Then, four years later, Dr Hubble noticed that the light coming from these distant galaxies was shifted a little towards the red end of the spectrum, in what he dubbed “red shift”.
This indicated that galaxies were moving away from us.
In the face of Dr Hubble’s evidence, Einstein was forced to abandon his idea of a force of cosmic repulsion, calling it the “biggest blunder” he had ever made.
However, what Einstein dubbed to have been his biggest mistake, was later proved to have actually been one of his most impressive finds.