An attempt to answer the question " Can we observe galaxies that recede faster than light " led to a re-examination of the notions of time, distance, velocity and redshift as they occur in newtonian physics, special relativity, general relativity and cosmol-ogy. A number of misconceptions were uncovered. It was found that, once freed of preconceptions of special relativity the above question is...

Year 2010 marks the 100-th anniversary since the paper by Ignatowsky was published that was devoted to the axiomatic analysis of the special theory of relativity. Despite such a long history, the ideas put forward by Ignatowsky, and later developed by Franck and Rothe, still have not earned a proper place in the physical curriculum. As a celebration of this jubilee, we would like to draw the at...

Einstein’s special theory of relativity postulates that the speed of light is a constant for all inertial observers. This postulate can be used to derive the Lorenz transformations relating length and time measurements by different observers. In this paper it is shown that the Lorentz transformations can be obtained for any type of wave simply by defining distance to be proportional to wave pro...

We investigate how deformations of special relativity in momentum space can be extended to position space in a consistent way, such that the dimensionless contraction between wave-vector and coordinate-vector remains invariant. By using a parametrization in terms of an energy dependent speed of light, and an energy dependent Planck’s constant, we are able to formulate simple requirements that c...

In this paper, the relation between the modified Lorenz boosts, proposed in the doubly relativity theories and a linear combination of Conformal Group generators in R1,d−1 is investigated. The introduction of a new generator is proposed in order to deform the Conformal Group to achieve the connection conjectured. The new generator is obtained trough a formal dimensional reduction from a free ma...

Nature succeeds in accelerating extended and massive objects to relativistic velocities. Jets in Active Galactic Nuclei and in galactic superluminal sources and gamma–ray bursts fireballs have bulk Lorentz factors from a few to several hundreds. A variety of effects then arises, such as the beaming of the produced radiation, light aberration, time contraction and the Doppler frequency shift. I ...

It is then easy to derive the well-known Lorentz transformation equations, those equations which allow us to convert between events measured in one frame to those measured in the other. Two observers in different frames may not measure the same events at the same place or time, but they must agree on all of the laws of physics regarding those events in order for the principle of relativity to h...

Historians of science have published many studies of the reception of Einstein’s special and general theories of relativity. Based on a review of these studies, and my own research on the role of the light-bending prediction in the reception of general relativity, I discuss the role of three kinds of reasons for accepting relativity: (1) empirical predictions and explanations; (2) social-psycho...

Newtonian gravity and special relativity combine to produce a gravitomagnetic precession of an orbiting gyroscope that is one fourth as large as predicted by General Relativity. The geodetic effect is the same in both cases.