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It is well known that simultaneity within an inertial frame is defined in relativity theory by a convention or definition. This definition leads to different simultaneities across inertial frames and the well-known principle of relativity of simultaneity. The lack of a universal present implies the existence of past, present, and future as a collection of events on a four-dimensional manifold or continuum wherein three dimensions are space like and one dimension is time like. However, such a continuum precludes the possibility of evolution of future from the present as all events exist "forever" so to speak on the continuum with the tenses past, present, and future merely being perceptions of different inertial frames. Such a far-reaching ontological concept, created by a mere convention, is yet to gain full acceptance. In this paper, we present arguments in favor of an absolute present, which means simultaneous events are simultaneous in all inertial frames, and subscribe to evolution of future from the present. [ABSTRACT FROM AUTHOR]

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]

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]

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 very simple, fundamental physical explanation is presented of time dilation and length contraction. This explanation is obtained from a classical model of physics that is Galilean. It assumes the existence of a medium (ether) that acts as an absolute reference in accordance with Mach's principle. Time and space are conventional, i.e., a three-dimensional space independent of time. In addition, the explanation relies on the assumption that all physics, including matter such as clocks and measuring rods, has a scalar wave structure. Matter is assumed to consist of locally stable scalar wave structures, specifically scalar standing wave structures. The scalar waves are just variations in space and time of medium density. Also, an element of special relativity is used, namely, the one taking into account the finite velocity of light. [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]

A question in physics is whether Special Relativity (SR) is the only theory that explains relativistic behavior. SR measures time dilation by a relative velocity between two frames. Laboratory experiments with a single moving body fit this concept. However, GPS satellites and their ground clocks measure time dilation by a velocity relative to a common non-rotating Earth inertial frame. To better understand the conceptual difference, an experimental survey was undertaken. The survey analysis showed that laboratory experiments also fit into the non-rotating Earth frame concept. The laboratory experiments only need to add the Earth rotational velocity to both the laboratory frame and the moving frame. The analysis also revealed that the relative velocity calculation was astonishingly close to the common Earth frame calculation. The common Earth frame then becomes the explanation for all experimental types. And it signifies that a gravity field – moving body interaction causes relativistic effects. The experimental record also contained enough data to draft an empirical kinetic theory different than SR. The “no preferred reference frame” of SR is replaced by “there is a preferred reference frame.” And the preferred frame is the nearby Earth gravity field.

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The light clock thought experiment can be shown to yield time contraction results. Consequently, two synchronous light clocks placed inside a space ship in uniform motion can simultaneously yield, from another frame, dilation and contraction of time, respectively. Based on these absurd results, we conclude that time dilation is not real or, at least, the light clock thought experiment cannot be used to infer time dilation. [ABSTRACT FROM AUTHOR]

The general theory of relativity extends the special theory of relativity to account for gravity (acceleration) and results in the postulation that matter curves spacetime, where gravitation is the embodiment of the spacetime curvature. The curvature of spacetime is modeled using Riemannian geometry. In this paper, it is proposed that matter rotates spacetime hyperbolically, rather than curves spacetime. As a result, gravitation is the embodiment of the hyperbolic rotation of spacetime. Regions in spacetime that have a larger magnitude of rotation relative to other regions of spacetime, ceteris paribus, experience stronger gravity, gravitational time dilation, gravitational length contraction, and gravitational frequency shift toward the red (blue) in the electromagnetic waves moving away (toward). [ABSTRACT FROM AUTHOR]

A review of experimental tests of time dilation in special relativity is given, with an emphasis on the recent heavy-ion storage-ring work, currently the most sensitive method. The experimental results are evaluated in the context of the kinematic test theories of Robertson and Mansouri and Sexl, which assume the existence of a preferred inertial reference frame. Prospects for future improvements and the sensitivity of time dilation experiments to Lorentz and CPT violating extensions of the standard model are discussed. [ABSTRACT FROM AUTHOR]

Special relativity is a half-baked theory in which Lorentz transformation only considers the outbound or departing motion where speed and distance change in the same direction. This paper considers the inbound or approaching motion where speed and distance change in the opposite direction. This paper derived a new form of transformation along with the new Lorentz factor, according to which, in addition to well-known time dilation caused by outbound motion, there would be time contraction caused by inbound motion. [ABSTRACT FROM AUTHOR]

Reflected laser light spots on distant targets were observed for 24 h periods by two separate laboratories. Although claims made in one study suggested this was not the case, in fact both data sets indicate no sufficiently significant shift of the centers of the reflected spots on the targets as the earth orbited and revolved during the measurements. This means that photons from the laser sources also travel lateral with the earth and targets so as not to shift the target arrival spot. This demonstrates the phenomenon termed synchronous aberration. The fact that photons do not follow the linear line along the ground between source and target but rather follow a diagonal, from the source at an original position to the target at a later shifted position, means that a stationary outside observer, but not an observer moving with the system, could be aware of the distance traveled to compute time for the event. Time dilation due to motion in special relativity theory is thus disproven, where a moving observer would merely use the ground distance between source and target to compute time incorrectly. Time for a light event is not dependent on motion of an observer that does not control the event, but may be incorrectly computed by an observer in motion. Physics texts must be corrected to avoid this long-held misconception in the future. [ABSTRACT FROM AUTHOR]

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Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, Lorentz-type coordinates' transformations are proposed to connect the coordinates of an accelerating reference frame with the coordinates of a fixed one. Next, these transformations are applied to accelerating frames of constant acceleration. Finally, the Lorentz-type transformations are applied to the twin paradox, in an attempt to describe how the acceleration affects this phenomenon. [ABSTRACT FROM AUTHOR]

We exemplify the role of acceleration in the twin paradox by calculating explicitly the elapsed proper time of each twin, according to each twin. In the limit that the coasting periods are much longer than the accelerating periods for the travelling twin, we find that the accelerating portions of the trajectory is crucial for the calculation of the elapsed proper time of the inertial twin according to the travelling twin, but irrelevant for all other calculations. We point out that the naive symmetry between the two twins is actually explicitly broken as soon as the turn around point is specified in the inertial twins reference frame. [ABSTRACT FROM AUTHOR]

What would the universe be like if we would give up the principle of equivalence and as a consequence incorporate gravity on a more traditional interaction basis within the theory of special relativity? The current work proposes such a gravitational model where a new law of gravitation is expressed in a Lorentz invariant form and is simultaneously in great agreement with many observations (including general relativity). We find the following predictions so far to be consistent with observations: (1) precession formulas explaining, for example, the Mercury apsidal precession, (2) gravitational bending of light near the limb of a massive object, (3) gravitational redshift, (4) escape velocity near a black hole, (5) several relativistic orbit details are derived in the strong field regime and found to be consistent with GR and also the observed shadow of the M87 black hole. Curved space effects such as gravitational time dilation or Shapiro delay cannot be explained within the realms of special relativity (Sect. 3.11). [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The observations of the M87 jet with the STIS instrument mounted on board the Hubble Space Telescope revealed that an outburst originating in the HST-1 knot occurred. Measuring the dimensions of the outburst in the epochs between 2001 July 30 and 2003 July 27 and correcting for optical illusion an expansion velocity v/c = 0.99893 ± 0.00007 is found. However, the relativistic model fails to correctly predict the dimensions of the source and the outburst brightness. For this reason, as the apparent motion suggests, a superluminal mechanical model where even the light rays travel faster than light is introduced. By applying this model to correct for optical illusion an expansion velocity v/c = 21.8 ± 0.7 is found along with reasonable source dimensions and brightness. This result, the study of the apparent motion of features in the M87 jet and the time-of-flight measurements of muonic neutrinos seem to confirm the possibility to travel faster than light. That does not imply a refusal of special relativity. Instead only the common interpretations of it are refused. Without them, we will also see that the so-called twin paradox does not have any reason to exist. [ABSTRACT FROM AUTHOR]

Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is shown that the correct explanation of the synchrotron radiation properties is provided by a combination of the Doppler shift, not dependent on time dilation effects, contrary to a common belief, and of the Lorentz transformation into the particle reference frame of the electromagnetic field of the emission-inducing device, also with no contribution from time dilation. Concluding, the reader is reminded that much, if not all, of our argument has been available since the inception of SR, a research discipline of its own standing. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Concepts from the special theory of relativity are widely held, including time dilation theory, perceived to have experimental confirmation, and believed to have no disproof from wellcontrolled prospective experiments. Demonstrated here is that although relativity for light is special, in being an entity always traveling at fixed speed in the propagation direction from its source coordinate, the notion that time "dilates" for objects in motion was an unfortunate extrapolation: (1) An element is derived, missing from the original analysis, which demonstrates that for bodies in motion, the time required to be illuminated differs compared with that in the absence of motion, but absolute time itself does not "dilate." The times required for a moving rod and for a stationary rod are identically calculated by both an observer in motion and one stationary. (2) Experiments with laser light sources, observed while the earth revolves and orbits and produces variable lateral source velocity, demonstrated that light pulses shift laterally along with the source and target while propagating at speed c to intercept the target. Pulses have a lateral velocity imparted by the orbiting earth, a necessary finding to understand special relativity. Examples are provided that clarify thought experiments commonly presented in Physics texts, and (3) intrinsic properties of light photons, such as self propagation, intrinsic speed, and relative velocity, are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A transverse "Doppler" effect is not by necessity the result of time dilation but may result from light traveling relative to a set. of coordinates apart from the coordinates of the source. [ABSTRACT FROM AUTHOR]

Einstein's own demonstration of time dilation taken from his book with L. Infeld [A. Einstein and L. Infeld, The Evolution of Physics (Cambridge University Press, U.K., 1938)] is analyzed. His ingenious circumnavigation of an apparent discrepancy between clock synchronization and Lorentz transformation is discussed. [ABSTRACT FROM AUTHOR]

In this paper, we endeavour to show that from the noncommutative nature of spacetime one can deduce the concept of relativity, in the sense that velocity cannot be infinite as in the case of Galilean relativity. [ABSTRACT FROM AUTHOR]

The concepts of a time ruler and space ruler are put forward, where the zoom of the space-time ruler provides for an intuitive explanation of the time dilation and length contraction effects associated with theory of relativity. Mass and energy can be regarded as measurements of matter by the time ruler, while momentum can be regarded as a measurement of matter by the space ruler. The space-time ruler can be divided into two kinds according to the causes of its deformation: a relative motion space-time ruler and a gravitational field space-time ruler. It is proved that there is equivalence between these two kinds of rulers under weak field conditions, with this amounting to another expression of the equivalence principle in general relativity. It is pointed out that the two kinds of space-time ruler can be superposed, with the formula for calculating the clock difference between satellites and ground stations being given by this superposition. A GPS satellite is used as an example to calculate clock difference in this way, and the calculation results are in agreement with the classical formula. [ABSTRACT FROM AUTHOR]