Correspondence, journals, reports, draft and published writings, scientific papers, printed matter, and photographs particularly relating to Ridenour's efforts to familiarize scientists, engineers, and the public with science policy issues stemming from the use of nuclear energy and computers through his books and articles in professional journals and general interest magazines. Also includes material on his work as assistant director of the Radiation Laboratory at Massachusetts Institute of Technology where he headed the team that developed the SCR 584 radar device that was effective as an antiaircraft gun laying system. Journals (1942-1945) and other papers document his World War II service as an expert consultant to the secretary of war, radar advisor in air operations in all theaters of the war, and especially as chief of the advisory specialist group for the United States Strategic Air Forces in Europe under Gen. Carl Spaatz.

Correspondents include Joseph Alsop, Cary F. Baker, Curtis G. Benjamin, Ralph D. Bennett, R. Vivian Bowden, Edward Lindley Bowles, Lyman Bryson, Norman Cousins, Peter Hobley Davison, Dennis Flanagan, Hugh Handsfield, Hiram Collins Haydn, Byron K. Ledgerwood, Lawrence Lessing, Lawrence Meyer Levin, Herrymon Maurer, Charles W. Morton, Abraham John Muste, Carl E. Nagel, Oliver A. Nelson, Isabel Paterson, Gerard Piel, James M. Reid, Kenʼichi Shinohara, Herbert Solow, Leon Svirsky, Orin Tovrov, Edward Weeks, Thornton Wilder, and Philip Wylie.