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14
The Mutual Exclusion Problem  Part I: A Theory of Interprocess Communication
, 2000
"... A novel formal theory of concurrent systems is introduced that does not assume any atomic operations. The execution of a concurrent program is modeled as an abstract set of operation executions with two temporal ordering relations: "precedence" and "can causally a#ect". A primiti ..."
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A novel formal theory of concurrent systems is introduced that does not assume any atomic operations. The execution of a concurrent program is modeled as an abstract set of operation executions with two temporal ordering relations: "precedence" and "can causally a#ect". A primitive interprocess communication mechanism is then defined. In Part II, the mutual exclusion is expressed precisely in terms of this model, and solutions using the communication mechanism are given. Contents 1 Introduction 2 2 The Model 2 2.1 Physical Considerations . . . . . . . . . . . . . . . . . . . . . 3 2.2 System Executions . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 HigherLevel Views . . . . . . . . . . . . . . . . . . . . . . . . 7 3 Interprocess Communication 9 4 Processes 14 5 MultipleReader Variables 17 6 Discussion of the Assumptions 18 7 Conclusion 19 1 1 Introduction The mutual exclusion problem was first described and solved by Dijkstra in [3]. In this problem, there is a collection...
Worlds in the Everett Interpretation
 Studies in the History and Philosopy of Modern Physics
, 2002
"... This is a discussion of how we can understand the worldview given to us by the Everett interpretation of quantum mechanics, and in particular the rôle played by the concept of ‘world’. The view presented is that we are entitled to use ‘manyworlds ’ terminology even if the theory does not specify t ..."
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Cited by 26 (5 self)
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This is a discussion of how we can understand the worldview given to us by the Everett interpretation of quantum mechanics, and in particular the rôle played by the concept of ‘world’. The view presented is that we are entitled to use ‘manyworlds ’ terminology even if the theory does not specify the worlds in the formalism; this is defended by means of an extensive analogy with the concept of an ‘instant ’ or moment of time in relativity, with the lack of a preferred foliation of spacetime being compared with the lack of a preferred basis in quantum theory. Implications for identity of worlds over time, and for relativistic quantum mechanics, are discussed.
Einstein’s Investigations of Galilean Covariant Electrodynamics Prior to 1905,” Archive for History of Exact Sciences
, 2004
"... Einstein learned from the magnet and conductor thought experiments how to use field transformation laws to extend the covariance to Maxwell’s electrodynamics. If he persisted in his use of this device, he would have found that the theory cleaves into two Galilean covariant parts, each with different ..."
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Cited by 13 (3 self)
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Einstein learned from the magnet and conductor thought experiments how to use field transformation laws to extend the covariance to Maxwell’s electrodynamics. If he persisted in his use of this device, he would have found that the theory cleaves into two Galilean covariant parts, each with different field transformation laws. The tension between the two parts reflects a failure not mentioned by Einstein: that the relativity of motion manifested by observables in the magnet and conductor thought experiment does not extend to all observables in electrodynamics. An examination of Ritz’s work shows that Einstein’s early view could not have coincided with Ritz’s on an emission theory of light, but only with that of a conveniently reconstructed Ritz. One Ritzlike emission theory, attributed by Pauli to Ritz, proves to be a natural extension of the Galilean covariant part of Maxwell’s theory that happens also to accommodate the magnet and conductor thought experiment. Einstein's famous chasing a light beam thought experiment fails as an objection to an etherbased, electrodynamical theory of light. However it would allow Einstein to formulate his general objections to all emission theories of light in a very sharp form. Einstein found two well known experimental results of 18th and19th century optics compelling (Fizeau’s experiment, stellar aberration), while the accomplished MichelsonMorley experiment played no memorable role. I suggest they owe their importance to their providing a direct experimental grounding for Lorentz ’ local time, the precursor of Einstein’s relativity of simultaneity, and do it essentially independently of electrodynamical theory. I attribute Einstein’s success to his determination to implement a principle of relativity in electrodynamics, but I urge that we not invest this stubbornness with any mystical prescience. 1 I am grateful to Diana Buchwald, Olivier Darrigol, Allen Janis, Michel Janssen, Robert Rynasiewicz and John Stachel for helpful discussion and for assistance in accessing source materials.
Atoms entropy quanta: Einstein’s miraculous argument of 1905
 Studies in History and Philosophy of Modern Physics
, 2006
"... miraculous argument, as I shall call it. Pointing out an analogy with ideal gases and dilute solutions, he showed that the macroscopic, thermodynamic properties of high frequency heat radiation carry a distinctive signature of finitely many, spatially localized, independent components and so inferre ..."
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Cited by 6 (3 self)
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miraculous argument, as I shall call it. Pointing out an analogy with ideal gases and dilute solutions, he showed that the macroscopic, thermodynamic properties of high frequency heat radiation carry a distinctive signature of finitely many, spatially localized, independent components and so inferred that it consists of quanta. I describe how Einstein’s other statistical papers of 1905 had already developed and exploited the idea that the ideal gas law is another macroscopic signature of finitely many, spatially localized, independent components and that these papers in turn drew on his first two, “worthless ” papers of 1901 and 1902 on intermolecular forces. However, while the ideal gas law was a secure signature of 1 I am grateful to Jos Uffink for helpful comments on an earlier version of this paper and for penetrating queries that led to the material in Section 2.2. 2 independence, it was harder to use as an indicator that there are finitely many components and that they are spatially localized. Further, since his analysis of the ideal gas law depended on the assumption that the number of components was fixed, its use was precluded for heat radiation, whose component quanta vary in number in most processes. So Einstein needed and found another, more powerful signature of discreteness applicable to heat radiation and which indicated all these properties. It used one of the few processes, volume fluctuation, in which heat radiation does not alter the number of quanta. 1.
How Hume and Mach Helped Einstein Find Special Relativity
 In
, 2005
"... Note to typesetter: The figures embedded here are low resolution gif files. Please set from EPS files provided separately. 1. ..."
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Note to typesetter: The figures embedded here are low resolution gif files. Please set from EPS files provided separately. 1.
unknown title
, 2005
"... of components was fixed, its use was precluded for heat radiation, whose component quanta vary in number in most processes. So Einstein needed and found another, more powerful signature of In a mildly worded series of papers in the Annalen der Physik of 1905, Einstein established the reality of atom ..."
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of components was fixed, its use was precluded for heat radiation, whose component quanta vary in number in most processes. So Einstein needed and found another, more powerful signature of In a mildly worded series of papers in the Annalen der Physik of 1905, Einstein established the reality of atoms, announced special relativity and the inertia of energy and www.elsevier.com/locate/shpsb13552198/ $ see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.shpsb.2005.07.003
FiveDimensional Brane World Theory
, 2001
"... A fivedimensional cosmological theory of gravitation that unifies space, time and velocity is presented. Within the framework of this theory we first discuss some general aspects of the universe in five dimensions. We then find the equations of motion of the expanding universe and show that it is a ..."
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A fivedimensional cosmological theory of gravitation that unifies space, time and velocity is presented. Within the framework of this theory we first discuss some general aspects of the universe in five dimensions. We then find the equations of motion of the expanding universe and show that it is accelerating. This followed by dealing with the important problem of halo dark matter around galaxies by deriving the equations of motion of a star moving around the field of a sphericallysymmetric galaxy. The equations obtained are not Newtonian; rather, the TullyFisher formula is obtained. The cosmological constant is subsequently discussed: our theory predicts that Λ ≈ 3H 2 0 ≈ 1.934 × 10 −35 s −2, in agreement with experimental results obtained by the HighZ Supernova Team and the Supernova Cosmology Project. Finally we derive a formula for the cosmological redshift in which appears the expression (1−ΩM), thus enabling us to determine the kind of the universe by means of the cosmological redshift. We find that ΩM should be less than 1 in order not to contradict redshift measurements, and therefore the universe is open.
Hence we obtain for the first six days the following lengths of time:
, 2000
"... The early stage of the Universe is discussed and the time lenghts of its first six days, as well as its age, are given. There seems to be no contradiction with the Bible’s ascertain that the Universe was created in six days. 1 Scientists have in recent years adopted the picture that the Universe was ..."
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The early stage of the Universe is discussed and the time lenghts of its first six days, as well as its age, are given. There seems to be no contradiction with the Bible’s ascertain that the Universe was created in six days. 1 Scientists have in recent years adopted the picture that the Universe was created in a single event of plasma explosion, called the Big Bang. This approach remarkably conforms with the Bible’s description of the creation of the Universe. However, there are still doubts about the meaning, mentioned in the Bible, that the Universe was created in six days. We actually know from the study of anthropology and cosmology that any development of the kind mentioned in the Bible takes millions or billions of years. We show in the following that the viewpoint of the Bible is actually compatible with the theory of cosmology – the days of our life now are not equal to the days at the time of the creation of the Universe. In this note we calculate the lengths of days of the early Universe, day by day, from the first day on up to our present time. We find that the first day actually lasted the Hubble time in the limit of zero gravity. If we denote the Hubble time in the zerogravity limit by τ which equals 11.5 billion years and Tn denotes the length of the nth day in units of times of the early Universe, then we have a very simple relation
Hence we obtain for the first few days the following lengths of time:
, 2001
"... Abstract. The early stage of the Universe is discussed and the time lengths of its first days are given. If we denote the Hubble time in the zerogravity limit by τ (approximately 12.16 billion years), and Tn denotes the length of the nth day, then we have the very simple relation Tn = τ/(2n − 1). ..."
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Abstract. The early stage of the Universe is discussed and the time lengths of its first days are given. If we denote the Hubble time in the zerogravity limit by τ (approximately 12.16 billion years), and Tn denotes the length of the nth day, then we have the very simple relation Tn = τ/(2n − 1). Hence we obtain for the first days the following lengths of time: T1 = τ, T2 = τ/3, T3 = τ/5, etc. In this Note we calculate the lengths of days of the early Universe, day by day, from the first day after the Big Bang on up to our present time. We find that the first day actually lasted the Hubble time in the limit of zero gravity. If we denote the Hubble time in the zerogravity limit by τ which equals about 12.16 billion years and Tn denotes the length of the nth day in units of times of the early Universe, then we have a very simple relation