Search results
Results from the WOW.Com Content Network
Atmospheric refraction of the light from a star is zero in the zenith, less than 1′ (one arc-minute) at 45° apparent altitude, and still only 5.3′ at 10° altitude; it quickly increases as altitude decreases, reaching 9.9′ at 5° altitude, 18.4′ at 2° altitude, and 35.4′ at the horizon; [4] all values are for 10 °C and 1013.25 hPa ...
Looming of the Canadian coast as seen from Rochester, New York, on April 16, 1871. Looming is the most noticeable and most often observed of these refraction phenomena. It is an abnormally large refraction of the object that increases the apparent elevation of the distant objects and sometimes allows an observer to see objects that are located below the horizon under normal conditions.
Common optical phenomena are often due to the interaction of light from the Sun or Moon with the atmosphere, clouds, water, dust, and other particulates. One common example is the rainbow , when light from the Sun is reflected and refracted by water droplets.
Due to a normal atmospheric refraction, sunrise occurs shortly before the Sun crosses above the horizon. Light from the Sun is bent, or refracted, as it enters Earth's atmosphere. This effect causes the apparent sunrise to be earlier than the actual sunrise. Similarly, apparent sunset occurs slightly later than actual sunset.
In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. [1] Refraction of light is the most commonly observed phenomenon, but other waves such as sound waves and water waves also experience refraction. How much a wave ...
Atmospheric refraction influences the apparent position of astronomical and terrestrial objects, usually causing them to appear higher than they actually are. For this reason navigators, astronomers, and surveyors observe positions when these effects are minimal.
Distorted image due to the mirage. The Novaya Zemlya effect is a polar mirage caused by high refraction of sunlight between atmospheric thermal layers.The effect gives the impression that the sun is rising earlier than it actually should, and depending on the meteorological situation, the effect will present the Sun as a line or a square — sometimes referred to as the rectangular sun ...
Atmospheric refraction causing an object below the horizon to be visible. If the measurement is close enough to the surface, this downward curve may match the mean curvature of the Earth's surface. In this case, the two effects of assumed curvature and refraction could cancel each other out, and the Earth will then appear flat in optical ...