A recent New Yorker online cartoon -- quite longform for them -- suggests that since our civilization is doomed (presumably by some combination of President Trump and global warming), we ought to leave not merely time capsules, but deliberately confusing ones, for Reasons.
But that's all we can leave; it's all our forebears have left us, and what we make of them is, at best, a guess. We're often wrong. The fine details of people's lives are generally lost or at best distorted.
We will leave puzzles. This is brilliantly spoofed in David Macaulay's Motel of the Mysteries but it's a fact. There's no need to work at it.
3 months ago