Typed letter signed ('A. Einstein') to Cornelius Lanczos, 112 Mercer Street, Princeton, 21 April 1942

Albert Einstein (1879-1955)
Typed letter signed ('A. Einstein') to Cornelius Lanczos, 112 Mercer Street, Princeton, 21 April 1942
In German. One page, 277 x 215mm, blind-stamped address. Provenance: Sotheby's, 26 November 1980, lot 163.

On wave tensors and difficulties for theoretical physicists in finding defence work. Einstein is hard at work and suffering from 'bilious attacks'. He expresses sympathy with Lanczos's discomfort at Purdue University, but advises him to remain in his position. 'The Institute for Advanced Study is suffering from such a lack of money that there is a constant danger that the salaries of permanent employees will have to be reduced', and it is therefore obliged to be careful about taking on new commitments. So Lanczos should be cautious about moving: 'A temporary leave of absence for defence purposes is different. But I understand that people who have predominantly worked theoretically are not so much sought-after, especially once xenophobia comes into the question'. He goes on to add one more remark on Lanczos's work in wave-tensors: 'It is indeed true that, taken as a whole, this is invariant in special-relativistic terms, but not the way in which it is constituted from individual waves of different frequencies'. Einstein has not yet finished his own researches on complex space: 'As soon as I have something definitive I will send it to you'.

Einstein's remarks about defence work are poignant: although the Einstein-Szilard letter to F.D. Roosevelt on 2 August 1939 effectively launched the Manhattan Project to construct an atomic bomb, he was himself denied clearance to work on it in July 1940, in part because of his pacifist views. In June 1943 he was however reported to be advising the Ordnance Bureau of the US Navy on the theory of explosives.