To the Caltech community, As many of you know, one of our own—Nobel Laureate Ahmed Zewail—has been in Cairo for the past two weeks. In a phone conversation I had with Ahmed this weekend, he said, "It is exhilarating to be part of this historic transition, to watch the emotions and joy of the Egyptian people, and to be able to give back in any way I can; it is a defining experience in one's lifetime."