Albert Einstein wasn't always convinced that the universe began with a big bang.

In a newly discovered manuscript, the famed physicist pondered over a so-called "steady state" theory and described a cosmos that can continuously and spontaneously replenish itself with new matter to form stars and galaxies. That would mean the overall density of space would remain stable, even as the universe expands.

Researchers believe Einstein's manuscript, found "hiding in plain sight" in the Hebrew University's online Albert Einstein Archives, was written in 1931 — nearly 20 years before British astrophysicist Fred Hoyle championed a similar and controversial theory.

Physicist Cormac O'Raifeartaigh, with the Waterford Institute of Technology in Ireland, tells Nature magazine he "almost fell out of his chair" when he realized what he had found. The document, written in German — Einstein's native tongue — was mistakenly identified as a first draft of another paper.

"If only Hoyle had known, he would certainly have used it to punch his opponents," O'Raifeartaigh told Nature.

Ultimately, Hoyle's theory didn't hold up to observational evidence. And Einstein apparently abandoned the idea when his calculations didn't jibe with equations for his general theory of relativity. The manuscript, translated into English and posted on the preprint server arxiv.org, shows Einstein's correction to his original calculation.

A paper about Einstein's rediscovered manuscript has been submitted to the European Physical Journal.

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