Ultraviolet not necessarily coincide; for example one applied physics publication used a boundary of 190 nm between hard and soft UV regions. Very hot objects emit UV radiation (see black-body radiation). The Sun emits ultraviolet radiation at all wavelengths, including the extreme ultraviolet where it crosses into X-rays at 10 nm. Extremely hot stars emit proportionally more UV radiation than the Sun. Sunlight in space at the top of Earth's atmosphere (see solar constant) is composed of about 50% infrared light, 40% visible light, and 10% ultraviolet light, for a total intensity of about 1400 W/m in vacuum. However, at ground
Yarkovsky–O'Keefe–Radzievskii–Paddack effect not pass through the centre of mass. Both fins present the same cross section to the incoming light (they have the same height and width), and so absorb and reflect the same amount of energy each and produce an equal force. Due to the fin surfaces being oblique, however, the normal forces from the reradiated photons do not cancel out. In the diagram, Fin A's outgoing radiation produces an equatorial force parallel to the incoming light and no vertical force, but Fin B's force has a smaller equatorial component and a vertical component. The unbalanced forces on the two fins