Sky

Sky
Name	Sky
Type	Atmospheric layer
Location	Earth

Sky The sky is the visible dome of the Earth's atmosphere and the region of the heavens observed from a planetary surface. It has been described across cultures, sciences, and arts, connecting studies from Aristotle and Claudius Ptolemy to Isaac Newton and James Clerk Maxwell. Observations of the sky underpin modern institutions such as the Royal Astronomical Society, National Aeronautics and Space Administration, and European Space Agency.

Etymology and Cultural Significance

The term for the sky in many languages appears in etymological studies alongside figures like Jacob Grimm and August Schleicher, and has inspired works by Homer, Virgil, Dante Alighieri, and Hesiod. Religious and cosmological systems from Zoroastrianism to Christianity, Islam, Hinduism, and Buddhism assign symbolic importance to the sky in texts such as the Bhagavad Gita, the Bible, and the Quran. Mythological traditions feature deities of the sky including Zeus, Uranus (mythology), Thor, and Tengri; ritual practices and calendars in societies such as the Maya civilization, Ancient Egypt, and Aztec Empire used sky observations recorded by astronomers like Imhotep and Kʼinich Janaabʼ Pakal for agriculture and governance. The sky figures prominently in literature by William Shakespeare, Emily Dickinson, Rainer Maria Rilke, and W. B. Yeats and in art movements from the Renaissance to Impressionism and Romanticism represented by painters like Leonardo da Vinci, J. M. W. Turner, Claude Monet, and Vincent van Gogh.

Physical Composition and Structure

The atmosphere observed as the sky is composed of gases studied by chemists such as Antoine Lavoisier and Dmitri Mendeleev and is stratified into layers defined by researchers at institutions like Scripps Institution of Oceanography and NOAA. Layers include the troposphere, stratosphere, mesosphere, thermosphere, and exosphere as characterized in work linked to Robert Boyle and John Dalton. Constituents such as nitrogen and oxygen and trace gases including argon, carbon dioxide, and ozone influence heat transfer mechanisms described in theories by Ludwig Boltzmann and Sadi Carnot. The ionosphere, important for radio propagation investigated by Guglielmo Marconi and Heinrich Hertz, overlaps the thermosphere and affects satellites operated by SpaceX and Intelsat.

Optical Phenomena and Colors

Coloration of the sky arises from scattering processes explained in seminal papers by Lord Rayleigh and Gustav Mie, elaborated in optical theory connected to Maxwell's equations. Phenomena such as rainbow formation were analyzed by René Descartes and Isaac Newton, while complex events like glory (optical phenomenon), halo (optical phenomenon), and sun dog have been cataloged by observatories including Greenwich Observatory. Twilight effects from the ozone layer and aerosol sources studied by Paul Crutzen and Mario Molina produce colors referenced in paintings by John Constable and poems by Percy Bysshe Shelley. Atmospheric optics research informs devices and surveys by European Southern Observatory and Keck Observatory.

Meteorological and Atmospheric Processes

Weather systems visible in the sky are modeled with mathematics developed by Edward Lorenz and operationalized by agencies like the Met Office and National Weather Service. Processes including convection, advection, condensation, and precipitation are central to chronicles of storms such as Hurricane Katrina and Typhoon Haiyan. Cloud classification by Luke Howard established types like cumulus, stratus, and cirrus, used by pilots in International Civil Aviation Organization guidance and by forecasters at European Centre for Medium-Range Weather Forecasts. Aerosol transport and pollution events studied by Rachel Carson and James Hansen link sky appearance to public health policy in organizations such as the World Health Organization.

Astronomical Perspective and Celestial Objects

From an astronomical viewpoint the sky contains celestial objects observed by instruments built under programs like the Hubble Space Telescope and James Webb Space Telescope, and described in catalogs beginning with Messier and Charles Messier. Visible bodies include the Sun, Moon, planets, and constellations cataloged by Ptolemy and modernized in the International Astronomical Union constellations list. Phenomena such as solar eclipse and lunar eclipse were predicted using mechanics of Johannes Kepler and Isaac Newton and are studied during missions by Apollo program and Apollo 11. Transient events like comet passages (e.g., Halley's Comet), meteor showers (e.g., Perseids), and aurorae resulting from interactions with the magnetosphere have been central to investigations at institutions such as CERN and Max Planck Institute for Solar System Research.

Human Perception and Artistic Representation

Human perception of the sky has been studied by psychologists like Hermann von Helmholtz and neuroscientists at Johns Hopkins University; perceptual effects such as color constancy relate to theories by Edwin Land. The sky is a recurrent motif in visual arts collected by museums like the Louvre, Tate Modern, and Museum of Modern Art and appears in films by directors such as Akira Kurosawa, Andrei Tarkovsky, and Terrence Malick. Photographers including Ansel Adams and Henri Cartier-Bresson explored sky composition, while composers like Claude Debussy and Gustav Holst evoked the heavens in works such as The Planets and Prélude à l'après-midi d'un faune. Sky-related engineering disciplines influence architecture by firms like Foster + Partners and aerospace design at companies such as Boeing and Airbus.

Category:Atmosphere