Excerpted from Exploring the Miraculous (OSV): On May 7, 1979, Philip Serna Callahan, an accomplished biologist who has written fourteen books and two hundred scientific papers, was invited by the rector of the shrine, Msgr. Enrique Salazar, to conduct infrared photographic tests on the tilma. Infrared photography allows the scientist to obtain “historical data of the historical derivation, the ..
