Problem solutions in area of diffraction and of scattering theory are considered from one point of view. The method common for them is based on approximate orthogonality of solution constituents, which oscillate on a body long frontier. Method potentiality is discussed.
The answer has been obtained for the A. Einstein question - How do body shapes change at acceleration? The metric has been found of uniformly accelerated system. The gravity field equation was established and its solution example was given.
