Using computer algorithms and an X-ray scanner designed for dental research, an international team of researchers unlocked the secrets of a tightly folded letter that had been sealed since 1697 – without opening it.
The ‘virtual unfolding’ of the letter – the culmination of a four-year project described in an article published Tuesday in the journal Nature Communications – points to a new line of historical research on the centuries-old practice of letter closure. This is the term used to describe the use of origami-like folds to hide the contents of letters before envelopes were widely used in the mid-1800s.
“It’s a dream come true in the field of conservation,” said Jana Dambrogio, curator at the Massachusetts Institute of Technology’s research library and one of the 11 authors of the article.
Experts believe that the technique used to describe the text of the letter, which reveals a type of imaging called X-ray micromography, may also be applicable in healthcare and engineering.
Letterheads vary in complexity, depending on the expertise of the sender and recipient and how tedious they want their messages to be during transport. Some involved dozens of folds, which had packets about the size of cards.