# Aspen Center for Physics

The Aspen Center for Physics (ACP) is a non-profit institution for physics research located in Aspen, Colorado, in the Rocky Mountains region of the United States. Since its foundation in 1962, it has hosted distinguished physicists for short-term visits during seasonal winter and summer programs, to promote collaborative research in fields including astrophysics, cosmology, condensed matter physics, string theory, quantum physics, biophysics, and more.
To date, sixty-six of the center's affiliates have won Nobel Prizes in Physics and three have won Fields Medals in mathematics. Its affiliates have garnered a wide array of other national and international distinctions, among them the Abel Prize, the Dirac Medal, the Guggenheim Fellowship, the MacArthur Prize, and the Breakthrough Prize. Its visitors have included figures such as the cosmologist and gravitational theorist Stephen Hawking, the particle physicist Murray Gell-Mann, the condensed matter theorist Philip W. Anderson, and the former Prime Minister of the United Kingdom, Margaret Thatcher.
In addition to serving as a locus for physics research, the ACP's mission has entailed public outreach: offering programs to educate the general public about physics and to stimulate interest in the subject among youth.

## History & public outreach

The Aspen Center for Physics was founded in 1962 by three people: George Stranahan, Michael Cohen, and Robert W. Craig. George Stranahan, then a postdoctoral fellow at Purdue University, played a critical role in raising funds and early public support for the initiative. He later left physics to become a craft brewer, rancher, and entrepreneur, although he remained a lifelong supporter of the center. Stranahan's enterprises included the Flying Dog Brewery. Michael Cohen, a professor at the University of Pennsylvania, is a condensed matter physicist whose work has investigated the properties of real-world material systems such as ferroelectrics, liquid helium, and biological membranes. Robert W. Craig was the first director of the Aspen Institute, an international non-profit center which supports the exchange of ideas on matters relating to public policy.
From its establishment, the ACP has developed a close relationship with the city of Aspen and has contributed to the cultural life of the local community. It has collaborated with other institutions such as the Aspen Institute, the Aspen Music Festival, the Wheeler Opera House, the Aspen Science Center, and the Pitkin County Library.
The center has benefitted from the generosity of public support, notably from the National Science Foundation, the US Department of Energy, NASA, and from the gifts of private donors. These funds have helped to bring hundreds of scientists to the center every year, and have enabled the ACP to host a wide array of public lectures and activities.
In addition to sponsoring these public events at its campus in Aspen, the ACP has also broadcast programs on a local-access television station – the “Physics Preview” show on Grassrootstv.org – and on radio, via its ″Radio Physics″ program for high school students on the KDNK station.

## Supporters & donors

The Aspen Center for Physics has benefitted over the years from many acts of philanthropy. Gifts from Aspen donors as well as from George Stranahan, Martin Flug, the Smart Family Foundation, and affiliated physicists have been especially important to sustaining the center's development and operation.
George Stranahan was an early driving force behind the establishment and funding of the ACP. After convincing the Aspen Institute to open in 1961 an independent physics division, where scientists could convene to conduct research, he began raising funds to open the Aspen Center for Physics, by collecting donations from locals and Aspen Institute participants. Stranahan raised funds for the original ACP building at a cost of $85,000, while contributing $38,000 himself. To recognize the central role that Stranahan played in establishing the center, the first building constructed on the ACP campus is named in his honor as Stranahan Hall. It was designed by Herbert Bayer, who pioneered Aspen's post-World War Two architectural revitalization.
Martin Flug, an Aspen businessman who had been interested in physics since his undergraduate time at Harvard University, funded the construction of an auditorium and a lecture series to accompany it: the Flug Forum. The auditorium is named to honor Flug's father Samuel Flug, an investment banker who was born in Warsaw, Poland and who died in 1962.
The Smart Family Foundation of Connecticut funded the construction of Smart Hall, a building on the ACP campus erected in 1996. The gift was arranged by A. Douglas Stone, a member of the Smart family, a physicist at Yale University, and a past ACP Scientific Secretary, Trustee, General Member, and Honorary Member.
The third building on the ACP campus, Bethe Hall, is named after Hans Bethe, the German-American nuclear physicist, based at Cornell University. Bethe donated part of his prize money to the ACP after winning the Nobel Prize for Physics in 1967 for his work on stellar nucleosynthesis. Bethe was a long-standing participant at the center: he was vice president and Trustee in the 1970s, then an Honorary Trustee from the 1970s until his death in 2005.
Following Bethe's example, several other physicists whose achievements merited awards went on to donate part of their prize money to the ACP. Recognizing these scientist-donors, the ACP established the “Bethe Circle.”
Bethe Circle :
| Name of Physicist | Award | Year |
| Gordon Baym | APS Medal for Exceptional Achievement in Research | 2021 |
| Daniel Freedman | Special Breakthrough Prize | 2019 |
| Vassiliki Kalogera | Hans A. Bethe Prize | 2016 |
| Greg Moore | Dannie Heineman Prize for Mathematical Physics | 2014 |
| Hirosi Ooguri | Hamburg Prize for Theoretical Physics | 2018 |
| Pierre Ramond | Dannie Heineman Prize for Mathematical Physics | 2015 |
| John Schwarz | Physics Frontiers Prize | 2013 |
| Matthias Troyer | Aneesur Rahman Prize for Computational Physics | 2016 |

## Luminaries

ACP participants have included hundreds of post–doctoral fellows, professors, researchers and experimentalists who have come for short-term visits. Some had already achieved distinction before coming to the center; others won prizes or gained international recognition after spending time at the ACP early in their careers. Dozens of ACP physicists have received prestigious awards for their work, including the Nobel Prize in Physics.
The following scientists have participated at the Aspen Center for Physics at least once. Several have attended for a number of years.
Nobel Prize Winners :
| Nobel Laureate | Year of Prize |
| Philip Warren Anderson | 1977 |
| Arthur Ashkin | 2018 |
| John Bardeen | 1956, 1972 |
| Barry C. Barish | 2017 |
| Hans Bethe | 1967 |
| Owen Chamberlain | 1959 |
| Steven Chu | 1997 |
| Leon N. Cooper | 1972 |
| Francis Harry C. Crick | 1962 |
| James Watson Cronin | 1980 |
| Richard Feynman | 1965 |
| Val Logsdon Fitch | 1980 |
| William Alfred Fowler | 1983 |
| Murray Gell-Mann | 1969 |
| Andrea Ghez | 2020 |
| Riccardo Giacconi | 2002 |
| Donald A. Glaser | 1960 |
| Sheldon L. Glashow | 1979 |
| David Gross | 2004 |
| Duncan M. Haldane | 2016 |
| John L. Hall | 2005 |
| Robert Hofstadter | 1961 |
| Russell Hulse | 1993 |
| Brian D. Josephson | 1973 |
| Takaaki Kajita | 2015 |
| Wolfgang Ketterle | 2001 |
| Walter Kohn | 1998 |
| Masatoshi Koshiba | 2002 |
| John M. Kosterlitz | 2016 |
| Robert B. Laughlin | 1998 |
| Leon Max Lederman | 1988 |
| David Morris Lee | 1996 |
| Tsung-Dao Lee | 1957 |
| Anthony James Leggett | 2003 |
| John C. Mather | 2006 |
| Michel Mayor | 2019 |
| W.E. Moerner | 2014 |
| Yoichiro Nambu | 2008 |
| Konstantin S. Novoselov | 2010 |
| Douglas D. Osheroff | 1996 |
| P. James E. Peebles | 2019 |
| Roger Penrose | 2020 |
| Martin L. Perl | 1995 |
| Saul Perlmutter | 2011 |
| Edward M. Purcell | 1952 |
| Didier Queloz | 2019 |
| Norman Foster Ramsey | 1989 |
| Frederick Reines | 1995 |
| Robert C. Richardson | 1996 |
| Adam Riess | 2011 |
| Carlo Rubbia | 1984 |
| Brian Schmidt | 2011 |
| J. Robert Schrieffer | 1972 |
| George Smoot | 2006 |
| Gerardus 't Hooft | 1999 |
| Joseph H. Taylor | 1993 |
| Kip S. Thorne | 2017 |
| David J. Thouless | 2016 |
| Samuel C. C. Ting | 1976 |
| Charles Hard Townes | 1964 |
| Daniel Tsui | 1998 |
| Martinus J.G. Veltman | 1999 |
| Rainer Weiss | 2017 |
| Carl E. Wieman | 2001 |
| Frank Wilczek | 2004 |
| Kenneth Geddes Wilson | 1982 |
Fields Medalists :
| Fields Medalists | Year of Prize |
| Michael Freedman | 1986 |
| Stephen Smale | 1966 |
| Edward Witten | 1990 |
Abel Prize Winners :
| Abel Laureates | Year of Prize |
| Karen Uhlenbeck | 2019 |
| Isador M. Singer | 2004 |
Recent Prizewinners :
| Prizewinners | Name of Prize | Year of Prize | Institution |
| Elihu Abrahams | Oliver E. Buckley Condensed Matter Prize | 2019 | University of California, Los Angeles |
| Gordon Baym | APS Medal for Exceptional Achievement in Research | 2021 | University of Illinois Urbana Champaign |
| Paul M. Chaikin | Oliver E. Buckley Condensed Matter Prize | 2018 | New York University |
| Sally Dawson | J.J. Sakurai Prize for Theoretical Particle Physics | 2017 | Brookhaven National Laboratory |
| Alexei Efros | Oliver E. Buckley Condensed Matter Prize | 2019 | University of Utah |
| Daniel Freedman | Special Breakthrough Prize | 2019 | Stanford University |
| Michael Green | Physics Frontiers Prize | 2014 | Cambridge University |
| John F. Gunion | J.J. Sakurai Prize for Theoretical Particle Physics | 2017 | University of California Davis |
| Howard Haber | J.J. Sakurai Prize for Theoretical Particle Physics | 2017 | University of California Santa Cruz |
| C. R. Hagen | J.J. Sakurai Prize for Theoretical Particle Physics | 2010 | University of Rochester |
| David Hitlin | W.K.H. Panofsky Prize in Experimental Particle Physics | 2016 | California Institute of Technology |
| Randy Hulet | Davisson–Germer Prize | 2016 | Rice University |
| Clifford Johnson | Klopsteg Memorial Lecture Award | 2018 | University of Southern California |
| Clifford Johnson | Simons Fellow in Theoretical Physics | 2016 | University of Southern California |
| Vassiliki Kalogera | Hans E. Bethe Prize | 2016 | Northwestern University |
| Marc Kamionkowski | Dannie Heineman Prize for Astrophysics | 2015 | Johns Hopkins University |
| Gordon Kane | J.J. Sakurai Prize for Theoretical Particle Physics | 2017 | University of Michigan |
| Alexei Kitaev | Dirac Medal of the ICTP | 2015 | California Institute of Technology |
| Alexei Kitaev | Oliver E. Buckley Condensed Matter Prize | 2017 | California Institute of Technology |
| Andy Millis | Hamburg Prize for Theoretical Physics | 2017 | Columbia University |
| Greg Moore | Dannie Heineman Prize for Mathematical Physics | 2014 | Rutgers University |
| Greg Moore | Dirac Medal of the ICTP | 2015 | Rutgers University |
| Ann Nelson | J.J. Sakurai Prize for Theoretical Particle Physics | 2018 | University of Washington |
| Hirosi Ooguri | Hamburg Prize for Theoretical Physics | 2018 | California Institute of Technology and Kavli IPMU |
| Hirosi Ooguri | Medal of Honor with Purple Ribbon | 2019 | California Institute of Technology and Kavli IPMU |
| David Pines | Julius Edgar Lilienfeld Prize | 2016 | University of California Davis |
| Pierre Ramond | Dannie Heineman Prize for Mathematical Physics | 2015 | University of Florida |
| Pierre Ramond | Dirac Medal of the ICTP | 2020 | University of Florida |
| Nicholas Read | Dirac Medal of the ICTP | 2015 | Yale University |
| Subir Sachdev | Dirac Medal of the ICTP | 2018 | Harvard University |
| John Schwarz | Physics Frontiers Prize | 2013 | California Institute of Technology |
| Boris Shklovskii | Oliver E. Buckley Condensed Matter Prize | 2019 | University of Minnesota |
| David Spergel | Dannie Heineman Prize for Astrophysics | 2015 | Princeton University |
| Ian Spielman | Rabi Prize in Atomic, Molecular & Optical Physics | 2015 | National Institute of Standards and Technology |
| Dam Thanh Son | Dirac Medal of the ICTP | 2018 | University of Chicago |
| Matthias Troyer | Aneesur Rahman Prize for Computational Physics | 2016 | Microsoft |
| Matthias Troyer | Hamburg Prize for Theoretical Physics | 2019 | Microsoft |
| Karen Uhlenbeck | Abel Prize | 2019 | University of Texas at Austin |
| Migual Virasoro | Dirac Medal of the ICTP | 2020 | Universidad Nacional de General Sarmient |
| Xiao-Gang Wen | Dirac Medal of the ICTP | 2018 | Massachusetts Institute of Technology |
| Xiao-Gang Wen | Oliver E. Buckley Condensed Matter Prize | 2017 | Massachusetts Institute of Technology |