Born in Frankfurt am Main into a wealthy Jewish family. Showed exceptional abilities: published his first scientific paper at the age of 16. Studied at the Universities of Munich and Strasbourg. Was director of the Potsdam Astrophysical Observatory. At the outbreak of World War I, he volunteered for the front. While in active service, he received the new theory from Einstein and within a few days derived his famous solution, sending it by letter. Soon died of pemphigus. Einstein presented his work to the Prussian Academy of Sciences, calling it outstanding.