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Sunbeam Manitou - Paris 1919 120220 P181
A sunbeam, in meteorological optics, is a beam of sunlight that appears to radiate from the position of the Sun. Shining through openings in clouds or between other objects such as mountains and buildings, these beams of particle-scattered sunlight are essentially parallel shafts separated by darker shadowed volumes. Their apparent convergence in the sky is a visual illusion from linear perspective. The same illusion causes the apparent convergence of parallel lines on a long straight road or hallway at a distant vanishing point. The scattering particles that make sunlight visible may be air molecules or particulates. Crepuscular rays ''Crepuscular rays'' or ''god rays'' are sunbeams that originate when the sun is just below the horizon, during twilight hours. Crepuscular rays are noticeable when the contrast between light and dark is most obvious. Crepuscular comes from the Latin word "crepusculum", meaning twilight. Crepuscular rays usually appear orange because the path t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crepuscular Rays Reno Nevada USA
In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine (biology), vespertine, or both. This is distinguished from diurnality, diurnal and nocturnality, nocturnal behavior, where an animal is active during the hours of daylight and of darkness, respectively. Some crepuscular animals may also be active by moonlight or during an overcast day. Matutinal animals are active only before sunrise, and vespertine (biology), vespertine only after sunset. A number of factors impact the time of day an animal is active. Predation, Predators hunt when their prey is available, and prey try to avoid the times when their principal predators are at large. The temperature at midday may be too high or at night too low. Some creatures may adjust their activities depending on local competition. Etymology and usage The word ''crepuscular'' derives from the Latin ''wiktionary:crepusculum, crepusculum'' ("twilight"). Its sense accordingly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crepuscular Rays
Crepuscular rays are sunbeams that originate when the Sun is just below the horizon, during the twilight period. Crepuscular rays are noticeable when the contrast between light and dark is most obvious. Crepuscular comes from the Latin word , meaning "twilight". Crepuscular rays usually appear orange because the path through the atmosphere at sunrise and sunset passes through up to 40 times as much air as rays from a high Sun at midday. Particles in the air scatter short-wavelength light (blue and green) through Rayleigh scattering much more strongly than longer-wavelength yellow and red light. Loosely, the term ''crepuscular rays'' is sometimes extended to the general phenomenon of rays of sunlight that appear to converge at a point in the sky, irrespective of time of day. A rare related phenomena are anticrepuscular rays Anticrepuscular rays, or antisolar rays, are meteorological optical phenomena similar to crepuscular rays, but appear opposite the Sun in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evaporation
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidity affects rate of evaporation of water. When the molecules of the liquid collide, they transfer energy to each other based on how they collide. When a molecule near the surface absorbs enough energy to overcome the vapor pressure, it will escape and enter the surrounding air as a gas. When evaporation occurs, the energy removed from the vaporized liquid will reduce the temperature of the liquid, resulting in evaporative cooling. On average, only a fraction of the molecules in a liquid have enough heat energy to escape from the liquid. The evaporation will continue until an equilibrium is reached when the evaporation of the liquid is equal to its condensation. In an enclosed environment, a liquid will evaporate until the surrounding air is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of culturally and linguistically related city-states and other territories. Most of these regions were officially unified only once, for 13 years, under Alexander the Great's empire from 336 to 323 BC (though this excludes a number of Greek city-states free from Alexander's jurisdiction in the western Mediterranean, around the Black Sea, Cyprus, and Cyrenaica). In Western history, the era of classical antiquity was immediately followed by the Early Middle Ages and the Byzantine period. Roughly three centuries after the Late Bronze Age collapse of Mycenaean Greece, Greek urban poleis began to form in the 8th century BC, ushering in the Archaic period and the colonization of the Mediterranean Basin. This was followed by the age of Classical G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unreal Engine
Unreal Engine (UE) is a 3D computer graphics game engine developed by Epic Games, first showcased in the 1998 first-person shooter game ''Unreal''. Initially developed for PC first-person shooters, it has since been used in a variety of genres of games and has seen adoption by other industries, most notably the film and television industry. Unreal Engine is written in C++ and features a high degree of portability, supporting a wide range of desktop, mobile, console, and virtual reality platforms. The latest generation, Unreal Engine 5, was launched in April 2022. Its source code is available on GitHub after registering an account, and commercial use is granted based on a royalty model. Epic waives their royalties margin for games until developers have earned in revenue and the fee is waived if developers publish on the Epic Games Store. Epic has included features from acquired companies like Quixel in the engine, which is seen as helped by ''Fortnite'''s revenue. Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacob's Ladder
Jacob's Ladder ( he, סֻלָּם יַעֲקֹב ) is a ladder leading to heaven that was featured in a dream the biblical Patriarch Jacob had during his flight from his brother Esau in the Book of Genesis (chapter 28). The significance of the dream has been debated, but most interpretations agree that it identified Jacob with the obligations and inheritance of the people chosen by God, as understood in Abrahamic religions. Biblical narrative The description of Jacob's Ladder appears in : Judaism The classic Torah commentaries offer several interpretations of Jacob's Ladder. According to the Midrash Genesis Rabbah, the ladder signified the exiles which the Jewish people would suffer before the coming of the Jewish messiah. First, the angel representing the 70-year exile of Babylonia climbed "up" 70 rungs, and then fell "down". Then the angel representing the exile of Persia went up a number of steps, and fell, as did the angel representing the exile of Greece. Only the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backstay
A backstay is a piece of standing rigging on a sailing vessel that runs from the mast to either its transom or rear quarter, counteracting the forestay and jib. It is an important sail trim control and has a direct effect on the shape of the mainsail and the headsail. Backstays are generally adjusted by block and tackle, hydraulic adjusters, or lines leading to winches. Types Backstays may be ''permanent'' or ''running''. A permanent backstay is attached to the top of the mast. Running backstays appear in pairs attached about two-thirds of the way up the mast (sometimes at multiple locations along the length of the mast). In general, most modern sailboats have a permanent backstay and some have a permanent backstay combined with running backstays. Backstays are not always found on all vessels, especially smaller ones. A permanent backstay is attached at the top of the mast and may or may not be readily adjustable. In a masthead rig, tensioning the permanent backstay directly te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perspective (graphical)
Linear or point-projection perspective (from la, perspicere 'to see through') is one of two types of 3D projection, graphical projection perspective in the graphic arts; the other is parallel projection. Linear perspective is an approximate representation, generally on a flat surface, of an image as it is seen by the eye. Perspective drawing is useful for representing a three-dimensional scene in a two-dimensional medium, like paper. The most characteristic features of linear perspective are that objects appear smaller as their distance from the observer increases, and that they are subject to ''foreshortening'', meaning that an object's dimensions along the line of sight appear shorter than its dimensions across the line of sight. All objects will recede to points in the distance, usually along the horizon line, but also above and below the horizon line depending on the view used. Italian Renaissance painters and architects including Masaccio, Paolo Uccello, Piero della Fran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticrepuscular Rays
Anticrepuscular rays, or antisolar rays, are meteorological optical phenomena similar to crepuscular rays, but appear opposite the Sun in the sky. Anticrepuscular rays are essentially parallel, but appear to converge toward the antisolar point, the vanishing point, due to a visual illusion from linear perspective. Anticrepuscular rays are most frequently visible around sunrise or sunset. This is because the atmospheric light scattering that makes them visible (backscattering) is larger for low angles to the horizon than most other angles. Anticrepuscular rays are dimmer than crepuscular rays because backscattering is less than forward scattering. Anticrepuscular rays can be continuous with crepuscular rays, curving across the whole sky in great circles.Lynch, D. K., & Livingston, W. (1995). Color and light in nature. Cambridge: Cambridge University Press. Mountain shadow A common example of a single anticrepuscular ray is provided by the shadow of a mountain at sunset, whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Sphere
In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer. If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location. The celestial sphere is a conceptual tool used in spherical astronomy to specify the position of an object in the sky without consideration of its linear distance from the observer. The celestial equator divides the celestial sphere into northern and southern hemispheres. Introduction Because astronomical objects are at such remote distances, casual observation of the sky offers no information on their actual distances. All celestial objects seem equally far away, as if fixed onto the inside of a sphere with a large but unknown radius, which appears to rotate westward o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antisolar Point
The antisolar point is the abstract point on the celestial sphere directly opposite the Sun from an observer's perspective. This means that the antisolar point lies above the horizon when the Sun is below it, and vice versa. On a sunny day, the antisolar point can be easily found; it is located within the shadow of the observer's head. Like the zenith and nadir, the antisolar point is not fixed in three-dimensional space, but is defined relative to the observer. Each observer has an antisolar point that moves as the observer changes position. The antisolar point forms the geometric center of several optical phenomena, including subhorizon haloes, rainbows, glories, the Brocken spectre, and heiligenschein. Occasionally, around sunset or sunrise, anticrepuscular rays appear to converge toward the antisolar point near the horizon. However, this is an optical illusion caused by perspective; in reality, the "rays" (i.e. bands of shadow) run near-parallel to each other. Also arou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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