ROBERT OPPENHEIMER' (1904-1967) ROBERT F. BACHER Professorof Physics,California Institute of Technology ROBERT OPPENHEIMER died in Princeton,New Island. His fatherpresented him witha sailboat Jerseyon February18, 1967, at the age of sixty- which Robert named Trimethyafter a chemical two. He was the leading American theoretical compoundthat interested him. He and his younger physicistof his generation,the founderof the brotherFrank, born in 1912, sailed the Great most importantschool of theoreticalphysics, and South Bay endlessly. He becamean accomplished one of the leadingintellectuals of our day. sailor and kept an interestin sailing for the rest Robert Oppenheimer,whose full name was J of his life. Robert Oppenheimer,was born in New York In spite of outdoorsummers, Robert was frail City on April 22, 1904. His father,Julius and was oftenill, especiallyduring the winters. Oppenheimer,was a very successfulmember of a He completedhis workat Ethical CultureSchool firmof textile importerswhich had been started earlyin 1921 and thentook some advanced chemis- by his uncle and which his fatherhad joined at trybefore the close of the springterm and gradua- an early age after immigratingfrom Germany. tion. Afterthat his familywent to Europe where His mother,Ella FriedmanOppenheimer, shared Robert and Frank had a finetime exploringand her husband's interest in the Ethical Culture seeing the sights. Robert became ill apparently Societyand had manyinterests of her own. She with dysenteryand was broughthome to recover was an accomplishedpainter. Robertgrew up in and recuperate. By fall he had not acquired suf- an atmosphereof cultureand affluencein which ficientstrength to enter Harvard where he had his intellectualcuriosity was stimulatedand en- been admitted. Instead he stayed in New York couraged. At a very early age he became in- and then his fatherpersuaded one of his former terested in minerals and by age eleven was a instructorsat Ethical Culture School to go west member of the New York Mineralogical Club, with him to a ranch in the upper Pecos area of largelyon the basis of an eruditecorrespondence the Sangre de Cristo Mountainsin New Mexico. whichhe carriedon withsome of the members. Katherine Page, who owned and operated this Robert attendedthe Ethical Culture School in ranch, encouragedRobert's interestin the out- New York where he apparentlykept much to doorsand riding. He rapidlygained strength and, himself, having little interaction with other after spendingthe summeragain at Bay Shore, students. He had great facilitywith languages headed for Harvard withenthusiasm. and beforehe graduatedhe had masteredseveral To quote his own wordshe "almostcame alive" languages as well as almost everythingelse the at Harvard. He was able to startwith advanced school had to offer. His familyhad long before standing and each year audited more courses recognizedhim as a prodigyand fedhis voracious (includingexaminations) than he took regularly. appetitefor learningwith books about his latest He soon realizedthat his interestswere in physics interests. His interestsmoved towardchemistry and was attractedto Percy Bridgman,who gave and he had the good fortuneto have a stimulating him help and good advice. Robert Oppenheimer teacher,Augustus Klock. graduatedsumma cum laude in three years. During the summersthe familywould move to The next year he went to Cambridge Uni- a house in Bay Shore on the southshore of Long versitywhere he tried his hand at some experi- ments. He was greatly attractedby visiting 1 Dr. Bacher's memoirof Robert Oppenheimer,dis- lecturerswho were reportingon the new work tinguishedmember of theAmerican Philosophical Society, in quantummechanics, especially Max Born. As preparedby requestfor the Society'sYear Book, is of such fullnessand historicalvalue thatit is presentedin- a result, he transferredto Gottingenand im- stead in the Proceedingsfor the benefitof a wider mediatelyfound himself in the midstof an extra- circleof readers. ordinarygroup of professors,postdoctoral fellows PROCEEDINGS OF THE AMERICAN PHILOSOPHICAL SOCIETY, VOL. 116,NO, 4, AUGUST 1972 279 This content downloaded from 131.215.225.219 on Tue, 14 Oct 2014 16:47:52 PM All use subject to JSTOR Terms and Conditions 280 ROBERT F. BACHER [PROC. AMER. PHIL. SOC. and studentswho were deep in the applicationof as a base fromwhich he and his brotherFrank the new quantum mechanics. Robert worked took long rides throughthe mountainsand high withgreat intensityand with such success that in desertfor days at a time. It was a vigorouslife the springof 1927 afterless than two years he and doubtlesshelped to developthe extraordinary was awarded the Ph.D degree. staminawhich he showed later. Many visitors, For the followingyear he had a National Re- especiallyhis studentsand physicistfriends, visited search Council fellowshipat Harvard and the thereand had lively discussionson new work in CaliforniaInstitute of Technology. By this time quantumtheory. he had made some major contributionsin the Robert Oppenheimergradually shortenedhis applicationof the new quantummechanics and was visitsto Caltechand made Berkeleyhis mainbase. widelysought after for a universityposition. He Justbefore World War II he lived almostentirely decided that he needed anotheryear to studybe- in Berkeleyexcept for occasional visits and a few fore he startedto teach and he was awarded an weeks in the early summerin Pasadena. He had InternationalEducation Board fellowshipto study manyfriends in Pasadena and always kepta close in Europe at Leiden and at Zurich. Ehrenfest interestin the work in cosmic rays and high- and especially Pauli made deep impressionson energyradiation, since it was so close to his long- him. time theoreticalinterests. During the years be- At thispoint he expresseda strongdesire to go fore the war, Robert Oppenheimer'sgroup in home. He had decidedon an unusualarrangement theoreticalphysics was the strongestone in the of a double appointmentas assistantprofessor at country.2 In addition to excellent graduate Caltech and at the Universityof Californiaat students,numerous postdoctoral fellows, including Berkeley. For several years he taughtthrough Schwinger,Serber, and manyothers, worked with group the fall term at Berkeley,then after Christmas him. It was a vigorous and productive most wentto Pasadena forthe spring.His teachingwas and formermembers now staffmany of the not an immediatesuccess. He felt that he was distinguisheduniversity faculties in theoretical going much too slowly; yet his studentshad real physics. Katherine difficultykeeping up the pace. In addition,he In 1940 RobertOppenheimer married in Pasadena. spokevery softly with a fairamount of mumbling. PueningHarrison, whom he had met in This once caused Ehrenfest,a sticklerfor clear In 1941 they had their first child, Peter, house exposition,to call repeatedlyin a Caltechseminar Pasadena. Aboutthis time Robert bought a over "Louder, please, dear Oppenheimer." When at 1 Eagle Hill whichcommanded a fineview Robert'svoice quicklydropped after the thirdcall San FranciscoBay and whichprovided a delight- co-workers. he banged his desk. Robert stopped and said ful spot to entertainhis studentsand "But this room is so big." Ehrenfestshouted The discoveryof nuclear fissionin 1939 tied "You always adjust your voice so we can't hear. intomany current activities in the RadiationLabo- I couldn'thear you in a telephonebooth." Before ratoryat Berkeley,where neptunium and laterplu- of very manyyears Robert Oppenheimerbecame an toniumwere discoverednot long after.The fall excellentlecturer and manyof his generallectures France and the battleof Britainbegan to displace are known for their lucid expositionsof funda- theoverpowering concern for research in Berkeley. mentalideas in physics. In late 1940 and early 1941, many of Robert's researchfor Studentswere attractedto RobertOppenheimer colleagues leftto work on weapons was not yet and he soon establisheda group of studentsand a war in which the United States be. postdoctoralfellows with whom he worked. Their involvedbut mightsoon relationwith him was close and personal. When Some work continuedon the fission project he went to Pasadena in the spring most of his whichwas financedon a relativelysmall scale by groupfollowed along. Some too, followedhim to the governmentthrough a committee. In early nuclear his ranchin the upper Pecos, a beautifulspot not 1942 workon thepossibility of producing a farfrom where he had stayedbefore and whichhe chain reactionwas broughttogether at the Metal- had acquiredbefore going to Europe in 1928. He lurgicalLaboratory of the Universityof Chicago called it "Perro Caliente," Hot Dog, reputedly 2 An accountof Robert Oppenheimer'swork in the exclamationhe made when he firstsaw it. theoreticalphysics by Hans Bethemay be foundin Through the thirtieshis summerswere almost BiographicalMemoirs of Fellows of the Royal Society always spentthere in New Mexico. He used it 14 (1968): p. 391. This content downloaded from 131.215.225.219 on Tue, 14 Oct 2014 16:47:52 PM All use subject to JSTOR Terms and Conditions VOL. 116, NO. 4, 1972] ROBERT OPPENHEIMER (1904-1967) 281 and given greatersupport. The director,Arthur Groves appointed Conant and Tolman as his Compton,asked Robert Oppenheimerto get a scientificadvisers. Tolman, especially,followed theoreticalgroup togetherin the summerof 1942 the project closely and provided a link to the to look into the possibilityof whether,if reason- scientificcommunity. ably pure fissionablematerial were available, an Grovesconsulted