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)

If is often taken for granted that on a rotating disk it is possible to operate a global 3+1 splitting of spacetime such that both lengths and time intervals are uniquely defined in terms of measurements performed by real rods and real clocks at rest on the platform. This paper shows that this assumption, although widespread and apparently trivial, leads to an anisotropy of the velocity of two light beams traveling in opposite directions along the rim of the disk, (...) which in turn implies some recently pointed out paradoxical consequences undermining the self-consistency of the special theory of relativity (SRT). A correct application of the SRT solves the problem and recovers complete internal consistency for the theory. As an immediate consequence, it is shown that the Sagnac effect only depends on the nonhomogeneity of time of the platform and has nothing to do with any anisotropy of the speed of light along the rim of the disk, contrary to an incorrect but widely held idea. (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)

While it has often been proposed that, fundamentally, Lorentz-invariance is not respected in a quantum theory of gravity, it has been difficult to reconcile deviations from Lorentz-invariance with quantum field theory. The most commonly used mechanisms either break Lorentz-invariance explicitly or deform it at high energies. However, the former option is very tightly constrained by experiment already, the latter generically leads to problems with locality. We show here that there exists a third way to integrate deviations from Lorentz-invariance into quantum (...) field theory that circumvents the problems of the other approaches. The way this is achieved is an extension of the standard model in which photons can have different speeds without singling out a preferred restframe, but only as long as they are in a quantum superposition. Once a measurement has been made, observables are subject to the laws of special relativity, and the process of measurement introduces a preferred frame. The speed of light can take on different values, both superluminal and subluminal (with respect to the usual value of the speed of light), without the need for Lorentz-invariance violating operators and without tachyons. We briefly discuss the relation to deformations of special relativity and phenomenological consequences. (shrink)

This article traces the significant links that Virilio's dromological analysis posits between the social and political impact of mechanical vehicles and communications media. Focusing on the way that the 'revolutions' of transportation and transmission have fundamentally altered contemporary experiences of space and time, the article explores the implications of Virilio s concept of spatio-temporal 'overexposure". My contention is that Virilio's work has been of critical importance in placing questions about differential spatio-temporal regimes Oin the political agenda. However, his critique of (...) 'tele-presence. is ultimately hampered by his continued attachment to a phenomenological subject, which I argue does not provide an adequate basis from which to rethink the dominant social relations of time and space manifest in the contemporary media. (shrink)

Recent years have seen the attention of physicists and philosophers, both at home and abroad, increasingly drawn, as is evident in the professional literature, to the question of the possibility of the existence of particles moving at speeds greater than that of light and to determining the physical and philosophical consequences of this hypothesis. The philosophical consequences have to do primarily with the causality principle. We are in receipt of two articles in which these questions are examined from different (...) perspectives and which supplement each other. (shrink)

Fundamental incompatibility arises at the interface of quantum mechanics and the special theory of relativity with Einstein synchronization, in which simultaneity is not absolute. It has, however, been shown that a relativistic theory preserving absolute simultaneity allows to formulate Lorentz-covariant quantum theory, at a price of introducing a preferred frame of reference manifesting itself in a directional anisotropy of the speed of light. We show that a supposed method of distinguishing between these two theories based on the Doppler (...) effect is insensitive to this anisotropy. Both theories are indistinguishable if only kinematic effects for light or subluminal signals are considered. (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)

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)

In connection with another article by the author, we show how it might be possible to travel faster than the speed of light. We show that for clocks and rods moving faster than the speed of light, we get instead of “time dilation” and “Lorentz contraction,” respectively, “time contraction” and “Lorentz expansion,” respectively. It is shown that this paper is in confirmation with earlier articles dealing with this subject.

There are two types of fluctuations in the quantum vacuum: type 1 vacuum fluctuations are on shell and can interact with matter in specific, limited ways that have observable consequences; type 2 vacuum fluctuations are off shell and cannot interact with matter. A photon will polarize a type 1, bound, charged lepton–antilepton vacuum fluctuation in much the same manner that it would polarize a dielectric, suggesting the method used here for calculating the permittivity $$\epsilon _{0}$$ϵ0 of the vacuum. In a (...) model that retains only leading terms, $$\epsilon _{0} \cong ^{2}= 9.10\times 10^{-12}$$ϵ0≅2=9.10×10-12 C/. The calculated value for $$\epsilon _{0}$$ϵ0 is 2.7% more than the accepted value. The permittivity of the vacuum, in turn, determines the speed c of light in the vacuum. Since the vacuum is at rest with respect to every inertial frame of reference, c is the same in every inertial reference frame. (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)

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)

In recent years there has been rather extensive discussion in the physics literature of the possibility of transmission of material effects at speeds exceeding that of light.

We describe our explicit Lorentz-invariant solution of the Einstein and null geodesic equations for the deflection experiment of 2002 September 8 when a massive moving body, Jupiter, passed within 3.7’ of a line-of-sight to a distant quasar. We develop a general relativistic framework which shows that our measurement of the retarded position of a moving light-ray deflecting body (Jupiter) by making use of the gravitational time delay of quasar’s radio wave is equivalent to comparison of the relativistic laws of (...) the Lorentz transformation for gravity and light. Because, according to Einstein, the Lorentz transformation of gravity field variables must depend on a fundamental speed c, its measurement through the retarded position of Jupiter in the gravitational time delay allows us to study the causal nature of gravity and to set an upper limit on the speed of propagation of gravity in the near zone of the solar system as contrasted to the speed of the radio waves. In particular, the v/c term beyond of the standard Einstein’s deflection, which we measured to 20% accuracy, is associated with the aberration of the null direction of the gravity force (“aberration of gravity”) caused by the Lorentz transformation of the Christoffel symbols from the static frame of Jupiter to the moving frame of observer. General relativistic formulation of the experiment identifies the aberration of gravity with the retardation of gravity because the speed of gravitational waves in Einstein’s theory is equal to the speed of propagation of the gravity force. We discuss the misconceptions which have inhibited the acceptance of this interpretation of the experiment. We also comment on other interpretations of this experiment by Asada, Will, Samuel, Pascual–Sánchez, and Carlip and show that their “speed of light” interpretations confuse the Lorentz transformation for gravity with that for light, and the fundamental speed of gravity with the physical speed of light from the quasar. For this reason, the “speed of light” interpretations are not entirely consistent with a retarded Liénard–Wiechert solution of the Einstein equations, and do not properly incorporate how the phase of the radio waves from the quasar is perturbed by the retarded gravitational field of Jupiter. Although all of the formulations predict the same deflection to the order of v/c, our formulation shows that the underlying cause of this deflection term is associated with the aberration of gravity and not of light, and that the interpretations predict different deflections at higher orders of v/c beyond the Shapiro delay, thus, making their measurement highly desirable for deeper testing of general relativity in future astrometric experiments like Gaia, SIM, and SKA. (shrink)

It is still perhaps not widely appreciated that in 1905 Einstein used his postulate concerning the ‘constancy’ of the light-speed in the ‘resting’ frame, in conjunction with the principle of relativity, to derive numerical light-speed invariance. Now a ‘weak’ version of the relativity principle (or, alternatively, appeal to the Michelson—Morley experiment) leads from Einstein's light postulate to a condition that we call universal light-speed constancy. which is weaker than light-speed invariance. It (...) follows from earlier independent investigations (Robertson [1949]; Steigler [1952]; Tzanakis and Kyritsis [1984]) that this condition is none the less sufficient to derive the Lorentz transformations up to a scale factor, given the well-known kinematic principle of ‘reciprocity’. In this paper, we follow Robertson and explore the kinematics consistent with universal light-speed constancy without imposing reciprocity, and we recover the Lorentz transformations by further appeal only to the weak relativity principle and spatial isotropy. (shrink)

This article addresses recent science fiction films about the colonization of outer worlds, or space-steading, in the context of the longer colonial history of the frontier. Paying particular attention to Interstellar (Christopher Nolan, 2014), Serenity (Joss Whedon, 2005) and The Wild Blue Yonder (Werner Herzog, 2005), I argue that colonizing outer space is not only a race to the new frontier, but that this takes place because technologies that picture space have quickened the pulse. Through its imagining of the end (...) of times as a reiteration of colonizing adventure, and the emptying of people from their place, the technology of film has itself produced the accident (Virilio, 2007) of an uninhabited earth. As suggested by the cinematically derived kinesis of wormholes, space wrinkles, and warp speeds, what might be left as a form of life is none other than film itself. The hyper-kinesis of film spectacle takes on a non-human life of its own, which, in science fiction film, constitutes a form of self-alienation, removing viewers from the places they actually inhabit and displacing the histories they unfold. In this way, I address what is truly cinematic about the film frontier traversed by the new space of uber-masculine adventurer-settlers. (shrink)

This study investigates how speed of motion is processed in language. In three eye-tracking experiments, participants were presented with visual scenes and spoken sentences describing fast or slow events (e.g., The lion ambled/dashed to the balloon). Results showed that looking time to relevant objects in the visual scene was affected by the speed of verb of the sentence, speaking rate, and configuration of a supporting visual scene. The results provide novel evidence for the mental simulation of speed (...) in language and show that internal dynamic simulations can be played out via eye movements toward a static visual scene. (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.

Olfaction has recently been highlighted as a sense poorly connected with language. Odor is difficult to verbalize, and it has few qualities that afford mimicry by vision or sound. At the same time, emotion is thought to be the most salient dimension of an odor, and it could therefore be an olfactory dimension more easily communicated. We investigated whether sounds imitative of an innate disgust response can be associated with unpleasant odors. In two experiments, participants were asked to make a (...) forced choice between a pseudoword including a disgust sound and a neutral pseudoword, for pleasant and unpleasant odors. Overall, participants chose more disgust pseudowords than neutral pseudowords for unpleasant odors, but this was not the case for pleasant odors. This effect was not driven by a general association between unpleasant sounds and unpleasant odors, but specifically the sounds [x/χ] and [f], thought to reflect physical responses to disgusting odors, as seen in the Polish fu! or the English ugh!. In line with growing evidence that language can encode odor, we provide the first experimental evidence for an association between the sound of a word and odor valence. (shrink)

How can digitised assets of Galleries, Libraries, Archives and Museums be reused to unlock new value? What are the implications of viewing large-scale cultural heritage data as an economic resource, to build new products and services upon? Drawing upon valuation studies, we reflect on both the theory and practicalities of using mass-digitised heritage content as an economic driver, stressing the need to consider the complexity of commercial-based outcomes within the context of cultural and creative industries. However, we also problematise the (...) act of considering such heritage content as a resource to be exploited for economic growth, in order to inform how we consider, develop, deliver and value mass-digitisation. Our research will be of interest to those wishing to understand a rapidly changing research and innovation landscape, those considering how to engage memory institutions in data-driven activities and those critically evaluating years of mass-digitisation across the heritage sector. (shrink)

Do we mentally simulate olfactory information? We investigated mental simulation of odors and sounds in two experiments. Participants retained a word while they smelled an odor or heard a sound, then rated odor/sound intensity and recalled the word. Later odor/sound recognition was also tested, and pleasantness and familiarity judgments were collected. Word recall was slower when the sound and sound-word mismatched. Sound recognition was higher when sounds were paired with a match or near-match word. This indicates sound-words are mentally simulated. (...) However, using the same paradigm no memory effects were observed for odor. Instead it appears odor-words only affect lexical-semantic representations, demonstrated by higher ratings of odor intensity and pleasantness when an odor was paired with a match or near-match word. These results suggest fundamental differences in how odor and sound-words are represented. (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 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)

The target article by Leech et al. presents a compelling computational theory of analogy-making. However, there is a key difficulty that persists in theoretical treatments of analogy-making, computational and otherwise: namely, the lack of a detailed account of the neurophysiological mechanisms that give rise to analogy behavior. My commentary explores this issue.

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)

We point out that the acceptance of the relativity principle together with the homogeneity and isotropy of space and the homogeneity of time inevitably leads to the Lorentz spacetime transformation with a universal limiting speed σ. Speculations on possible new four-dimensional symmetries involving a variable “speed of light” such as that proposed by Hsu must therefore be dismissed on such a basis alone. In this paper we draw attention to some logical inconsistencies in Hsu's attempt at establishing (...) a new space-light transformation law, and follow with a discussion on why such an attempt must necessarily fail. (shrink)

Odor and color are strongly associated. Numerous studies demonstrate consistent odor‐color associations, as well as effects of color on odor perception and language. Yet, we know little about how these associations arise. Here, we test whether language is a possible mediator of odor‐color associations, specifically whether odor‐color associations are mediated by implicit odor naming. In two experiments, we used an interference paradigm to prevent the verbalization of odors during an odor‐color matching task. If participants generate color associations subsequent to labeling (...) an odor, interfering with verbalization during the task should affect the ability to make color associations. In Experiment 1, contrary to our hypothesis, verbal interference did not affect odor‐color matches. However, since performance accuracy on the verbal interference task was high, it is possible our task did not sufficiently disrupt verbal processing. In Experiment 2, we, therefore, used an active verbal interference task, and still found no difference across interference conditions. Odor naming accuracy, odor familiarity, and odor pleasantness, however, did predict odor‐color matches. This suggests that although color associations are related to semantic factors, they are not generated by recruiting odor labels in the moment. Overall, our results do not provide evidence that language plays an online role in odor‐color associations, instead, they are consistent with the claim that language may have shaped associations during development. (shrink)

We propose an analogy between optical holography and neural behavior as a hypothesis about the physical mechanisms of neural reuse. Specifically, parameters in optical holography (frequency, amplitude, and phase of the reference beam) may provide useful analogues for understanding the role of different parameters in determining the behavior of neurons (e.g., frequency, amplitude, and phase of spiking behavior).

Complex‐trait genetics has advanced dramatically through methods to estimate the heritability tagged by SNPs, both genome‐wide and in genomic regions of interest such as those defined by functional annotations. The models underlying many of these analyses are inadequate, and consequently many SNP‐heritability results published to date are inaccurate. Here, we review the modelling issues, both for analyses based on individual genotype data and association test statistics, highlighting the role of a low‐dimensional model for the heritability of each SNP. We use (...) state‐of‐art models to present updated results about how heritability is distributed with respect to functional annotations in the human genome, and how it varies with allele frequency, which can reflect purifying selection. Our results give finer detail to the picture that has emerged in recent years of complex trait heritability widely dispersed across the genome. Confounding due to population structure remains a problem that summary statistic analyses cannot reliably overcome. Also see the video abstract here: https://youtu.be/WC2u03V65MQ. (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)