If, during an otherwise unremarkable afternoon, you happen to look at the sky and see a dazzling circular rainbow around the sun, you might wonder whether you’re witnessing a portent or miracle. There is a scientific cause for such a phenomenon—a meteorological anomaly known as a 22-degree halo—but explications of sunrays and ice crystals in the atmosphere would hardly dampen the feelings of disbelief and awe such a sighting might provoke.