Albert Einstein's letter warning of atomic weapons sold at auction for Rs 32.7 crore

In the note, Albert Einstein alerted US President Franklin Roosevelt that Germany could be working on nuclear weapons. (Image credit: AFP, Chritie's)

A copy of a letter signed by Albert Einstein that helped usher in the nuclear age in 1939 has recently been sold at a Christie's auction for $3.9 million (about Rs 32.7 crore). The letter, whose original would eventually reach the desk of US President Franklin Roosevelt and lead to the development of the world's first atomic bomb, was also what Einstein considered his "one great mistake".

The original letter is part of the Franklin D. Roosevelt Library's collection in New York.

In the note, Einstein alerted the US President that Germany could be working on nuclear weapons. "Recent work in nuclear physics made it probable that uranium may be turned into a new and important source of energy," he wrote. This energy, he warned, could be harnessed "for the construction of extremely powerful bombs." Given the threat of this development, Einstein urged the US government to initiate its own research into nuclear fission.

Peter Klarnet, senior specialist for Americana, books, and manuscripts at Christie's described the letter as "one of the most influential letters in history".

Written in the summer of 1939, the letter warned that Germany could develop "extremely powerful bombs" using uranium and urged the US President to "speed up" the country's work on the subject eventually leading to the Manhattan Project and the development of atomic bombs.

According to a Business Insider report, the copy sold at the auction with Einstein's signature was the only version in private hands. It was part of a larger collection belonging to the late Microsoft co-founder Paul Allen who had bought the letter in 2002 for $2.1 million.

Prior to that, the letter had belonged to publisher Malcolm Forbes, who had acquired it from Hungarian physicist Leo Szilard's estate. As per The Guardian, Szilard wrote the letter and Einstein signed it. Both the Jewish scientists had fled Europe during Adolf Hitler's rise to power.

But Einstein soon felt that the use of nuclear weapons was not justified especially after Germany surrendered.

"Woe is me," the scientist is known to have said when he learned of the attacks on Hiroshima and Nagasaki, Japan that killed about 200,000 people in 1945.