodynamics at the University of Naples, Lavenda published his critical appraisal of the then current theories of irreversible thermodynamics, Thermodynamics of Irreversible Processes, in 1978. It was originally published by the Macmillan Press and later became a Dover Classic of Science and Mathematics.
In 1980 he won a chair in Physical Chemistry. Transferring to Camerino, he was to spend more than three decades there. His first book during this period, "Nonequilibrium Statistical Thermodynamics", published by Wiley in 1985, developed the nonlinear generalization of the Onsager-Machlup formulation of nonequilibrium fluctuations which was restricted to linear (Gaussian) processes. Just as equilibrium is characterized by the state of maximum entropy, corresponding to maximum probability, nonequilibrium states are characterized by the principle of least dissipation of energy, corresponding to the maximum probability of a transition between nonequilibrium states that are not well-separated in time. This principle can be generalized to non-Gaussian fluctuations in the limit of small thermal noise and constitutes a kinetic analog to Boltzmann's principle.
During a sabbatical year in 1986 in Porto Alegre, Lavenda had ample time to browse through the well-furnished library at the Universidade Federale di Rio Grande del Sud. He was impressed by the parallelism between statistical inference and statistical thermodynamics: two distinct and separate branches that are essentially working on the same problems but with no apparent connection. His work, summarized in Statistical Physics: A Probabilistic Approach, published by Wiley-Interscience in 1991, completes Boltzmann's principle, which expresses the entropy as the logarithm of a combinatorial factor, by showing that the entropy is the potential that determines Gauss’ law of error for which the average value is the most probable value. Just as there are frequency and degree- of-belief (Bayes' theorem) interpretations of statistical inference, the same should apply to statistical thermodynamics. The frequency interpretation applies to extensive variables, like energy and volume which can be sampled, while the degree-of-belief interpretations applies to the intensive variables, like temperature and pressure, for which sampling has no meaning. The connection between the two branches translates the Cramer-Rao inequality into thermodynamic uncertainty relations, analogous to quantum mechanical uncertainty relations, where the more knowledge we have about a thermodynamic variable the less we know about its conjugate. Since the lack of a probability distribution means the absence of its statistics, the possibility of an intermediate statistics, or what is referred to as parastatistics, between Bose–Einstein statistics and Fermi–Dirac statistics is nonexistent.
Statistical thermodynamics is usually concerned with most probable behavior which becomes almost certainty if large enough samples are taken. But sometimes surprises are in store where extreme behavior becomes the prevalent one. Turning his attention to such rare events Lavenda published Thermodynamics of Extremes in 1995, whose real interest lies in the formulation of a thermodynamics of earthquakes that was subsequently published in Annali di Geofisica (Extreme value statistics and thermodynamics of earthquakes: "Large earthquakes"; [2] "aftershock sequences" [3] ), and which is gaining increasing attention. By properly defining entropy and energy, a temperature can be associated to an aftershock sequence giving it an additional means of characterization. A new magnitude-frequency relation is predicted which applies to clustered after-shocks in contrast to the [Gutenberg-Richter law] which treats them as independent and identically distributed random events.
In the nineties, Lavenda saw thermodynamics as a cultural heritage that could have a place in Italian society, and would be pertinent to both industrial research and to the preservation of its artistic patrimony. He was a proponent for the establishment of a National Centre of Thermodynamics for which financial funding was unavailable. Capturing the interest of the ENEA, or the Italian agency for alternative energy resources, he applied for funding in the European Commission of Human Capital and Mobility Programme. His project, "Thermodynamics of Complex Systems", came in sixth place in Chemistry section with maximum funding in 1992. This led to the formation of a European Thermodynamics Network consisting of 16 partners in the EU and Switzerland. It was later extended to the Eastern European Countries in the European Commission PECO Programme. This eventually led to the establishment of a National Centre for Thermodynamics that was brought into existence by the ENEA, but lasted only several months, because European funds were absorbed by other projects [4]
Often critical of new fashions and modes in thermodynamics, Lavenda wrote A New Perspective on Thermodynamics, [5] published in 2009, by returning to Carnot's original conception that work can only be done when there is a difference in temperature, and the necessity of closing the cycle before that work can be assessed. More recently Lavenda has directed his interests to relativity by providing it with a new foundation based on non-Euclidean geometries. Rather than measuring distances in terms of the usual Euclidean metric, distances are defined in terms of what is known as a cross-ratio, a perspective invariant of four points, which, for the space of velocities, just happens to be the compounding of longitudinal Doppler shifts. Doppler shifts are fundamental to relativity: oblique Doppler shifts describe aberration, while second order ones describe length contraction, but rather than being in the direction of the motion are perpendicular to it. [6] The uniformly rotating disc, which is considered by some to be the missing link in Einstein's formulation of general relativity, is exactly described by the hyperbolic metric in polar coordinates, named after the nineteenth century Italian geometer Eugenio Beltrami, which predicts the circumference of the disc to be greater when in motion than when it is at rest. Thus a uniformly rotating disc belongs to hyperbolic, and not Euclidean, space and so, too, does relativity.
Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. Chemical thermodynamics involves not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods to the study of chemical questions and the spontaneity of processes.
Entropy is a scientific concept that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory. It has found far-ranging applications in chemistry and physics, in biological systems and their relation to life, in cosmology, economics, sociology, weather science, climate change, and information systems including the transmission of information in telecommunication.
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of thermodynamics, which convey a quantitative description using measurable macroscopic physical quantities, but may be explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to a wide variety of topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering and mechanical engineering, but also in other complex fields such as meteorology.
Maxwell's demon is a thought experiment that appears to disprove the second law of thermodynamics. It was proposed by the physicist James Clerk Maxwell in 1867. In his first letter, Maxwell referred to the entity as a "finite being" or a "being who can play a game of skill with the molecules". Lord Kelvin would later call it a "demon".
The second law of thermodynamics is a physical law based on universal empirical observation concerning heat and energy interconversions. A simple statement of the law is that heat always flows spontaneously from hotter to colder regions of matter. Another statement is: "Not all heat can be converted into work in a cyclic process."
In thermodynamics, dissipation is the result of an irreversible process that affects a thermodynamic system. In a dissipative process, energy transforms from an initial form to a final form, where the capacity of the final form to do thermodynamic work is less than that of the initial form. For example, transfer of energy as heat is dissipative because it is a transfer of energy other than by thermodynamic work or by transfer of matter, and spreads previously concentrated energy. Following the second law of thermodynamics, in conduction and radiation from one body to another, the entropy varies with temperature, but never decreases in an isolated system.
The first law of thermodynamics is a formulation of the law of conservation of energy in the context of thermodynamic processes. The law distinguishes two principal forms of energy transfer, heat and thermodynamic work, that modify a thermodynamic system containing a constant amount of matter. The law also defines the internal energy of a system, an extensive property for taking account of the balance of heat and work in the system. Energy cannot be created or destroyed, but it can be transformed from one form to another. In an isolated system the sum of all forms of energy is constant.
Viscount Ilya Romanovich Prigogine was a Belgian physical chemist of Russian-Jewish origin, noted for his work on dissipative structures, complex systems, and irreversibility.
The zeroth law of thermodynamics is one of the four principal laws of thermodynamics. It provides an independent definition of temperature without reference to entropy, which is defined in the second law. The law was established by Ralph H. Fowler in the 1930s, long after the first, second, and third laws had been widely recognized.
Thermodynamic equilibrium is an axiomatic concept of thermodynamics. It is an internal state of a single thermodynamic system, or a relation between several thermodynamic systems connected by more or less permeable or impermeable walls. In thermodynamic equilibrium, there are no net macroscopic flows of matter nor of energy within a system or between systems. In a system that is in its own state of internal thermodynamic equilibrium, not only is there an absence of macroscopic change, but there is an “absence of any tendency toward change on a macroscopic scale.”
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 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.
A thermodynamic system is a body of matter and/or radiation separate from its surroundings that can be studied using the laws of thermodynamics.
Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of macroscopic quantities that represent an extrapolation of the variables used to specify the system in thermodynamic equilibrium. Non-equilibrium thermodynamics is concerned with transport processes and with the rates of chemical reactions.
In science, a process that is not reversible is called irreversible. This concept arises frequently in thermodynamics. All complex natural processes are irreversible, although a phase transition at the coexistence temperature is well approximated as reversible.
The laws of thermodynamics are a set of scientific laws which define a group of physical quantities, such as temperature, energy, and entropy, that characterize thermodynamic systems in thermodynamic equilibrium. The laws also use various parameters for thermodynamic processes, such as thermodynamic work and heat, and establish relationships between them. They state empirical facts that form a basis of precluding the possibility of certain phenomena, such as perpetual motion. In addition to their use in thermodynamics, they are important fundamental laws of physics in general and are applicable in other natural sciences.
Classical thermodynamics considers three main kinds of thermodynamic processes: (1) changes in a system, (2) cycles in a system, and (3) flow processes.
Thermodynamic work is one of the principal processes by which a thermodynamic system can interact with its surroundings and exchange energy. This exchange results in externally measurable macroscopic forces on the system's surroundings, which can cause mechanical work, to lift a weight, for example, or cause changes in electromagnetic, or gravitational variables. The surroundings also can perform work on a thermodynamic system, which is measured by an opposite sign convention.
Thermoeconomics, also referred to as biophysical economics, is a school of heterodox economics that applies the laws of statistical mechanics to economic theory. Thermoeconomics can be thought of as the statistical physics of economic value and is a subfield of econophysics.
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance.
Energy dissipation and entropy production extremal principles are ideas developed within non-equilibrium thermodynamics that attempt to predict the likely steady states and dynamical structures that a physical system might show. The search for extremum principles for non-equilibrium thermodynamics follows their successful use in other branches of physics. According to Kondepudi (2008), and to Grandy (2008), there is no general rule that provides an extremum principle that governs the evolution of a far-from-equilibrium system to a steady state. According to Glansdorff and Prigogine, irreversible processes usually are not governed by global extremal principles because description of their evolution requires differential equations which are not self-adjoint, but local extremal principles can be used for local solutions. Lebon Jou and Casas-Vásquez (2008) state that "In non-equilibrium ... it is generally not possible to construct thermodynamic potentials depending on the whole set of variables". Šilhavý (1997) offers the opinion that "... the extremum principles of thermodynamics ... do not have any counterpart for [non-equilibrium] steady states ." It follows that any general extremal principle for a non-equilibrium problem will need to refer in some detail to the constraints that are specific for the structure of the system considered in the problem.