"I am 72, recently retired from a position as Professor of Earth and Planetary Sciences at Washington University in St Louis. I received a BA in Physics at Harvard University and a PhD in Physics from the University of California, Berkeley. I also had a four-year postdoctoral appointment at Cal Tech before accepting a position at Washington University. Along with the Physics I also learned a great deal of Mathematics, of course. At Cal Tech and Washington University my primary research interest w"