The ICTP Dirac selection committee has announced the winners of the 1998 Dirac Medal. The recipients are Stephen Adler, a professor at the Institute for Advanced Study in Princeton, and Roman Jackiw, a professor with the Massachusetts Institute of Technology. Adler and Jackiw are being honoured for their contributions to quantum field theory. Their research crossed paths with their studies of the triangular anomaly. On the one hand, the theory explains the decay of such elementary particles as pions. On the other hand, it places severe restrictions on grand unified theories of the fundamental forces of nature. The award carries a US$ 5,000 cash prize.