Radioactive waste is harmful for ten thousand years. Written language has been around for only about half that long, and some of it is already unreadable to us. So how do we warn the people of the far future not to dig up our waste storage facilities? In the eighties the US government assembled experts from various disciplines and asked them to come up with some ideas. The problem before the Human Interference Task Force was threefold: anyone who wanted to leave a message for the people of the year 12000 would have to decide not only what to convey, but how to convey it and how to make the message last for ten thousand years. You can read the message they came up with and get the creeps from it here (“This place is not a place of honor…. What is here is dangerous and repulsive to us…. The danger is still present”), but what about the other two parts of the problem? My favorite proposed solution (so far) is the creation of the ray cat and its attendant mythology. Much as some have suggested modern Europeans are still repulsed by the idea of eating horse meat because their distant ancestors worshipped the horse goddess Epona, others think we can make proximity to radiation abhorrent to our distant descendants, even if no knowledge of the current world survives.

But why a ray cat and not a ray dog or a ray chicken? Dogs and chickens are far more useful, so I’d think the people of 12000 would be more likely to have them around. Is it because superstition clusters readily around the cat? Is it because they are insidious, and radioactivity harms in an insidious way? Ask Françoise Bastide and Paolo Fabbri—it was their idea.