Here's your explanation chief.
Joe Nickell notes: "Not surprisingly, perhaps, Sun Miracles have been reported at other Marian sites—at Lubbock, Texas, in 1989; Mother Cabrini Shrine near Denver, Colorado, in 1992; Conyers, Georgia, in the early to mid-1990s".[23] Nickell also suggests that the dancing effects witnessed at Fatima may have been due to optical effects resulting from temporary retinal distortion caused by staring at such an intense light.[23]
Professor Auguste Meessen of the Institute of Physics, Catholic University of Leuven, has stated sun miracles cannot be taken at face value and that the reported observations were optical effects caused by prolonged staring at the sun. Meessen contends that retinal after-images produced after brief periods of sun gazing are a likely cause of the observed dancing effects. Similarly Meessen states that the color changes witnessed were most likely caused by the bleaching of photosensitive retinal cells.[24] Meessen observes that Sun Miracles have been witnessed in many places where religiously charged pilgrims have been encouraged to stare at the sun. He cites the apparitions at Heroldsbach, Germany (1949) as an example, where many people within a crowd of over 10,000 testified to witnessing similar observations as at Fatima.[24] Meessen also cites a British Journal of Ophthalmology article that discusses some modern examples of Sun Miracles.[25] While Meessen suggests possible psychological or neurological explanations for the apparitions he notes, "It is impossible to provide any direct evidence for or against the supernatural origin of apparitions".[24] He also notes that "[t]here may be some exceptions, but in general, the seers are honestly experiencing what they report." [24]
De Marchi claims that the prediction of an unspecified "miracle", the abrupt beginning and end of the alleged miracle of the sun, the varied religious backgrounds of the observers, the sheer numbers of people present, and the lack of any known scientific causative factor make a mass hallucination unlikely.[26] That the activity of the sun was reported as visible by those up to 18 kilometres (11 mi) away, also precludes the theory of a collective hallucination or mass hysteria.[26]
Despite these assertions, not all witnesses reported seeing the sun "dance". Some people only saw the radiant colors. Others, including some believers, saw nothing at all.[27] No scientific accounts[clarification needed] exist of any unusual solar or astronomic activity during the time the sun was reported to have "danced", and there are no witness reports of any unusual solar phenomenon further than 64 kilometres (40 mi) out from Cova da Iria.[28]
Miracle of the Sun - Wikipedia, the free encyclopedia