An up-to-date description of progress and current problems with the gravitational constant, both in terms of generalized gravitational theories and experiments either in the laboratory, using Casimir force measurements, or in space at solar system distances and in cosmological observations.
Contributions cover different aspects of the state and prediction of unified theories of the physical interactions including gravitation as a cardinal link, the role of experimental gravitation and observational cosmology in discriminating between them, the problem of the precise measurement and stability of fundamental physical constants in space and time, and the gravitational constant in particular.
Recent advances discussed include unified and scalar-tensor theories, theories in diverse dimensions and their observational windows, gravitational experiments in space, rotational and torsional effects in gravity, basic problems in cosmology, early universe as an arena for testing unified models, and big bang nucleosynthesis.

Inhalt
Screening and Absorption of Gravitation in Pre-Relativistic and Relativistic Theories.- Conformal Frames and D-Dimensional Gravity.- Graviton Exchange and the Gravitational Constant.- Some base for Quantum Gravity.- Brane-inspired models in Gravitation and Cosmology.- Experimental test of a Time-Temperature formulation of the Uncertainty Principle.- The Newtonian Gravitational Constant: Present Status and Directions for future Research.- Toward testing the Fundamental physics by SNIa data.- Investigation of Schmutzer's Exact External spherically Symmetric Static solution for a Central Body within the framework of the 5-Dimensional Projective Unified Field theory.- On exact solutions in Multidimensional Gravity with antisymmetric forms.- 5D Gravity and the discrepant G measurements.- 2-component cosmological models with perfect fluid and scalar field: exact solutions.- Constraints on Non-Newtonian Gravity from recent Casimir Force measurements.- Searching for Scalar-Tensor Gravity with Lunar Laser Ranging.- Is a hypothetical Long Range Spin Interaction Observable with a Laboratory Detector?.- Prospects for a Space-Based determination of G with an error below 1PPM.- Projective Unified Field Theory revisited and adapted to the new measured values (WMAP). New results refer to approximate static interior and exterior solution of a spherically symmetric perfect fluid sphere with applications to celestial bodies, Einstein effects with particular treatment of the perihelion shift of Mercury including the quadrupole moment of the sun.- The Interface of Quantum Mechanics and Gravity.- Quaternionic Program.