Professor Kosterlitz joined the faculty of Brown University in 1982. He received his B.A. and M.A. from Cambridge University and Ph.D. in high energy physics from Oxford University in 1969. He has engaged in research at the Instituto di Fisica Teorica, Torino, Italy, and in this country at Cornell University, Princeton University, Bell Telephone Laboratories and Harvard University. He has also served on the faculty of the Department of Mathematical Physics, University of Birmingham.