摘要：What is a presidential address? From those I have attended in the past, addresses seem to fall into two general categories: an address is either a description of the president’s science and its significance and implications, or it presents wisdom and expe- rience on some topic of broader import, such as the need to volunteer, or the importance of geology in the modern world. While I find my own science supremely fascinating, I suspect- ed that more than a few of you might not want to hear a 50- minute exposition on fossil jellyfish; I have thus chosen the second approach.
