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Geometrical optics, or ray optics, is a model of optics that describes light propagation in terms of rays. The ray in geometrical optics is an abstraction useful for approximating the paths along which light propagates under certain circumstances. The simplifying assumptions of geometrical optics include that light rays:
Gamma rays, at the high-frequency end of the spectrum, have the highest photon energies and the shortest wavelengths—much smaller than an atomic nucleus. Gamma rays, X-rays, and extreme ultraviolet rays are called ionizing radiation because their high photon energy is able to ionize atoms, causing chemical reactions. Longer-wavelength ...
The principal ray or chief ray (sometimes known as the b ray) in an optical system is the meridional ray that starts at an edge of an object and passes through the center of the aperture stop. [ 5 ] [ 8 ] [ 7 ] The distance between the chief ray (or an extension of it for a virtual image) and the optical axis at an image location defines the ...
galactic cosmic rays (GCR) and extragalactic cosmic rays, i.e., high-energy particles originating outside the solar system, and; solar energetic particles, high-energy particles (predominantly protons) emitted by the sun, primarily in solar eruptions. However, the term "cosmic ray" is often used to refer to only the extrasolar flux.
Light exerts physical pressure on objects in its path, a phenomenon which can be deduced by Maxwell's equations, but can be more easily explained by the particle nature of light: photons strike and transfer their momentum. Light pressure is equal to the power of the light beam divided by c, the speed of light.
During the Apollo 16 and Apollo 17 transits, astronauts conducted the Apollo Light Flash Moving Emulsion Detector (ALFMED) experiment where an astronaut wore a helmet designed to capture the tracks of cosmic ray particles to determine if they coincided with the visual observation. Examination of the results showed that two of fifteen tracks ...
For geometric optics—i.e., to incoherent light and to objects larger than the wavelength of light—the fundamental carrier of light is a ray. The measure for the amount of light traveling along a ray is radiance, denoted by L and measured in W·sr −1 ·m −2; i.e., watts (W) per steradian (sr) per square meter (m 2).
Nonimaging optics (also called anidolic optics) [1] [2] [3] is a branch of optics that is concerned with the optimal transfer of light radiation between a source and a target. . Unlike traditional imaging optics, the techniques involved do not attempt to form an image of the source; instead an optimized optical system for optimal radiative transfer from a source to a target is desi