COMMENT DESCRIPTION Three lines of text DESCRIPTION Three lines of text DESCRIPTION Three lines of DESCRIPTION Three lines of go in heere go in heere until go in heere go in heere until text go in heere go in heere text go in heere go in its time for p.xxx its time for p.xxx until its time for p.xxx heere until its time CS I S HY P PEN CENTER FOR PEN CENTER FOR AS S. MAXWELL/ Summer workshops at the Aspen Center for Physics give researchers respite from their academic duties. Aspen physics turns 50 Michael S. Turner reflects on how mountain serenity has bred big breakthroughs at the Aspen Center for Physics in Colorado. heoretical physicists are an odd lot: theoretical physicists, including 53 Nobel Victorian buildings and wonderful skiing. She bad communicators (Niels Bohr laureates, from 65 countries. The centre can persuaded her husband, a devotee of German and Werner Heisenberg); brilliant lay claim to the string theory revolution, the writer Johann Wolfgang von Goethe, to visit Tshowmen (Richard Feynman and George birth of the arXiv preprint archive and to set- in 1945. Seeing it as the ideal place to bring Gamow); the ‘strangest man’ (Paul Dirac), ting the agenda in condensed matter physics. together the three elements of life — eco- lots of Hungarians (Leó Szilárd, Edward Its history is tied to the revival of a silver min- nomic, cultural and physical — he invested Teller and Eugene Wigner); bad hair (Albert ing town and the American entrepreneurial millions of dollars in rebuilding it. In 1946, he Einstein); and too few women. They don’t spirit, and includes a fascinating cast of char- formed the Aspen Skiing Corporation, which need fancy equipment — a pencil and paper acters, from philosopher Mortimer Adler to remains the financial engine of the valley. will do. But they do like a serene environ- journalist Hunter S. Thompson. Aspen’s cultural transformation came ment, with blackboards and others of their The centre’s story cannot be separated from with the 1949 Goethe bicentennial. Organ- ilk, in which to come up with big ideas: that of the town. The 1893 repeal of the Sher- ized by Walter Paepcke (with guidance from among them relativity, the Big Bang, quan- man Silver Purchase Act demonetized silver Adler and Robert Maynard Hutchins, then tum mechanics and the atomic bomb. and almost overnight turned Aspen, with president of the University of Chicago), the Over the past 50 years, the Aspen Center a population of about 15,000, into a ghost bicentennial aimed to rehabilitate German for Physics (ACP), nestled in a beautiful val- town. Elizabeth Paepcke, wife of Chicago culture and to revive humanism in the wake ley at 2,400 metres in the Colorado Rocky industrialist Walter Paepcke, visited in 1939, of the Second World War and the dawn of Mountains, has provided a ‘circle of seren- describing it as a place that “had slept since the atomic age. Around 2,000 people gath- ity’ during the summer months for 10,000 1893”. She found 700 residents, decaying ered in a tent designed by architect Eero 21 JUNE 2012 | VOL 486 | NATURE | 315 COMMENT Saarinen for the 20-day celebration. interruptions, but sometimes provided enter- in establishing the ACP in the theoretical They included German–French theologian tainment. I once overheard particle physicist community: Philip Anderson, Bethe and Albert Schweitzer, pianist Artur Rubinstein, Murray Gell-Mann quipping, “I don’t know Gell-Mann. Coincidentally, each began com- philosopher Jose Ortega y Gasset and poet the English for it, but the Japanese is …” ing to Aspen two years before he received a Stephen Spender. The event led to the for- An early attempt to engage physicists and Nobel prize. They set the agenda, served as mation of the Aspen Music Festival (now philosophers failed because of Adler’s insist- scientific magnets and gave early legitimacy. the Aspen Music Festival and School) and, ence that they first agree on “the pyramid of Any high-energy theorist would kill to spend in 1950, of the Aspen Institute for Human- knowledge”, which had physics at the bottom three weeks discussing physics with Gell- istic Studies (now the Aspen Institute). Just and philosophy on top. Because of the clash of Mann; Bethe helped to get astrophysics going as Paepcke had imagined, today the town cultures and egos, the centre did not stay tied at the ACP; and Anderson shaped condensed- brings together culture, wealth and athleti- to the Aspen Institute for long and became an matter physics there for three decades. cism — with a touch of glitz. independent entity in 1968. Since then, the Anderson set the tone for the condensed- ACP has been run by physicists who volun- matter field with his influential paper ‘More BEGINNINGS teer their time, helped by just two full-time is Different’ (P. W. Anderson Science 177, The ACP’s origins lie with physicist George staff. More than 200 top theorists have shaped 393–396; 1972). Contrary to particle phys- Stranahan, heir to the fortunes of the Cham- and guided the centre — including five Nobel ics, in which scientists pursue a reductionist pion Spark Plug company and a graduate laureates and Stephen Hawking. quest for simplicity at smaller and smaller student at the Carnegie Institute of Tech- An early grant from the Sloan Foundation scales, condensed-matter physics applies nology in Pittsburgh. In the late 1950s, he was crucial, and Hans Bethe donated part the basic rules to discover and study the decided that he would rather do his physics of his 1967 Nobel prize money. Bethe Hall, often unexpected, emergent phenomena during the summer months in the moun- built in 1978, was named in his honour. Rob- that arise in large systems with complicated tains of Colorado, where fishing and hiking ert Rathbun Wilson, the first director and interactions, such as superconductivity or in provided a more enjoyable backdrop than builder of Fermilab, visited Aspen in 1967 biological systems. Today, biological physics an office in steamy Pittsburgh. After a few and convinced the US Department of Energy has emerged as a major activity at the ACP. years, he realized that theoretical physics is to build a large, temporary office building Two other condensed-matter theorists best done with others, and set out to draw there, where Fermilab’s facilities for particle- played a crucial part: David Pines of the physicists to Aspen. When he later moved physics experiments were designed. Hilbert University of Illinois at Urbana–Champaign to Colorado, Stranahan became the landlord Hall, named after mathematician David Hil- and Elihu Abrahams of Rutgers University and close friend of Thompson. bert, almost tripled the number of physicists in New Jersey. They pioneered workshops Stranahan got things going with help from that the centre could accommodate. on the latest topics to attract a balance of Michael Cohen, a condensed-matter theorist researchers from universities and from at the University of Pennsylvania in Philadel- SOLID FOUNDATIONS industry (mostly Bell Labs). These work- phia, who was one of Feynman’s few PhD stu- In 1972, the US National Science Foundation shops brought in young hotshots, keeping dents, and Robert Craig, executive director became the ACP’s main funder, with support the talent pool fresh. One area of scientific of the Aspen Institute. The Stranahan fam- from other US science agencies including focus, strongly correlated electrons in met- ily’s Needmor Fund paid for the first build- the Department of Energy and NASA. In the als, laid the foundations for the current ing, Stranahan Hall, designed by Bauhaus mid-1990s, a $3-million fund-raising cam- understanding of high-temperature and architect Herbert Bayer, who also planned paign led by astrophysicist David Schramm other unconventional superconductors. the Aspen Institute campus. Cohen got the of the University of Chicago financed the In addition to Bethe’s presence, astro- physics talent, and Craig convinced the Aspen final and largest building, Smart Hall. Con- physics at the ACP was jump-started by the Institute to create a physics division. tributions came from physicists, friends in discovery of pulsars in 1967 and their iden- In spring 1962, a letter was sent out to the the Aspen community and the Smart Family tification with neutron stars. The exotic physics community tentatively announcing Foundation in Connecticut. properties of neutron stars — rapid rota- “the possibility of a summer physics insti- Three towering figures played a major part tion, superfluidity and superconductivity — tute”. The purpose was “to provide a place intrigued Pines and other condensed-matter CS for physicists to work on their own problems theorists. They brought in astrophysicists I S during the summer, in a stimulating physics with expertise in relativity and nuclear phys- HY atmosphere, and in a location with pleasant ics, and work done at the centre linked pul- P surroundings and natural beauty”. That year, sar glitches to superfluidity within neutron 42 brave souls came to Aspen to “pursue stars, advancing both fields. In 1972, NASA their work with minimal distractions”. started funding an annual workshop, and PEN CENTER FOR PEN CENTER FOR The Aspen formula was — and still is — astrophysics had a foothold in Aspen. AS to bring the best theorists together in an But it was cosmology that caused astro- informal setting for weeks or months, free physics to rise to the same level as particle . MAXWELL/ from their usual responsibilities of students physics and condensed matter. Around S and teaching and isolated from distractions. 1980, Schramm and others began to real- There, they could talk with one another, ize that theories of unification in particle think big thoughts and come up with game- physics might revolutionize the sleepy changing ideas.