Hod claimed to have a method to deal with a simplified two-body problem. The basic error of Hod and the previous researchers is that they failed to see that in general relativity there is no bounded dynamic solution for a two-body problem. A common error is that the linearized equation is considered as always providing a valid approximation in mathematics. However, validity of the linearization is proven only for the static and the stable cases when the gravitational wave is not involved. In a dynamic problem when gravitational wave is involved, since it is proven in 1995 that there is no bounded dynamic solution, the process of linearization is not valid in mathematics. This is the difference between Einstein and Gullstrand who suspected that a dynamic solution does not exist. In fact, for the dynamic case, the Einstein equation and the linearized equation are essentially independent equations, and the perturbation approach is not valid. Note that the linearized equation is a linearization of the Lorentz-Levi-Einstein equation, which has bounded dynamic solutions but not the Einstein equation, which has no bounded dynamic solution. Because of inadequacy in non-linear mathematics, many had made errors without knowing them
