############################################################################# From nstarr@amherst.edu Tue Feb 11 16:34:18 1997 Return-Path: Date: Tue, 11 Feb 1997 16:33:09 -0500 (EST) Subject: Response to rotesque commentary To: nevai@math.ohio-state.edu Dear Paul Nevai, I write regarding the rotesque advice in "Ten Lessons I Wish I Had Been Taught" about which you commented in the latest issue of the AMS Notices. Rota's message was, of course, more suitable for a mature audience. Indeed, his record suggests that he is able to ignore his own advice, when appropriate. For instance, although he recommended not worrying about one's mistakes, I recall a striking instance of the recognition and subsequent remedy of his own error: In the first offering of his course on combinatorial mathematics, which I audited, he made a hash of a lecture. The next lecture it became evident that he was going over the same material, and at first there was resentment at having again to deal with the same subject. But he gave such a magnificent presentation that one almost appreciated the cause for the repetition. Without any explicit acknowledgment of the antecedent, he made clear his understanding of what had happened and his ability to give the type of exposition for which he is so famous. In another direction, Rota's work in analysis (I am more familiar with that than with his work in other fields) did not display the duplication of results that his advice would suggest. He published seminal work in numerous areas, without inappropriate reduplication. (One could argue that in those early years, there was an even greater premium on quantity than is the case for a mature mathematician.) Prominent examples of these publications include: On Models for Linear Operators, Comm. Pure and App. Math., XIII (1960), 469-472; On the Spectra of Singular Boundary Value Problems, J. Math. Mech., 10 (1961), 83-90; Une theorie unifiee des martingales et des moyennes ergodiques, Comptes Rendus (Paris), 252 (1961), 2064-2066; On the eigenvalues of positive operators, Bull. Amer. Math. Soc., 67 (1961), 556- 558; An "alternierende Verfahren" for general positive operators, Bull. Amer. Math. Soc., 68 (1962), 92-102; etc. (One of my favorites is his paper on averaging operators, which appeared in Rendiconti del Seminario Matematico dell'Universita di Padova in 1960. Scarcely a widely found resource.) These were and remain to this day catalysts for many other mathematicians - Rota didn't mine out his own fields. He intended to pursue suggestive avenues illuminated by brief notes such as those just cited, and even tried to find time and collaborators for a book on positive operators. However, I suspect his fertile imagination exposed too many exciting new areas to allow time to harvest the old ones. Third, though my analogy is off the mark, I doubt that those many souls who have been skewered by his epigrammatic book reviews will view Rota as a glad-hander. I must add that the most valuable pedagogical lesson I learned from Gian-Carlo was to let class out just a tad early. Run overtime and the audience frets; finish with some time to spare and they feel as though a gift has been bestowed. (I couple this with starting on time, without regard for latecomers.) So there is my own view of some historical connections to the correctives you have contributed to the Notices. Sincerely, Norton Starr Amherst College #############################################################################