File:Einstein en Lorentz.jpg

Albert Einstein and Hendrik Antoon Lorentz, photographed by Ehrenfest (1880-1933) in front of his home in Leiden in 1921. Source: Museum Boerhaave, Leiden http://www.museumboerhaave.nl/contact/pers2a.html http://www.museumboerhaave.nl/contact/persfotos_einstein/Einstein_en_Lorentz.jpg