Back when I was writing my thesis, I hung out a lot with physicists working with a small detector - so I got a glimpse, occasionally, of small things being scanned and imaged in incredible detail. It made me aware of the fact that with modern technology, a lot of really mind-boggling things are possible.
Something along the same lines of "really cool things that are now possible" is the virtual unfolding of old letters. Over the centuries, quite a lot of letters were never delivered, due to some reason or other, and most of them still hang out somewhere. Now, before the advent of the modern envelope, those letters were folded and sealed, and the folding was sometimes very intricate. In order to read the letters, though, this means that they have to be opened... and apparently that is not always easy, and usually leads to some damage to the letter.
Enter modern technology. Or, to be more precise, X-ray microtomography, which makes it possible to scan the many layers of the letterlocked letters, then reconstruct the whole thing in a 3D-simulation, and finally to unfold the whole thing virtually so it can actually be read. Isn't that incredible?
You can read more about this in
this article on nature.com titled "Unlocking history through automated virtual unfolding of sealed documents imaged by X-ray microtomography", or, if you prefer to read German, there's also an article
here on Spiegel.de.
And now I want to learn at least one of these cool folding methods...