ERICH KRETTSCHMANN'S ATTACK ON EINTEIN'S THEORY OF GENERAL RELATIVITY (GENERAL COVARIANCE FORM)

After the death of ether theories once relativity theories came to the forefront it was clear that there was no special reference frame. Hence all physics should be the same in all reference frames. Einstein formulated his equations and thru covariant transformation of tensors showed that his equations were valid for all reference frames. Einstein thought that was the greatest achievement of his theory. But Erich Krettscmann showed that general covariance can be achieved for any theory. Einstein argued it cannot be achieved for Newton's theory. But Einstein was proven wrong by others who showed that general covariance can be achieved for Newton's theory as well. Einstein also maintained that any theory may not be compatible with observations. He was correct on that issue. But Krettssschman was correct that achieving general covariance does not make the theory better.