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Both quantum mechanics and general relativity are based on principles that defy our daily intuitions, such as time dilation, quantum interference and entanglement. Because the regimes where the two theories are typically tested are widely separated, their foundational principles are rarely jointly studied. Recent works have found that novel phenomena appear for quantum particles with an internal structure in the presence of time dilation, which can take place at low energies and in weak gravitational fields. Here we briefly review the effects of time dilation on quantum interference and generalize the results to a variety of systems. In addition, we provide an extended study of the basic principles of quantum theory and relativity that are of relevance for the effects and also address several questions that have been raised, such as the description in different reference frames, the role of the equivalence principle and the effective irreversibility of the decoherence. The manuscript clarifies some of the counterintuitive aspects arising when quantum phenomena and general relativistic effects are jointly considered.

The common opinion that the Lorentz transformation distorts the Minkowski spacetime arises from a mathematically incorrect neglect of its non-diagonal terms. When the non-diagonal Lorentz transformation is properly treated, the time dilation and the space distortion disappear. Consequently, the Lorentz metric produced by the Lorentz transformation is identical to the Minkowski metric. The spacetime distortion in moving inertial frames is properly described by the so-called Doppler metric produced by the Doppler transformation. This transformation assumes the existence of a preferred frame and depicts the Doppler shift of light for a moving light source and/or observer. The Doppler metric is Lorentz invariant and leaves the Maxwell's equations unchanged from their form in the Minkowski spacetime. Moreover, the Doppler metric is experimentally confirmed because it yields the null result in the Michelson–Morley experiment and other interferometric experiments. The suitability of the Doppler metric for describing light properties in Special and General Relativity is supported by recent cosmological observations of the cosmic microwave background. [ABSTRACT FROM AUTHOR]

This paper examines the possibility of controlling the outcome of measured (flat space-time) relativistic effects, such as time dilation or length contractions, using pure rotations and their nontrivial interactions with Lorentz boosts in the isometry group SO + (3 , 1) . In particular, boost contributions may annihilate leaving only a geometric phase (Wigner rotation), which we see in the complex solutions of the generalized Euler decomposition problem in R 3 . We consider numerical examples involving specific matrix factorizations, along with possible applications in special relativity, electrodynamics and quantum scattering. For clearer interpretation and simplified calculations we use a convenient projective biquaternion parametrization which emphasizes the geometric phases and for a large class of problems allows for closed-form solutions in terms of only rational functions. [ABSTRACT FROM AUTHOR]

A large number of studies have demonstrated that intertemporal decision making process usually results in preferences that reverse over time, or choices that are inconsistent over time. Inconsistency can be explained by different discount models by the effect of reward value perception at different moments. Otherwise, one can also understand inconsistency as the result of the time perception effect. Here, we address inconsistency as the result of a subjective time dilation perception effect. We use arguments inspired by the special theory of relativity and focused our study on a generalized model that encompasses psychophysical effects on time perception, where we look for a transformation of the time interval between the pay times of two rewards. Additionally, we present a generalized two-argument hyperbolic utility function for the Bernoulli (logarithmic) one, associating their difference to subjective time intervals.

The rates of chemical reactions are not absolute but their magnitude depends upon the relative speeds of the moving observers. This has been proved by unifying basic theories of chemical kinetics, which are transition state theory, collision theory, RRKM and Marcus theory, with the special theory of relativity. Boltzmann constant and energy spacing between permitted quantum levels of molecules are quantum mechanically proved to be Lorentz variant. The relativistic statistical thermodynamics has been developed to explain quasi-equilibrium existing between reactants and activated complex. The newly formulated Lorentz transformation of the rate constant from Arrhenius equation, of the collision frequency and of the Eyring and Marcus equations renders the rate of reaction to be Lorentz variant. For a moving observer moving at fractions of the speed of light along the reaction coordinate, the transition state possess less kinetic energy to sweep translation over it. This results in the slower transformation of reactants into products and in a stretched time frame for the chemical reaction to complete. Lorentz transformation of the half-life equation explains time dilation of the half-life period of chemical reactions and proves special theory of relativity and presents theory in accord with each other. To demonstrate the effectiveness of the present theory, the enzymatic reaction of methylamine dehydrogenase and radioactive disintegration of Astatine into Bismuth are considered as numerical examples. [ABSTRACT FROM AUTHOR]

Background: Cervical dilatation is an essential aspect of active labour, which is necessary for the progress of delivery. Delayed or inadequate cervical dilatation can lead to prolonged labour, fetal distress, and the need for instrumental delivery. Pharmacological agents, such as Drotaverine Hydrochloride and Valethamate Bromide, are commonly used to promote cervical dilatation and facilitate delivery. Aim: To Observe the effectiveness of Drotaverine Hydrochloride and Valethamate Bromide in Promoting Cervical Dilatation during Active Labour. Methodology: This was a randomized, observational study conducted at a tertiary care hospital. A total of 100 women in active labour, with a cervical dilatation of less than 4 cm, were included in the study. They were randomly divided into two groups, with 50 women in each group. The first group received Drotaverine Hydrochloride, while the second group received Valethamate Bromide. The drugs were administered intravenously as per the standard protocol. The rate of cervical dilatation was monitored in both groups for a period of 6 hours. Results: The mean rate of cervical dilatation in the Drotaverine Hydrochloride group was 1.7 cm/hour, while in the Valethamate Bromide group it was 1.2 cm/hour. The difference was statistically significant (p<0.05). The mean time for cervical dilatation of 4 cm was 2.5 hours in the Drotaverine Hydrochloride group, while in the Valethamate Bromide group it was 3.5 hours. The difference was statistically significant (p<0.05). The adverse effects observed in both groups were similar and mild. Conclusion: In this observational study, Drotaverine Hydrochloride was found to be more effective in promoting cervical dilatation during active labour as compared to Valethamate Bromide. However, further studies are needed to validate these findings and to explore the long-term effects of these drugs on maternal and fetal outcomes. [ABSTRACT FROM AUTHOR]

Several Scriptures imply that at the end of this age, presumably not long from now, distant stars will be much older than we see them now. The time required for most stars to get old is many billions of years, yet that much aging must occur within the roughly 6,000 years the Bible says have elapsed on Earth since Creation. Cosmologies using Einstein's gravitational time dilation assert that clocks (and all physical processes) in the distant cosmos once ticked much faster than they did on Earth, so the above-mentioned Scriptures support those theories. But the Anisotropic Synchrony Convention (ASC) cosmology does not allow for time dilation, so the above-mentioned Scriptures are evidence against the ASC view. [ABSTRACT FROM AUTHOR]

In the real world, object arrangement follows a number of rules. Some of the rules pertain to the spatial relations between objects and scenes (i.e., syntactic rules) and others about the contextual relations (i.e., semantic rules). Research has shown that violation of semantic rules influences interval timing with the duration of scenes containing such violations to be overestimated as compared to scenes with no violations. However, no study has yet investigated whether both semantic and syntactic violations can affect timing in the same way. Furthermore, it is unclear whether the effect of scene violations on timing is due to attentional or other cognitive accounts. Using an oddball paradigm and real-world scenes with or without semantic and syntactic violations, we conducted two experiments on whether time dilation will be obtained in the presence of any type of scene violation and the role of attention in any such effect. Our results from Experiment 1 showed that time dilation indeed occurred in the presence of syntactic violations, while time compression was observed for semantic violations. In Experiment 2, we further investigated whether these estimations were driven by attentional accounts, by utilizing a contrast manipulation of the target objects. The results showed that an increased contrast led to duration overestimation for both semantic and syntactic oddballs. Together, our results indicate that scene violations differentially affect timing due to violation processing differences and, moreover, their effect on timing seems to be sensitive to attentional manipulations such as target contrast. [ABSTRACT FROM AUTHOR]

The importance of synchronization of spatially separated clocks in observing event coordinates cannot be overemphasized. We illustrate this with a real-world example. The results show the dependence of both length contraction and time dilation on the adopted synchronization convention. It is illustrated that a change in synchronization convention completely alters the appearance of the physical world. This is to be viewed in the context of the stated position in physics that synchronization of spatially separated clocks in any inertial frame depended on the adoption of a convention for its resolution. The preferred method of synchronization of spatially separated clocks is the standard convention recommended by the theory of relativity; however, it still remains a convention. [ABSTRACT FROM AUTHOR]

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In this paper, we revisit the question of relativistic mass to clarify the meaning of this concept within special relativity, and consider time dilation and length contraction in more detail. We see that 'length contraction' is a misnomer and that it should really be named 'space contraction' to avoid confusion, and demonstrate the complementary nature of time dilation and space contraction. We see that relativistic mass is dependent on the difference in velocity v between an object's proper frame of reference that is at rest with the object and the frame of reference from which it is observed. We show that the inertial mass of a body is its proper mass while the relativistic mass [m.sup.*] is in effect an effective mass. We find that relativistic mass results from dealing with dynamic equations in local time t in a frame of reference moving with respect to the object of interest, instead of the invariant proper time t in the frame of reference at rest with the object. The results obtained are in agreement with the Elastodynamics of the Spacetime Continuum., 1 Introduction The concept of relativistic mass has been a part of special relativistic physics since it was first introduced by Einstein [1,2] and explored by the early relativists (see [...]

The Robertson–Walker (RW) metric, derived from the cosmological principle and Weyl’s postulate, characterizes the ΛCDM cosmological model. Traditionally, in this framework, the assumption of a constant speed of light leads to specific cosmological time dilation (TD). However, because the Robertson–Walker metric lacks a way to define time dilation, the speed of light, like wavelength and temperature, may vary with cosmic time. The minimally extended varying speed of light (meVSL) model fits standard cosmological observations while considering the evolution of physical constants. One model-independent test for the meVSL model is cosmological time dilation. However, current data cannot distinguish between the meVSL model and the standard model.

In General Relativity, the gravitational field of a spherically symmetric non-rotating body is described by the Schwarzschild metric. This metric is invariant under time reversal, which implies that the power series expansion of the time dilation contains only even powers of v / c . The weak-field post-Newtonian approximation defines the relativistic time dilation of order ϵ (or of order ( v / c ) 2 ) of the small parameter. The next non-zero term of the time dilation is expected to be of order ϵ 2 , which is impossible to measure with current technology. The new model presented here, called Relativistic Newtonian Dynamics, describes the field with respect to the coordinate system of a far-removed observer. The resulting metric preserves the symmetries of the problem and satisfies Einstein’s field equations, but predicts an additional term of order ϵ 3 / 2 for the time dilation. This term will cause an additional periodic time delay for clocks in eccentric orbits. The analysis of the gravitational redshift data from the Galileo satellites in eccentric orbits indicates that, by performing an improved satellite mission, it would be possible to test this additional time delay. This would reveal which of the coordinate systems and which of the above metrics are real. In addition to the increase of accuracy of the time dilation predictions, such an experiment could determine whether the metric of a spherically symmetric body is time reversible and whether the speed of light propagating toward the gravitating body is the same as the speed propagating away from it. More accurate time dilation and one-way speed of light formulas are important for astronomical research and for global positioning systems.

For the first time, the possibility of measuring the difference in gravitational potentials and orthometric heights by a quantum level based on the gravitational effect of time dilation using ground communication lines is considered. The duplex mode of measurements using two opposite radio channels is theoretically described. The dilation effect was experimentally measured using a one-way radio communication line implemented based on a fiber-optic link. For measurements, stationary and mobile (transportable) quantum hydrogen clocks were used with relative instabilities of (0.5-0.7)×10-15 and 1×10-15, respectively. It was found that in the experiment, the gravitational redshift of the frequency between the utilized clocks has two components: the redshift of the master oscillator frequency and the classical redshift in the radio channel. Based on the measurement results, the displacement height of the transportable quantum hydrogen clock was calculated to be (–34.0 ± 0.8) m, while the actual height was –34 m. [ABSTRACT FROM AUTHOR]

General relativity predicts that clocks run more slowly near massive objects. The effect is small--a clock at sea level lags behind one 1000m above sea level by only 9.4 ns/day. Here, we demonstrate that a measurement of this effect can be done by undergraduate students. Our paper describes an experiment conducted by undergraduate researchers at Colorado College and the United States Air Force Academy to measure gravitational time dilation. The measurement was done by comparing the signals generated by a GPS frequency standard (sea-level time) to a Cs-beam frequency standard at seven different altitudes above sea level. We found that our measurements are consistent with the predictions of general relativity. [ABSTRACT FROM AUTHOR]

The neural basis of time perception has long attracted the interests of researchers. Recently, a conceptual model consisting of neural oscillators was proposed and validated by behavioral experiments that measured the dilated duration in perception of a flickering stimulus (Hashimoto and Yotsumoto, 2015). The model proposed that flickering stimuli cause neural entrainment of oscillators, resulting in dilated time perception. In this study, we examined the oscillator-based model of time perception, by collecting electroencephalography (EEG) data during an interval-timing task. Initially, subjects observed a stimulus, either flickering at 10-Hz or constantly illuminated. The subjects then reproduced the duration of the stimulus by pressing a button. As reported in previous studies, the subjects reproduced 1.22 times longer durations for flickering stimuli than for continuously illuminated stimuli. The event-related potential (ERP) during the observation of a flicker oscillated at 10 Hz, reflecting the 10-Hz neural activity phase-locked to the flicker. Importantly, the longer reproduced duration was associated with a larger amplitude of the 10-Hz ERP component during the inter-stimulus interval, as well as during the presentation of the flicker. The correlation between the reproduced duration and the 10-Hz oscillation during the inter-stimulus interval suggested that the flicker-induced neural entrainment affected time dilation. While the 10-Hz flickering stimuli induced phase-locked entrainments at 10 Hz, we also observed event-related desynchronizations of spontaneous neural oscillations in the alpha-frequency range. These could be attributed to the activation of excitatory neurons while observing the flicker stimuli. In addition, neural activity at approximately the alpha frequency increased during the reproduction phase, indicating that flicker-induced neural entrainment persisted even after the offset of the flicker. In summary, our results suggest that the duration perception is mediated by neural oscillations, and that time dilation induced by flickering visual stimuli can be attributed to neural entrainment.

In this paper, it has been shown that some experimental confirmations for the so-called "time dilation effect" may be in a rational way explained on the basis of a thought experiment presented in a previous paper [J. Drozdzynski, Phys. Essays 26, 321 (2013)]. The performed analysis has proven, that in order to carry out a round trip of a laser pulse from the source to a perpendicular located mirror and back to the starting point, the laser source in motion of the spaceship with a constant speed must be pointed at an angle in the direction of movement; whereas at rest it should be directed perpendicular to that axis. This means, that we have not to deal with a "time dilation effect" but with two separate measurements of two separate laser signals, moving at two different distances. The ratio of the two time intervals is expressed by a somewhat different equation as stated by the Special Theory Relativity and possesses also a dissimilar meaning. It has been shown also that it can be evaluated by the observer in motion by himself as well as that the phenomenon of a reiativistic length contraction does not exist. On this basis, a quantitative relation between time intervals of such oscillations in two reference frames, which are in motion with a different speed with respect to the frame at absolute rest, has been received. The relation may be of some significance for the Global Positioning System (GPS). A rational explanation of the "moving clocks" experiments as well as the "time dilation effect" of muons is presented. The existence of "paradoxes," resulting from Special Relativity has been excluded. A new elucidation of the null result in the Michelson-Morley experiment is presented. The analysis was based on classical physics and is giving additional evidence for the erroneousness of the principle of relativity. [ABSTRACT FROM AUTHOR]

Undergraduate physics majors typically begin their study of modern physics with special relativity. It is here that physics students first encounter the counterintuitive concepts of time dilation and length contraction. Unfortunately, the derivations of these results are often cloaked in several layers of analysis that render them rather mysterious and otherworldly for novice students. Here we show how a very simple thought experiment leads directly to a student-friendly derivation of time dilation and length contraction. The only assumption needed is the constancy of the speed of light.

Research on media's effects on body perception has mainly focused on the role of vision of extreme body types. However, haptics is a major part of the way children experience bodies. Playing with unrealistically thin dolls has been linked to the emergence of body image concerns, but the perceptual mechanisms remain unknown. We explore the effects of haptic experience of extreme body types on body perception, using adaptation aftereffects. Blindfolded participants judged whether the doll-like stimuli explored haptically were thinner or fatter than the average body before and after adaptation to an underweight or overweight doll. In a second experiment, participants underwent a traditional visual adaptation paradigm to extreme bodies, using stimuli matched to those in Experiment 1. For both modalities, after adaptation to an underweight body test bodies were judged as fatter. Adaptation to an overweight body produced opposite results. For the first time, we show adiposity aftereffects in haptic modality, analogous to those established in vision, using matched stimuli across visual and haptic paradigms. [ABSTRACT FROM AUTHOR]

We showed to the same observers both dynamic and static 2D patterns that can both evoke distinctive perceptions of motion or optic flow, as if moving in a tunnel or into a dark hole. At all times pupil diameters were monitored with an infrared eye tracker. We found a converging set of results indicating stronger pupil dilations to expansive growth of shapes or optic flows evoking a forward motion into a dark tunnel. Multiple regression analyses showed that the pupil responses to the illusory expanding black holes of static patterns were predicted by the individuals' pupil response to optic flows showing spiraling motion or "free fall" into a black hole. Also, individuals' pupil responses to spiraling motion into dark tunnels predicted the individuals' sense of illusory expansion with the static, illusory expanding, dark holes. This correspondence across individuals between their pupil responses to both dynamic and static, illusory expanding, holes suggests that these percepts reflect a common perceptual mechanism, deriving motion from 2D scenes, and that the observers' pupil adjustments reflect the direction and strength of motion they perceive and the expected outcome of an increase in darkness. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of vitamin D deficiency on pupillary responses in the pediatric population. Methods: The study was conducted using data from the right eyes of 52 children with vitamin D deficiency and 52 healthy children. Measurements were taken under static and dynamic conditions with automatic pupillometry. Static measurements were performed at scotopic, mesopic, and photopic light intensities. The mean pupil dilation speed was calculated by observing the changes in pupil dilation over time according to dynamic measurements. Differences between patient and control groups were analyzed for the static and dynamic measurements and the mean pupil dilation speed. Results: While the two groups were similar in terms of scotopic, mesopic, the first dynamic measurements, and the pupil dilation speed data (p > 0.05), a significant difference was found in the photopic conditions (p = 0.001). The mean pupil diameter of the patient group was 4.46 ± 0.928 mm and 3.95 ± 0.556 mm in the control group under photopic conditions. Conclusions: Pediatric patients with vitamin D deficiency have significantly larger pupil diameters in photopic conditions than healthy children. These results suggest that there is an autonomic dysfunction in vitamin D deficiency in the pediatric population, especially pointing to the parasympathetic system. [ABSTRACT FROM AUTHOR]