A letter from the famous physicist Albert Einstein that includes one of few known examples of his equation, E = mc2, sold for more than $1.2 million at an auction this week.
The auction began on May 13 and officially ended Thursday, with an anonymous buyer identified as a document collector winning the letter in the over million-dollar bid.
Bobby Livingston, executive vice president at Boston-based RR Auction, which oversaw the bidding process, told The Associated Press that the letter sold for far more than the $400,000 they had initially predicted.
The one-page, handwritten letter, which recently became public, was sent to Polish American physicist Ludwik Silberstein and is dated Oct. 26, 1946, according to an image of the letter and description included on RR Auction's website.
“It’s an important letter from both a holographic and a physics point of view,” Livingston told the news agency.
The letter to Silberstein, who was widely known for challenging Einstein’s theories, included the groundbreaking equation that went on to influence the field of physics, showing that mass and energy are interchangeable and that time is not an absolute.
According to RR auction, Einstein wrote in the letter, "Your question can be answered from the E = mc2 formula, without any erudition.”
The auction website said Einstein in his later years explained on-camera that his famous equation “followed from the special theory of relativity that mass and energy are but different manifestations of the same thing.”
“Furthermore, the equation E is equal to m c-squared, in which energy is put equal to mass multiplied by the velocity of light squared, showed that a very small amount of mass may be converted into a very large amount of energy, and vice versa,” Einstein explained.
RR Auction noted that according to archivists at the Einstein Papers Project at Caltech and the Hebrew University of Jerusalem, there are only three other known examples of Einstein writing out the famous equation.
Livingston told the AP that the letter auctioned Friday was found among Silberstein’s personal archives that were sold by his descendants.
Five parties were initially engaged in a bidding war over the letter, Livingston said, though it eventually came down to two prospective buyers.