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Animal reflectors or animal mirrors are important to the survival of many kinds of animal, and, in some cases, have been mimicked by engineers developing photonic crystals. Examples are the scales of silvery fish, and the tapetum lucidum that causes the eyeshine of dogs and cats. All these reflectors work by interference of light in multilayer ...
Space mirrors are designed either to increase or decrease the amount of energy that reaches a planet from the sun with the goal of changing the impact of UV radiation; or, to reflect light onto or deflect light off of a planet in order to change the sun's lighting conditions.
The azimuth can be used along with sun compass orientation to help animals navigate. The Sun's azimuth can be defined as the direction of a celestial object from the observer, expressed as the angular distance from the north or south point of the horizon to the point at which a vertical circle passing through the object intersects the horizon.
Some animals can navigate using celestial cues such as the position of the Sun. Since the Sun moves in the sky, navigation by this means also requires an internal clock. Many animals depend on such a clock to maintain their circadian rhythm. [14] Animals that use sun compass orientation are fish, birds, sea-turtles, butterflies, bees ...
Heliostats should be distinguished from solar trackers or sun-trackers that point directly at the sun in the sky. However, some older types of heliostat incorporate solar trackers, together with additional components to bisect the sun-mirror-target angle. A siderostat is a similar device which is designed to follow a fainter star, rather than ...
The Sun has also undergone periodic changes in luminosity that can have a significant impact on the Earth. [108] The Maunder minimum, for example, is believed to have caused the Little Ice Age phenomenon during the Middle Ages. [109] At the center of the Sun is the core region, a volume of sufficient temperature and pressure for nuclear fusion ...
Chimpanzee Ham, who flew America's first suborbital space flight on Jan. 31, 1961, toasts NASA's anniversary by sampling a Skylab space drink on Oct. 01, 1973 at the National Zoo in Washington D.C.
Celestial globes show the apparent positions of the stars in the sky. They omit the Sun, Moon, and planets because the positions of these bodies vary relative to those of the stars, but the ecliptic, along which the Sun moves, is indicated. There is an issue regarding the "handedness" of celestial globes.