One of the major symptoms encountered is that of hyperventilation, which produce dizziness, faintness, etc. Darwin's disappointment brought on ten days of vomiting, faintness and stomach distress. RR Lyraes have proven difficult to observe in external galaxies because of their intrinsic faintness. Its relative faintness suggests an M0 V spectral type. The unusual faintness of white dwarfs was first recognized in 1910. He pointed out that it was difficult to recognize the nebula because of its faintness. Its relative faintness means that it is not practical for navigation.