Born 1951 in Lansing (Michigan/USA). Study of history and science at Harvard Univ. (BA 1973 summa cum laude), diploma in history and philosophy of science Univ. of Cambridge/Engl. (1974), PhD in the history of science Harvard Univ. (1979), Assistant Professor Harvard Univ. (1980-1983) and Princeton Univ. (1983-1986), Associate Professor Brandeis Univ., Dibner Chair for the History of Science (1986-1990), Professor and Director of the Institute for the History of Science Göttingen Univ. (1990-1992), Professor Univ. of Chicago (1992-1997), Director and Scientific Member at the Max Planck Institute for the History of Science (since 1995), Honorary Professor Humboldt University, Berlin (since 1997), Visiting Professor at Harvard University (2002-2003) and at University of Chicago (2005-2008). Recipient of the the Pfizer Award of the History of Science Society and Order of Merit of the Federal Republic of Germany (2010), Fellow of the American Academy of Arts and Sciences, corresponding member of the British Academy, member of the Berlin-Brandenburg Academy of Sciences and Humanities and the German National Academy of Sciences Leopoldina.