1985 Timoshenko Medal Lecture by Eli Sternberg
Rumination of a Reclusive Elastician
By Eli Sternberg
Delivered at the Applied Mechanics Dinner of the 1985 Annual ASME Meeting in Miami Beach, Florida
Ladies and Gentlemen: As you know, medals - much like arthritis - are a common symptom of advancing years. Be this as it may, I am grateful for the recognition implied by this award.
Every medal has a proverbial reverse side. The reverse side of the Timoshenko Medal is the requirement that the recipient must make a speech. In view of my lifelong allergy to after-dinner speeches, the thought of having to give one has been rather unsettling. To make matters worse, I was asked over two months ago to submit a title for my talk.
Since a technical topic seemed inappropriate for the occasion, I tried hard to think of a suitably broad and vacuous subject: something with a sexy title, like "Applied Mechanics - Past, Present, and Future." I abandoned this idea, first, because I always feel a little uneasy in making pronouncements about the future of anything and, second, because I am not sure I know what is meant by "Applied Mechanics".
I had been in a similar quandary as to the meaning of "Applied Mathematics" until a good many years ago, when Lester Ford, who was then chairman of the mathematics department at the Illinois Institute of Technology, called me into his office to show me a letter he had just received from an inmate of Alcatraz Prison. It read: "Dear Professor Ford, I am serving a life sentence at Alcatraz and am studying calculus on my own. I don't know how to solve Problem No. 3 on p. 275 of the calculus book by Granville, Smith, and Longley. Can you help me?" I allowed that this was an amusing letter, at which point Professor Ford handed me a copy of the book. Problem No. 3 on p. 275 started with the sentence: "A tunnel is to be drilled." If this isn't Applied Mathematics, what is?
Anyway, under duress to supply a title for this talk well in advance, I attempted to concoct one sufficiently noncommittal to permit me to hold forth on just about anything that might eventually come to my mind. I think you will agree that I succeeded admirably in choosing such a title.
Having spent all of my professional life in mechanics at academia, I finally decided to take advantage of a predominantly academic, captive audience and dwell on certain developments that have detracted from my favorite environment. Although some of what I intend to say applies to the contemporary academic scene in general, a more communicative heading for my remarks this evening might be: "Mechanics - an Apprehensive View from the Ivory Tower."
To begin with, there is the undeniable observation that mechanics, as an independent academic discipline, has suffered worrisome setbacks during the past twenty years or so. This fact is reflected in the demise of several mechanics departments at major American universities, the erosion of existing mechanics faculties, and the decline of the student population in mechanics. There are various and diverse reasons for this trend. Among them is the not uncommon perception of mechanics as an essentially stagnant field. After all, some of my physicist friends still regard the discovery of Hooke's law in the seventeenth century as the last noteworthy event in the history of the theory of elasticity.
Another, related circumstance is the need to cultivate important emerging disciplines. Given the financial limitations on university budget, as well as the inevitable time constraints on academic curricula, engineering schools are apt to look for compensatory cutbacks in traditional activities and at times see in mechanics a natural victim of such efforts toward modernization.
As far as the furtherance of computer science is concerned - and here I speak out of the richest store of ignorance conceivable - no one would earnestly question the enormous value of computing to applied mechanics and indeed to all of applied science. Yet computing without a proper theoretical background can be hazardous to the public health. Thus there are grounds to worry about the rising traffic in finite element codes for stress analysis, which are often secret codes (in the sense that their theoretical basis remains a closely guarded secret) and the authors of which are occasionally uninhibited by a more than cursory acquaintance with the theory governing the problems they purport to solve.
For this reason alone a serious background in mechanics is hardly a luxury safely to be done away with. But mechanics need not rely on such a tenuous defense. Not only has it provided unparalleled inspiration for far-reaching scientific achievements in the past, it has made impressive strides in more recent times that have illuminated its foundations, enlarged its scope, and encompassed new technological applications.
Even elasticity theory, which (to my unbiased mind) is the very model of a mathematically sound and physically successful theory – though declared dead in some premature obituaries, has not stood idle. Nor is it likely to become obsolete in the future. I am rather confident that the theory of elasticity will be around and useful long after some of the more glamorous additions to engineering curricula have joined the company of fading fads and discarded fashions.
By and large teaching has been one of my favorite preoccupations over the years. In fact, trying to make things clear, whether in lecturing or in writing, is an ultimately rewarding, if often painful, obsession of mine. And, incidentally, whenever I have particular trouble in explaining something to others, I usually find that it is not clear to me either.
My enthusiasm for teaching has been somewhat dampened by a no longer novel phenomenon that has, in my view, contaminated the academic teaching atmosphere. I am alluding to the teaching-quality surveys conducted by students, which are firmly entrenched at most universities and enjoy a blissful immunity from criticism: any faculty member venturing to question the merits of this ritual can count on having his own motives questioned in turn. Now this is hardly an issue to become exercised about, but it is cause for some legitimate concern. Let me start with a few truisms.
First, these surveys evidently serve a useful purpose: for example, in making teachers aware of distracting mannerism and bad habits, like speaking too fast, writing illegibly on the blackboard, or standing in front of what has been written.
Next, as the husband of a psychologist, I know that polls of this kind are conducive to the mental health of students in enabling them to vent their resentment against a teacher by taking anonymous potshots at him or her. I still remember from my own undergraduate days being handed a questionnaire at the end of an explosively dull course. It called for the usual ratings of the instructor for "mastery of subject," "clarity of presentation," "fairness," and so on. In addition, it asked for an overall grade for his performance: A, B, C, etc. In a fit of mischievous inspiration, I gave the man an "Incomplete." I doubt if he enjoyed the joke nearly as much as I did at the time.
Lastly, nobody can prevent students from carrying out and publicizing the results of such surveys.
My misgivings pertain to the official sanctioning of this sort of enterprise by university administrations and the weight assigned to its outcome in connection with faculty promotions. At my own university the annual teaching-quality evaluation is undertaken with the cooperation of the Registrar and reported on in a publication funded by the Office of the Vice-President for Student Affairs.
Why misgivings? Because such evaluations tend to inflate the importance of the most superficial aspects of teaching; because they invite a popularity contest among the faculty that may favor glib and facile efforts over more demanding expositions in depth. Further, it seems to me that students - even graduate students -may not be in a position to assess the true competence of an instructor or the permanent value of the material presented. Perhaps the most memorable teacher I ever had was a notoriously poor lecturer, and I failed to appreciate fully the influence of my exposure to him until later in life.
I might add my surmise that there is little of substance that can be taught about teaching at the university level and - Schools of Education notwithstanding - even less on a level of generality that divorces teaching from the subject to be taught.
Along with teaching, most universities place considerable emphasis on scholarly accomplishments of their faculty. I am glad to say that the old chestnut about an inherent antagonism between teaching and research has largely been put to rest nowadays.
But the dangers arising from an indiscriminate reliance on the number of publications as a criterion for academic advancement are too self-evident to be belabored. One way of coping with the perennial academic dilemma of "Publish or Perish!" is to publish perishables. There is a natural temptation, especially among younger people, to pad one's list of publications with minor spin-offs of earlier work, and an understandable reluctance to invest the time needed to learn something new.
Such pressures are in part responsible for the current avalanche of papers on mechanics, the number of authors of which threatens to exceed the number of their readers. Moreover, this state of affairs has led to a proliferation of ever more specialized journals catering to mechanics of one kind or another: any day now I expect to receive notice of a new International Journal of Shear Stresses.
Let me move on to some troubling trends in the role played by sponsored research at our universities. It is a fact - a regrettable fact, but a fact of life just the same - that American universities depend on sponsored research for their survival. As a consequence professors are expected to cover a substantial portion of their salaries through outside support. This, in turn, compels them to spend an appreciable portion of their time on entrepreneurial chores, such as the composition of seductive proposals - hardly the most appealing genre of creative writing.
More disturbing is the spreading practice of making new academic appointments explicitly contingent upon the faculty member's ability to attract a specified percentage of outside support. This practice is particularly burdensome for younger faculty, and especially so in a field such as mechanics, where funding is increasingly difficult to come by. It seems to be easier to obtain a multi-million dollar grant for an accelerator or a giant telescope then to secure relatively modest support for a study of, say, the foundations of the theory of elastic instability.
A major share of the support for the university-based research has come from various federal agencies and from the different branches of the Department of Defense. The policies governing such federal funding have on the whole been enlightened in recognizing the specific nature of academic, as distinct from industrial research. One of the most significant functions of government research grants and contracts has been to sustain the advanced education of scientists and engineers, which is of equally crucial and obvious benefit to the country as a whole.
I personally owe a large and lasting debt to the Office of Naval Research, which for a period of over thirty years allowed me to pursue my research interests and to contribute to the training of graduate students, with essentially no interference and with a minimum of bureaucratic harassment.
Of late, however, federal support for academic research in engineering has taken a rather ominous turn. Apparently, while physicists or chemists remain free to do their own thing, engineers are to be held to delivering the goods. In particular, I gather that according to some recent edicts, research in applied mechanics is "to be made relevant to national defense" and is "to impact the competitive vitality of the economy" - if I may use some in-language. Since the National Science Foundation is presumably a guardian of fundamental research, I was all the more taken aback by a list of ten recommended research areas, which was distributed at an NSF conference on "Future Directions in Solid Mechanics Research", about a year ago.
My first qualms concerning this manifesto were aroused on noting that it comprised exactly ten items, "ten" being a conspicuously round number. I always suspected that the committee charged with drafting the Ten Commandments initially arrived at only nine and then added "Thou shalt not commit adultery" for good measure. I will not bore you by quoting the complete list of suggested research areas to which I am referring. Suffice it to mention that one of the categories listed is the "Mechanics of Modern Manufacturing", while another is headed "Mechanics in Strategic and Conventional Military Systems"; here "missile systems", "tube-launch systems", and "warhead design" are cited as representative examples.
I realize of course that this document originated in response to new government directives and that it is intended to make research in solid mechanics more attractive to those in control of funds. Yet if this is a vision of the future role of such research, I cannot help feeling that it is at best a vision impaired by a well-intentioned myopia.
There is a general consensus that research conducted at universities ought to be basic research. Admittedly, everyone has his own definition of "basic research", tailored to include his own work. But I cannot conceive of any acceptable definition that would accommodate the design of warheads.
Nor am I making a plea for the license to do irrelevant work. Bent on platitudes, I ought to remind you, however, that "relevance" is a slippery notion and that what is irrelevant or even frivolous work to some, may be regarded to be of fundamental worth by others. Finally, it is well to keep in mind that many of the most enduring and consequential contributions to applied science and engineering stem from research that was prompted by sheer intellectual curiosity and unencumbered by an insistence on its immediate applicability.
I must not test your patience by prolonging these opinionated and rambling ruminations. Otherwise I might suffer the fate of the speaker who apologized for having carried on interminably on the grounds that there was no clock within his view, only to provoke a member of his audience into pointing out a calendar on a wall of the lecture room.