Search results
Results From The WOW.Com Content Network
The global irradiance on a horizontal surface on Earth consists of the direct irradiance E e,dir and diffuse irradiance E e,diff. On a tilted plane, there is another irradiance component, E e,refl, which is the component that is reflected from the ground. The average ground reflection is about 20% of the global irradiance.
Four original oil paintings by American artist Ellery Kurtz were flown in one of NASA's GetAway Special (G.A.S.) containers mounted to a bridge in the shuttle cargo bay. These original works of art are the first oil paintings to enter Earth's orbit. This NASA GAS canister, designated G-481, was the 46th such canister flown aboard a Space Shuttle.
This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outside the atmosphere of Earth. The field of astronomy features an extensive vocabulary and a ...
The irradiation illusion is an illusion of visual perception in which a light area of the visual field looks larger than an otherwise identical dark area. It was named by Hermann von Helmholtz around 1867; [1] but the illusion was familiar to scientists long before then; Galileo mentions it in his 1632 book Dialogue Concerning the Two Chief World Systems. [2]
Mathematically, for the spectral power distribution of a radiant exitance or irradiance one may write: =where M(λ) is the spectral irradiance (or exitance) of the light (SI units: W/m 2 = kg·m −1 ·s −3); Φ is the radiant flux of the source (SI unit: watt, W); A is the area over which the radiant flux is integrated (SI unit: square meter, m 2); and λ is the wavelength (SI unit: meter, m).
Irradiance in space is a function of distance from the Sun, the solar cycle, and cross-cycle changes. [2] Irradiance on the Earth's surface additionally depends on the tilt of the measuring surface, the height of the Sun above the horizon, and atmospheric conditions. [3] Solar irradiance affects plant metabolism and animal behavior. [4]
Many fields still use this nomenclature. It is especially dominant in heat transfer , astrophysics and astronomy . "Intensity" has many other meanings in physics , with the most common being power per unit area (so the radiance is the intensity per solid angle in this case).
This is the subject of study in the field of optomechanics. The weakest waves are generally those that are generated by the radiation pressure acting during the reflection of the light. Such light-pressure-induced elastic waves have for example observed inside an ultrahigh-reflectivity dielectric mirror. [26]