Fundamental Laws Of Physics Research Articles

Thermal conductivity and the Wiedemann–Franz law in the fractional quantum Hall effect regime around [formula omitted

The range of validity of Wiedemann–Franz (WF) law is investigated for the quantum Hall effect regime around ν = 1 / 2 . The composite fermions (CFs) picture along with the appropriate transport theory enables us to use the integer quantum Hall effect and Shubnikov–de Haas conductivity models to calculate the diagonal and non-diagonal components of the electrical and thermal diffusion conductivity tensors. The analysis shows that at ν = 1 / 2 the system and CF components satisfy the Wiedemann–Franz law. The CF components satisfy the Wiedemann–Franz law for the whole range of the low effective magnetic fields while away from ν = 1 / 2 the system components violate it. At high effective magnetic fields the CF components behave exactly as in the integer quantum Hall effect regime. The system’s behavior at high effective magnetic fields violate the Wiedemann–Franz law for any value of the Landau level broadening. This along with the system’s behavior at low fields around ν = 1 / 2 demonstrates the fact that the difference in the physical mechanisms responsible for the Integer and the Fractional quantum Hall effect is reflected upon fundamental physical laws such as the Wiedemann–Franz law.

Comment on Makarieva et al . ‘A critique of some modern applications of the Carnot heat engine concept: the dissipative heat engine cannot exist’

Makarieva et al . (2010) assert that a dissipative heat engine is impossible and criticize earlier published work that they claim violates the laws of thermodynamics. Here we show that the earlier work does not violate fundamental physical laws and suggest that Makarieva et al . (2010) were misinterpreting expressions for wind speed as ones for work done on external objects. Moreover, we dispute their assertion that dissipative heating is necessarily compensated by a reduction of external heating.

A non-canonical approach to arithmetic spin geometry and physical applications

A basic requirement of adelic physics is the principle of invariance of the fundamental physical laws under a change of the underlying number field proposed by I.V. Volovich (cf. [20]). In this paper, we develop a manifestly number field invariant approach to Yang-Mills theory, which is formulated within the framework of arithmetic geometry. As well source fields as the Higgs mechanism are incorporated. For this purpose a non-canonical approach to arithmetic spin geometry is proposed, and its physical applications are analyzed. The associated bundle construction is performed in the setting of arithmetic geometry. Furthermore the arithmetic analogue of the following well-known differential geometric fact is proven: Every covariant derivation on a torsor induces a canonical covariant derivation on the associated object.

The Emergence of Temporal Structures in Dynamical Systems

Dynamical systems in classical, relativistic and quantum physics are ruled by laws with time reversibility. Complex dynamical systems with time-irreversibility are known from thermodynamics, biological evolution, growth of organisms, brain research, aging of people, and historical processes in social sciences. Complex systems are systems that compromise many interacting parts with the ability to generate a new quality of macroscopic collective behavior the manifestations of which are the spontaneous emergence of distinctive temporal, spatial or functional structures. But, emergence is no mystery. In a general meaning, the emergence of macroscopic features results from the nonlinear interactions of the elements in a complex system. Mathematically, the emergence of irreversible structures is modelled by phase transitions in non-equilibrium dynamics of complex systems. These methods have been modified even for chemical, biological, economic and societal applications (e.g., econophysics). Emergence of irreversible structures can also be simulated by computational systems. The question arises how the emergence of irreversible structures is compatible with the reversibility of fundamental physical laws. It is argued that, according to quantum cosmology, cosmic evolution leads from symmetry to complexity of irreversible structures by symmetry breaking and phase transitions. Thus, arrows of time and aging processes are not only subjective experiences or even contradictions to natural laws, but they can be explained by quantum cosmology and the nonlinear dynamics of complex systems. Human experiences and religious concepts of arrows of time are considered in a modern scientific framework. Platonic ideas of eternity are at least understandable with respect to mathematical invariance and symmetry of physical laws. Heraclit’s world of change and dynamics can be mapped onto our daily real-life experiences of arrows of time.

Number theory as the ultimate physical theory

At the Planck scale doubt is cast on the usual notion of space-time and one cannot think about elementary particles. Thus, the fundamental entities of which we consider our Universe to be composed cannot be particles, fields or strings. In this paper the numbers are considered as the fundamental entities. We discuss the construction of the corresponding physical theory. A hypothesis on the quantum fluctuations of the number field is advanced for discussion. If these fluctuations actually take place then instead of the usual quantum mechanics over the complex number field a new quantum mechanics over an arbitrary field must be developed. Moreover, it is tempting to speculate that a principle of invariance of the fundamental physical laws under a change of the number field does hold. The fluctuations of the number field could appear on the Planck length, in particular in the gravitational collapse or near the cosmological singularity. These fluctuations can lead to the appearance of domains with non-Archimedean p-adic or finite geometry. We present a short review of the p-adic mathematics necessary, in this context.

On the physics of power, energy and economics of renewable electric energy sources – Part I

Environmental concerns have increasingly led to the installation of Renewable Energy Technologies (RETs) despite the fact that they are recognized as expensive. Innovative efforts within the area are beset with difficulties [1], and they are at risk of producing misdirected or insignificant improvements in terms of the cost effectiveness of total energy conversion systems. This paper investigates how RETs can be evaluated, in terms of economy and engineering solutions, by studying the fundamental physics of renewable energy sources and how it matches with the RETs. This match is described by the “Degree of Utilization”. The findings indicate that new innovations should focus on the possible number of full loading hours. RETs that are correctly matched to their energy source generate a higher amount of electric energy and have a higher potential of becoming more competitive. In cases where this aspect has been ignored, leading to relatively small degrees of utilization, it can be understood as an engineering mismatch between installed power, converted energy, and the fundamental physics of the renewable energy sources. Since there is a strong and possibly biased support for so-called mature RETs and already existing solutions, a clarification of how fundamental physical laws affect the cost of investments and payback of investments is needed. The present paper is part I out of II and it focuses on the difference between power and energy and the physics of different energy sources and their utilization.

Os experimentos de Joule e a primeira lei da termodinâmica

A formulação do princípio da conservação da energia é um exemplo de longo amadurecimento, quase dois séculos e meio, de uma idéia que se tornou uma das leis básicas da física e cuja generalização foi alcançada ao ser formalizada como primeira lei da termodinâmica. No presente artigo, apresenta-se uma análise das diferentes formulações da primeira lei com o objetivo de resgatar informações históricas que poderão contribuir para o ensino da termodinâmica. O estudo mostra que no final do século XIX já se considerava difícil afirmar quem teria descoberto o princípio da equivalência entre calor e trabalho, já que diversos estudiosos haviam abordado o tema, e como as meticulosas pesquisas experimentais de Joule permitiram a demonstração da equivalência de diferentes tipos de energia e contribuíram de forma definitiva para a elaboração da primeira lei da termodinâmica.

Goethe's dream

The German philosopher Immanuel Kant (1724–1804) defined living organisms as objects with an intrinsic purpose, which are self‐organized in such a way that every part is a function of the whole and the whole is a function of every part, and in which “nothing is for nothing”. Kant already anticipated the tension between agency and structure, and between forward and backward causation. He also perceived living beings as entities that, being extremely complex, are not amenable to descriptions based on laws that are similar to the fundamental laws of physics: “There will never be a Newton of a grass blade,” he wrote. Less metaphorically, Kant believed that science would not be able to understand living entities by focusing exclusively on their component parts, and, therefore, that it would never be able to explain a whole organism completely and exhaustively. > The history of biological research can be regarded as an attempt to prove Kant wrong The history of biological research can be regarded as an attempt to prove Kant wrong. We can mainly distinguish two major strategies to achieve this, analytical and synthetic, which in turn have determined how biologists have tried to understand what is a living being. Analytical biology, or the so‐called reductionist approach to biology, has mainly focused on the study of the individual components of living organisms. Its last incarnation, molecular biology, has been extraordinarily successful at producing a deluge of data on the molecular mechanisms underpinning life processes and has resulted in tremendous advances in the explanation of life workings (Morange, 2005). There is a complementary—sometimes antagonistic—tradition in biology, the synthetic tradition, which states that the essence of a living entity cannot be understood by merely studying its parts (Keller, 2002; Pereto & Catala, 2007). The German poet and naturalist Johann Wolfgang von Goethe …

Noise-Immune Conjugate Large-Area Atom Interferometers

We present a pair of simultaneous conjugate Ramsey-Bordé atom interferometers using large (20variant Planck's over 2pik)-momentum transfer beam splitters, where variant Planck's over 2pik is the photon momentum. Simultaneous operation allows for common-mode rejection of vibrational noise. This allows us to surpass the enclosed space-time area of previous interferometers with a splitting of 20variant Planck's over 2pik by a factor of 2500. Using a splitting of 10variant Planck's over 2pik, we demonstrate a 3.4 ppb resolution in the measurement of the fine structure constant. Examples for applications in tests of fundamental laws of physics are given.

Broken CP symmetry and the Physics Nobel Prize 2008

Kobayashi and Maskawa shared half the Physics Nobel Prize for 2008 for their work which incorporated CP violation in the standard model using three generations of quarks. We give an elementary discussion of this work and its importance in our understanding of the fundamental physical laws of nature.

Parallel issues in nanotech, climate science

The feature article on ethical, legal, and social issues (ELSI) in nanotechnology (Physics Today, October 2008, page 38) struck me as extremely enlightening. I liked the balanced tone of Cyrus Mody’s text, including the application of the term “folk theory” to all sides. Other fields of science, and science policymakers, would probably do well to learn from the example of ELSI nanotechnology research.In my own field, climate research, something keeps astonishing me. Many people I talk to still believe that there is a debate about the existence of the greenhouse effect due to carbon dioxide. But I remember seeing the effect demonstrated on TV, notably by Pieter Tans, a leading researcher from the Earth System Research Laboratory of the National Oceanic and Atmospheric Administration. Mody’s article made me realize that the lack of belief in fundamental physics laws might not have to do with a lack of understanding or education. Disbelief might rather be the result of distrust—the same distrust Mody mentions toward genetically modified organisms and nanotechnology. In the case of the greenhouse effect, people are wary of the complicated climate models that only a few experts understand.The contribution of climate science to society is not through development of mitigation technologies such as renewable energy, but through development of tools that allow better anticipation of what the future might bring (see how I avoid the term “prediction”). Climate science by itself will not lead to fewer greenhouse gases in the atmosphere. The mitigation of climate change is a job that policymakers and the general public need to put into action. However, given this limited but distinctive role of climate research, it is all the more important that the public have faith in the scientists who use those predictive tools. A prophet nobody will listen to is useless. But these are just my own observations; Mody’s article convinced me that it is possible to do systematic and objective research that will pinpoint the misunderstandings and gaps in perception between scientists and the public.What ultimately persuaded me that there is a parallel case between nanotechnology and climate science was when Mody mentioned Michael Crichton’s anti-nanotech novel Prey (Harper, 2008) and reminded me of the controversy surrounding his State of Fear (Avon, 2005).© 2009 American Institute of Physics.

Restoration of a Poisson distributed image using a principle of extreme physical information

Suppose that an object which reflects or emits light is captured by a sensor. The image data are distorted in various ways. The aim is to restore the object. For this purpose, a new restoration method is devised. It uses the Fisher-information based principle of extreme physical information (EPI). This solves a variational problem I − J = extremum, expressing a flow of information J → I from source to output in the restoration problem. Here, the source of information is the Poissonian image data, and J is modeled as its Hartley information level. Also, I is the Fisher information in the output restored object. The approach dates from the 1980s. It has been already shown that many fundamental physical laws may be derived using EPI. In this paper, the EPI approach is applied to the restoration problem, wherein it regards the unknown restoration as another fundamental law. It models the source information J as obeying Poisson statistics, and assumes additional image distortions that are due to additive Gaussian noise and quantization of the image data. It is found that the quantization level determines the degree of smoothness (or sharpness) of the restored signal. An optimal level of image quantization can be accomplished by adjusting its cross entropy. Finally, the restoration method by EPI is validated by numerical simulations of the image forming and restoring system.

THM-coupled finite element analysis of frozen soil: formulation and application

A fully coupled thermo-hydro-mechanical (THM) finite element (FE) formulation is presented that considers freezing and thawing in water-saturated soils. The formulation considers each thermal, hydraulic and mechanical process, and their various interactions, through fundamental physical laws and models. By employing a combination of ice pressure, liquid pressure and total stress as state variables, a new mechanical model has been developed that encompasses frozen and unfrozen behaviour within a unified effective-stress-based framework. Important frozen soil features such as temperature and porosity dependence of shear strength are captured inherently by the model. Potential applications to geotechnics include analysis of frost heave, foundation stability or mass movements in cold regions. The model's performance is demonstrated with reference to the in situ pipeline frost heave tests conducted by Slusarchuk et al. Detailed consideration is given to FE mesh design, the influence of hydraulic parameters, and the treatment of air/ground interface boundary conditions. The THM simulation is shown to reproduce, with fair accuracy, the observed pipeline heave and the porosity growth driven by water migration.

Quantum Key Distribution Using Decoy State Protocol

Problem statement: Quantum key distribution provides unconditional security guaranteed by the fundamental laws of quantum physics. Unfortunately, for real-life experimental set-ups, which mainly based on faint laser pulses, the occasional production of multi-photons and channel loss make it possible for sophisticated eavesdroppers to launch various subtle eavesdropping attacks including the Photon Number Splitting (PNS) attack. The decoy state protocols recently proposed to beat PNS attack and to improve dramatically distance and secure key generation rate of Quantum Key Distribution (QKD). Approach: Objective of this study was experimental implementation of weak decoy + vacuum states QKD for increasing the performance of QKD system. To show conceptually how simple it was to apply the weak decoy + vacuum state idea to a commercial QKD system, we chosen ID-3000 commercial quantum key distribution system manufactured by id quantique. To implement the weak decoy + vacuum state protocol, we had to add some new optical and electronics components to id quantique and to attenuate each signal to the intensity of either signal state or weak decoy or vacuum state randomly. Results: In our implementation, the attenuation will be done by placing a VOA (variable optical attenuator) in Alice’s side. Specifically, our QKD system required the polarizations of 2 pulses from the same signal to be orthogonal. Therefore the VOA must be polarization independent so as to attenuate the two pulses equally. The VOA utilized in experiment to attenuate signals dynamically was Intensity Modulator (IM). We had implemented weak + vacuum protocol on a modified commercial QKD system over a 25 km of telecom fibers with an unconditionally secure key rate of 6.2931×10-4 per pulse. Conclusion: By making simple modifications to a commercial quantum key distribution system, we could achieve much better performance with substantially higher key generation rate and longer distance than QKD system without decoy state.

Clarifying tetrapod embryogenesis, a physicist's point of view

The origin of tetrapods is a complex question that webs together genetic, paleontological, developmental and physical facts. Basically, the development of embryos is described by a complex mix of mechanical movements and biochemical inductions of genetic origin. It is difficult to sort out in this scientific question what are the fundamental features imposed by conservation laws of physics, and by force equilibria, and what can be ascribed to successive, very specific, stop-and-go inductions of genetic nature. A posteriori, evolution selects the parameters of this process as found in the observed species. Whether there is a general law to animal formation seems out of the question. However, several concepts developed in biology, like the concept of “organizer” seem questionable from a physics point of view, since the entire deformation and force field should be the “organizer” of development, and one can hardly ascribe such a role to a single small area of the embryo body. In the same spirit, the concept of “positional information” encapsulated in concentration of chemicals seems questionable since the deformation and force fields in embryonic tissues are tensors. Finally, the concept of a development organized in space along three orthogonal (“Cartesian”) axes associated to chemical gradients seems also questionable, since early embryo development is driven by complex vortex fields, with hyperbolic trajectories which span the entire embryo. Such hyperbolic trajectories are best understood by a description in terms of dipolar components of the morphogenetic forces, whose projections along orthogonal axe have no specific meaning except as a mathematical tool. I review here the present state of description of several aspects of tetrapods morphogenesis and evolution, from the point of view of physics. It is getting clear that several basic features of tetrapods body are a direct consequences of fundamental laws of physics. Several lines of work reviewed here show that the topology of the tetrapods may be directly related to the structure of the earliest movements in embryos. The bio-mechanical approach leads to important consequences for the constraints on evolution of the craniates. Such consequences have received a controversial welcome in the last decade, although they may encapsulate the true origin of craniates, esp. simians, and eventually homo .

The reductionist blind spot

AbstractCan there be higher level laws of nature even though everything is reducible to the fundamental laws of physics? The computer science notion of level of abstraction explains how there can be. The key relationship between elements on different levels of abstraction is not the is‐composed‐of relationship but the implements relationship. I take a scientific realist position with respect to (material) levels of abstraction and their instantiation as (material) entities. They exist as objective elements of nature. Reducing them away to lower order phenomena produces a reductionist blind spot and is bad science. © 2009 Wiley Periodicals, Inc. Complexity, 2009.

Optimization of gettering processes of metallurgical-grade silicon for solar cell applications

AbstractConversion efficiency of a solar energy in the electric is substantially determined not only by the total impurity concentration in solar cell element, but also by impurity chemical and physical state. Gettering processes, which are included in the technology of solar cell manufacturing, are usually used for such impurity redistribution. In order to optimize gettering processes we developed a program tool based on the fundamental physical and chemical laws. The description of physical and chemical behaviour of impurities in silicon is based both on known experimental data, and on calculations of necessary parameters by means of present-day thermodynamic and quantum-chemical methods. Developed tool helps to choose a gettering regime (a temperature profile, time, getter layer thickness) for optimization of these processes for the given initial chemical composition of the silicon wafer. Possibility of analysis of recombination activity of various types of defects in silicon on the basis of carrier lifetime criterion allows to obtain an estimation of efficiency of the gettering processes. Using this program tool we demonstrated that solar cell efficiency can be significantly increased by optimal choice of gettering conditions.

Implementation of the “KINEROS” Model for Estimation of the Flood Prone Territories in the Malki Iskar River Basin

This article presents main results from the implementation of the KINEROS model to the Malki Iskar river basin above the town of Etropole. KINEROS is a mathematical model based on fundamental physical laws aimed at simulating the spatial distribution of water balance elements for a given meteoro- logical event. A detailed study of the set of physical geographical flood risk factors (relief, climate, waters, soils, LC/LU) has been performed. The analysis has been carried out on the basis of specific methods for estimation of the role of each factor. The results show the importance and practicality of implementation of the GIS, RS and flood risk modeling in generally unpredictable dangerous situations, which are typical for small mountain catchments. The application of the KINEROS model for simulation of events depending on the changes in the landscape conditions may in- crease significantly the effect of flood risk management in mountainous munici- palities.

The fundamental physics explorer: An ESA technology reference study

ESA technology reference studies are used as a process to identify key technologies and technical challenges of potential future missions not yet in the science programme. This paper reports on the study of the Fundamental Physics Explorer (FPE), a re-usable platform targeted to small missions testing fundamental laws of physics in space. The study addresses three specific areas of interest: special and general relativity tests based on atomic clocks, experiments on the Weak Equivalence Principle (WEP), and studies of Bose–Einstein condensates under microgravity conditions. Starting from preliminary science objectives and payload requirements, three reference missions in the small/medium class range are discussed, based on a re-adaptation of the LISA Pathfinder spacecraft. A 700/3600km elliptic orbit has been selected to conduct clock tests of special and general relativity, a 700km circular orbit to perform experiments on the Weak Equivalence Principle and to study Bose–Einstein condensates, each mission being based on a three-axis stabilised spacecraft. It was determined that adaptation of LISA Pathfinder would be required in order to meet the demands of the FPE missions. Moreover it was established that specific payload and spacecraft technology development would be required to realise such a programme.

CT and MR Angiography of the Peripheral Circulation—Practical Approach with Clinical Protocols

In physics, a problem-solving approach that begins from a fundamental physical law is said to be derived ab initio or from first principles. In subspecialty medical texts, the presentation of clinical subject matter from first principles is usually cumbersome, steeped in jargon, and largely irrelevant to the actual bread and butter clinical process and, moreover, actual patient outcomes. Among subspecialty medical texts, CT and MR Angiography of the Peripheral Circulation, edited by Debabrata Mukherjee and Sanjay Rajagopalan, succeeds in a clinically relevant presentation of detailed technical material ab initio. Furthermore, an application of the technical material that is presented promises better patient outcomes through improved imaging.