Search results
Results from the WOW.Com Content Network
Optical phenomena encompass a broad range of events, including those caused by atmospheric optical properties, other natural occurrences, man-made effects, and interactions involving human vision (entoptic phenomena).
Refraction of light at the interface between two media of different refractive indices, with n 2 > n 1. Since the phase velocity is lower in the second medium (v 2 < v 1), the angle of refraction θ 2 is less than the angle of incidence θ 1; that is, the ray in the higher-index medium is closer to the normal.
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.
Fig. 1: Underwater plants in a fish tank, and their inverted images (top) formed by total internal reflection in the water–air surface. In physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into ...
In atmospheric applications, refractivity is defined as N = n – 1, often rescaled as either [60] N = 10 6 (n – 1) [61] [62] or N = 10 8 (n – 1); [63] the multiplication factors are used because the refractive index for air, n deviates from unity by at most a few parts per ten thousand.
Refraction occurs when light travels through an area of space that has a changing index of refraction; this principle allows for lenses and the focusing of light. The simplest case of refraction occurs when there is an interface between a uniform medium with index of refraction n 1 and another medium with index of refraction n 2.
Due to refraction, the straw dipped in water appears bent and the ruler scale compressed when viewed from a shallow angle. Refraction is the bending of light rays when passing through a surface between one transparent material and another. It is described by Snell's Law: