Physical books are a whole lot easier to keep going in an unbroken chain. Any literate person can sit down and physically copy it out. Your wax or clay tablet becomes someone else’s papyrus scroll, becomes yet a later person’s vellum folio, becomes a pulp mass-market paperback and can go right back to being inscribed in wax or chiselled into stone if need be.
Even then there is so much that has been lost - mainly because no one saw fit to keep it.
And so much that we can’t read because we either don’t understand the alphabet or the language or both.
The same will apply to digital info if not more so since it is now trivially easy to produce and record information. Which means that most of it is not considered worth keeping.
How many photos for example never get printed out? How many of the ones that aren’t will ever be looked at by anyone - including the people who took them?
Keeping an unbroken line of information is a nice idea and certainly worth striving for - so far the indications are not good that it will be possible.
For an interesting if rather chilling discussion of some of the difficulties and how one might get around them in a very specialised field:
overview article:
“Expert Judgment on Markers To Deter Inadvertent Human Intrusion Into the Waste Isolation Pilot Plant”
http://www.wipp.energy.gov/PICsProg/Test1/SAND%2092-1382.pdf
“Communication Measures To Bridge Ten Millennia,”
By the way the last one contains a wonderful bit of sci-fi geekery. Written in 1984, it suggests that at some point:
…messages vitally important to the race, affecting its survival, will be transmissible by microsurgical intervention with the human molecular blueprint…
The author adds: the technology required for this form of temporal communication is far from available as yet. Therefore, in what follows, this theoretical possibility will not be further considered.
