Albert Einstein was undoubtedly one of the greatest scientists that has ever lived. The German-born theoretical physicist is famous for his work developing theories about gravity, quantum mechanics, and importantly, his unruly hairstyle.

In November 2021, a 54-page manuscript written by Einstein and another scientist, Michele Bessom, was put on auction in Paris. Dated to 1915, the pages are sprawled with their calculations, doodles, and symbols. Many of which even feature notes in the margins such as “stimmit!”, which is German for “it works!”. Experts think around 26 of the pages are written by Einstein, 25 written by Bessom, with three pages being a joint endeavor.

The calculations aimed to describe an anomaly in Mercury’s orbit. Unfortunately for the pair, these equations were actually incorrect, though Einstein used parts of them to build new equations in his future work. Using these thoughts as the foundation for his most famous work: the theory of relativity.

“The manuscript isn’t bound, and there are many different types of loose paper, so you get the impression of a working document that’s full of energy, as if both men would grab the first page they could find to scribble their findings on,” Vincent Belloy, a specialist in books and manuscripts, said in a statement shared by the auction house. Christie’s, the charity that was auctioning off the document, also described the pages as “one of the most important scientific documents of the 20th century.”

So how much exactly did this important document sell for? Before the auction itself, the document was thought to sell for $3.5 million. Though this was a huge underestimate, with someone buying the pages for just over $13 million! This is not the first document this year from Einstein that has left a hefty hole in someone’s pocket. A letter where the genius wrote out his famous equation E=mc2, sold in Boston for a whopping $1.2 million.