1993p95-stearns

Complexity
The complexity work with Hartmanis appeared in b”th a c”nfcrmcc vrrsi”” [5] and a,jownal version [6].’ ‘I’he cow ference versi”n was given at the Fifth Annual Symposium “n Switching Circuit Theory and Logical Design which has underg”ne a couple of name changes and is now known as FOGS (Foundations of Computer Science). B”th versions of the article had the phrase “computational complexity” in their title, the tint time this phrase was used. Thus, we were the first t” call what we were doing “computational comptrxity.” Although the conference version appeal-cd brforr the ,j”urnat vetsion, the text of the conference version was written later and referred to i&elf as an “update” “n the ,j”omat version. One updatr was inclusion “f a reference t” Blum’s Ph.D. thesis from MIT which was t” apprar as [I]. This work, developed independently of ours, provided a more abstract view of complexity classes. ‘Ibis was a very significant contribution wbicb should also be credited with inspiring the rarly intet-est and rapid growth of the complexity field. In [ti], we developed our theory on input-lrrs multitape Turing machines which produced an infinite sequence of zeros and ones. This ws essentially the same model used by Yamada in his wark about ‘irrat-time countable functions” (141. How~ever, the now famitiw language recognition model was rapidly ascending t” the prominent positi”” in aut”mata thtuxy it holds today. Recognizers are a valuable model because, despite their simplistic yes/no outputs, they are aheady sufficient t” discuss mat computational issues. Furthermore, they ax ideally suited for the study of nondeterminism. In the update, we discussed the application of our methods to this model. A third update was to discuss the implication of using the Hennir-Stearns two-tape n lrrg n simulation [7] instead “f the Hartmanis-Stearns one-tape ny simulation. (Fred Hennie worked at GE from time t” time as a visitor.) The implication was a sharper, s&i&m condition for distinguishing complexity classes. The primary contribution “f OUT work was the USF of deterministic time to define complexity classes. Using modern tmtati”” and the language recognition model, our definition was this:ຫໍສະໝຸດ AwardTurCng
It’s Time to
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Richard Edwin Stearns
lo 1960, I was hired by Richatd 1.. Sbuey t” wnrk fix the xtmmer at Genes-al Electric’s Rrsrarcb Laboratory in Schenectady, NCK Y”rk. Shuey was manager of a group called the “Inf”mlatiott Studies Section” which included ,Juria Hartmania and Philip M. Lewis II. This g-mop was part “f a larger gr”up ratted “Electron Physics.” During that summer, 1 worked with Hartmanib continuing s”me work hr had started “n the decomposition of sequential machines. As a result, the first Harrmanis-Stearns article [Y] was pt-aducect. 1 was very impressed with the quality “f the people at GE and the freedom thry had to define their own research goats. ‘l‘hus, when Shuey invited me f” rcturn in l9til as a permanent employee, I ,jumped at thr chance. There were a nombcr of jokes made ab”ut my Ph.D. thesis since GE had just settled an antitrust suit for cooperating with tw” “thcr companies t” fix prices (no ride payments involved!). When l started at GE, it was strictly as a mathematician. The resrarch laboratory did not have a computer and 1 had never used i, computer. A few yews later, the taboratory “brained a GE300 and installed a copy of the timrsharing system developed at Dartmouth. My first programming experiences we,-e using Basic on this machine thr”ugh a teletype interface. These cxprricnces came slier Hartmanis and I had worked “ut our thrwy “fconlputarionat camplexity. My eansformation intr) a c”mputer scientist was a matter “f evolution rather than a conscious decision. I was pursuing the mathematical problems I f”und mwt interesting and fbund myself in the middle of computer science. l continue t” hold a simultanr”us interest in both game theory and computer science. In fact, my lint article with Hartmanis preceded my thesis wwk. You may wonder if these fields have anything in common. I think they d”. One commonality is that they were both started by John v”n Neumann. The beginning “f game theory is clearly marked by the famous hook by van Neumann and Morgemtern [l3] and van Neumann with his “wm Neumann stored pr”gram computer model” is also considered a frmnding father of computer science. A second thing they have in c”mm”n is the need t” understand something very intangible yet very real. In the case “fgame theory, it is the nature ofcompetition. In the case of computer science, it is the nature of computathm. Both areas have required s”me completely new mathematics Irequiring the development of new mathematical models. My attracti”n COgame thewy began as an undergraduate one summer when I l.eead [IS] for recrration and saw how much attend”” was given to discus&n about the choices of model. To me, the mat interesting mathematics is that which tells us something about the real world. Thus, the first question we as mathematicians and computer scientists should ask is “how well do our models reflect the salient features of the objects or situations we wish to describe?” The significance “fa result depends m”re on the information it conveys rather than on the complexity of its proof. Ga,hage-in/garbage-out applies t” theory as well as software.