The color in the pigment of the stain is caused when molecules absorb light in the visible wavelength range (400-780 nm) [10]. The wavelengths that are not absorbed will be reflected instead and are visible to the human eye. For example, red wine stains are red because the molecules absorb every wavelength that is not in the red range, and the red wavelengths (500-600 nm) are then reflected to ...

Why do plants reflect in the green and have a "red edge" in the red, and should extrasolar photosynthesis be the same? We provide (1) a brief review of how photosynthesis works, (2) an overview of the diversity of photosynthetic organisms, their light harvesting systems, and environmental ranges, (3) a synthesis of photosynthetic surface spectral signatures, and (4) evolutionary rationales for ...

About 80 to 85 per cent of the fecal bile pigmients are believed to be derived from the hemoglobin of senescent erythrocytes that are destroyed in the reticuloendothelial system (1). It is not known, however, whether the hemoglobin of sequestered red cells is converted quantitatively to bilirubin and eventually to urobilinogen, or is in part metabolized to other products (2, 3). Earlier studies...