Is this some kind of fake AI written article? I'm skimming along and see a passage:

    Recent theoretical and experimental studies have produced
    several unusual and interesting results on the cold fusion
    of matter experienced on dense lithium [24]. The existence
    of this exciting propriety of matter relates to zero-point
    energy estimates that suggest quantum effects play a
    significant role in shaping the phase diagram of lithium.

From the beginning of the abstract it looked like this might be an interesting article, but the probability is basically zero that a genuine advance in stone-structure-tomography for giant structures would include such an aside on "cold fusion" and "zero-point energy".

Why do you think this is reputable research? MDPI does not inspire confidence, and it's written by a UFOlogist-chemist. And what is "radar ultrasound"?!

I've often wondered about how even with Legos it's very difficult to create perfectly aligned little passages running diagonally in such structures.

Would be cool to learn how they did it with multi-ton blocks of stone.

OP here: I posted it because there was some woo versions of it posted in 'new' on HN, and this was the source document but the original title wouldn't fit in the 80 char HN limit. I've seen it show up around X as well, and figured this would be the place to assess the value of the original document.

In the acknowledgements it also states: "We also thank the Italian Space Agency for providing the SAR data." which was interesting because, if they had in fact done this, there's a diplomatic and culture angle on doing archeology by other means like this without the the host country's permission.

If it's a hoax, it's as persuasive as any other irreproducible result in the social sciences. If it's not a hoax, it's pretty interesting.

Edit: there's a version of this on arxiv from August 2022 (https://arxiv.org/abs/2208.00811) so there's definitely something suspicious about it now. happy to delete, or really, what would motivate that effort.