The juicy content of a sealed 300-year-old letter is now available to everyone, thanks to a new algorithm that deconstructs X-rays to virtually unfold documents. Researchers at MIT developed the virtual letter opening method to read unopened letters that, due to wax seals and intense creases, are too fragile to open.
Wait a minute, did I say this letter is juicy? It̵
Curious researchers cannot open these unsealed letters because they are all letterlocked. Letter locking, a process of folding and sealing a letter to the point that it cannot be opened without tearing, has been a common trick in Europe and other continents for hundreds of years. It serves as a deterrent to snoops, who by opening a “locked” letter would damage it and leave evidence that the letter has been tampered with.
After 300 years in a dusty French box, the letters are too fragile to ‘unlock’ without causing significant damage. And even in cases where researchers could successfully unfold a letter, clearing the letter lock, which is a valuable piece of history in itself.
Researchers can use this virtual “unlock” method to reveal the contents of unopened letters, which is quite common given the prevalence of letters before the late 20th century. The technology may also be useful for researchers studying other fragile documents, such as old books and scrolls.
Source: Nature Communications via New Scientist