A letter written by legendary physicist Albert Einstein in 1928 was sold for 103,700 US dollars at a Jerusalem auction on Tuesday. According to the auction house, Einstein outlined his ideas of the "Third Stage of the Theory of Relativity" in this letter. /VCG Photo

It also included a note on the back of the envelope, refining the physicist's thinking. /VCG Photo

Along with this letter, a note showing his admiration to an Italian woman scientist who had declined to meet him was sold too. /VCG Photo

Written in German, this 1921 note fetched 6,100 US dollars at the auction./VCG Photo