One thing I find interesting is how interested people are by these tiles, myself included. From the Wikipedia article, it seems pretty clear that this was the work of one man who believed in a crazy conspiracy theory - humans can send their dead to Jupiter where they will be resurrected, and his proof is wholly found in fictional stories. But how he went about expressing it, the effort and permanence of his method of communication, somehow makes it a fascinating mystery. If he had instead written the same cryptic message on a cardboard sign and stood along the road, nobody would have given him or his ideas a second thought.

Yup, these used to be all over the place in Philly. There are less of them now because they often get covered over when road work happens.