November 2, 1943
Dear General Groves:
After you gave me the list during your last visit of the men whom we may expect from the United Kingdom, it occurred to me that it might be wise before they arrive here to give them new names. This refers especially to Niels Bohr. I am thinking of the fact that mail will be addressed to them, that they may on occasion originate or receive long-distance calls, that they will be making some local purchases, and that for all these routine matters it would be preferable if such well known names were not put in circulation.
It has, in fact, troubled us some that we are forced to place calls for Dr. Conant, Fermi, Lawrence, etc. This does not happen very often, but in view of the fact that we try not to use these names over the telephone, the placing of the calls themselves seems to us rather unwise. I doubt whether at this late date it would be practicable to assign new names to those who have been associated with the project in the past. In the case of Bohr and Chadwick I think it would be advisable to do so before they get here.
J. R. Oppenheimer