The standard phenomenological model for the interaction for ionising radiation with matter, originally formulated by Bethe and widely used to calculate the transfer of energy, can also be used to model the quantum exchange processes that mediate forces. Such models are shown to be compatible with Newtonian gravitation and with the principle of weak equivalence. The gravitational constant G (kg –1 m3 s –2) can be related to Planck’s constant h, the speed of light c, the atomic mass unit u, and a dimensionless coupling constant ag. The applications and implications of the derived formulation will be examined. This formulation for G gives a new interpretation of Planck quantities, and a prediction emerges for experimental values of G to increase with increasing temperature of the attracting mass. Finally, gravitational shielding is predicted to occur but at vanishingly small proportions both in the laboratory and in the cosmos.
* M J Clark is at the National Radiological Protection Board, Chilton, Didcot, OX11 0RQ, UK (e-mail email@example.com).