At Yucca Mountain, where nuclear waste will remain stored for over 1,000,000 years, the issue is how to create a warning durable enough to last for that long. The answer is in diversification:
We have looked very closely at what WIPP is doing—the Waste Isolation Pilot Plant in New Mexico. They did a study with futurists and other people-sociologists and language specialists. They decided to come up with markers in seven languages, basically like a Rosetta Stone, with the idea that there will always be someone in the world who studies ancient languages, even 10,000 years from now, someone who will be able to resurrect what the meanings of these stelae are. They will basically say, “This is not a place of honor, don’t dig here, this is not good material,” etc.
New problems, classic solutions (via Kottke). One of my students at Parsons arrived at the same solution earlier this year when I put the challenge to my Experimental Typography class. Project description here.