AbstractGravity – Galileo to Einstein and Back starts with a revision of the fundamentals of the theory of dynamics and gravitation. The object is to present a relativistic theory of gravitation which is an extension of the Special Theory of Relativity. The new approach to gravitomagnetics now expresses the relative acceleration in terms of the relative velocity in addition to relative separation. This produces results for the precession of the perihelion of Mercury and for the deflection of light grazing the Sun which are identical to those given by the General Theory of Relativity. Both of these were hailed as justifications of the general theory. When the new theory is applied to the motion of groups of particles or the rotation of solid bodies the results differ slightly from published papers but not all of these results are conclusive.
In order to explain the new approach it is necessary to re-examine Newtonian dynamics and special relativity. Certain aspects are better seen if force is treated as a defined quantity rather than a primary one. This idea is not new: it was the view of d'Alembert and especially H R Hertz. One result is that the principle of equivalence, in its weak form, does not arise, yet this is stated to be one of the foundations of general relativity. Curved space time may be regarded as just another invention to replace the invention of force. Neither are needed but are very useful concepts, as is money to commerce.
In this revised edition, an extra term has been added to the basic equation which is in the direction of the relative velocity and is a function of the radial velocity. This affects the speed of light. The new equation generates the accepted value for the Last Stable Orbit and agrees with the measured results of the Shapiro Time Delay. As it is a function of the fourth power of the relative velocity, it has a minimal effect on solar orbits.