Wheeler, whose back is to the camera, is drawing a diagram during one of his physics courses at Princeton.

Wheeler, standing in front of the blackboard, is admiring his diagram of black holes during a Princeton physics class.

Wheeler, standing in front of a blackboard, is teaching his Princeton students about black holes.

Wheeler is teaching a course in physics at Princeton. He is standing in front of a blackboard.

Wheeler is teaching a course in physics at Princeton. He is looking pensively at the blackboard.

Wheeler is starting to draw his diagram of the formation of the universe during a Princeton physics class.

Wheeler is advising an unidentified Princeton student.

Wheeler is advising an unidentified Princeton student in an office that is extraordinary for its untidiness.

Wheeler is adding to his elaborate diagram of black holes and the creation of the universe during a Princeton class.

Wheeler and his students at Princeton are working out a problem on the blackboard.