TED for the rest of us.\nThe main purpose of the project Videolectures.Net is to provide free and open access of a high quality video lectures presented by distinguished scholars and scientists at the most important and prominent events like conferences, summer schools, workshops and science promotional events from many fields of Science. The portal is aimed at promoting science, exchanging ideas and fostering knowledge sharing by providing high quality didactic contents not only to a scientific community but also to a general public. All lectures, accompanying documents, information and links are systematically selected and classified through the editorial process taking into account also users' comments.
IN 1999, legendary theoretical physicist Hans Bethe delivered three lectures on quantum theory to his neighbors at the Kendal of Ithaca retirement community (near Cornell University). Given by Professor Bethe at age 93, the lectures are presented here as