Current historians who study ancient civilizations have the problem of very little being preserved. They go on whatever, perhaps by chance, happened to survive. King Tut is studied NOT because he was an important king, but because we have LOTS of his stuff. (What if America is destroyed and all that is left is the Gerald Ford Library?}
Future Historians may have the problem of having too much written down, recorded, emailed, blogged, tweeted. Or they may have the problem current historians have if some of these technologies go out-of-date so a lot is lost. Floppy's are already unreadable, Video Tapes and VCR's are degrading, beta-tapes--- as your grandparents what they were. They may also have the Galaxy Quest problem of mistaking our TV shows for historical documents (oh that poor Gilligan!).
What do we and don't we preserve?
- Almost every TV show and Movie produced since DVDs came out, no matter how bad, is on DVD. Is there a directors cuts of Dude, where's my car?? Will future generations need that?
- News shows are not preserved. Too bad- I might want a complete set of THE DAILY SHOW and THE COLBERT REPORT. Future historians may have the problem of mistaking these shows for satire.
- Quiz shows are not preserved. Too bad- I liked BEAT THE GEEKS but all I have are some video tapes I recorded when it was on.
- Sporting events- This is borderline since there are DVDs of past Superbowl's, World Series, etc, but not of ordinary games.
- Many TV movies don't make it to DVD. Is that a loss?
- Much TV from before the video tape age is lost. Some survives. It is somewhat arbitrary. I Love Lucy was done on some sort of medium that survived, others did not.
- A very odd case: Dr. Who. There are rumors that some fans audiotaped the early episodes and that the only form in which they are preserved. See here, here.
- Commercials. Aside from arbitrary things people happen to have taped, most commercials will not survive! What will future generations do without all of those insurance companies claiming that they are cheaper than the other ones?
- What if the only knowledge of complexity theory that survives is Lance's book. That would be okay!
- What if the only knowledge of complexity theory that survives are the Bill/Lance Podcasts. Hmm...
What about journal articles? Do we do the future a DISservice by publishing too much and making it harder to find stuff? Or will they have the tools to find what they want? Today we have Google Scholar and some other tools- but are we putting all of our eggs in one basket? Will all of our papers survive or only the good ones? Or is every paper a gem worthy of preserving for future generations? While I doubt this is true, you never know when someone is going to need the Canonical a-ary Ramsey Theorem to prove something in geometry.