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We present multiepoch spectra of 13 high-redshift Type Ia supernovae (SNe Ia) drawn from the literature, the ESSENCE and SNLS projects, and our own separate dedicated program on the ESO Very Large Telescope. We use the Supernova Identification (SNID) code of Blondin & Tonry to determine the spectral ages in the supernova rest frame. Comparison with the observed elapsed time yields an apparent aging rate consistent with the 1/(1+z) factor (where z is the redshift) expected in a homogeneous, isotropic, expanding universe. These measurements thus confirm the expansion hypothesis, while unambiguously excluding models that predict no time dilation, such as Zwicky's "tired light" hypothesis. We also test for power-law dependencies of the aging rate on redshift. The best-fit exponent for these models is consistent with the expected 1/(1+z) factor., Comment: 14 pages (emulateapj), 10 figures; accepted for publication in ApJ. Version with full-resolution figures available at http://www.cfa.harvard.edu/~sblondin/publications/timedilation/

The principle of invariance of the velocity of light is only valid for the wrong measurements of inertial observers who ignore their own movement and consider themselves at rest. The Langevin (or clock) paradox arises when it is assumed that the real velocity (and not only the wrong measured velocity) of light in free space can be the same for different observers. Nevertheless, it is generally assumed as true such incoherent assumption that leads to the paradox. To clarify the issue is of great interest to analyse the physics underlying the phenomenon of time dilation (which is not only the result of a mathematical formula) and this has been done in this work. The exact value of light dragging coefficient is also derived., Comment: 7 pages, 6 figures

In this paper, the modern theory of infinitesimals is applied to the General Relativity metric dS and its geometric and physical meanings are rigorously investigated. Employing results obtained via the time-dependent Schrodinger equation, gravitational time-dilation expressions are obtained and are shown to be caused by gravitationally altered photon interactions with atomic structures., Comment: 20 pages

The measurements of the absolute magnitudes and redshifts of supernovas Ia show that conventional physics, which includes plasma redshift, fully explains the observed magnitude-redshift relation of the supernovas. The only parameter that is required is the Hubble constant, which in principle can be measured independently. The contemporary theory of the expansion of the universe (Big Bang) requires in addition to the Hubble constant several adjustable parameters, such as an initial explosion, the dark matter parameter, and a time adjustable dark energy parameter for explaining the supernova Ia data. The contemporary Big Bang theory also requires time dilation of distant events as an inherent premise. The contention is usually that the light curves of distant supernovas show or even prove the time dilation. In the present article, we challenge this assertion. We document and show that the previously reported data in fact indicate that there is no time dilation. The data reported by Riess et al. in the Astrophysical Journal in June 2004 confirm the plasma redshift, the absence of time dilation, dark matter, and dark energy., Comment: 7 pages, 1 figure

We present a simple derivation of the Lorentz transformations for the space-time coordinates of the same event. It is based on the relative character of length and time interval as measured by observes in relative motion. We begin by accepting that the relative motion modifies in some particular way the result of these measurements. However we do not postulate the character of this distortion i.e. whatever it is dilation or contraction. The formulas accounting for length contraction, time dilation and Doppler shift are a byproduct of this derivation., Comment: vers. Nov. 2007, 9 pages, 2 figures

The fluxon dynamics in a long Josephson junction with a ferromagnetic insulating layer is investigated. It is found that the Josephson phase obeys a double sine-Gordon equation involving a bound pi fluxon solution, and the internal oscillations of the bound pair acting as a clock exhibit Lorentz reductions in their frequencies regarded as a relativistic effect in the time domain, i.e., time dilation. This is the complement to the Lorentz contraction of fluxons with no clock. A possible observation scheme is also discussed., Comment: 4 pages, 5 figures, to appear in Physical Review Letters

An interpretation of the inertial mass increase due to an object's velocity which is derived from the theory of special relativity is discussed. A Lorentz transformation of the reference time causes the inertial mass increase. It is assumed that the real physical phenomenon that occurs is an expansion of the reference time by a Lorentz transformation (that is, a dilation of time). Only the reference time is assumed to be variant, which causes relativistic mass. Time dilation is real. Relativistic mass originates in a Lorentz transformation of reference time., Comment: 16 pages, 10 figures

We consider a scenario that involves a machine gun, the bullets it fires and a moving target, considered from the rest frame of the machine gun and from the rest frame of the target respectively. Involving the special relativity via its two postulates and the time dilation formula we derive the relativistic velocity addition law showing that it leads to the Lorentz transformations for the space-time coordinates of the same event., Comment: 6 pages, 1 figure

Using only a thought experiment and Einstein's correspondence principal, a model is derived that correctly predicts the Schwarzschild time dilation expression in limiting cases. The method requires almost no prerequisite knowledge from the student and is carried out with only algebraic techniques, allowing the introduction of a mathematical example of general relativity to introductory physics students., Comment: 5 pages, two figures

We have previously shown that the type Ia supernovae data by Riess et al. match the prediction of the magnitude-redshift relation in the plasma-redshift cosmology. In this article, we also show that the recent SNLS data, which have a slightly narrower distribution as reported by Astier et al. in 2005, match the predictions of the plasma-redshift cosmology. The standard deviation of the SNLS-magnitude from the predicted curve is only about 0.14. The data indicate that there is no cosmic time dilation. The big-bang cosmology therefore appears false. The plasma redshift, which follows from exact evaluation of photons interaction with hot sparse electron plasma, leads to a quasi-static, infinite, and everlasting universe. It does not need big bang, dark energy, or dark matter for describing the observations. It predicts intrinsic redshifts of galaxies consistent with what is observed. The Hubble constant that best fits the SNLS data is about 63 km per sec per Mpc. This corresponds to an average electron density of about 0.0002 per cubic centimeter in intergalactic space. This density together with the plasma redshift heating to an average plasma temperature in intergalactic space of about 3 million K explains the observed isotropic cosmic microwave background (CMB) and the cosmic X-ray background., Comment: 8 pages, 4 figures, presented at APS April 2006 meeting

We describe a compact apparatus that automatically measures the charge averaged lifetime of atmospheric muons in plastic scintillator using low-cost, low-power electronics and that measures the stopping rate of atmospheric muons as a function of altitude to demonstrate relativistic time dilation. The apparatus is designed for the advanced undergraduate physics laboratory and is suitable for field measurements., Comment: 5 pages, 2 figures

We study the power density spectrum (PDS) of light curves of the observed gamma-ray bursts (GRBs) to search for a direct signature for cosmological time dilation in the PDS statistics with the GRBs whose redshifts $z$'s are known. The anticorrelation of a timescale measure and a brightness measure is indirect evidence of its effect. On the other hand, we directly demonstrate that a time dilation effect can be seen in GRB light curves. We find that timescales tend to be shorter in bursts with small redshift, as expected from cosmological time-dilation effects, and we also find that there may be non-cosmological effects constituting to this correlation. We discuss its implication on interpretations of the PDS analysis results. We put forward another caution to this kind of analysis when we statistically exercise with GRBs whose $z$ is unknown., Comment: 12 pages, 2 figures, 2 tables, accepted to ApJL

The timescale of quasar variability is widely expected to show the effects of time dilation. In this paper we analyse the Fourier power spectra of a large sample of quasar light curves to look for such an effect. We find that the timescale of quasar variation does not increase with redshift as required by time dilation. Possible explanations of this result all conflict with widely held consensus in the scientific community., Comment: 6 pages including 3 figures. Accepted for publication in ApJ Letters

We present results of Moessbauer experiment in a rotating system, which is induced by our recent disclosure (Phys. Scr., 77 (2008) 035302) and which consisted in the fact that a correct processing of Kundig experiment data on the subject gives an appreciable deviation of a relative energy shift dE/E between emission and absorption resonant lines from the standard prediction based on the relativistic dilation of time (that is dE/E=-v2/2c2 to the accuracy c-2, where v is the tangential velocity of absorber of resonant radiation, and c is the light velocity in vacuum). Namely, the Kundig result following the correction we brought to it, is dE/E=-(0.596+/-0.006)v2/c2. In our own experiment we carried out measurements for two absorbers with substantially different isomer shift, which allowed us to make a correction of Moessbauer data to a level of vibrations in the rotor system at various rotational frequencies. As a result we got the estimation dE/E=-(0.68+/-0.03)v2/c2. A deviation from the relativistic formula is discussed., Comment: 17 pages, 10 figures, submitted into Phys. Rev. Lett

Experimental tests on `time dilation' began in 1938 with Ives and Stilwell's work of the transverse Doppler effect due to atoms in inertial flight. Rossi and Hall (1941) inaugurated the era of fast moving elementary particles that dominated the scene until the discovery of the Mossbauer effect (1957). This discovery suggested the use of photons emitted without recoil in crystalline solids for testing both time dilation and gravitational red shift. Finally, around 1970, Hafele and Keating dealt again with time dilation by sending macroscopic atomic clocks around the Earth. The interpretations of these experiments by experimenters have been characterized by the use of additional hypotheses not necessary for the formal development of the theories under test (the idea that all clocks measure proper time) or hypotheses completely extraneous to the theories themselves (the idea that atoms are clocks). If these assumptions are dropped, it turns out that the only experiments concerning time dilation are those performed with elementary particles in inertial flight. The historical and epistemological implications are discussed., Comment: This paper has been withdrawn by the authors due to wrong treatments of some topics

The time profiles of many gamma-ray bursts consist of distinct pulses, which offers the possibility of characterizing the temporal structure of these bursts using a relatively small set of pulse shape parameters. We have used a pulse decomposition procedure to analyze the Time-to-Spill (TTS) data for all bursts observed by BATSE up through trigger number 2000, in all energy channels for which TTS data is available. We obtain amplitude, rise and decay timescales, a pulse shape parameter, and the fluences of individual pulses in all of the bursts. We investigate the correlations between brightness measures (amplitude and fluence) and timescale measures (pulse width and separation) which may result from cosmological time dilation of bursts, or from intrinsic properties of burst sources or from selection effects. The effects of selection biases are evaluated through simulations. The correlations between these parameters among pulses within individual bursts give a measure of the intrinsic effects while the correlations among bursts could result both from intrinsic and cosmological effects. We find that timescales tend to be shorter in bursts with higher peak fluxes, as expected from cosmological time dilation effects, but also find that there are non-cosmological effects contributing to this inverse correlation. We find that timescales tend to be longer in bursts with higher total fluences, contrary to what is expected from cosmological effects. We also find that peak fluxes and total fluences of bursts are uncorrelated, indicating that they cannot both be good distance indicators for bursts., Comment: 39 pages, 17 figures composed of 30 EPS files. Submitted to Astrophysical Journal. PostScript and PDF with un-bitmapped figures available at http://www.slac.stanford.edu/pubs/slacpubs/8000/slac-pub-8365.html . Accompanies astro-ph/0002217

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 favour of an absolute present, which means simultaneous events are simultaneous in all inertial frames, and subscribe to evolution of future from the present., Comment: typo corrected in Appendix B

Assuming a model of aether non-entrained by the motion of celestial bodies, one can provide a rational explanation of the experimental processes affecting the measurement of time when clocks are in motion. Contrary to special relativity, aether theory does not assume that the time itself is affected by motion; the reading displayed by the moving clocks results from two facts: 1/ Due to their movement through the aether, they tick at a slower rate than in the aether frame. 2/ The usual synchronization procedures generate a synchronism discrepancy effect. These facts give rise to an alteration of the measurement of time which, as we shall show, exactly explains the experimental results. In particular, they enable to solve an apparent paradox that special relativity cannot explain (see chapter 4). When the measurement distortions are corrected, the time proves to be the same in all co-ordinate systems moving away from one another with rectilinear uniform motion. These considerations strongly support the existence of a privileged aether frame. The consequences concern special relativity (SR) as well as general relativity (GR) which is an extension of SR. We should note that Einstein himself became conscious of the necessity of the aether from 1916, in contrast with conventional relativity. Yet the model of aether presented here differs from Einsein in that it assumes the existence of an aether drift, in agreement with the discoveries of G.F. Smoot and his co-workers listed in Smoot Nobel Lecture, December 8th 2006. Although it makes reference to previous studies, this text remains self-sufficient., Comment: PDF, 15 pages, 3 figures, Version supplemented by additional information and another chapter (Resolution of a paradox). Contribution to the book Ether space-time and cosmology, Volume 2, Michael C. Duffy and Joseph Levy Editors, to be published

We discuss the emergence of time dilation as a normal feature expected of any system where a central processor may have to wait one or more clock cycles before concluding a local calculation. We show how the process of causal implication in a typical Newtonian cellular automaton leads naturally to Lorentz transformations and invariant causal structure., Comment: 11 pages, 1 eps figure. Second replacement amends the diagram

We perform several nonparametric correlation tests on the BATSE 3B data to search for evidence of cosmological time dilation. These tests account for the effects of data truncation due to threshold effects in both limiting brightness and limiting duration, enabling us to utilize a larger number of bursts than in previous analyses. We find little significant evidence for correlation between various measures of peak intensity and duration, but the tests cannot conclusively rule out time dilation factors of 2 or less without more data. There is stronger evidence for a positive correlation between fluence and duration, which if confirmed would rule out simple no-evolution cosmological models unless there is a strong intrinsic correlation between the total radiant energy and the duration of bursts., Comment: 21 pages, 5 Postscript figures, uses aaspp4.sty and psfig.sty, to appear in ApJ volume 474. Paper also available at http://www-bigbang.stanford.edu/~ted/paper5.html

We investigate whether a simple cosmology can fit GRB results in both time dilation and Log N - Log P simultaneously. Simplifying assumptions include: all GRBs are spectrally identical to BATSE trigger 143, $\Omega=1$ universe, and no luminosity and number density evolution. Observational data used includes: the BATSE 3B peak brightness distribution (64-ms time scale), the Pioneer Venus Orbiter (PVO) brightness distribution, and the Norris et al. time dilation results for peak aligned profiles presented at this meeting. We find acceptable cosmological fits to the brightness distributions when placing BATSE trigger 143 at a redshift of 0.15 $\pm$ 0.10. This translates into a $(1 + z_{dim}) / (1 + z_{bright})$ factor of about 1.50 $\pm$ 0.50 between selected brightness extremes of the Norris et al. sample. Norris et al. estimate, however, that $(1 + z_{dim}) / (1 + z_{bright})$ $\approx$ 2.0 $\pm$ 0.5 when considering duration tests. The difference is marginal and could be accounted for by evolution. We therefore find that evolution of GRBs is preferred but not demanded., Comment: 5 pages in LATeX, REVTEX style, 2 embedded figures. To appear in Third Huntsville Symposium on Gamma Ray Bursts Proceedings

If $\gamma$-ray bursts are at cosmological distances, then not only their constituent pulses but also the intervals between pulses should be time-dilated. Unlike time-dilation measures of pulse emission, intervals would appear to require negligible correction for redshift of narrower temporal structure from higher energy into the band of observation. However, stretching of pulse intervals is inherently difficult to measure without incurring a timescale-dependent bias since, as time profiles are stretched, more structure can appear near the limit of resolution. This problem is compounded in dimmer bursts because identification of significant structures becomes more problematic. We attempt to minimize brightness bias by equalizing signal-to-noise (s/n) level of all bursts. We analyze wavelet-denoised burst profiles binned to several resolutions, identifying significant fluctuations between pulse structures and interjacent valleys. When bursts are ranked by peak flux, an interval time-dilation signature is evident, but its magnitude and significance are dependent upon temporal resolution and s/n level., Comment: 5 pages in LATeX, REVTEX style, 2 embedded figures. To appear in Third Huntsville GRB Workshop Proceedings

Two tests for cosmological time dilation in $\gamma$-ray bursts -- the peak alignment and auto-correlation statistics -- involve averaging information near the times of peak intensity. Both tests require width corrections, assuming cosmological origin for bursts, since narrower temporal structure from higher energy would be redshifted into the band of observation, and since intervals between pulse structures are included in the averaging procedures. We analyze long ($>$ 2 s) BATSE bursts and estimate total width corrections for trial time-dilation factors (TDF = [1+$z_{\rm dim}$]/[1+$z_{\rm brt}$]) by time-dilating and redshifting bright bursts. Both tests reveal significant trends of increasing TDF with decreasing peak flux, but neither provides sufficient discriminatory power to distinguish between actual TDFs in the range 2--3., Comment: 5 pages in LATeX, REVTEX style, 2 embedded figures. To appear in Third Huntsville GRB Workshop Proceedings