A letter written by Albert Einstein that included his E = mc² equation was sold for more than $ 1.2 million (or R $ 6.4 million) at an auction in the United States, three times more than expected.
Experts say that the physicist has only three other known examples of the equation in his handwriting.
The auctioned letter is the only example of the equation in a private collection and has recently gone public, according to the RR auction auction house in Boston, United States, which sold the letter.
This equation was first published in a scientific article by Einstein in 1905 and establishes a similarity between matter and energy. The equation (energy is equal to the mass of the speed of the light square) is a fundamental concept in modern physics.
“This is an important card from a holographic and physical point of view,” RR Auction said in a statement, calling it “the best-known equation ever.”
A one-page letter in German, dated October 26, 1946 and addressed to the Polish-American physicist Ludwik Silberstein, who opposed some of Einstein’s theories.
According to the Associated Press news agency, the letter was part of Silberstein’s personal files, sold by his descendants, stating that the buyer was identified only as an anonymous document collector.
