The coherence properties of sunlight were first studied by Verdet around 1869 and were later examined by other scientists. However, all the previous calculations assumed that the Earth is in the far zone of the Sun, an assumption that is incorrect. An investigation of why Verdet's result is nevertheless correct reveals a surprising property of radiation from incoherent sources.

BACKGROUND Previous experimental studies showed that single ultraviolet B (UVB) light irradiation increased levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a well-established biomarker of carcinogenesis and oxidative DNA damage, in epithelial cells in animals and humans. We conducted for the first time an epidemiologic study to investigate the correlations among levels of oxidative DNA damage, ...

deficiency of diet or sunlight, or more frequently where there is a relative deficiency in both these factors. Improvement in diet leads to improvement in symptoms only when sunlight is available and, conversely, the provision of sunlight for cases on deficient diet is of little avail. An analysis of 400 urban cases of late rickets and osteomalacia shows that about half ?he patients live under ...