I met a woman who claimed to have seen angels. "They are all around us," she explained. "You can spot them from the corner  of your eye.  They look like flickers of vibrating energy and appear in the moment of sadness, offering comfort  and unconditional love." Her words reflected widespread belief in the healing power of faith and were so touching that I couldn't bring myself to tell her it was her peripheral vision playing tricks on her . Fig.1.   The brain is unable to pr