The Origin of Gravity

In this document an attempt is made to explain the origin of gravity. The basis for the analysis is a merger of Quantum theory and Relativity. Nowhere in the analysis there is any need to deviate from well proven and successful concepts of both theories and rules of calculation, and no exotic new particles will have to be introduced. By doing so it is demonstrated that, next to its local interactions of a multi-particle system, the Schrödinger equation leads to pairs of two and only two members. This solution is used as the invariant term in the quantized Einstein energy equation which finally leads to gravitational interactions between members of the pairs. With this particular solution for the quantum-mechanical wave function it is found that gravity is a second order effect operating over a long range. In this document it is tried to give a complete and consistent account of all steps that have been taken in de derivation of the classical Newton¿s law. Further the document emphasizes precise justification of some of the basic assumptions made and how it works out on a cosmological scale.