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In this work, we obtain a relation for average quantum time dilation between two clocks A and B in the near-horizon region of a black hole supported by the Rindler metric and conformal tortoise coordinate. It is indicated that this relation is identified with time dilation in classical and flat background limits.

Reciprocal length contraction and time dilation, as enshrined in the Lorentz transformation, are the bulwark of the special relativity theory. Reciprocal time dilation is typically discussed (in the context of its apparent contradiction) and usually explained away as the result of differing synchronization in inertial reference frames and the relativity of simultaneity. Further, it is generally suggested that time is an abstract concept, and its perceptions may differ with context. However, we suggest that regarding length measurements no such abstraction can be envisaged. In this manuscript, we examine the reciprocal length contraction in detail to assess whether it leads to any contradiction. [ABSTRACT FROM AUTHOR]

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As was found in the first paper of this series of papers, the rotation of space produces a significant curvature (Progr. Phys., 2022, v.18, 31-49). In the second paper, we showed that light rays and mass-bearing particles are deflected near a rotating body due to the curvature of space caused by its rotation (ibid., 50-55). In this article we show that, since the rotation of the Earth around its axis curves the Earth's space making it 'stretched' along the geographical longitudes, the measured length of a standard rod is greater when the rod is installed in the longitudinal direction. Due to the same reason, there is a time loss on board an airplane flying to the East (the direction in which the Earth's space rotates), and also a time gain when flying in the opposite direction, to the West. Both of the above effects are maximum at the equator (where the curvature of the Earth's space caused by its rotation is maximum and, therefore, space is maximally 'stretched') and descrease towards the North and South Poles., This paper is dedicated to the memory of Joseph C. Hafele, the outstanding American experimental physicist known due to his famous around-the-world-clocks experiment. This is the third paper in the [...]

The explanation of Einstein’s special theory of relativity in his original 1905 paper is examined. His analysis is confusing, as terms x, y, z, t, etc., have different meanings at various points, and he presents equations based on different and inconsistent assumptions. Adding subscripts clarifies these issues but exposes errors in his reasoning. To calculate his transformation equations, he selects a combination of equations which gives results matching the Lorentz transformation but he ignores other possible valid solutions. Also his calculations contain serious errors. Therefore, he fails to prove that his theory leads to the Lorentz equations as a unique solution. Einstein’s analysis includes “moving” clocks which show “stationary” time t, so the idea that a moving clock should run slower than a stationary clock is incompatible with his theory. Also, his calculation of time dilation contains serious errors. As a result, he fails to provide a theoretical justification for his famous “clocks paradox.” [ABSTRACT FROM AUTHOR]

Our experience of time is strikingly plastic: Depending on contextual factors, the same objective duration can seem to fly by or drag on. Perhaps the most direct demonstration of such subjective time dilation is the oddball effect: when seeing identical objects appear one after another, followed by an "oddball" (e.g., a disc that suddenly grows in size, in a sequence of otherwise static discs), observers experience this oddball as having lasted longer than its nonoddball counterparts. Despite extensive work on this phenomenon, a surprisingly foundational question remains unasked: What actually gets dilated? Beyond the oddball, are the objects just before (or just after) the oddball also dilated? As in previous studies, observers viewed sequences of colored discs, one of which could be the oddball—and subsequently reproduced the oddball's duration. Unlike previous studies, however, there were also critical trials in which observers instead reproduced the duration of the disc immediately before or after the oddball. A clear pattern emerged: oddball-induced time dilation extended to the post-oddball disc, but not the pre-oddball disc. Whence this temporal asymmetry? We suggest that an oddball's sudden appearance may induce uncertainty about what will happen next, heightening attention until after the uncertainty is resolved. [ABSTRACT FROM AUTHOR]

Atomic clock interferometers are a valuable tool to test the interface between quantum theory and gravity, in particular via the measurement of gravitational time dilation in the quantum regime. Here, we investigate whether gravitational time dilation may be also used as a resource in quantum information theory. In particular, we show that for a freely falling interferometer and for a Mach-Zehnder interferometer, the gravitational time dilation may enhance the precision in estimating the gravitational acceleration for long interferometric times. To this aim, the interferometric measurements should be performed on both the path and the clock degrees of freedom.

General relativity is the exact theory of gravity which has been experimentally found to be correct with extremely high accuracy. One of the most surprising predictions of the general theory is that time runs slow in a gravitational field. Its proof formally comes from Schwarzschild metric which is a solution of Einstein field equation for a spherically symmetric mass. However, as Einstein field equation is too complex, attempts have been made earlier to derive gravitational time dilation by direct use of principle of equivalence and special theory of relativity. But, this objective has been accomplished partially till date as the resulting expression agrees with the exact expression only upto first order. In this paper, by using principle of equivalence and special relativity, we present a thought experiment which helps us to derive an expression that exactly matches with the expression for gravitational time delay.

Background: This study aims to compare patency rates of the 0- and 30-s (sec) balloon dilation time in hemodialysis (HD) patients with restenosis after percutaneous transluminal angioplasty (PTA). Methods: The patients who underwent PTA within 6 months for failed arteriovenous fistula at the forearm were randomly assigned the 0-s or 30-s dilation time group. Effect of dilation time on the 3- and 6-month patency rates after PTA was examined. Results: Fifty patients were enrolled in this study. The 3-month patency rate in the 30-s dilation group was better than that in the 0-s dilation group (P = 0.0050), while the 6-month patency rates did not show a significant difference between the two groups (P = 0.28). Cox's proportional hazard model revealed that 30-s of inflation time (hazard ratio 0.027; P = 0.0072), diameter of the proximal (hazard ratio 0.32; P = 0.031), and dilation pressure (hazard ratio 0.63; P = 0.014) were associated with better 3-month patency. Dilation pressure between previous and present PTA did not differ in the 0-s (P = 0.15) and 30-s dilation groups (P = 0.16). The 6-month patency rate of the present PTA in the 30-s dilation group was higher than that of the previous PTA (P = 0.015). The visual analog scale did not differ between the two groups (P = 0.51). Conclusion: The presenting data suggest that 30-s dilation potentially results in a better 3-month patency rate than 0-s dilation in HD patients with restenosis after PTA. [ABSTRACT FROM AUTHOR]

Recently, the physics education community has taken a keen interest in modernising physics education. However, while topics in modern physics have great potential to engage students, these topics are abstract and hard-to-visualise. Therefore, many students hold mistaken pictures and misconceptions, which can impede learning. In this article, we expose a pervasive misconception about relativistic time dilation by presenting a thought experiment illustrating the difference between visual observation and coordinate measurement. We also point out how existing language can mislead and confuse students. In response, we describe an instructional approach that introduces world-maps, world-pictures and event-diagrams to clarify the applicability of key equations in special relativity for improved understanding. By unpacking 'the invisibility of time dilation' from the perspectives of both physics and pedagogy, we aim to help teachers provide clearer instruction. [ABSTRACT FROM AUTHOR]

Introductory textbooks for the theory of special relativity discuss the time dilation effect after introducing the Lorentz transformations. Reading the dictum 'moving clocks run slow' a student is likely to have the impression that this is a measured effect. On the other hand, after considering the relativistic Doppler effect the same student might be puzzled that this effect depends on the relative emitter-observer direction, contrary to Einstein's time dilation. Simple thought experiments are presented here where the inferred time dilation and the observed relativistic Doppler effect give quite opposite answers. Before solving the puzzle, we show how easily one can get confused and obtain apparently contradictory results. [ABSTRACT FROM AUTHOR]

According to Einstein's general theory of relativity, a clock runs more slowly if it is close to a large gravitating object. This principle was highlighted in the movie "Interstellar," in which the main character spends several hours on a planet orbiting a massive black hole, and returns to find that his young daughter has become an elderly woman. In the movie, one hour on the planet equates to seven years on Earth. The same effect can be measured on a much smaller scale by changing locations within Earth's gravitational field. Using atomic clocks, we have compared the ticking of time at Colorado College (elevation 1845 m above sea level), at the United States Air Force Academy (elevation 2165 m), and near the summit of Pikes Peak (elevation 4288 m). Our results confirm that clocks do indeed tick more quickly at higher altitudes, in accordance with Einstein's theory. This work was carried out as a collaboration of physics majors and faculty at Colorado College (CC) and the United States Air Force Academy (USAFA). The experimental technique is straightforward and our results can be reproduced by other students and teachers, given access to an atomic clock and reasonably large changes in elevation. Indeed, a similar endeavor has been reported by amateur clock enthusiasts.

The theory of special relativity is one of the most significant achievements in modern physics, with several important predictions such as time dilation, size contraction for a moving object, and mass-energy equivalence. Recent studies have demonstrated size contraction for an antiferromagnetic (AFM) domain wall (DW). Here, we show the excitation of terahertz (THz) magnons from a moving AFM DW under the magnetic anisotropy energy gradient. The energy of magnons comes from the loss of the effective DW mass due to the reduction in anisotropy energy. Also, the excitation of THz magnons is accompanied by a DW width broadening, overcoming the Lorentz contraction effect. Our results pave the way to study relativistic physics in AFM textures and to efficiently generate THz magnons by DC electric means. [ABSTRACT FROM AUTHOR]

The perceived duration of time does not veridically reflect the physical duration but is distorted by various factors, such as the stimulus magnitude or the observer's emotional state. Here, we showed that knowledge about an event's termination time is another significant factor. We often experience time passage differently when we know that an event will terminate soon. To quantify this, we asked 33 university students to report a rotating clock hand's duration with or without a termination cue that indicated the position at which the clock hand disappeared. The results showed that the presence of the termination cue dilated perceived durations, and the dilating effect was larger when the stimulus duration was longer, or the speed of the rotating stimulus was slower. A control experiment with a start-cue excluded the possibility that the cue's mere existence caused the results. Further computational analyses based on the attention theory-of-time perception revealed that the size of dilation is best explained by neither an event's duration nor the distance traveled by the clock hand, but by how long the clock hand spends time near the termination cue. The results imply that an event-termination cue generates a field in which the perceived time dilates. [ABSTRACT FROM AUTHOR]

We present a novel test of the cosmological principle: the idea that, on sufficiently large scales, the Universe should appear homogeneous and isotropic to observers comoving with the Hubble flow. This is a fundamental assumption in modern cosmology, underpinning the use of the Friedmann–Lemaître–Robertson–Walker metric as part of the concordance ΛCDM paradigm. However, the observed dipole imprinted on the cosmic microwave background (CMB) is interpreted as our departure from the Hubble flow, and such a proper motion will induce a directionally-dependent time dilation over the sky. We illustrate the feasibility of detection of this 'time dilation dipole' and sketch the practical steps involved in its extraction from a catalogue of sources with intrinsic time-scales. In essence, whilst the scale of this dilation is small, being of the order of 0.1 per cent, it will in principle be detectable in large-scale surveys of variable cosmological sources, such as quasars and supernovae. The degree of alignment of the time dilation dipole with the kinematic dipole derived from the CMB will provide a new assessment of the cosmological principle and address the tension in dipole measures from other observations. [ABSTRACT FROM AUTHOR]

We demonstrate that the de Broglie wave of a particle in a gravitational field turns toward the region of lower gravitational potential, causing the particle to fall. This turning is caused by clocks running slower in the smaller potential. We use the analogy of ocean waves that are slower in shallower water and turn toward beaches. This approach implies that the motion is along a geodesic and explains the free fall qualitatively and quantitatively with only elementary algebra. [ABSTRACT FROM AUTHOR]

Non-universal topological quantum computation models, such as the Majorana fermion-based Ising anyon model, have to be supplemented with an additional non-topological noisy gate in order to achieve universality. Here we endeavour to remedy this using an Einstein­—Cartan analog gravity picture of scalar fields. Specifically, we show that the analog gravity picture enables unitary transformations to be realized in two distinct ways: (i) via space-time holonomy and (ii) as gravitational time dilation. The non-abelian geometric phases are enabled by gravitational interactions, which are mediated by the spin-connection. We analytically compute its matrix elements as a function of the scalar field density distribution. This density can be regarded as the gravitating distribution of matter in an analog universe. We show via explicit calculations that there exists an infinite set of asymptotically flat analog gravitational fields, each of which implements a unique unitary transformation, that render the interactions topological. We emphasise the generality of this result by asserting that such gravitational gates could potentially be implemented in a broad range of real systems modeled by scalar field with an acoustic metric.