A rare Albert Einstein handwritten letter has sold at International Autograph Auctions in Marbella, Spain for €44,000 against an estimate of €40,000-€50,000.
The two page letter dated 19th April 1950 is written in German and addressed To Ernst Gabor Straus, A German-American mathematician who co-authored many theories with Einstein.
The contents of the letter contained several mathematical references, calculations and formula relating to the relativistic theory of gravitation.
The letter reads:
'The compatibility proof can be simplified so much that it is not necessary to specify conditions for different types of cuts. One gives from the compatible system'
'The only thing that changes in our table is that (in the first row) there is an equation between the g i k, so that only 15 functions remain free. Sub does not change in the counting of quantities and relationships for the derived g i k. The adjunction only adds a single cut condition, so that apart from the free coordinate a b l only 19 fractions remain free instead of 20.
'However, this means a far-reaching change in the way of determining the functions for the system of equations, since the additional cutting condition can only be clearly expressed for a special choice of coordinates'.
Albert Einstein memorabilia is one of our 'blue chip stocks' of collecting.
In November 2021 a 54 page manuscript written by Einstein and Michele Besso, in which they tested calculations that became the foundations of the Theory of Relativity, sold for $13m at a Christies auction in Paris, making it both the most expensive piece of Albert Einstein memorabilia and the most valuable scientific document ever sold.
That manuscript had previously been sold by Christies in 2002 for $559,000.