This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value c, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of (...) class='Hi'>light has a universal value. We also discuss an old incomplete proof by Weyl which is important from an historical perspective. (shrink)

This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value c, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of (...) class='Hi'>light has a universal value. We also discuss an old incomplete proof by Weyl which is important from an historical perspective. (shrink)

The convention that the one-way velocity of light is isotropic is shown to be independent of the postulates of relativity in a globally Minkowskian continuum, but not in a continuum which is only locally Minkowskian.

This paper (i) gives necessary and sufficient conditions that clocks in an inertial lattice can be synchronized, (ii) shows that these conditions do not imply a universal light speed, and (iii) shows that the terrestrial redshift experiment provides evidence that clocks in a small inertial lattice in a gravitational field can be synchronized.

The Reichenbach-Grunbaum thesis of the conventionality of simultaneity is clarified and defended by developing the consequences of the Special Theory when assumptions are not made concerning the one-way speed of light. It is first shown that the conventionality of simultaneity leads immediately to the conventionality of all relative speeds. From this result, the general-length-contraction and time-dilation relations are then derived. Next, the place of time-dilation and length-contraction effects within the Special Theory is examined in the light of (...) the conventionality thesis. The slow-transport method of synchrony is then examined in the light of these results and is shown not to provide an adequate method of uniquely determining the one-way speed of light. Finally, the general ε -Lorentz transformations for events along the x-axis are derived from three principles: the round-trip light principle, the principle of equal passage times, and the linearity principle. These principles are shown to be independent of one-way velocity assumptions, and thus may form the basis of a Special Theory of Relativity without simultaneity assumptions. (shrink)

The Reichenbach-Grunbaum thesis of the conventionality of simultaneity is clarified and defended by developing the consequences of the Special Theory when assumptions are not made concerning the one-way speed of light. It is first shown that the conventionality of simultaneity leads immediately to the conventionality of all relative speeds. From this result, the general-length-contraction and time-dilation relations are then derived. Next, the place of time-dilation and length-contraction effects within the Special Theory is examined in the light of (...) the conventionality thesis. The slow-transport method of synchrony is then examined in the light of these results and is shown not to provide an adequate method of uniquely determining the one-way speed of light. Finally, the general ε -Lorentz transformations for events along the x-axis are derived from three principles: the round-trip light principle, the principle of equal passage times, and the linearity principle. These principles are shown to be independent of one-way velocity assumptions, and thus may form the basis of a Special Theory of Relativity without distant simultaneity assumptions. (shrink)

The most recent attempt at factually establishing a "true" value for the one-way velocity of light is shown to be faulty. The proposal consists of two round-trip photons travelling first in vacuo and then through a medium of refractive index n before returning to their common point of origin. It is shown that this proposal, as well as a similar one considered by Salmon (1977), presupposes that the one-way velocities of light are equal to the round-trip value. Furthermore, (...) experiments of this type, involving regions of space with varying refractive indices, cannot "single out" any factual value for the Reichenbach-Grünbaum ε factor thus posing no threat to the conventionalist thesis. (shrink)

After discussing in the first five sections the meaning and the difficulties of the principle of relativity we present a new sel of spacetime transformations between inertial systems (“inertial” transformations), based on three assumptions: (1) The two-way velocity of light is c in all inertial systems and in all directions; (2) Time dilation effects take place with the usual relativistic factor; (3) Clocks are synchronized in the way chosen by nature itself, e.g., in the Sagnac effect. We show that (...) our new transformation laws can explain the available experimental evidence in spite of the implied noninvariance of the one-way velocity of light. (shrink)

The purpose of the present paper is to develop kinematics of the special relativity with an anisotropy of the one-way speed of light. As distinct from a common approach, when the issue of anisotropy of the light propagation is placed into the context of conventionality of distant simultaneity, it is supposed that an anisotropy of the one-way speed of light is due to a real space anisotropy. In that situation, some assumptions used in developing the (...) standard special relativity kinematics are not valid so that the “anisotropic special relativity” kinematics should be developed based on the first principles, without refereeing to the relations of the standard relativity theory. In particular, using condition of invariance of the interval between two events becomes unfounded in the presence of anisotropy of space since the standard proofs drawing the interval invariance from the invariance of equation of light propagation are not valid in that situation. Instead, the invariance of the equation of light propagation, which is a physical law, should be taken as a first principle. A number of other physical requirements, associativity, reciprocity and so on are satisfied by the requirement that the transformations between the frames form a group. Finally, the correspondence principle is to be satisfied which implies that the coordinate transformations should turn into the Galilean transformations in the limit of small velocities. The above formulation based on the invariance and group property suggests applying the Lie group theory apparatus which includes the following steps: constructing determining equations for the infinitesimal group generators using the invariance condition; solving the determining equations; specifying the solutions using the correspondence principle; defining the finite transformations by solving the Lie equations; relating the group parameter to physical parameters. The transformations derived in such a way, as distinct from the transformations derived in the context of conventionality of distant simultaneity, cannot be converted into the standard Lorentz transformations by a coordinate change. The anisotropic nature of the presented transformations manifests itself in that they do not leave the interval invariant but only provide the conformal invariance of the interval. The relations that represent measurable effects include the conformal factor which depends on the relative velocity of the frames and the anisotropy degree. It is important to note the use of the correspondence principle as a heuristic principle which allows to relate the conformal factor to the anisotropy degree and thus completely specify the transformations and observable quantities. (shrink)

In a previous work, we have shown that the null result of the Michelson–Morley experiment in vacuum is deeply connected with the notion of time. The same is true for the postulate of constancy of the two-way speed of light in vacuum in all frames independently of the state of motion of the emitting body. The argumentation formerly given is very general and has to be true not only within Special Relativity and its “equivalence” of all inertial frames, (...) but as well as in Lorentz-Poincaré scenario of a preferred reference frame. This paper is the second of a trilogy intending to revisit the foundations of Special Relativity, and addresses the question of the constancy of the one-way speed of light and of the differences and similarities between both scenarios. Although they manifestly differ in philosophy, it is debated why and how the assumption of a “special system of reference experimentally inaccessible” is indeed compatible with Einstein’s Special Relativity, as beautifully outlined and discussed by Bell [Speakable and Unspeakable in Quantum Mechanics (Cambridge University Press, Cambridge, 1988)]. This rather trivial statement is still astonishing nowadays to a big majority of scientists. The purpose of this work is to bring such assertion into perspective, widening the somewhat narrow view of Special Relativity often presented in textbooks and scientific papers. (shrink)

The two center time dependent Dirac equation, for an electron in the external field of two colliding ultrarelativistic heavy ions is considered. In the ultrarelativistic limit, the ions are practically moving at the speed of light and the electromagnetic fields of the ions are confined to the light fronts by the extreme Lorentz contraction and by the choice of gauge, designed to remove the long-range Coulomb effects. An exact solution to the ultrarelativistic limit of the two-center Dirac (...) equation is found by using light-front variables and a light-fronts representation. Previously unexplained experimental results obtained at CERN's SPS are explained in this way and predictions are made as to where one should look, in momentum space, and in space-time, if one wants to study and observe non-perturbative electromagnetic pair-production effects in extremely relativistic heavy-ion collisions. (shrink)

A number of physical processes and experimental procedures are listed which appear to be inexplicable in the context of the conventionality thesis of Reichenbach and Grünbaum. Distant synchrony can be produced by procedures based on the free displacement or rotation of elastic solids. Results are expected to agree with Einstein's definition of distant synchrony (by means of light signals, assuming isotropy). The one-way velocity of light can be measured using a rotating shaft, slotted disks, and one stationary clock.

As is well know from Einstein the choice of a criterion for distant simultaneity is equivalent to stipulating one-way speeds for the transit of light. It is shown that any choice of non-standard synchrony is equivalent to a Lorentz local time boost. From this and considerations from the hole argument, it follows that there is a non-trivial sense in which distant simultaneity is conventional, at least to the extent that the “gauge freedom” arising in the hole argument is non-trivial.

A Michelson interferometer with a phase-conjugate mirror (PCM) is described and discussed. The behavior of phase conjugate mirrors is discussed and the result of an experiment with a Michelson interferometer with a phase-conjugate mirror is described and commented. This interferometer has been proposed to be used to test the intrinsic non-locality of quantum mechanics. In this paper a new experimental setup to study the one-way velocity of light is proposed, which uses this new interesting device.

ABSTRACT In Einstein’s physical geometry, the geometry of space and the uniformity of time are taken to be non-conventional. However, due to the stipulation of the isotropy of the one-way speed of light in the synchronization of clocks, as it stands, Einstein’s views do not seem to apply to the whole of the Minkowski space-time. In this work we will see how Einstein’s views can be applied to the Minkowski space-time. In this way, when adopting Einstein’s views, chronogeometry (...) is a physical chronogeometry. (shrink)

According to logical positivism, so the story goes, metaphysical questions are meaningless, since they do not admit of empirical confirmation or refutation. However, the logical positivists did not in fact reject as meaningless all questions about for example, the structure of space and time. Rather, key figures such as Reichenbach and Schlick believed that scientific theories often presupposed a conceptual framework that was not itself empirically testable, but which was required for the theory as a whole to be empirically testable. (...) For example, the theory of Special Relativity relies upon the simultaneity convention introduced by Einstein that assumes that the one-way speed of light is the same in all directions of space. Hence, the logical positivists accepted an a priori component to physical theories. However, they denied that this a priori component is necessarily true. Whereas for Kant, metaphysics is the a priori science of the necessary structure of rational thought about reality, the logical positivists were forced by the history of science to accept that the a priori structure of theories could change. Hence, they defended a notion of what Michael Friedman calls the ‘relativised’ or the ‘constitutive’ a priori. Carnap and Reichenbach held that such an a priori framework was conventional, whereas Schlick seems to have been more of a realist and held that the overall relative simplicity of different theories could count as evidence for their truth, notwithstanding the fact that some parts of them are not directly testable. All this is part of the story of how the verification principle came to be abandoned, and how logical positivism transmuted into logical empiricism. (shrink)

The date of composition of King Horn has in recent years been moved from ca. 1225 to ca. 1250, or even as late as the 1270s, as more information about the three manuscripts of the poem has become available. Nevertheless, King Horn still seems to lie at, or at least very near, the beginning of the Middle English romance tradition, and it thus holds a special interest as a potential indicator of the way in which that tradition came into existence. (...) This paper explores one key element in King Horn as a step towards a better understanding of both the poem itself and its literary context. (shrink)

There are hints that the connectivity of space-time in quantum gravity could emerge from entanglement, and it has further been proposed that any two entangled particles may be connected by a quantum wormhole. One way to test this proposal is by probing the electric field of an entangled charged particle to determine whether its electric field leaks through the putative wormhole. In addition, if such a wormhole is traversable, then it could be possible for the collapse of the wave function (...) to occur in a causal manner, with information about the collapse travelling through the wormhole at the speed of light, rather than the wave function collapse being a global and instantaneous event. (shrink)

The objective of this article is to provide a formalism to deal with the special theory of relativity (STR, in short) as riewed by Reichenbach, according to which STR involves an ineradicableconventionality of simultaneity. One of the two postulates of STR asserts that, in empty space, the one-way speed of light relative to inertial frames is constant. Experimental evidence, however, is related to the constancy of the round-trip speed of light and has no bearing on one-way (...) speeds. Following Reichenbach's viewpoint, we relax the second postulate of STR, abandoning the constancy of the one-way speed of light to the more realistic one asserting the constancy of the round-trip speed of light. This, in turn, results in a formalism to deal with Reichenbach's special theory of relativity (RSTR, in short) in which the two one-way speeds of light in empty space, C±, in the two senses of a round-trip are arbitrarily selected in such a way that their harmonic mean is the measurable round-trip speed of light, c. Experimentally, RSTR and STR are indistinguishable and, hence, represent the same physical theory. It is only the formalism that we use to deal with STR which is extended in RSTR to accommodate the immeasurability of one-way velocities. The usefulness of the proposed formalism to study special relativity is demonstrated. (shrink)

The claim that distant simultaneity with respect to an inertial observer is conventional arose in the context of a space-and-time rather than a spacetime ontology. Reformulating this problem in terms of a spacetime ontology merely trivializes it. In the context of flat space, flat time, and a linear inertial structure (a purely space-and-time formalism), we prove that the hyperplanes of space for a given inertial observer are determined by a purely spatial criterion that depends for its validity only on the (...) two-way light principle, which is universally regarded as empirically verified. All (empirically determined) “spacetime” entities, such as the conformal structure or light surface equation, are used in a purely mathematical manner that is independent of and hence isneutral with respect to the ontological status that is ascribed to them. In this regard, our criterion is significantly stronger than thespacetime criterion recently advanced by D. Malament, which appeals explicitly to the conformal orthogonality of spacetime vectors and to the invariance of the conformal-orthogonal structure of spacetime under the causal automorphisms of spacetime. Once the hyperplanes of space for a given inertial observer have been determined by our empirical and purely spatial criterion, the following holds: there exists one and only one $\vec \varepsilon $ -synchronization procedure, namely the standard procedure proposed by Einstein, such that the planes of common time are thesame as the nonconventional hyperplanes of space for the inertial observer. It follows that our criterion provides an empirical even if indirect method for determining that the one-way speed of light is the same as the average two-way speed of light. In addition, two inertial observers that are not at rest with respect to each other necessarily havedifferent hyperplanes of space, and consequently their respective spatial views cannot be encompassed in a single three-dimensional space. Hence, our purely spatial criterion provides an empirical motivation for adopting the more comprehensive spacetime ontology. (shrink)

According to logical positivism, so the story goes, metaphysical questions are meaningless, since they do not admit of empirical confirmation or refutation. However, the logical positivists did not in fact reject as meaningless all questions about for example, the structure of space and time. Rather, key figures such as Reichenbach and Schlick believed that scientific theories often presupposed a conceptual framework that was not itself empirically testable, but which was required for the theory as a whole to be empirically testable. (...) For example, the theory of Special Relativity relies upon the simultaneity convention introduced by Einstein that assumes that the one-way speed of light is the same in all directions of space. Hence, the logical positivists accepted an a priori component to physical theories. However, they denied that this a priori component is necessarily true. Whereas for Kant, metaphysics is the a priori science of the necessary structure of rational thought about reality , the logical positivists were forced by the history of science to accept that the a priori structure of theories could change. Hence, they defended a notion of what Michael Friedman calls the ‘relativised’ or the ‘constitutive’ a priori. Carnap and Reichenbach held that such an a priori framework was conventional, whereas Schlick seems to have been more of a realist and held that the overall relative simplicity of different theories could count as evidence for their truth, notwithstanding the fact that some parts of them are not directly testable. All this is part of the story of how the verification principle came to be abandoned, and how logical positivism transmuted into logical empiricism. (shrink)

Special relativity insists that the speed of light in a vacuum is constant for all inertial observers. This is often said to be counterintuitive: why should light alone, among all things in the world, return the same speed value to all inertial observers, regardless of their different states of motion? I argue that this question or puzzle arises because physics misconstrues light by characterizing it as a freestanding phenomenon. As James Gibson insisted, and as any (...) analysis of the visual experience makes plain, light, the agency of sight, cannot be overtaken by sight. A better characterization of light is Gibson's optic array, which prompts the realization that our prior complicity with light keeps us from getting leverage on it as a freestanding phenomenon, and this is why it returns the same speed value to all observers. To show the limitation of freestanding light, I offer two derivations of relativistic time dilation. The first imagines freestanding light and then, to complete the derivation, artificially requires light speed constancy; the second achieves the same result in a fully natural way?that is, without putting observers in an abstract, arguably impossible, situation?by merely attending to the seeing experience. (shrink)

In recent articles, Zangari (1994) and Karakostas (1997) observe that while an &unknown;-extended version of the proper orthochronous Lorentz group O + (1,3) exists for values of &unknown; not equal to zero, no similar &unknown;-extended version of its double covering group SL(2, C) exists (where &unknown;=1-2&unknown; R , with &unknown; R the non-standard simultaneity parameter of Reichenbach). Thus, they maintain, since SL(2, C) is essential in describing the rotational behaviour of half-integer spin fields, and since there is empirical evidence for (...) such behaviour, &unknown;-coordinate transformations for any value of &unknown;<>0 are ruled out empirically. In this article, I make two observations:(a)There is an isomorphism between even-indexed 2-spinor fields and Minkowski world-tensors which can be exploited to obtain generally covariant expressions of such spinor fields.(b)There is a 2-1 isomorphism between odd-indexed 2-spinor fields and Minkowski world-tensors which can be exploited to obtain generally covariant expressions for such spinor fields up to a sign. Evidence that the components of such fields do take unique values is not decisive in favour of the realist in the debate over the conventionality of simultaneity in so far as such fields do not play a role in clock synchrony experiments in general, and determinations of the one-way speed of light in particular.I claim that these observations are made clear when one considers the coordinate-independent 2-spinor formalism. They are less evident if one restricts oneself to earlier coordinate-dependent formalisms. I end by distinguishing these conclusions from those drawn by the critique of Zangari given by Gunn and Vetharaniam (1995). (shrink)

According to the Special Theory of Relativity, there is no such thing as absolute simultaneity, contrary to the view defended in the book. However, this chapter demonstrates that the Special Theory of Relativity can be modified so as to allow absolute simultaneity. This modification involves reference to absolute space and the causal relations between space‐time points, and drops the assumption that the one‐way speed of light is constant through all frames of reference. Contrary to the orthodox theory, the (...) modified version has the additional advantage of avoiding a clash with quantum mechanics, such as brought out by the Einstein‐Podolsky‐Rosen thought experiment and Bell's Theorem. (shrink)

Contemporary debate over laws of nature centers around Humean supervenience, the thesis that everything supervenes on the distribution of non-nomic facts. The key ingredient of this thesis is the idea that nomic-like concepts—law, chance, causation, etc.—are expressible in terms of the regularities of non-nomic facts. Inherent to this idea is the tacit conviction that regularities, “constant conjunctions” of non-nomic facts do supervene on the distribution of non-nomic facts. This paper raises a challenge for this conviction. It will be pointed out (...) that the notion of regularity, understood as statistical correlation, has a necessary conceptual component not clearly identified before—I shall call this the “conjunctive relation” of the correlated events. On the other hand, it will be argued that there exists no unambiguous, non-circular way in which this relation could be determined. In this regard, the notion of correlation is similar to that of distant simultaneity where the necessary conceptual component is the one-way speed of light, whose value doesn’t seem to be determined by matters of facts. (shrink)

Following the ideas of Poincaré, Reichenbach, and Grunbaum concerning the convention of setting up clock systems, we analyze clock systems and light propagation within the framework of four-dimensional symmetry. It is possible to construct a new four-dimensional symmetry framework incorporatingcommon time: observers in different inertial frames of reference use one and the same clock system, which is located in any one of the frames. Consequently, simultaneity has a meaning independent of position and independent of frame of reference. A further (...) consequence is that the two-way speeds of light alone are isotropic in any frame. By the choice of clock system there will be one frame in which the one-way speed of light is isotropic. This frame can be arbitrarily chosen. The difference between one-way speeds and two-way speeds of light signals is considered in detail. (shrink)

Using Finsler brane solutions [see details and methods in: S. Vacaru, Class. Quant. Grav. 28:215001, 2011], we show that neutrinos may surpass the speed of light in vacuum which can be explained by trapping effects from gravity theories on eight dimensional (co) tangent bundles on Lorentzian manifolds to spacetimes in general and special relativity. In nonholonomic variables, the bulk gravity is described by Finsler modifications depending on velocity/momentum coordinates. Possible super-luminal phenomena are determined by the width of locally (...) anisotropic brane (spacetime) and induced by generating functions and integration functions and constants in coefficients of metrics and nonlinear connections. We conclude that Finsler brane gravity trapping mechanism may explain neutrino super-luminal effects and almost preserve the paradigm of Einstein relativity as the standard one for particle physics and gravity. (shrink)

This chapter examines central philosophical themes and doctrines of twentieth century philosophy in the light of the Agency Theory. Craig argues that despite the unpopularity of philosophical visions of high generality in contemporary philosophy, the Agency Theory is the one vision, or Weltbild, on which much twentieth century philosophy explicitly or implicitly relies. It is evident in the philosophical doctrines of the Vienna Circle, with its radically emotivist accounts of value and radically conventionalist accounts of the a priori. It (...) is evident in the numerous attacks on moral realism, which invite us, instead of thinking about morality not in terms of an independent realm of moral facts that obtain independently of our thinking about them, to see ourselves as the creators of ethical value. It is evident in existentialism, with its belief in absolute human freedom and its demand for absolute moral independence, manifested in the existentialist ethics of authenticity. It is evident in the prevalence of ‘opacity’, our willing acceptance of brute facts without further explanation as long as our beliefs about those facts are reliable. Finally, the dominance of the Agency Theory is evident in epistemology, where the community has taken over many responsibilities that the individual used to have, as well as in the theory of meaning, where accounts of meaning are given in terms of the use of words in a linguistic community, as by Wittgenstein and Austin, or in terms of the speaker’s environment, as in the externalist account of meaning advocated by Putnam. But, as Aldous Huxley’s Brave New World and George Orwell’s Nineteen-Eighty-Four illustrate, too much enthusiasm for human activity has its dangers. (shrink)

The twin paradox (i.e. the reasoning made by the traveling twin, reversing the reasoning made by the earthbound twin, by which it is he who should be older) can be resolved by taking into account the relativity of simultaneity. However, simultaneity depends on a convention about the one-way velocity of light provided that the Reichenbach-Grünbaum hypothesis, is time. So far the resolution has been presented only for the Einstein convention. We show that for all possible choices of the relevant (...) synchronization parameters the calculations performed by both twins yield the same final results when carefully taking into account the relativity of simultaneity according to the conventions they have chosen. Since the final results do not depend on any of the synchronization parameters, the Reichenbach-Grünbaum hypothesis is thereby supported. (shrink)

There are many ways to describe cities. As a physical environment, more so than many other environments, they are at least an extension of our present intentions. But cities are not confined to the moment. Built spaces are also in conversation with the past and oriented toward the future as physical manifestations of our values and priorities. But even with all of the ways we have to describe cities we do not normally think of them as in any way akin (...) to the “natural” environment. City and country, nature and culture, are opposed. We move through cities differently, with a different set of values, whether articulated or not. Consider just one small example: Even the most jaded urban dweller may hesitate to sully the environment around him when he perceives it to be something other than a product of the human community. Though we have all seen trash in a national park, we suspect (or at least hope) that there is a kind of hesitancy that occurs with a person wondering what to do with her candy wrappers on a trail in Yosemite. On the other hand, a visitor to my home, Greenwich Village, will usually not think twice about tossing his cigarette butts on the ground as he walks toward his next destination. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Ethics & the Environment 7.1 (2002) 102-108 [Access article in PDF] Symposium IntroductionEric Katz's Nature As Subject Andrew Light Can and should we distinguish between nature and culture? The question has become a perennial one in environmental ethics, as well as in allied fields in environmental history, sociology, and politics. And just when we think it is settled—as many did after William Cronon's famous deconstruction of wilderness in (...) 1995—and it feels safe to go back into the metaphysical waters of environmental philosophy, such issues pop up again to send us running.What follows extends this debate in the context of Eric Katz's well-known work in environmental ethics. Brought together here are Katz and two critics sympathetic to his positions, Wayne Ouderkirk and Ned Hettinger. While the occasion for the exchange was the publication of Katz's book, Nature as Subject: Human Obligation and Natural Community (1997), which collects his papers from 1979 to 1996, the focus quickly became somewhat narrower, centering on possible problems with Katz's ontological dualism between natural and artifactual entities.Katz has exerted a strong influence on the development of environmental ethics, particularly through his persistent arguments for a distinction between individualist and holist approaches to obligations to the nonhuman natural world and his metaphysical and moral critique of attempts [End Page 102] by humans to create, repair, or restore nature. While these positions continue to be on display here, there is also something more. In this exchange Katz throws down the gauntlet on his nature-culture dualism, admitting at the start that the accusation is true. Like the Protestants in Monty Python's The Meaning of Life, he is a dualist—and fiercely proud of it! Despite whatever misgivings I or others may have about this position, I believe that in making this claim, Katz, similar to David Chalmers's open embrace and resuscitation of dualism in philosophy of mind, has done us a great service. For it is arguably true that many environmental philosophers, along with other academics, have settled into a complacent "labeling as argument" pattern. If we can label a position as "dualist" or "essentialist," then our work is done. But surely not every form of dualism is necessarily wrong, even if, as Ouderkirk reminds us in his reading of Val Plumwood's work, the logic of many forms of dualism has tended toward a pernicious pattern. Arguments are needed in both directions. If nature-culture dualism is mistaken or wrongheaded, or leads to unfortunate conclusions, then we must know why; if dualism is the only way to make sense of the hurdles presented to us in coming to a better understanding of the value of nature and culture then we must know why as well. And further, because many in the field have assumed a nature-culture dualism without admitting to it, we can admire that Katz chooses to "fess up" and finally put the issue squarely on the table.If this is the road we are heading down with this particular exchange, then we are off to a good start. Both critics of Katz do a thorough job of pressing home their arguments, rather than only pointing accusatory fingers. Ned Hettinger, in "The Problem of Finding a Positive Role for Humans in the Natural World," avoids using the term "dualism," but nonetheless argues that Katz has a tendency to "rigidly dichotomize the natural/artifactual distinction." Additionally, Hettinger argues that Katz tends to overlook his own admission that the differences between nature and artifacts admit to degrees rather than a strict dualism. Hettinger focuses the bulk of his critique on the unfortunate upshot of such a position: given such a distinction, there is little if any place for a positive role for human intervention in nature, or for a philosophical contribution to the formation of better environmental policies.Wayne Ouderkirk, in "Katz's Problematic Dualism and its 'Seismic' Effects on His Theory," is sympathetic with Katz's intuitions that some distinction is needed between artifacts and natural entities. The problem [End Page 103] he sees is that such... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Ethics & the Environment 7.1 (2002) 102-108 [Access article in PDF] Symposium IntroductionEric Katz's Nature As Subject Andrew Light Can and should we distinguish between nature and culture? The question has become a perennial one in environmental ethics, as well as in allied fields in environmental history, sociology, and politics. And just when we think it is settled—as many did after William Cronon's famous deconstruction of wilderness in (...) 1995—and it feels safe to go back into the metaphysical waters of environmental philosophy, such issues pop up again to send us running.What follows extends this debate in the context of Eric Katz's well-known work in environmental ethics. Brought together here are Katz and two critics sympathetic to his positions, Wayne Ouderkirk and Ned Hettinger. While the occasion for the exchange was the publication of Katz's book, Nature as Subject: Human Obligation and Natural Community (1997), which collects his papers from 1979 to 1996, the focus quickly became somewhat narrower, centering on possible problems with Katz's ontological dualism between natural and artifactual entities.Katz has exerted a strong influence on the development of environmental ethics, particularly through his persistent arguments for a distinction between individualist and holist approaches to obligations to the nonhuman natural world and his metaphysical and moral critique of attempts [End Page 102] by humans to create, repair, or restore nature. While these positions continue to be on display here, there is also something more. In this exchange Katz throws down the gauntlet on his nature-culture dualism, admitting at the start that the accusation is true. Like the Protestants in Monty Python's The Meaning of Life, he is a dualist—and fiercely proud of it! Despite whatever misgivings I or others may have about this position, I believe that in making this claim, Katz, similar to David Chalmers's open embrace and resuscitation of dualism in philosophy of mind, has done us a great service. For it is arguably true that many environmental philosophers, along with other academics, have settled into a complacent "labeling as argument" pattern. If we can label a position as "dualist" or "essentialist," then our work is done. But surely not every form of dualism is necessarily wrong, even if, as Ouderkirk reminds us in his reading of Val Plumwood's work, the logic of many forms of dualism has tended toward a pernicious pattern. Arguments are needed in both directions. If nature-culture dualism is mistaken or wrongheaded, or leads to unfortunate conclusions, then we must know why; if dualism is the only way to make sense of the hurdles presented to us in coming to a better understanding of the value of nature and culture then we must know why as well. And further, because many in the field have assumed a nature-culture dualism without admitting to it, we can admire that Katz chooses to "fess up" and finally put the issue squarely on the table.If this is the road we are heading down with this particular exchange, then we are off to a good start. Both critics of Katz do a thorough job of pressing home their arguments, rather than only pointing accusatory fingers. Ned Hettinger, in "The Problem of Finding a Positive Role for Humans in the Natural World," avoids using the term "dualism," but nonetheless argues that Katz has a tendency to "rigidly dichotomize the natural/artifactual distinction." Additionally, Hettinger argues that Katz tends to overlook his own admission that the differences between nature and artifacts admit to degrees rather than a strict dualism. Hettinger focuses the bulk of his critique on the unfortunate upshot of such a position: given such a distinction, there is little if any place for a positive role for human intervention in nature, or for a philosophical contribution to the formation of better environmental policies.Wayne Ouderkirk, in "Katz's Problematic Dualism and its 'Seismic' Effects on His Theory," is sympathetic with Katz's intuitions that some distinction is needed between artifacts and natural entities. The problem [End Page 103] he sees is that such... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Ethics & the Environment 7.1 (2002) 102-108 [Access article in PDF] Symposium IntroductionEric Katz's Nature As Subject Andrew Light Can and should we distinguish between nature and culture? The question has become a perennial one in environmental ethics, as well as in allied fields in environmental history, sociology, and politics. And just when we think it is settled—as many did after William Cronon's famous deconstruction of wilderness in (...) 1995—and it feels safe to go back into the metaphysical waters of environmental philosophy, such issues pop up again to send us running.What follows extends this debate in the context of Eric Katz's well-known work in environmental ethics. Brought together here are Katz and two critics sympathetic to his positions, Wayne Ouderkirk and Ned Hettinger. While the occasion for the exchange was the publication of Katz's book, Nature as Subject: Human Obligation and Natural Community (1997), which collects his papers from 1979 to 1996, the focus quickly became somewhat narrower, centering on possible problems with Katz's ontological dualism between natural and artifactual entities.Katz has exerted a strong influence on the development of environmental ethics, particularly through his persistent arguments for a distinction between individualist and holist approaches to obligations to the nonhuman natural world and his metaphysical and moral critique of attempts [End Page 102] by humans to create, repair, or restore nature. While these positions continue to be on display here, there is also something more. In this exchange Katz throws down the gauntlet on his nature-culture dualism, admitting at the start that the accusation is true. Like the Protestants in Monty Python's The Meaning of Life, he is a dualist—and fiercely proud of it! Despite whatever misgivings I or others may have about this position, I believe that in making this claim, Katz, similar to David Chalmers's open embrace and resuscitation of dualism in philosophy of mind, has done us a great service. For it is arguably true that many environmental philosophers, along with other academics, have settled into a complacent "labeling as argument" pattern. If we can label a position as "dualist" or "essentialist," then our work is done. But surely not every form of dualism is necessarily wrong, even if, as Ouderkirk reminds us in his reading of Val Plumwood's work, the logic of many forms of dualism has tended toward a pernicious pattern. Arguments are needed in both directions. If nature-culture dualism is mistaken or wrongheaded, or leads to unfortunate conclusions, then we must know why; if dualism is the only way to make sense of the hurdles presented to us in coming to a better understanding of the value of nature and culture then we must know why as well. And further, because many in the field have assumed a nature-culture dualism without admitting to it, we can admire that Katz chooses to "fess up" and finally put the issue squarely on the table.If this is the road we are heading down with this particular exchange, then we are off to a good start. Both critics of Katz do a thorough job of pressing home their arguments, rather than only pointing accusatory fingers. Ned Hettinger, in "The Problem of Finding a Positive Role for Humans in the Natural World," avoids using the term "dualism," but nonetheless argues that Katz has a tendency to "rigidly dichotomize the natural/artifactual distinction." Additionally, Hettinger argues that Katz tends to overlook his own admission that the differences between nature and artifacts admit to degrees rather than a strict dualism. Hettinger focuses the bulk of his critique on the unfortunate upshot of such a position: given such a distinction, there is little if any place for a positive role for human intervention in nature, or for a philosophical contribution to the formation of better environmental policies.Wayne Ouderkirk, in "Katz's Problematic Dualism and its 'Seismic' Effects on His Theory," is sympathetic with Katz's intuitions that some distinction is needed between artifacts and natural entities. The problem [End Page 103] he sees is that such... (shrink)

The North American environmental movement has historically sought to redress the depletion and degradation of natural resources that has been the legacy of the industrial revolution. Predominant in this approach has been the preservation of wilderness, conservation of species biodiversity and the restoration of natural ecosystems. While the results of such activity have often been commendable, several scholars have pointed out that the environmental movement has inherited an unfortunate bias against urban environments, and consequently, a blind spot to ways in (...) which densely populated built spaces can serve to enhance rather than degrade efforts to achieve sustainability. After exploring this concern we argue that environmental architecture can serve as a counter-balance to this bias, focused, as it is, on the ways in which the construction and organisation of built spaces for humans can help or hinder the pursuit of environmental priorities. But if environmental architecture is to take this role then it must be understood in a broader context, one which does not exclude other moral, political and aesthetic values in the production of human environments. We will highlight several examples of how environmental architecture has combined success and failure at taking a broader view of environmental questions, with a specific focus on one green skyscraper that may be good for the natural environment but not necessarily for the human environment of the city. (shrink)

Time is analyzed by considering the actual setup of clock system within the four-dimensional framework. We find that both relativistic time and universal time can be embedded in such a symmetry framework. Although Poincaré and Einstein both understood the meaning of Lorentz's local time in terms of sending light signals to calibrate clocks, they differed on a basic point: Einstein believed local time to be the necessary and unique time, while Poincaré admitted flexibility in the definitions of time and (...) regarded local time as only a convention. The results of our analysis shed light on Poincaré's original idea concerning conventions of time and provide the conceptual basis for the formulation of a new four-dimensional symmetry with a universal time. We demonstrate that the one-way speeds of light measured by stable atomic clocks in rockets may not be isotropic, in contrast to the two-way speeds of light. Furthermore, atomic clocks can be used to set up a clock system which reads a universal (but not absolute) time. (shrink)

In this paper we describe a propagation experiment to measure the one-way velocity of electromagnetic radiation. The experiment utilizes the rotation of the earth to interchange the positions of two rubidium vapor frequency standards over12 h, thereby canceling initial clock phase differences. It is demonstrated that although the drift characteristics of modern rubidium atomic clocks may be large for long-term absolute timing requirements, the short-term random fluctuations are small. It is found that over a24-h period, the long-term drift can be (...) accurately parameterized in retrospect and removed, thereby permitting the detection of temporal variations less than1 nsec in magnitude. With coherent summing techniques this value may be significantly reduced, and it becomes realistic to consider an experiment where the clocks are separated by distances of the order of several hundreds of meters in order to detect velocities of the order of that of the solar system with respect to the center of the galaxy(≈10 5 m sec −1 ), thus ensuring that the rotational motion of the earth has a negligible effect in altering the relative inertial characteristics of the reference frames of each clock. It is demonstrated that under such conditions the measurement of the one-way speed of propagation of electromagnetic radiation is not only meaningful, but can be simply implemented with commercially available instrumentation. (shrink)

Following aluminum as part of a material culture of speed and lightness, this article examines how assemblages of energy and metals connect built environments, ways of life, and ideologies of acceleration. Aluminum can be theorized as a circulatory matrix that forms an energy culture. Through a discussion of speed and social justice, the history of aluminium-based socioecologies reveals how the materiality of energy forms assemblages of objects, infrastructures, and practices. The article then traces the aluminum industry’s involvement in (...) the production and distribution of energy itself both at the national scale of power grids and in the emergence of transnational transfers of energy, such as hydropowered smelters in Iceland. Finally, this analysis of deeply embedded energy cultures calls for a transnational approach to the accelerated socioecologies of aluminum production and consumption; and for energy transition theories to pay closer attention to the figured worlds and figuring work of the military-industrial complex. (shrink)

One of Ole Römer's most influential contributions to astronomy was the theory that light has a finite speed, which he calculated from inequalities in the motion of a satellite of Jupiter. The English astronomer John Flamsteed, first director of the Royal Observatory at Greenwich, is credited with being an early and influential supporter of the theory. This article examines how he came to be so, taking issue with the claim that he was instantly converted to the idea by (...) a personal encounter with Römer. The publication of Flamsteed's Correspondence has made illuminating material newly accessible; through letters it is possible to track the gradual development of his thinking and how it related to his dealings with Römer and with Giovanni Domenico Cassini (director of the Paris Observatory). The resulting account offers new insights into their attempts to share information, in a situation where motives for collaborating were counterbalanced by a potential for rivalry and conflict, and into the interlinked roles played by written correspondence, personal meetings and empirical investigation in the spreading of new ideas. (shrink)

The Robertson–Walker (RW) metric allows us to apply general relativity to model the behavior of the Universe as a whole (i.e., cosmology). We can properly interpret various cosmological observations, like the cosmological redshift, the Hubble parameter, geometrical distances, and so on, if we identify fundamental observers with individual galaxies. That is to say that the interpretation of observations of modern cosmology relies on the RW metric. The RW model satisfies the cosmological principle in which the 3-space always remains isotropic and (...) homogeneous. One can derive the cosmological redshift relation from this condition. We show that it is still possible for us to obtain consistent results in a specific time-varying speed-of-light model without spoiling the success of the standard model. The validity of this model needs to be determined by observations. (shrink)

We show how faceted search using a combination of traditional classification systems and mixed-membership topic models can go beyond keyword search to inform resource discovery, hypothesis formulation, and argument extraction for interdisciplinary research. Our test domain is the history and philosophy of scientific work on animal mind and cognition. The methods can be generalized to other research areas and ultimately support a system for semi-automatic identification of argument structures. We provide a case study for the application of the methods to (...) the problem of identifying and extracting arguments about anthropomorphism during a critical period in the development of comparative psychology. We show how a combination of classification systems and mixed-membership models trained over large digital libraries can inform resource discovery in this domain. Through a novel approach of “drill-down” topic modeling—simultaneously reducing both the size of the corpus and the unit of analysis—we are able to reduce a large collection of fulltext volumes to a much smaller set of pages within six focal volumes containing arguments of interest to historians and philosophers of comparative psychology. The volumes identified in this way did not appear among the first ten results of the keyword search in the HathiTrust digital library and the pages bear the kind of “close reading” needed to generate original interpretations that is the heart of scholarly work in the humanities. Zooming back out, we provide a way to place the books onto a map of science originally constructed from very different data and for different purposes. The multilevel approach advances understanding of the intellectual and societal contexts in which writings are interpreted. (shrink)

It has been argued that the existence of a minimum observable interval of space and time is a model-independent result of the combination of quantum field theory and general relativity. In this paper, I promote this result to a fundamental postulate, called the MOIST postulate. It is argued that the postulate leads to the existence of a maximum signal speed and its invariance. This new result may have two interesting implications. On the one hand, it suggests that the MOIST (...) postulate can explain the invariance of the speed of light, and thus it might provide a deeper logical foundation for special relativity. Moreover, it suggests that the speed constant c in modern physics is not the actual speed of light in vacuum, but the ratio of the minimum observable length to the minimum observable time interval. On the other hand, the result also suggests that the existing experiments confirming the invariance of the speed of light already provide observational evidence to support the MOIST postulate. (shrink)