"It was typical of Lindemann's mind to bring together ideas in this way from different branches of physics in an order-of-magnitude calculation. His mind was extraordinarily lively, and he also had an unusually wide knowledge of physics, including astronomy, and what is now called geophysics. He had a gift for picking out the essentials in a piece of physics, even if sometimes he went too far in ignoring the aspects of secondary importance. He was a most stimulating conversationalist on matters of physics, and one went away from a session with him feeling that he had rearranged all one's mental furniture and added one or two rather bizarre objects to the room."