Cyrus Reed Teed was a U.S. eclectic physician and alchemist turned pseudoscientific religious leader and self-proclaimed messiah. In 1869, claiming divine inspiration, Teed took on the name Koresh and proposed a new set of scientific and religious ideas which he called Koreshanity, including the belief in the existence of a concave, or "cellular", Hollow Earth cosmology positing that the sky, humanity, and the surface of the Earth exist on the inside of a universe-encompassing sphere.