The Modern Forgery Hypothesis

[JustAnotherTheory]

foldouts are not documented from that period

Many other things are not documented from that period. The most obvious is the text, if it is a cipher, it is unbreakable, from a period where homophonic ciphers were the most advanced technology.

Then the Alberti disk on f57v. That kind of cipher disk, if indeed that is what is depicts, was not invented at that time.

The plump bodies of the nymphs, were not at all depicted in that way in early 1400s. Not even close.

Poxleber as a word is only recorded in literature after 1500.

Some images in the cosmology section have non-trivial parallels in microscopy imagery.

All of these observations, and more, should be enough to at least look at this with a critical eye.