Supernatural explanations, such as those by Father Pio Scatizzi, who argues that observers in Fátima could not be collectively deceived, or that the effect was not seen by observatories in distant places because of divine intervention have been dismissed by critics who say those taking part in the event could certainly be deceived by their senses, or they could have experienced a localized, natural phenomenon. Others, such as professor of physics Auguste Meessen, suggest that optical effects created by the human eye can account for the reported phenomenon. Meessen presented his analysis of apparitions and "Miracles of the Sun" at the International Symposium "Science, Religion and Conscience" in 2003. While Meessen felt those who claim to have experienced miracles were "honestly experiencing what they report", he 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 concluded that the color changes witnessed were most likely caused by the bleaching of photosensitive retinal cells. Shortly after the miracle, the Catholic lawyer named Coelho said in his article that he returned to Fatima with his friends the day after and saw the exact same motions and colour changes in the Sun. He says, "One doubt remained with us however. Was what we saw in the Sun an exceptional thing? Or could it be reproduced in analogous circumstances? Now it was precisely this analogy of circumstances that presented itself to us yesterday . We could see the Sun half overcast as on Saturday. And sincerely, we saw on that day the same succession of colors, the same rotary movement, etc."