for reasons never satisfactorily explained by experiment, the metal migrates from place to place and can quickly contaminate large areas. “This isotope has been observed to migrate upstream against a current of air,” notes a postwar British report on polonium, “and to translocate under conditions where it would appear to be doing so of its own accord.”2169 Chemists at Los Alamos learned to look for it embedded in the walls of shipping containers when Thomas’ foils came up short.
