EINSTEIN, Albert (1879-1955). Autograph letter signed ("Albert") to Michele Besso, Geneva, 28 July 1925.

In German, in pencil on thin paper, two pages, 242 x 192mm. Envelope; with three newspaper cuttings relating to Einstein.

The equations for a new mixed unified field theory: "a splendid possibility which could well correspond with reality."

Einstein had hoped to see Besso in Bern, but his children are impatient to see him, and he must also see Mileva and his friend Marcel Grossmann, who is ill. "I would have liked to have presented you in person with the egg which I have laid recently, but now I shall do it in writing."

He then presents the equations for a mixed unified theory, noting that if one stipulates that the two elements are symmetrical, one reaches the old gravitational law for empty space. "If you drop the hypothesis of symmetry, you obtain as a first approximation the laws of gravitation and Maxwell's field laws for empty space, in which the asymmetrical parts [of the tensor] represent the electromagnetic field. This is a splendid possibility which could well correspond with reality. The question is now whether this field theory is incompatible with the existence of atoms and quanta ... If only the mathematics of special problems were easier! But there are ghosts everywhere."

In a postscript, Einstein notes that he penciled this letter during "a boring sitting of the League of Nations."

Michele Besso (1873-1955)
Sold by his heirs; Christie's, Einstein: Letters to a Friend Part I, 13 July 2017, lot 26
Acquired by the current owner at that auction

Pierre Speziali (ed.) Albert Einstein. Michele Besso. Correspondence 1903-1955. Paris: Hermann, 1972. No. 76