Erwin Finlay-Freundlich

Erwin Finlay-Freundlich FRSE FRAS (German: [ˈfʀɔɪntlɪç]; 29 May 1885 – 24 July 1964) was a German astronomer, a pupil of Felix Klein. Freundlich was a working associate of Albert Einstein and introduced experiments for which the general theory of relativity could be tested by astronomical observations based on the gravitational redshift.