History question: I searched all over the web and cannot find the answer. I knew that Albert Einstein earned his phd from university of zurich. from wiki: In 1900, Einstein was awarded the Zürich Polytechnic teaching diploma. (Between 1900 to 4/30/1905, I deduced that Einstein was unemployed and working for jobs like clerk.) On 30 April 1905, Einstein completed his thesis, with Alfred Kleiner, Professor of Experimental Physics, serving as pro-forma advisor. Einstein was awarded a PhD by the University of Zürich. (Therefore, I am curious of how he could complete a PhD when he was unemployed and working full time in 5 years) It would be great if you could provide me with historical writings in this aspect. Thank you very much.