About ACAP

The Array of Contemporary American Physicists is a resource produced by the Center for History of Physics at the American Institute of Physics (AIP). At present it contains information on over 800 physicists and associated scientists who worked in the United States of America for extended periods between 1945 and the present. This information is interlinked, so that users can explore how different scientists were connected through institutions and by the intellectual content of their work. Links and references are provided to additional resources from AIP's own collections and from independent sources. (More Information)

Work on ACAP has been supported by U. S. National Science Foundation Award 0823235

Conceptualization, Design, Research, and JSP Programming
William Thomas

Web Design
Ada Uzoma

Research and Data-Entry Assistance
Christopher Donohue

Additional Advice and Assistance Provided by
Spencer Weart, Joe Anderson, Greg Good, Meghan Petersen, and the AIP Niels Bohr Library & Archives staff

Inclusion Criteria
ACAP is designed to grow and change with time, so there is no fixed roster of people who can be found in it. In our initial presentation, we have tried to take into account those scientists who are well-known for their intellectual contributions as well as those who are known as institution-builders or managers. With this in mind, we chose a set of selection criteria that would include a wide field of people, and that would help us find people who might be left out if only historical judgment were to be used. Most people included in ACAP have won a major prize (see the list we have used), or have been elected members of the National Academy of Sciences (NAS). Others have directed major research institutions, have been president of the American Physical Society, or have been high-level government advisers. One uncompleted but ongoing project is to include the past and present chairs of major physics departments. In a few isolated cases we have included people we thought would be of interest, but who would have slipped through the cracks if we adhered to our selection criteria too rigidly.

Attentive users will note that for the time being ACAP pays attention to certain fields in the physical sciences more than others. For example, astrophysics and geophysics are unevenly represented. Meanwhile, there are a number of people in ACAP who worked squarely in fields such as electrical engineering or physical chemistry. Our mentality here was to build ACAP with a "frayed edges" policy. Rather than try and keep ACAP conceptually tidy, we have purposely included some important figures who can serve as a bridge between the history central to ACAP and the history of other areas. Particularly in the cases of deceased NAS members, we have been forced to use ad hoc judgment to determine whether, for example, a mathematician's work was sufficiently connected to the concerns of physicists to warrant inclusion in the edges of ACAP. In cases such as meteorology, we have included figures from the early years of the field, when meteorological research was fairly close to research in fluid dynamics, but have left out figures who worked in the field after it established a greater degree of autonomy.

While we are very much aware of the international character of science, in our initial presentation we have found it necessary to restrict ACAP to those who have worked in the United States for extended periods. Establishing reasonably consistent selection criteria, finding basic biographical information, and keeping the total number of physicists included within reach of our capabilities, were all problems that we were able to make more manageable by keeping ACAP confined to a single-nation context. However, we hope that future expansions will allow for the full international scope of physics to be represented.

We have assembled the data in ACAP from a wide variety of sources, but have tried to avoid information with uncertain provenance, such as much of what is found at Wikipedia. The best information often comes from CVs that physicists have made available on their websites, or that we have solicited from them. American Men and Women of Science has been a crucial source of information, though in some cases we have found it necessary to correct or clarify some information found there. Obituaries and NAS Biographical Memoirs have provided important supplemental information. In addition, we have made use of unpublished biographical information kept on file at the AIP Niels Bohr Library & Archives. We have not included any information that has not been previously made available to the public, except in a few cases where that information has been obtained directly from the physicists themselves. We believe that the information in ACAP is as reliable as that found in any other resource; nevertheless, we cannot vouch that the information is absolutely reliable, and welcome any documented corrections.

Position Classification
A "major position" is generally a permanent position, or a highly significant on-leave position. "Other positions" are those positions in which scientists have been employed on a more-or-less constant basis, but which do not constitute their central position, such as visiting professorships, editorship of journals, or directorship of laboratories. Special positions held during World War II are considered major if no other permanent position was held at the time, but "other" if the scientist was on leave during the war. "Part-time positions" are generally committee memberships or consultant positions, and are usually "selected" based upon available documentation rather than any consistent criteria. However, we have systematically left out departmental committees and positions on editorial boards. Absent a full understanding of what any given position entails, we have generally had to use our best judgment in making classificatory decisions, and criteria have not always been applied consistently.

Most photographs used in ACAP are taken from the AIP Emilio Segrè Visual Archives. Where the image has not come to our archives as a gift of the owner, such as by way of our Physics Today collection, and where original ownership of the image has been discernable (as marked on the backs of photographs), we have sought permission of the copyright holder to use the image. If you are the photographer or owner of an image contained here, and are not properly credited or otherwise feel the photograph is being used improperly, please contact us and we will alter the image credit, or remove the image from ACAP. We have tried to use images that convey personality or action, and therefore have not always used the most straightforward portraits in our collection; in some cases, we simply do not have high quality images in our possession, or we do not have permission to use them free of charge. If you would like to donate an image to our collection, please visit our photo donation page. Our visual archives makes images available on a not-for-profit basis, and for many of the images we make no claim to ownership. For further information, please see the FAQ at our visual archives.

Front Page Images

"Biographies": Victor Weisskopf, Maria Goeppert Mayer, and Max Born.
Photo credit: AIP Emilio Segrè Visual Archives, Gift of Jost Lemmerich.

"Institutions": Robert R. Wilson Hall, Fermi National Accelerator Laboratory.
Photo credit: courtesy of Fermilab.

"Topic Guides": The Berkeley Bevatron synchrotron accelerator.
Photo credit: Lawrence Berkeley National Laboratory, courtesy AIP Emilio Segrè Visual Archives.