The Committee to Nuke Elysium

But who knows what language its discoverers will understand in thousands or hundreds of thousands of years—or even if they will be human beings? Holtorf points out that a much earlier attempt to warn off future excavations, the Egyptian pyramids, were looted within a generation. “The future will be radically different from today,” says archaeologist Anders Högberg, who is also from Linnaeus University. “We have no idea how humans will think.”

…

The sapphire disk is one product of that effort. It’s made from two thin disks, about 20 centimeters across, of industrial sapphire. On one side, text or images are etched in platinum—Charton says a single disk can store 40,000 miniaturized pages—and then the two disks are molecularly fused together. All a future archaeologist would need to read them is a microscope. The disks have been immersed in acid to test their durability and to simulate ageing. Charton says they hope to demonstrate a lifetime of 10 million years.