- published: 26 Jul 2014
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The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2×1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. The remainder (1.69%, which nonetheless equals 5,628 times the mass of Earth) consists of heavier elements, including oxygen, carbon, neon and iron, among others.
The Sun's stellar classification, based on spectral class, is G2V, and is informally designated as a yellow dwarf, because its visible radiation is most intense in the yellow-green portion of the spectrum and although its color is white, from the surface of the Earth it may appear yellow because of atmospheric scattering of blue light. In the spectral class label, G2 indicates its surface temperature of approximately 5778 K (5505 °C), and V indicates that the Sun, like most stars, is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 620 million metric tons of hydrogen each second. Once regarded by astronomers as a small and relatively insignificant star, the Sun is now thought to be brighter than about 85% of the stars in the Milky Way galaxy, most of which are red dwarfs. The absolute magnitude of the Sun is +4.83; however, as the star closest to Earth, the Sun is the brightest object in the sky with an apparent magnitude of −26.74. The Sun's hot corona continuously expands in space creating the solar wind, a stream of charged particles that extends to the heliopause at roughly 100 astronomical units. The bubble in the interstellar medium formed by the solar wind, the heliosphere, is the largest continuous structure in the Solar System.
Stephen Knapp (born 1947, Worcester, Massachusetts) is an American artist best known for his use of the medium of lightpainting He has gained an international reputation for large-scale works of art held in museums, public, corporate, and private collections, which are executed in media as diverse as light, kiln-formed glass, metal, stone, mosaic, and ceramic.
Knapp has written and lectured on architectural art glass, the collaborative process, and the integration of art and architecture. His work has appeared in many publications including Art and Antiques, Architectural Record, ARTnews, Ceramics Monthly, The Chicago Sun Times, Honoho Geijutsu, Identity, Interior Design, Interiors, The New York Times, Nikkei Architecture, Progressive Architecture, Sculpture (magazine), and 90+10.
Stephen Knapp was born in Worcester, Massachusetts in 1947, graduated from Worcester Academy in 1965, and received his B.A. from Hamilton College in 1969. For nearly a decade after graduating from college, he worked as a fine art photographer, selling his work to corporate and private collectors in the United States and abroad. During this early stage in his career Knapp worked closely with Polaroid Corporation on their 20x24 camera, creating large scale instant photographs.
Poverty Point (French: Pointe de Pauvreté) is a prehistoric earthworks of the Poverty Point culture, now a historic monument located in the Southern United States. It is 15.5 miles (24.9 km) from the current Mississippi River, and situated on the edge of Maçon Ridge, near the village of Epps in West Carroll Parish, Louisiana.
Poverty Point comprises several earthworks and mounds built between 1650 and 700 BCE, during the Archaic period in the Americas by a group of Native Americans of the Poverty Point culture. The culture extended 100 miles (160 km) across the Mississippi Delta. The original purposes of Poverty Point have not been determined by archaeologists, although they have proposed various possibilities including that it was: a settlement, a trading center, and/or a ceremonial religious complex.
The 910-acre (1.42 sq mi; 3.68 km2) site, which has been described as "the largest and most complex Late Archaic earthwork occupation and ceremonial site yet found in North America" is a registered National Monument. The monument was brought to the attention of archaeologists in the early 20th century, when it was given the name of Poverty Point after a nearby plantation. Since then, various excavations have taken place at the site. Scholars have advanced various theories regarding the purpose of the mound site, including religious and ceremonial. Other writers have proposed pseudo-archaeological and the New Age associations. The complex attracts many tourists as a destination.