An Albert Einstein "puzzle" has been solved thanks to a missing page of his manuscript emerging in a collection of his writings acquired by Jerusalem's Hebrew University, officials announced Wednesday.
The handwritten page, part of an appendix to a 1930 paper on the Nobel winner's efforts towards a unified field theory, was discovered among the 110-page trove the university's Albert Einstein archives received some two weeks ago.
Most of the documents constitute handwritten mathematical calculations behind Einstein's scientific writings in the late 1940s.
There are also letters that Einstein, born in Germany in 1879, wrote to collaborators which deal with a range of scientific and personal issues, including one to his son, Hans Albert.
The 1935 letter to his son expresses concern about the rise of the Nazi party in Germany.
Nearly all the documents had been known to researchers and available in the form of copies – "sometimes better copies, sometimes very poor copies", said Hanoch Gutfreund, scientific advisor to the university's Einstein archives.
Gutfreund, a physics professor and former president of the university, said the eight-page appendix of the 1930 unified theory paper had never been published, though researchers had copies of it.
"But in the copies we had, one page was missing, and that was a problem. That was a puzzle," Gutfreund told AFP.
"And to our surprise, to our delight, that page is now here. It came with the new material," he said.
Hebrew University said: "This article was one of many in Einstein's attempts to unify the forces of nature into one, single theory and he devoted the last 30 years of his life to this effort."
The collection, acquired through a donation from the Crown-Goodman foundation in Chicago, was bought from Gary Berger, a North Carolina doctor who had a private collection of Einstein writings.
Gutfreund refused to divulge the sum paid for the 110 papers.
Einstein was one of a founding father of the Hebrew University and served as a non-resident governor of the Jerusalem institution.
When the German-born physicist died in 1955, he bequeathed the university his archives, with curator Roni Grosz saying its 82,000 items make it the world's most extensive collection of Einstein documents.