Artykuły w czasopismach na temat „Relativity (physics) – popular works”
Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Relativity (physics) – popular works.
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych artykułów w czasopismach naukowych na temat „Relativity (physics) – popular works”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj artykuły w czasopismach z różnych dziedzin i twórz odpowiednie bibliografie.
1
Capiberibe Nunes, Ricardo, Wivirkins Nogueira Marciel, Wellington Pereira de Queirós, Luiz Gonzaga Roversi Genovese i Jefferson Adriany Ribeiro da Cunha. "Uma Análise Histórica Do Filme Einstein E Eddington: Possíveis Contribuições Para O Ensino De Física". História da Ciência e Ensino: construindo interfaces 22 (26.12.2020): 162–85. http://dx.doi.org/10.23925/2178-2911.2020v22p162-185-161.
Pełny tekst źródłaStreszczenie:
ResumoUma obra semificcional é aquela que utiliza personagens e fatos históricos, envolvendo elementos de ficção. Nessa pesquisa, mostramos, a partir do filme Einstein e Eddigton, como essas obras podem ser usadas no ensino de ciências para fomentar discussões sobre a natureza da ciência bem como desenvolver o espírito questionador sobre as narrativas populares e sensos comuns. Assim, parte dessa pesquisa consiste de uma análise documental, em que foi utilizado estudos sobre a história da teoria da relatividade para analisar o filme, revelando alguns anacronismos sobre a relatividade, a mistificação do cientista Albert Einstein e algumas visões distorcidas da natureza do conhecimento científico. Ao final, mostramos como é possível transformar o filme em um recurso didático. Nessa direção, sugerimos algumas atividades pedagógicas de como utilizar o filme analisado como estratégia de ensino de física.Palavras-chave: Ensino de Física, Filmes, História da Ciência, Teoria da Relatividade.AbstractA semi fictional work is one that uses characters and historical facts, involving elements of fiction. In this research, we show, from the work Einstein and Eddigton, how these works can be used in science teaching to foster discussions about the nature of science as well as to develop the questioning spirit about popular narratives and common senses. Thus, part of this research consists of a documentary analysis, in which studies on the history of the theory of relativity were used to analyze the film, revealing some anachronisms about relativity, the mystification of the scientist Albert Einstein and some distorted views of the nature of scientific knowledge. At the end, we show how it is possible to transform the film into a didactic resource. In this direction, we suggest some pedagogical activities on how to use the analyzed film as a strategy for teaching physics.Keywords: Teaching Physics, Movies, History of Science, Theory of Relativity.
2
Ma, Yunhao, Xiwei Fang, Xinyu Guan, Ke Li, Lei Chen i Fengwei An. "Five-Direction Occlusion Filling with Five Layer Parallel Two-Stage Pipeline for Stereo Matching with Sub-Pixel Disparity Map Estimation". Sensors 22, nr 22 (8.11.2022): 8605. http://dx.doi.org/10.3390/s22228605.
Pełny tekst źródłaStreszczenie:
Binocular stereoscopic matching is an essential method in computer vision, imitating human binocular technology to obtain distance information. Among plentiful stereo matching algorithms, Semi-Global Matching (SGM) is recognized as one of the most popular vision algorithms due to its relatively low power consumption and high accuracy, resulting in many excellent SGM-based hardware accelerators. However, vision algorithms, including SGM, are still somewhat inaccurate in actual long-range applications. Therefore, this paper proposes a disparity improvement strategy based on subpixel interpolation and disparity optimization post-processing using an area optimization strategy, hardware-friendly divider, split look-up table, and the clock alignment multi-directional disparity occlusion filling, and depth acquisition based on floating-point operations. The hardware architecture based on optimization algorithms is on the Stratix-IV platform. It consumes about 5.6 K LUTs, 12.8 K registers, and 2.5 M bits of on-chip memory. Meanwhile, the non-occlusion error rate of only 4.61% is about 1% better than the state-of-the-art works in the KITTI2015 dataset. The maximum working frequency can reach up to 98.28 MHz for the 640 × 480 resolution video and 128 disparity range with the power dissipation of 1.459 W and 320 frames per second processing speed.
3
Collamati, Anthony. "Review of Dark Energy: Hitchcock’s Absolute Camera and the Physics of Cinematic Spacetime". CINEJ Cinema Journal 3, nr 2 (13.10.2014): 234–38. http://dx.doi.org/10.5195/cinej.2014.105.
Pełny tekst źródłaStreszczenie:
Skerry’s Dark Energy draws from astrophysics’ most popular and intriguing concepts—from Eisenstein’s theories of relativity to questions surrounding the expanding universe—and trace them metaphorically through Hitchcock’s films.
4
Lekan, Thomas M. "“A Delicate Equilibrium of the Most Complex Sort”". Historical Studies in the Natural Sciences 53, nr 2 (1.04.2023): 147–88. http://dx.doi.org/10.1525/hsns.2023.53.2.147.
Pełny tekst źródłaStreszczenie:
This article examines the intertidal ecological research of the commercial lab owner and popular science writer Edward F. Ricketts, best known as the prototype for John Steinbeck’s character “Doc” in the novel Cannery Row (1945). Ricketts’s friendship with Steinbeck and unconventional philosophical style have regrettably overshadowed his scientific work, particularly his novel faunal zonation surveys of the North American Pacific littoral in the 1930s and 1940s. These surveys resulted in a landmark handbook, Between Pacific Tides (1939), designed for novices and specialists alike. Ricketts’s work demonstrates how the place of ecological investigation (Billick and Price)—here Monterey Bay’s pounding surf, storm-tossed debris, eclectic bohemianism, and the collaborative energies at Hopkins Marine Station—“imprinted” West Coast animal ecology. At first, Ricketts adopted the physiological methods and conceptions of ecological holism he had learned at the University of Chicago under mentor Warder C. Allee in the early 1920s. Allee had conducted his investigations of intertidal organisms in the relatively placid bays and estuaries at the Woods Hole research center on Cape Cod, Massachusetts. Allee envisioned animal aggregations as higher-order societies guided by “unconscious cooperation” and evolving toward a climax state. Yet Ricketts found that physiochemical factors, such as temperature and salinity, could not explain the distribution of organisms amid the Pacific’s far more precarious rough-and-tumble surf, nor could they account for fierce competition among organisms. Rejecting Allee’s cooperative metaphors, Ricketts came to see community structure as an unintended result of tidepool invertebrates’ Darwinian struggle to occupy resource niches—a “set of sieves” that transferred nourishment from one part of the aggregation to the next, binding it together in interlocking food webs. Through dialogue with Steinbeck about the implications of modern physics during their Sea of Cortez voyage (1940), Ricketts developed a “unified field hypothesis” to conceptualize the dynamic interwovenness created by transfers of metabolic energy. Yet Steinbeck ultimately held fast to a super-organismic understanding of ecological holism—a hierarchical relationship between constituents and the whole that underlays the novelist’s idea of the human “phalanx” in Grapes of Wrath and other works. The article offers new insights about the ecological origins of Steinbeck and Ricketts’s disputes over “non-teleological” reasoning and the pair’s divergent understandings of nature, society, and progressive politics.
5
Erawati, Ni Ketut Ratna. "The Relativity Strategy of Old Javanese". Journal of Language Teaching and Research 8, nr 6 (1.11.2017): 1100. http://dx.doi.org/10.17507/jltr.0806.10.
Pełny tekst źródłaStreszczenie:
Old Javanese is one of the temporal dialects in Indonesia that is estimated to develop from the IX-XV century. The language has a lot of langues inherited in the form of literature kakawin (Old Javanese poetry) and the form of parwa (Old Javanese language prose) until now. Literary works in the form kakawin and parwa are very popular work to be sung in Balinese society especially in religious ceremonies. Therefore, the Old Javanese is very worthy of being used as a linguistic study even though the language is categorized as a dead language. In morphological typology, Old Javanese is an agglutinative type. On the other hand, syntactically the Old Javanese language includes the Split-S typology. Associated with morphological typology and syntax, the Old Javanese has a core system or verb. Thus, the Old Javanese has various forms of verb-alternation in clause structures, either in single clauses or complex clauses. Relative clauses are one part of the complex clause having a change of grammatical relation when the insertion of certain linguistic elements. The topic of this study was the relativity strategy in Old Javanese. The relativity strategy of Old Javanese was described with related theories and concepts. Based on the result the Old Javanese could make the subject to be relative by inserting element of the relative sang and ikang. On the other hand there was also an indirect relativity by marking of verbs and penloping.
6
Shi, Yu. "Hunting the gravitational waves: From Einstein to LIGO". International Journal of Modern Physics D 28, nr 04 (marzec 2019): 1930008. http://dx.doi.org/10.1142/s0218271819300088.
Pełny tekst źródłaStreszczenie:
This is a popular introduction to the scientific background of the detection of gravitational waves, starting from relativity and gravitation. It originates in a Chinese popular article the author wrote for the second Fudan-Zhongzhi Science Award presented to the three scientists who twelve days later also received the 2017 Nobel Prize in Physics.
7
SALTI, MUSTAFA. "DIFFERENT APPROACHES FOR MØLLER'S ENERGY IN THE KASNER-TYPE SPACETIME". Modern Physics Letters A 20, nr 28 (14.09.2005): 2175–82. http://dx.doi.org/10.1142/s0217732305017901.
Pełny tekst źródłaStreszczenie:
Considering the Møller energy definition in both Einstein's theory of general relativity and tele-parallel theory of gravity, we find the energy of the universe based on viscous Kasner-type metrics. The energy distribution which includes both the matter and gravitational field is found to be zero in both of these different gravitation theories and this result agrees with previous works of Cooperstock and Israelit et al., Banerjee–Sen, Vargas who investigated the problem of the energy in Friedmann–Robertson–Walker universe in Einstein's theory of general relativity and Aydogdu–Saltı who considered the same problem in tele-parallel gravity. In all of these works, they found that the energy of the Friedmann–Robertson–Walker spacetime is zero. Our result is the same as that obtained in the studies of Saltı and Havare. They used the viscous Kasner-type metric and found the total energy and momentum by using Bergmann–Thomson energy–momentum formulation in both general relativity and tele-parallel gravity. The result that the total energy and momentum components of the universe is zero supports the viewpoints of Albrow and Tryon.
8
Huguet, E., M. Le Delliou i M. Fontanini. "Cartan approach to Teleparallel Equivalent to General Relativity: A review". International Journal of Geometric Methods in Modern Physics 18, supp01 (24.02.2021): 2140004. http://dx.doi.org/10.1142/s0219887821400041.
Pełny tekst źródłaStreszczenie:
In previous works, questioning the mathematical nature of the connection in the translations gauge theory formulation of Teleparallel Equivalent to General Relativity (TEGR) Theory led us to propose a new formulation using a Cartan connection. In this review, we summarize the presentation of that proposal and discuss it from a gauge theoretic perspective.
9
AYDOGDU, OKTAY. "MØLLER ENERGY–MOMENTUM PRESCRIPTION FOR A LOCALLY ROTATIONALLY SYMMETRIC SPACE–TIME". International Journal of Modern Physics A 21, nr 18 (20.07.2006): 3845–53. http://dx.doi.org/10.1142/s0217751x06030990.
Pełny tekst źródłaStreszczenie:
The energy distribution in the Locally Rotationally Symmetric (LRS) Bianchi type II space–time is obtained by considering the Møller energy–momentum definition in both Einstein's theory of general relativity and teleparallel theory of relativity. The energy distribution which includes both the matter and gravitational field is found to be zero in both of these different gravitation theories. This result agrees with previous works of Cooperstock and Israelit, Rosen, Johri et al., Banerjee and Sen, Vargas, and Aydogdu and Salti. Our result — the total energy of the universe is zero — supports the view points of Albrow and Tryon.
10
Güémez, J., i M. Fiolhais. "A 4-vector formalism for classical mechanics". Revista Brasileira de Ensino de Física 35, nr 4 (grudzień 2013): 1–13. http://dx.doi.org/10.1590/s1806-11172013000400010.
Pełny tekst źródłaStreszczenie:
We present a matrix formalism, inspired by the Minkowski four-vectors of special relativity, useful to solve classical physics problems related to both mechanics and thermodynamics. The formalism turns out to be convenient to deal with exercises involving non-conservative forces and production or destruction of mechanical energy. On the other hand, it provides a framework to treat straightforwardly changes of inertial reference frames, since it embodies the Principle of Relativity. We apply the formalism to a few cases to better show how it works.
11
Brown, Laurie M. "Paul Dirac: Building Bridges of the Mind". International Journal of Modern Physics A 19, supp01 (luty 2004): 9–20. http://dx.doi.org/10.1142/s0217751x04018567.
Pełny tekst źródłaStreszczenie:
Paul Dirac was a brilliant and original thinker. He used his physical intuition and his ideal of mathematical beauty to construct bridges between major areas of physics. This article discusses several such important works, including the bridge between quantum mechanics and relativity that led to his prediction of the existence of antimatter.
12
ACCIOLY, ANTONIO, RUBEN ALDROVANDI i RICARDO PASZKO. "IS THE EQUIVALENCE PRINCIPLE DOOMED FOREVER TO DANTE'S INFERNO ON ACCOUNT OF QUANTUM MECHANICS?" International Journal of Modern Physics D 15, nr 12 (grudzień 2006): 2249–55. http://dx.doi.org/10.1142/s0218271806009686.
Pełny tekst źródłaStreszczenie:
It is commonly assumed that the equivalence principle can coexist without conflict with quantum mechanics. We shall argue here that, contrary to popular belief, this principle does not hold in quantum mechanics. We illustrate this point by computing the second-order correction for the scattering of a massive scalar boson by a weak gravitational field, treated as an external field. The resulting cross-section turns out to be mass-dependent. A way out of this dilemma would be, perhaps, to consider gravitation without the equivalence principle. At first sight, this seems to be a too much drastic attitude toward general relativity. Fortunately, the teleparallel version of general relativity — a description of the gravitational interaction by a force similar to the Lorentz force of electromagnetism and that, of course, dispenses with the equivalence principle — is equivalent to general relativity, thus providing a consistent theory for gravitation in the absence of the aforementioned principle.
13
Anastopoulos, Charis, i Ntina Savvidou. "Quantum Information in Relativity: The Challenge of QFT Measurements". Entropy 24, nr 1 (21.12.2021): 4. http://dx.doi.org/10.3390/e24010004.
Pełny tekst źródłaStreszczenie:
Proposed quantum experiments in deep space will be able to explore quantum information issues in regimes where relativistic effects are important. In this essay, we argue that a proper extension of quantum information theory into the relativistic domain requires the expression of all informational notions in terms of quantum field theoretic (QFT) concepts. This task requires a working and practicable theory of QFT measurements. We present the foundational problems in constructing such a theory, especially in relation to longstanding causality and locality issues in the foundations of QFT. Finally, we present the ongoing Quantum Temporal Probabilities program for constructing a measurement theory that (i) works, in principle, for any QFT, (ii) allows for a first- principles investigation of all relevant issues of causality and locality, and (iii) it can be directly applied to experiments of current interest.
14
Rozov, Andrey Leonidovich. "Modelling of Electrodynamic Phenomena in Slowly Moving Media". Zeitschrift für Naturforschung A 72, nr 8 (28.08.2017): 757–62. http://dx.doi.org/10.1515/zna-2016-0287.
Pełny tekst źródłaStreszczenie:
AbstractWe discuss the feasibility of using, along with Minkowski equations obtained on the basis of the theory of relativity and used at present in electrodynamics, alternative methods of describing the processes of interaction between electromagnetic fields and moving media. In this article, a way of describing electromagnetic fields in terms of classical mechanics is offered. A system of electrodynamic equations for slowly moving media was derived on the basis of Maxwell’s theory within the framework of classical mechanics using Wilsons’ experimental data with dielectrics in a previous article [A. Rozov, Z. Naturforsch. 70, 1019 (2015)]. This article puts forward a physical model that explains the features of the derived equations. The offered model made it possible to suggest a new approach to the derivation of electrodynamic equations for slowly moving media. A variant of Galileo’s relativity principle, in accordance with which the electrodynamic equations for slowly moving media should be considered as Galilean-invariant, is laid down on the basis of both the interpretation of Galileo’s concept following from Galileo’s works and Pauli’s concept of postulate of relativity within the framework of the represented physical model.
15
CAPOZZIELLO, S., R. DE RITIS i A. FEOLI. "ON THE DERIVATION OF THE STRING EFFECTIVE ACTION FROM AN ACCELERATION FIELD". International Journal of Modern Physics D 04, nr 02 (kwiecień 1995): 259–66. http://dx.doi.org/10.1142/s0218271895000193.
Pełny tekst źródłaStreszczenie:
We show that the string cosmology with dilaton can be derived, as a special case, from Caianiello’s model of General Relativity with maximal acceleration interpreting the dilaton as an acceleration field. In fact Caianiello’s theory allows us to recover the stringdilaton effective action starting from a gravitational action which is minimally coupled to a scalar field by means of a particular conformal transformation of the Friedman-Robertson-Walker (FRW) metric. We show that this scheme works near the Planck scale where the pure string-dilaton dynamics works.
16
Schemmel, Matthias. "An Astronomical Road to General Relativity: The Continuity between Classical and Relativistic Cosmology in the Work of Karl Schwarzschild". Science in Context 18, nr 3 (wrzesień 2005): 451–78. http://dx.doi.org/10.1017/s026988970500061x.
Pełny tekst źródłaStreszczenie:
In this article it is argued that a continuity exists between Karl Schwarzschild's work on foundational problems on the borderline of physics and astronomy and his later occupation with general relativity. Based on an analysis of Schwarzschild's published works as well as formerly neglected unpublished notes it is shown that, long before the rise of general relativity, Schwarzschild was concerned with problems that later became associated with that theory. In particular he considered non-Euclidean cosmologies, linked the phenomena of gravitation and inertia to the problem of the precession of Mercury's perihelion, and entertained the possibility of inertial frames rotating with respect to one another. It is argued that these earlier considerations, which reflect his interdisciplinary outlook on the foundations of the exact sciences, enabled Schwarzschild to recognize the significance of general relativity for astronomy, astrophysics, and cosmology earlier than most of his collegues and shaped his contributions to this theory.
17
Aragoneses, Andres, M. Nuria Salan i Antonio Hernandez Fernandez. "Disclosure day on relativity: A science activity beyond the classroom". World Journal on Educational Technology: Current Issues 9, nr 2 (11.04.2017): 59. http://dx.doi.org/10.18844/wjet.v9i2.729.
Pełny tekst źródłaStreszczenie:
An important goal for students in engineering education is the ability to present and defend a project in front of a technical audience. We have designed an activity for helping students to work the independent learning and communication skills, while they are introduced in the dynamics of a conference. In this activity, students prepare and present a poster at a popular physics conference on relativity. This activity is shown to provide them with communication skills, related to generic skills at the core of Universitat Politècnica de Catalunya (UPC) degrees, and which are relevant in most of the duties of an engineer.
18
LAU, STEPHEN R. "DIFFERENTIAL FORMS AND WAVE EQUATIONS FOR GENERAL RELATIVITY". International Journal of Modern Physics D 07, nr 06 (grudzień 1998): 857–85. http://dx.doi.org/10.1142/s0218271898000577.
Pełny tekst źródłaStreszczenie:
In recent papers, Choquet–Bruhat and York and Abrahams, Anderson, Choquet–Bruhat, and York (we refer to both works jointly as AACY) have cast the 3 + 1 evolution equations of general relativity in gauge-covariant and causal "first-order symmetric hyperbolic form," thereby cleanly separating physical from gauge degrees of freedom in the Cauchy problem for general relativity. A key ingredient in their construction is a certain wave equation which governs the light-speed propagation of the extrinsic curvature tensor. Along a similar line, we construct a related wave equation which, as the key equation in a system, describes vacuum general relativity. Whereas the approach of AACY is based on tensor-index methods, the present formulation is written solely in the language of differential forms. Our approach starts with Sparling's tetrad-dependent differential forms, and our wave equation governs the propagation of Sparling's two-form, which in the "time-gauge" is built linearly from the "extrinsic curvature one-form." The tensor-index version of our wave equation describes the propagation of (what is essentially) the Arnowitt–Deser–Misner gravitational momentum.
19
Marr, John H. "A novel visualization of the geometry of special relativity". International Journal of Modern Physics C 27, nr 05 (maj 2016): 1650055. http://dx.doi.org/10.1142/s0129183116500558.
Pełny tekst źródłaStreszczenie:
The mathematical treatment and graphical representation of Special Relativity (SR) are well established, yet carry deep implications that remain hard to visualize. This paper presents a new graphical interpretation of the geometry of SR that may, by complementing the standard works, aid the understanding of SR and its fundamental principles in a more intuitive way. From the axiom that the velocity of light remains constant to any inertial observer, the geodesic is presented as a line of constant angle on the complex plane across a set of diverging reference frames. The resultant curve is a logarithmic spiral, and this view of the geodesic is extended to illustrate the relativistic Doppler effect, time dilation, length contraction, the twin paradox, and relativistic radar distance in an original way, whilst retaining the essential mathematical relationships of SR. Using a computer-generated graphical representation of photon trajectories allows a visual comparison between the relativistic relationships and their classical counterparts, to visualize the consequences of SR as velocities become relativistic. The model may readily be extended to other situations, and may be found useful in presenting a fresh understanding of SR through geometric visualization.
20
CAO, ZHOUJIAN. "NEW METHOD FOR CHARACTERISTIC EVOLUTIONS IN NUMERICAL RELATIVITY". International Journal of Modern Physics D 22, nr 08 (21.06.2013): 1350042. http://dx.doi.org/10.1142/s0218271813500429.
Pełny tekst źródłaStreszczenie:
The main task of numerical relativity is to solve Einstein equations with the aid of supercomputer. There are two main schemes to write Einstein equations explicitly as differential equations. One is based on 3 + 1 decomposition and reduces the Einstein equations to a Cauchy problem. The another takes the advantage of the characteristic property of Einstein equations and reduces them to a set of ordinary differential equations. The latter scheme is called characteristic formalism which is free of constraint equations in contrast to the corresponding Cauchy problem. Till now there is only one well developed code (PITT code) for characteristic formalism. In PITT code, special finite difference algorithm is adopted for the numerical calculation. And it is this special difference algorithm that restricts the numerical accuracy order to second-order. In addition, this special difference algorithm makes the popular Runge–Kutta method used in Cauchy problem not available. In this paper, we modify the equations for characteristic formalism. Based on our new set of equations, we can use usual finite difference method as done in usual Cauchy evolution. And Runge–Kutta method can also be adopted naturally. We develop a set of code in the framework of AMSS-NCKU code based on our new method and some numerical tests are done.
21
Dalitz, Richard H., P. A. M. Dirac i R. Corby Hovis. "The Collected Works of P. A. M. Dirac, 1924–1948 and General Theory of Relativity". Physics Today 49, nr 9 (wrzesień 1996): 84–88. http://dx.doi.org/10.1063/1.2807771.
Pełny tekst źródła
22
GUEDES, SEBASTIÃO NETO RIBEIRO, i RODRIGO CONSTANTINO JERÔNIMO. "The unexplored influences of modern physics on John R. Commons’ economic theory". Brazilian Journal of Political Economy 41, nr 2 (kwiecień 2021): 333–50. http://dx.doi.org/10.1590/0101-31572021-3170.
Pełny tekst źródłaStreszczenie:
ABSTRACT Previous works of John R. Commons’ interpreters have emphasized the influence of numerous theoretical-methodological references (e.g., pragmatism, evolutionism, etc.) in shaping his economic thought. However, almost no mention is made of the influence of particle and relativity physics, which, as we debate, provide sources of insights to his work. This paper explores these connections by showing that John R. Commons was not only interested in the advances of that science but was also inspired by them to produce parallels and analogies that allowed his theory to escape the pitfalls of individualism and determinism while incorporating time and space in an innovative way in the economic discourse.
23
RAY, SAIBAL, i SUMANA BHADRA. "CLASSICAL ELECTRON MODEL WITH NEGATIVE ENERGY DENSITY IN EINSTEIN–CARTAN THEORY OF GRAVITATION". International Journal of Modern Physics D 13, nr 03 (marzec 2004): 555–65. http://dx.doi.org/10.1142/s0218271804004712.
Pełny tekst źródłaStreszczenie:
Experimental result regarding the maximum limit of the radius of the electron (~10-16 cm ) and a few of the theoretical works suggest that there might be some negative energy density regions within the particle in the general theory of relativity. It is argued in the present investigation that such a negative energy density also can be obtained with a better physical interpretation in the framework of Einstein–Cartan theory.
24
Bambi, Cosimo. "X-ray Tests of General Relativity with Black Holes". Symmetry 15, nr 6 (18.06.2023): 1277. http://dx.doi.org/10.3390/sym15061277.
Pełny tekst źródłaStreszczenie:
General relativity is one of the pillars of modern physics. For decades, the theory has been mainly tested in the weak-field regime with experiments in the solar system and radio observations of binary pulsars. Until 2015, the strong-field regime was almost completely unexplored. Thanks to new observational facilities, the situation has dramatically changed in the last few years. Today, we have gravitational wave data of the coalesce of stellar-mass compact objects from the LIGO-Virgo-KAGRA collaboration, images at mm wavelengths of the supermassive black holes in M87* and Sgr A* from the Event Horizon Telescope collaboration, and X-ray data of accreting compact objects from a number of X-ray missions. Gravitational wave tests and black hole imaging tests are certainly more popular and are discussed in other articles of this Special Issue. The aim of the present manuscript is to provide a pedagogical review on X-ray tests of general relativity with black holes and to compare these kinds of tests with those possible with gravitational wave data and black hole imaging.
25
Ladyman, James, i Stuart Presnell. "The Hole Argument in Homotopy Type Theory". Foundations of Physics 50, nr 4 (4.10.2019): 319–29. http://dx.doi.org/10.1007/s10701-019-00293-9.
Pełny tekst źródłaStreszczenie:
Abstract The Hole Argument is primarily about the meaning of general covariance in general relativity. As such it raises many deep issues about identity in mathematics and physics, the ontology of space–time, and how scientific representation works. This paper is about the application of a new foundational programme in mathematics, namely homotopy type theory (HoTT), to the Hole Argument. It is argued that the framework of HoTT provides a natural resolution of the Hole Argument. The role of the Univalence Axiom in the treatment of the Hole Argument in HoTT is clarified.
26
ABBASSI, AMIR M., i SAEED MIRSHEKARI. "ENERGY–MOMENTUM DENSITY OF GRAVITATIONAL WAVES". International Journal of Modern Physics A 23, nr 27n28 (10.11.2008): 4569–77. http://dx.doi.org/10.1142/s0217751x08041487.
Pełny tekst źródłaStreszczenie:
In this paper, we elaborate the problem of energy–momentum in general relativity by energy–momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to the same results that have been obtained by Einstein and Papapetrou prescriptions.
27
van Wijngaarden, W. A. "A second century of Einstein?BoseEinstein condensation and quantum information". Canadian Journal of Physics 83, nr 7 (1.07.2005): 671–85. http://dx.doi.org/10.1139/p05-042.
Pełny tekst źródłaStreszczenie:
A century ago Albert Einstein transformed classical physics with his seminal papers on Brownian motion, the Photoelectric effect, and, of course, special and later general relativity. Lesser well-known are his contributions to BoseEinstein Condensation and the EinsteinPodolskyRosen paradox, the latter being a criticism of Quantum Mechanics. These later works were regarded even by physicists for decades as mere Gedanken or thought experiments. In recent years, not only have they been verified experimentally but revolutionary technological applications are emerging including quantum cryptography and possibly quantum computing. PACS Nos.: 03.65, 03.67, 03.75, 05.30.Jp
28
Takka, N. "Exact form of the generalized Lorentz force in Fock’s nonlinear relativity". International Journal of Modern Physics A 34, nr 03n04 (10.02.2019): 1950016. http://dx.doi.org/10.1142/s0217751x19500167.
Pełny tekst źródłaStreszczenie:
This work completes a series of two papers devoted to the extension of the fundamental laws of electrodynamics in the context of Fock’s nonlinear relativity (FNLR). Indeed, after having established in the previous study the exact generalizations of both Maxwell’s equations and Dirac’s magnetic monopole, we present here the remaining exact Lorentz force. As in [Formula: see text]-Minkowski space–time, two different contributions appear in the corresponding equation of motion where the new effect is interpreted as the gravitational-type Lorentz force. This common point separately induced by the radius of the universe in our case, or Planck energy in other works, reinforces once more the analogy between electromagnetism and gravity in two different scientific approaches. As a relative difference, it is very important to highlight that more homogeneity characterizes our results where each effect is exclusively generated by mass or charge but not both at the same time. Even more, the new effect emerges as the result of the triple effect of the R-deformation, mass and the square of the velocity but completely independent of electromagnetic field.
29
König, Heidi. "General Relativity in the English-speaking World: The Contributions of Henry L. Brose". Historical Records of Australian Science 17, nr 2 (2006): 169. http://dx.doi.org/10.1071/hr06007.
Pełny tekst źródłaStreszczenie:
The story of how the theory of general relativity found its way into the English speaking world during the Great War has often been told: it is dominated by the towering figure of the Cambridge astronomer Arthur Stanley Eddington, who (in 1916, and through the good services of the Dutch physicist Willem de Sitter) received copies of the papers Einstein had presented to the Berlin Academy in 1915. Eddington engaged in promoting the new theory, and in order to put one of its predictions — the bending of light in a gravitational field — to the test, he arranged for the famous expeditions to observe the eclipse of 29 May 1919 to be mounted, the results of which, presented in November of the same year, were the major breakthrough of general relativity and provoked a public interest unprecedented in the whole history of science. But a history of general relativity in the English-speaking world would be thoroughly incomplete if it did not take into account the contributions made by another, nowadays almost forgotten but at that time probably the most prolific and most dedicated of its popularizers, the Australian physicist and translator Henry L. Brose. Largely overlooked in recent accounts of the history of general relativity, Brose's rendering into English of a series of excellent German works on the theory was decisive for its understanding in the Anglo-Saxon world. The texts he chose (including Moritz Schlick's Space and Time in Contemporary Physics and Hermann Weyl's Space, Time, Matter) were among the first and most important that had so far appeared on the subject, and their English translations were published at a time when accounts of what was to be called 'one of the greatest of achievements in the history of human thought' were scarce and badly needed in Britain. Also, it will become clear from a closer look at both Brose's biography and the tense political situation between Britain and Germany shortly after the Great War, that hardly any of those works would have made its way into England so promptly (if at all) if not for Brose's enormous personal efforts and dedication. This paper retraces Brose's role as a translator and promotor of general relativity in its early days, thus shedding light on the mechanisms of knowledge transfer during and after the First World War.
30
Cavalcanti, Eric G., i Howard M. Wiseman. "Implications of Local Friendliness Violation for Quantum Causality". Entropy 23, nr 8 (21.07.2021): 925. http://dx.doi.org/10.3390/e23080925.
Pełny tekst źródłaStreszczenie:
We provide a new formulation of the Local Friendliness no-go theorem of Bong et al. [Nat. Phys. 16, 1199 (2020)] from fundamental causal principles, providing another perspective on how it puts strictly stronger bounds on quantum reality than Bell’s theorem. In particular, quantum causal models have been proposed as a way to maintain a peaceful coexistence between quantum mechanics and relativistic causality while respecting Leibniz’s methodological principle. This works for Bell’s theorem but does not work for the Local Friendliness no-go theorem, which considers an extended Wigner’s Friend scenario. More radical conceptual renewal is required; we suggest that cleaving to Leibniz’s principle requires extending relativity to events themselves.
31
Czuchry, Ewa. "Resolution of Cosmological Singularity in Hořava–Lifshitz Cosmology". Universe 9, nr 4 (25.03.2023): 160. http://dx.doi.org/10.3390/universe9040160.
Pełny tekst źródłaStreszczenie:
The standard ΛCDM model, despite its agreement with observational data, still has some issues unaddressed, such as the problem of initial singularity. Solving that problem usually requires modifications of general relativity. However, there appeared the Hořava–Lifshitz (HL) theory of gravity, in which equations governing cosmological evolution include a new term scaling similarly as the dark radiation term in the Friedmann equations, enabling a bounce of the universe instead of initial singularity. This review describes past works on the stability of such a bounce in different formulations of HL theory, an initial detailed balance scenario, and further projectable versions containing higher than quadratic terms to the original action.
32
Fioresi, Rita, Pratik Chaudhari i Stefano Soatto. "A Geometric Interpretation of Stochastic Gradient Descent Using Diffusion Metrics". Entropy 22, nr 1 (15.01.2020): 101. http://dx.doi.org/10.3390/e22010101.
Pełny tekst źródłaStreszczenie:
This paper is a step towards developing a geometric understanding of a popular algorithm for training deep neural networks named stochastic gradient descent (SGD). We built upon a recent result which observed that the noise in SGD while training typical networks is highly non-isotropic. That motivated a deterministic model in which the trajectories of our dynamical systems are described via geodesics of a family of metrics arising from a certain diffusion matrix; namely, the covariance of the stochastic gradients in SGD. Our model is analogous to models in general relativity: the role of the electromagnetic field in the latter is played by the gradient of the loss function of a deep network in the former.
33
AYDOGDU, OKTAY. "GRAVITATIONAL ENERGY–MOMENTUM DENSITY IN BIANCHI TYPE II SPACE–TIMES". International Journal of Modern Physics D 15, nr 04 (kwiecień 2006): 459–68. http://dx.doi.org/10.1142/s0218271806008255.
Pełny tekst źródłaStreszczenie:
In this paper, using Einstein, Landau and Lifshitz's energy–momentum complexes both in general relativity and teleparallel gravity, we calculate the total energy distribution (due to matter and fields, including gravitation) associated with locally rotationally symmetric (LRS) Bianchi type II cosmological models. We show that energy densities in these different gravitation theories are the same, so they agree with each other. We obtain the result that the total energy is zero. This result agrees with previous works of Cooperstock and Israelit, Rosen, Johri et al., Banerjee and Sen, Vargas, Aydogdu and Saltı. Moreover, our result supports the viewpoints of Albrow and Tryon.
34
Elbaz, Claude. "Incompleteness of General Relativity Regarding Einstein's Program". Applied Physics Research 10, nr 5 (27.09.2018): 47. http://dx.doi.org/10.5539/apr.v10n5p47.
Pełny tekst źródłaStreszczenie:
The detection of gravitational waves substantiates the undeniable achievement of general relativity theory by increasing its theoretical and experimental accuracy. One century after predicting it has set again Einstein's works at the front of research. Absence of quantum particle associated to gravitation emphasizes that general relativity theory remains not included in the standard model of physics. Then Einstein’s disagreement about it incompleteness regarding wave-particle and matter-field becomes actualized. In order to circumvent these difficulties he privileged field, rather than matter for universe description in his program. In consequence a scalar field e(r0,t0) propagating at speed of light c yields matter from standing waves moving at speed strictly inferior to c, and interactions from progressive waves. Electromagnetic interactions derive from local variations of frequencies, and gravitation from local variations of speed of light. A space-like amplitude functions u0(k0r0) supplements fundamental time-like functions of classical and quantum mechanics. It tends toward Dirac’s distribution Delta (r0) in geometrical optics approximation conditions, when frequencies are infinitely high, and then hidden.
More generally, it allows theoretical economies by deriving energy-momentum conservation laws, and least action law. Quantum domain corresponds to wave optics approximation conditions. Variations of frequencies give rise to an adiabatic constant, formally identical with Planck's constant, leading to first quantification for electromagnetic interactions and to second quantification for matter.
35
Rajput, Shailendra, i Asher Yahalom. "Newton’s Third Law in the Framework of Special Relativity for Charged Bodies". Symmetry 13, nr 7 (12.07.2021): 1250. http://dx.doi.org/10.3390/sym13071250.
Pełny tekst źródłaStreszczenie:
Newton’s third law states that any action is countered by a reaction of equal magnitude but opposite direction. The total force in a system not affected by external forces is, therefore, zero. However, according to the principles of relativity, a signal cannot propagate at speeds exceeding the speed of light. Hence, the action and reaction cannot be generated at the same time due to the relativity of simultaneity. Thus, the total force cannot be null at a given time. In a previous paper, we showed that Newton’s third law cannot strictly hold in a distributed system where the different parts are at a finite distance from each other. This analysis led to the suggestion of a relativistic engine. As the system is affected by a total force for a finite period, the system acquires mechanical momentum and energy. The subject of momentum conversation was discussed in another previous paper, while energy conservation was discussed in additional previous papers. In those works, we relied on the fact that the bodies were macroscopically natural. Here, we relax this assumption and study charged bodies, thus analyzing the consequences on a possible electric relativistic engine.
36
Tu, Runsheng. "The contradictions in the existing physics and the psychological factors that influence them to be valued". International Journal of Scientific Reports 6, nr 10 (21.09.2020): 418. http://dx.doi.org/10.18203/issn.2454-2156.intjscirep20204035.
Pełny tekst źródłaStreszczenie:
<p class="1">Besides the limitation of cognition level, the factors that affect the correctness of academic evaluation are as follows: collusion-recognization effect, backfire effect, cognitive maladjustment, inattentional blindness and aesthetic fatigue. It's hard for readers (especially the reviewers of academic achievements) not to fall into the trap. Therefore, the probability of misjudgment of academic achievements of "questioning and denying current prevailing theories or creating new theories" is very high. The intolerable contradictions in the existing physical theories, such as space paradox, time paradox, quantum entanglement paradox, are exposed by means of thought experiments and "to present the facts, reason things out", and take these works as examples to reveal the formation and utilization of these adverse psychological effects. The conclusions are as follows: both special relativity and Copenhagen interpretation of quantum mechanics have fatal injury; it is difficult to eliminate the misjudgment of academic achievements, but the misjudgment rate can be reduced. The concepts of “invariance of spatial attribution” and “inaction association” are established. These works can urge readers to treat new and old physics theories more carefully, promote the development of physics, and promote the birth and improvement of the evaluation theory of science and technology.</p>
37
Aharonov, Y., i L. Vaidman. "Sending Signals to Space-Like Separated Regions". Zeitschrift für Naturforschung A 56, nr 1-2 (1.02.2001): 20–26. http://dx.doi.org/10.1515/zna-2001-0105.
Pełny tekst źródłaStreszczenie:
AbstractTwo recent works suggest a possibility of sending signals to a space-like separated region, contrary to the spirit of special relativity. In the first work (J. Grunhaus, S. Popescu, and D. Rohrlich, Phys. Rev. A 53, 3781 (1996)) it has been shown that sending signals to a particular union of space-like separated regions cannot cause causality paradoxes. Another work (Y. Aharonov and L. Vaidman, Phys. Rev. A 61, 052108 (2000)) showed that the relative phase of the quantum superposition of a particle at two separate locations can be measured locally. Together with the possibility of changing the relative phase in a nonlocal way using the potential effect we, apparently, have a method of sending signals to space-like separated regions. These arguments are critically analyzed in this paper.
38
Barbero, Fernando, Marc Basquens, Valle Varo i Eduardo J. S. Villaseñor. "Three Roads to the Geometric Constraint Formulation of Gravitational Theories with Boundaries". Symmetry 13, nr 8 (4.08.2021): 1430. http://dx.doi.org/10.3390/sym13081430.
Pełny tekst źródłaStreszczenie:
The Hamiltonian description of mechanical or field models defined by singular Lagrangians plays a central role in physics. A number of methods are known for this purpose, the most popular of them being the one developed by Dirac. Here, we discuss other approaches to this problem that rely on the direct use of the equations of motion (and the tangency requirements characteristic of the Gotay, Nester and Hinds method), or are formulated in the tangent bundle of the configuration space. Owing to its interesting relation with general relativity we use a concrete example as a test bed: an extension of the Pontryagin and Husain–Kuchař actions to four dimensional manifolds with boundary.
39
Moraes, P. H. R. S., P. K. Sahoo, Barkha Taori i Parbati Sahoo. "Phantom energy-dominated universe as a transient stage in f(R) cosmology". International Journal of Modern Physics D 28, nr 10 (lipiec 2019): 1950124. http://dx.doi.org/10.1142/s0218271819501244.
Pełny tekst źródłaStreszczenie:
The [Formula: see text] theories of gravity are the most popular, simple and well-succeeded extension of Einstein’s General Relativity. They can account for some observational issues of standard cosmology with no need for evoking the dark sector of the universe. In the present paper, we will investigate LRS Bianchi type-I spacetime in [Formula: see text] gravity theory within the phantom energy-dominated era. We show that in this formalism the phantom energy-dominated universe is a transient stage and in the further stage of the universe dynamics, it is dominated, once again, by dark energy. Such an important feature is obtained from the model, rather than imposed to it, and may have a relation to loop quantum cosmology.
40
Wu, Fan, Can Yang, Xue Zheng, Dongsheng Li i Kebin Chen. "Research on Overlapping Communities in Scientific Cooperation Network". Journal of Physics: Conference Series 2281, nr 1 (1.06.2022): 012013. http://dx.doi.org/10.1088/1742-6596/2281/1/012013.
Pełny tekst źródłaStreszczenie:
Abstract Science of science provides quantitative means for scientific research activities and can reveal the basic laws of scientific research. Taking the scientist cooperation network of Condensed matter physics, General relativity quantum cosmology and High energy physics phenomenology as the research object, the overlapping community structure in the network is detected by using the label propagation algorithm based on seed diffusion. Through community analysis, it is found that when the scale of scientists' cooperative network increases, the increase in the number of communities is not obvious, but the scale of each community will increase, and the probability of scientists belonging to overlapping communities will decrease. This shows that the increase in the number of authoritative scientists is not obvious after the unpopular research field becomes a popular research field. In hot research fields, the division of scientists' cooperation circles is clearer, and the cooperation frequency between circles will decrease significantly.
41
Karavaev, E. F., i S. Y. Kolomiytsev. "Ideas of Conventionalism in Russian Science and Philosophy". Solov’evskie issledovaniya, nr 1 (30.03.2022): 155–68. http://dx.doi.org/10.17588/2076-9210.2022.1.155-168.
Pełny tekst źródłaStreszczenie:
The paper examines the conventionalism that arose within the framework of the second positivism in European philosophy at the turn of the XIX–XX centuries, in connection with Russian science and philosophy. Despite its being popular and developed mainly in Western philosophy, we demonstrate that its ideas were also reflected in Russian culture. Moreover, we argue that it was the achievements of Russian mathematicians that influenced the emergence of this direction in European philosophy. To determine the place of conventionalism in Russian culture, the works of such scientists, philosophers and historians of science as A. Poincaré, N.V. Efimov, G.V. Florovsky, P.S. Yushkevich and others were used. The article also provides an overview of their main works and ideas. The analysis also deals with the influence of ideological and political factors on the development of philosophy in the XX century in Russia and the USSR. It is shown that the achievements of Russian mathematicians had a significant influence on the emergence of conventionalism, and the ideas of conventionalism, in turn, were reflected in the concepts of Russian thinkers concerning the philosophy of science and the philosophy of history. Thus, N.I. Lobachevsky can be called a harbinger of mathematical conventionalism, some ideas of P.S. Yushkevich and A.A. Bogdanov can be referred to natural-scientific conventionalism, and some ideas of G.V. Florovsky can be called historical conventionalism. We conclude that Russian science, firstly, was one of the reasons for the emergence of conventionalism in Europe, and secondly, Russian philosophy adopted and applied some of its ideas, in particular, concerning the impossibility of complete knowledge of the world or the relativity of ways of expressing truth, which remain relevant today.
42
Mukhtar, N. M., i F. M. Penkov. "EINSTEIN'S WORK IN THE FIELD OF THERMODYNAMICS". BULLETIN Series of Physics & Mathematical Sciences 72, nr 4 (29.12.2020): 137–42. http://dx.doi.org/10.51889/2020-4.1728-7901.21.
Pełny tekst źródłaStreszczenie:
In this article, we review Einstein's work in the field of thermodynamics. Einstein is one of the most famous scientists who have their place in the field of physics. One of the most important innovations was the discovery of the theory of relativity. However, Einstein also conducted research in other areas of physics. One of them is thermodynamics. The main purpose of this article is to give a small description of Einstein's work in the field of thermodynamics. Comparing the work of scientists and Einstein, who did the same work in the field of thermodynamics, you can see the main differences or similarities between it and it. Einstein laid the groundwork for some new ideas in this area. Currently, the scope of Einstein's work in the field of thermodynamics is unknown. There are works of scientists who mistakenly call their theories in the field of thermodynamics. However, it is enough that Einstein's idea of Brownian motion could provide answers to some questions in the field of nanotechnology and serve as the initial basis for many new works.
43
Ren, Wei, Tang Li, Qiuzhi Qu, Bin Wang, Lin Li, Desheng Lü, Weibiao Chen i Liang Liu. "Development of a space cold atom clock". National Science Review 7, nr 12 (31.08.2020): 1828–36. http://dx.doi.org/10.1093/nsr/nwaa215.
Pełny tekst źródłaStreszczenie:
Abstract Atomic clocks with cold atoms play important roles in the field of fundamental physics as well as primary frequency standards. Operating such cold atom clocks in space paves the way for further exploration in fundamental physics, for example dark matter and general relativity. We developed a space cold atom clock (SCAC), which was launched into orbit with the Space Lab TG-2 in 2016. Before it deorbited with TG-2 in 2019, the SCAC had been working continuously for almost 3 years. During the period in orbit, many scientific experiments and engineering tests were performed. In this article, we summarize the principle, development and in-orbit results. These works provide the basis for construction of a space-borne time-frequency system in deep space.
44
Sevalnikov, Andrey Yu. "Time in the Physical Picture of the World". Epistemology & Philosophy of Science 57, nr 4 (2020): 128–32. http://dx.doi.org/10.5840/eps202057465.
Pełny tekst źródłaStreszczenie:
The article is devoted to the problem of time in modern science, where in recent years there have been major changes related to the latest discoveries in the field of the foundations of quantum theory. The author refers to works of K.-F. von Weizsacker (which works are not well-known in Russian-speaking field). Weizsacker deploys a large-scale program of building modern physics, while starting (not only as a physicist, but also a professional philosopher) with questions of philosophical interpretation of postulates of modern physics, especially quantum mechanics. His key thesis is that time in physics is fundamentally distinct, which represents the whole physics as an integral scientific discipline. Weizsacker comes from physical and philosophical reflections, that give a special value to his work. Analyzing the conclusions of theoretical physics, namely the issues of substantiation of statistical mechanics, thermodynamics, and, above all, quantum mechanics, Weizsacker comes to the key idea of the structure of time in the substantiation of physical theory. The author in this conclusion disagrees with the opinion of most modern physicists that time has a subjective character, and the modus of the past, present and future reflects its essential character. The allocation of the time structure requires special logic. Such a logic is temporal and quantum. Starting from temporal logic, introducing the concept of possibility and probability, he comes to the substantiation of quantum mechanics. Being modal logic, it is based on the concept of possibility and probability. Key concept for Weizsacker is a binary alternative (Uralternative), closely related to the principle of superposition in quantum mechanics. By introducing the concept of certain alternatives, essentially actualized alternatives, Weizsacker shows how one can get the theory of relativity with its space-time structure. Further, he shows that based on its structure, you can get the theory of relativity. The space-time structure in this case is secondary, relational, as understood by Leibniz, Mach, and Einstein.
45
Sivaram, Chandra, Kenath Arun i Avijeet Prasad. "Gravity of Negative Mass: Some Subtle Aspects and Implications". Mapana Journal of Sciences 21, nr 4 (1.01.2023): 01–11. http://dx.doi.org/10.12723/mjs.63.4.
Pełny tekst źródłaStreszczenie:
The gravitational interaction has mass of only one sign as the source that is conventionally taken to be positive. The existence of negative mass is not precluded in either Newtonian gravity or general relativity. Negative masses have been invoked in many recent papers to understand the dominance of repulsive dark energy that is accelerating the universe. Here we discuss the various gravitating properties of negative mass particles and their implications for black holes, cosmology, and fundamental physics. Inconsistencies in the earlier works are also discussed. We study the possibility of such negative mass particles accounting for the accelerated expansion of the universe. We set constraints on the density of these negative mass particles based on astrophysical observations.
46
Williams, Hollis. "A High-Speed Test of the Equivalence Principle". Physics Teacher 60, nr 7 (październik 2022): 594–96. http://dx.doi.org/10.1119/5.0038935.
Pełny tekst źródłaStreszczenie:
It is well known that Newton’s work on mechanics depended in a crucial way on the previous observations of Galileo. The key insight of Galileo was that one can analyze the motion of bodies using experiments and mathematical equations. One experimental observation that roughly emerges from this work in modern terms is that two objects of different mass that are simultaneously released from rest and allowed to fall under the influence of gravity through a vacuum should hit the ground at the same time (this is essentially what is called the equivalence principle in general relativity). In popular legend, it is said that Galileo tested this by dropping two balls of different masses from the Leaning Tower of Pisa and showing that they hit the ground at the same time, but the historical evidence suggests that this is unlikely as he seems to have experimented mostly with balls rolling down inclined slopes.
47
Navarro, Jaume. "Ether and Wireless". Historical Studies in the Natural Sciences 46, nr 4 (1.09.2016): 460–89. http://dx.doi.org/10.1525/hsns.2016.46.4.460.
Pełny tekst źródłaStreszczenie:
With the creation of the BBC in 1922, wireless sets ceased to be obscure devices for military and commercial communication, and became household goods to entertain the British middle classes. Wireless amateurs, electrical engineers, inventors, and specialized physicists engaged in a cultural exchange among themselves and with the general public to explain and understand the mechanisms and possibilities of the new technology. This created a new arena for discussions on the existence of the ether at a time when highly esoteric physics (mainly relativity, but also quantum physics) had triggered a debate about its very existence. In this paper I explore the ways in which the ether saw its popularity renewed by its link to the modern wireless technologies. I argue that far from being part of an old, outdated physics, radio broadcasting was instrumental for the ether to remain popular, and even an element of modernity, among many wireless amateurs, engineers, and the general public in the 1920s and early 1930s.
48
Chianese, Marco, Damiano F. G. Fiorillo, Gianpiero Mangano, Gennaro Miele, Stefano Morisi i Ofelia Pisanti. "Sensitivity of KM3NeT to Violation of Equivalence Principle". Symmetry 13, nr 8 (26.07.2021): 1353. http://dx.doi.org/10.3390/sym13081353.
Pełny tekst źródłaStreszczenie:
The symmetry of the theory of relativity under diffeomorphisms strongly depends on the equivalence principle. Violation of Equivalence Principle (VEP) can be tested by looking for deviations from the standard framework of neutrino oscillations. In recent works, it has been shown that strong constraints on the VEP parameter space can be placed by means of the atmospheric neutrinos observed by the IceCube neutrino telescope. In this paper, we focus on the KM3NeT neutrino telescope and perform a forecast analysis to assess its capacity to probe VEP. Most importantly, we examine the crucial role played by systematic uncertainties affecting the neutrino observations. We find that KM3NeT will constrain VEP parameters times the local gravitational potential at the level of 10−27. Due to the systematic-dominated regime, independent analyses from different neutrino telescopes are fundamental for robustly testing the equivalence principle.
49
Pszota, Gábor, i Endre Kovács. "X-ray Spectroscopic Study of Low-Mass X-ray Binaries: A Review of Recent Progress via the Example of GX 339-4". Universe 9, nr 9 (4.09.2023): 404. http://dx.doi.org/10.3390/universe9090404.
Pełny tekst źródłaStreszczenie:
Low-mass X-ray binaries (LMXB) serve as natural laboratories, where the predictions of general relativity can be tested in the strong field regime. The primary object of such sources can be a neutron star (NS) or a black hole (BH), and this object captures material from the secondary object through the inner Lagrange point via a process called Roche lobe overflow. Because of the angular momentum of the infalling matter, an accretion disk is formed, in which viscous effects transport the angular momentum radially outward. In the high/soft state of these sources, the accretion disk can extend all the way to the innermost stable circular orbit (ISCO); therefore, when the primary object is a BH, its X-ray spectrum contains information about the region very close to the event horizon. This paper aims to review the theoretical and observational works related to the X-ray spectroscopy of such sources via the example of GX 339-4, which is one of the most well-known and well-studied LMXBs.
50
Mastrobisi, Giorgio Jules. "Why Relativity needs Phenomenology ? Eidetic-Relativistic Kinesthetics and Temporality in Hus-serl, Weyl and Einstein." Aoristo - International Journal of Phenomenology, Hermeneutics and Metaphysics 2, nr 2 (20.09.2019): 140–72. http://dx.doi.org/10.48075/aoristo.v2i2.23257.
Pełny tekst źródłaStreszczenie:
This paper aims to explain how the insights Weyl gleaned from Husserl played an important role in his scientific work, and then how Einstein’s major work exhibit important parallels to Weyl’s work, thereby establishing phenomenology both as an indirect historical influence and a systematic underpinning for Einstein’s work in theoretical physics. In so doing, this paper seeks to show how some of the most basic problems that Einstein addresses have a kinship not just to problems addressed in a completely different context by Edmund Husserl’s phenomenology and his circle, but also to perennial problems in ontology and epistemology that go back to Kant, Hume and Leibniz. The conclusion seems to suggest that it not only shows how phenomenology both historically and systematically provides a backdrop for Einstein’s work; my thesis actually situates issues in twentieth-century scientific thought against the backdrop of a philosophical development, and perhaps the most original idea of this study consists not just in showing how phenomenology influenced Einstein, but also how Einstein’s work on relativity had an important influence on the work of Edmund Husserl in Crisis of European Sciences and in his later works.