{"title":"IN MEMORIAM: GERALD E. SACKS, 1933–2019","authors":"M. Lerman, T. Slaman","doi":"10.1017/bsl.2022.8","DOIUrl":null,"url":null,"abstract":"Gerald E. Sacks, age 86, Professor Emeritus of Mathematics at Harvard and M.I.T., passed away at his home in Falmouth, Maine, after a long illness. Sacks was born in Brooklyn and graduated from Brooklyn Technical High School. He initially was an engineering major, but interrupted his college studies at Cornell University to serve in the U.S. Army from 1953 to 1956. After returning to Cornell, he developed an interest in Mathematical Logic and continued his studies in that area, receiving his Ph.D. in 1961 as a student of J. Barclay Rosser. He began his academic career at Cornell University, but moved to M.I.T. in 1966, and later accepted a joint appointment at M.I.T. and Harvard. During his career, he held visiting positions at The Institute for Advanced Study and several prestigious universities. Sacks had a brilliant mind for Mathematics and an abiding curiosity about it. In addition, he had a magnetic personality, and was always a center of attention. He was a captivating speaker, and a witty and deep thinker. His knowledge and interests were broad, covering not only his field of expertise but also the major developments in mathematics as a whole and in the world at large. His interests were varied; he enjoyed reading and had an extensive library, wrote poetry, and was a movie buff with a fantastic recall of highlights of movies. He gave willingly of his time and encouragement to his students, colleagues, and friends, and that encouragement frequently bore fruit. One cannot overestimate the effect he had on his main area of interest, Computability Theory, not only through his innovative work, but also through the work of his more than 30 students and more than 750 mathematical descendents. Sacks began his work in Classical Computability Theory when the field was in its infancy. Kleene and Post had begun the study of degrees of unsolvability, or Turing degrees, and Post the study of the computably enumerable Turing degrees. The results of Friedberg and independently Muchnik (incomparable computably enumerable Turing degrees) and Spector (minimal degrees) stimulated interest in the area. But it was the pioneering work of Sacks in his monograph, Degrees of Unsolvability [1] that generated an exhaustive study of those degrees. Sacks’ work in that monograph covered many aspects of degree theory, and his innovative techniques produced several theorems that bear his name. Moreover, the importance of the results was equalled by the importance of the techniques he introduced. The degrees of unsolvability form an algebraic structure that provides a measure of the complexity of information inherent in an oracle attached","PeriodicalId":22265,"journal":{"name":"The Bulletin of Symbolic Logic","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Bulletin of Symbolic Logic","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1017/bsl.2022.8","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Gerald E. Sacks, age 86, Professor Emeritus of Mathematics at Harvard and M.I.T., passed away at his home in Falmouth, Maine, after a long illness. Sacks was born in Brooklyn and graduated from Brooklyn Technical High School. He initially was an engineering major, but interrupted his college studies at Cornell University to serve in the U.S. Army from 1953 to 1956. After returning to Cornell, he developed an interest in Mathematical Logic and continued his studies in that area, receiving his Ph.D. in 1961 as a student of J. Barclay Rosser. He began his academic career at Cornell University, but moved to M.I.T. in 1966, and later accepted a joint appointment at M.I.T. and Harvard. During his career, he held visiting positions at The Institute for Advanced Study and several prestigious universities. Sacks had a brilliant mind for Mathematics and an abiding curiosity about it. In addition, he had a magnetic personality, and was always a center of attention. He was a captivating speaker, and a witty and deep thinker. His knowledge and interests were broad, covering not only his field of expertise but also the major developments in mathematics as a whole and in the world at large. His interests were varied; he enjoyed reading and had an extensive library, wrote poetry, and was a movie buff with a fantastic recall of highlights of movies. He gave willingly of his time and encouragement to his students, colleagues, and friends, and that encouragement frequently bore fruit. One cannot overestimate the effect he had on his main area of interest, Computability Theory, not only through his innovative work, but also through the work of his more than 30 students and more than 750 mathematical descendents. Sacks began his work in Classical Computability Theory when the field was in its infancy. Kleene and Post had begun the study of degrees of unsolvability, or Turing degrees, and Post the study of the computably enumerable Turing degrees. The results of Friedberg and independently Muchnik (incomparable computably enumerable Turing degrees) and Spector (minimal degrees) stimulated interest in the area. But it was the pioneering work of Sacks in his monograph, Degrees of Unsolvability [1] that generated an exhaustive study of those degrees. Sacks’ work in that monograph covered many aspects of degree theory, and his innovative techniques produced several theorems that bear his name. Moreover, the importance of the results was equalled by the importance of the techniques he introduced. The degrees of unsolvability form an algebraic structure that provides a measure of the complexity of information inherent in an oracle attached
杰拉尔德·e·萨克斯,86岁,哈佛大学和麻省理工学院数学荣誉教授,在长期患病后,在缅因州法尔茅斯的家中去世。萨克斯出生在布鲁克林,毕业于布鲁克林技术高中。他最初主修工程学,但中断了他在康奈尔大学的大学学业,于1953年至1956年在美国陆军服役。回到康奈尔大学后,他对数理逻辑产生了兴趣,并继续在该领域的研究,1961年作为J. Barclay Rosser的学生获得博士学位。他的学术生涯始于康奈尔大学,1966年转到麻省理工学院,后来接受了麻省理工学院和哈佛大学的联合聘用。在他的职业生涯中,他曾在高级研究所和几所著名大学担任访问职位。萨克斯对数学有着杰出的头脑和持久的好奇心。此外,他的个性很有吸引力,总是人们关注的焦点。他是一位引人入胜的演说家,也是一位机智而深刻的思想家。他的知识和兴趣广泛,不仅涵盖了他的专业领域,而且涵盖了整个数学和世界上的主要发展。他的兴趣是多种多样的;他喜欢阅读,藏书丰富,写诗,还是个电影迷,对电影的精彩片段有着惊人的记忆。他乐于为他的学生、同事和朋友付出时间和鼓励,这种鼓励经常结出果实。他不仅通过他的创新工作,而且通过他的30多名学生和750多名数学后代的工作,对他的主要兴趣领域——可计算性理论——产生了不可估量的影响。萨克斯开始研究经典可计算理论时,该领域还处于起步阶段。克莱因和波斯特开始研究不可解度,也就是图灵度,而波斯特开始研究可计算的图灵度。弗里德伯格和穆奇尼克(不可比拟的可计算的图灵度)和斯佩克特(最小度)的结果激发了人们对这一领域的兴趣。但是,萨克斯在他的专著《不可解度》(Degrees of Unsolvability)中的开创性工作[1]引发了对这些度的详尽研究。萨克斯在那本专著中的工作涵盖了学位理论的许多方面,他的创新技术产生了几个以他的名字命名的定理。此外,他所介绍的技术的重要性与结果的重要性相当。不可解的程度形成了一个代数结构,它提供了附加的oracle中固有信息复杂性的度量