Every May and December, thousands of Catholics gather in Naples to witness a miracle: The dried blood of Saint Januarius, which is kept in small capsules, liquefies when it’s brought near his body.

Januarius was martyred in 305, and the “miracle of the blood” has been happening since at least 1389, which is pretty impressive.

But investigator Joe Nickell notes that a thixotropic gel such as hydrated iron oxide remains highly viscous until it’s stirred or moved. And the same miracle is claimed for several other saints … all in the Naples area. Hmm.