Standing before the Virgin of the Rock (well, actually, facing one with another behind), I was quite struck by how much data Leonardo left behind. We have his finished projects (in varying states of repair), prototypes, cartoons, unfinished work and numerous clones/copies or homages by students and followers. We have enough that when we see another painting that might be Leonardo, the experts can debate for ages whether it is or isn't, claiming various "facts" by reference to the existing body of data.
Two things flow from that for me.
Someone should write the Da Vinci guide to IT with chapters to include: practice lots first, prototype everything, freely licence your work, break projects into sensible chunks, reuse what others have done, careful with plaster, train youngsters in your work, don't be afraid of new methodologies ... And more
How much data will we leave behind, individually, for discovery 500 years from now? Much of my electronic data is already lost - on countless 5 1/4" and 3 1/2" discs, or on zipdrives or on machines long since destroyed at companies I've long since left.
But in the last few years, increasing amounts of data are stored in "free" repositories such as Facebook and Gmail. How long will they keep my data? Not so much as "on the Internet no one knows you're a dog" but "on the Internet no one knows you're dead"?
As data grows following an inexorable rise from petabytes through exabytes to zettabytes and whatever comes after that, what will these companies do with the data? Prune it every 20 years? Every 50? Every 100? Surely they have to at some point? Assuming they're still around anyway.
I was toying with the idea of writing a script that would activate when I'm gone (note to self ... On the Internet ....) and write a random weekly post to my blog, which is kindly hosted by google. Would they prune my data then?
Already I see the ghosts of friends who died tragically young follow me around the 'net - "people you used to know" perhaps. As I get older and assuming I stay sane, this will doubtless become more common.
In 200 years or more, the data we all leave behind will be an interesting archaeological source for how we lived our lives, our passions and fashions, our moods, tolerances and intolerances. If it's still there.