John A. Wheeler, a witness of 20th century physics, died at the age of 97 on April 13 2008. His career spanned most of 20th century physics, from the early days of 1930s, when he worked with Niels Bohr on nuclear fission theory, through 1940s, when he  worked with his student Richard Feynman on half retarded and half advanced formulation of electrodynamics, and worked on atomic bombs, and 1950s, when he worked on weak interaction, gravitation and foundations of quantum theory, and 1960s, when he coined the name black hole, to later days, when he became more and more poetic and inspiring. I do not need to list his numerous contributions.

在我印象里，惠勒七八十年代来过中国，好像中国科大的一位天体物理学家就此写过介绍文章。一次看封神演义的戏剧，看到姜子牙旗子上的“无”，大为惊叹。惠勒晚年的风格有点禅宗的味道。