Okay, I came here to talk about how the images are a bit soft and a quick, subtle pass of Richardson-Lucy deconvolution restores some detail (and enhances the film grain, that's a plus for me but some people may find it a bit too much -- it is still there in the pictures though).
And then I read your comment and you totally throw me into a Wikipedia rabbit hole with the Roman concrete... Speaking of which, what do you mean we can't make Roman concrete nowadays? Wikipedia even says that there are corporations and municipalities looking into it as a viable, environmental-friendly, long-lasting alternative to regular concrete[0] !
It's essentially an old meme; the exact details had been lost, since the technology was not in continuous use and no written record survived, but the footnote on Wikipedia details its reconstruction. This great paper: https://pubs.geoscienceworld.org/msa/ammin/article/98/10/166...
Essentially it relied on volcanic ash from specific locations, and they forensically traced those locations.
Right, that's the impression I got from reading. And it looks like we have regained that technology, which is what threw me off the remark. Will take a look at that paper, however I'm totally a stranger to most geo-something sciences, just a regular software engineer here (with quite a bit of scientific curiosity though).
And then I read your comment and you totally throw me into a Wikipedia rabbit hole with the Roman concrete... Speaking of which, what do you mean we can't make Roman concrete nowadays? Wikipedia even says that there are corporations and municipalities looking into it as a viable, environmental-friendly, long-lasting alternative to regular concrete[0] !
[0] https://en.wikipedia.org/wiki/Roman_concrete#Modern_use