On a modified-Lorentz-transformation based gravity model confirming basic GRT experiments

Implementing Poincar\'e's `geometric conventionalism' a scalar Lorentz-covariant gravity model is obtained based on gravitationally modified Lorentz transformations (or GMLT). The modification essentially consists of an appropriate space-time and momentum-energy scaling ("normalization") relative to a nondynamical flat background geometry according to an isotropic, nonsingular gravitational `affecting' function Phi(r). Elimination of the gravitationally `unaffected' S_0 perspective by local composition of space-time GMLT recovers the local Minkowskian metric and thus preserves the invariance of the locally observed velocity of light. The associated energy-momentum GMLT provides a covariant Hamiltonian description for test particles and photons which, in a static gravitational field configuration, endorses the four `basic' experiments for testing General Relativity Theory: gravitational i) deflection of light, ii) precession of perihelia, iii) delay of radar echo, iv) shift of spectral lines. The model recovers the Lagrangian of the Lorentz-Poincar\'e gravity model by Torgny Sj\"odin and integrates elements of the precursor gravitational theories, with spatially Variable Speed of Light (VSL) by Einstein and Abraham, and gravitationally variable mass by Nordstr\"om.Comment: v1: 14 pages, extended version of conf. paper PIRT VIII, London, 2002. v2: section added on effective tensorial rank, references added, appendix added, WEP issue deleted, abstract and other parts rewritten, same results (to appear in Found. Phys.

Towards a quantum universe

In this short review we study the state of the art of the great problems in cosmology and their interrelationships. The reconciliation of these problems passes undoubtedly through the idea of a quantum universe.Comment: 7 pages, Accepted for publication in Astrophysics & Space Scienc

Atoms and the universe: an account of modern view on the structure of matter and the universe

+254hlm.;22c

Times, theories and practices in social psychology.

This paper begins by problematizing the `taken for granted' status of Newtonian linear time at the heart of (social) psychology. Borrowing from Adam, the paper makes a distinction between an `events in time' and `time in events' approach to social psychology. It argues that a `time in events' approach helps to reveal the importance of multiple times for social psychological theories and practices. To demonstrate this approach, it considers some of the multiple times that are relevant for analysing the concept of `identity'. It also explores the multiple times of the research encounter. In doing so, it suggests that traditional dichotomies in social psychology between synchronic and diachronic methods, and between experimental and qualitative methods, can be dissolved by this focus on the temporal. The paper concludes with some observations about the importance of time for thinking about social psychology as a knowledge-producing practice