Foreword
L. Brink, D. Friedan, A.M. Polyakov, eds. (World Scientific, 1990)
I met Dima Knizhnik only three times — first in Moscow in the spring of 1983, again in Moscow at the Landau-Nordita meeting in June, 1984 and, finally, at the Yukawa Symposium in Kyoto in October, 1987. Because of the political situation in those years, direct contacts were infrequent between physicists working in the Soviet Union and physicists working in the U.S. or even Europe.
On several occasions Dima and I were thinking independently about the same subjects at the same times, usually from somewhat different points of view. It might have been interesting if we had had more freedom to interact. Beginning in 1984, Steve Shenker and I made Dima a standing offer of a position, but he was not able even to consider visiting until just before his death.
Consequently, I was forced to know Dima mostly from his published work. It is clear that he was in a state of explosive intellectual growth throughout his short career. It is impossible to imagine where time might have led him.
Theoretical physics is, by and large, an improvisational ensemble work, although the psychology of physicists seems to require that the official history be written otherwise. When such a creative voice as Dima Knizhnik is lost, we are all irreversibly diminished.