Sir

Mark Walker's review1 of my book Heisenberg and the Nazi Atomic Bomb Project distorts the record in several ways.

Walker conceals from readers the fact that the book contains documented proof of his own past suppression of crucial evidence. This raises a question of reviewing ethics.

Walker hides the scientific issues relating to Werner Heisenberg's misunderstanding of the critical mass of an atomic bomb which he calculated to be tons of uranium-235. Heisenberg's mistake has been fully demonstrated by the publication by Sir Charles Frank in 1993 of the Farm Hall transcripts2. Walker has already been reprimanded in an article in Nature3 for misleading readers, but he still does not see fit to mention the fundamental Farm Hall evidence in his review. In his own writings, Walker has all along suppressed Frank's explanation to him, in a taped interview of 1985, of the Heisenberg error.

Walker pretends that Heisenberg never seriously considered an exploding reactor-bomb. My book cites German reports analysing such a bomb, including two by a member of Heisenberg's team and a lengthy 1942 synoptic report, as well as Heisenberg's own comments, which show the idea to have been serious.

Any one of these three points should suffice to warn your readers against taking on trust any statement in Walker's review.