- published: 03 Aug 2010
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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.
Sun Wu (simplified Chinese: 孙武; traditional Chinese: 孫武; pinyin: Sūn Wǔ), style name Changqing (長卿), better known as Sun Tzu or Sunzi (simplified Chinese: 孙子; traditional Chinese: 孫子; pinyin: Sūnzǐ; pronounced [swə́n tsɨ̀]), was an ancient Chinese military general, strategist and philosopher who is traditionally believed to be the author of The Art of War, an influential ancient Chinese book on military strategy. Sun Tzu has had a significant impact on Chinese and Asian history and culture, both as an author of The Art of War and through legend.
Sun Tzu, also known as Sun Tze or Sun Wu in other translations, was a historical figure whose authenticity is questioned by historians. Traditional accounts place him in the Spring and Autumn Period of China (722–481 BC) as a military general serving under King Helü of Wu, who lived c. 544–496 BC. Modern scholars accepting his historicity place the completion of The Art of War in the Warring States Period (476–221 BC), based on the descriptions of warfare in the text, and on the similarity of text's prose to other works completed in the early Warring States period.
Gene Wolfe (born May 7, 1931) is an American science fiction and fantasy writer. He is noted for his dense, allusive prose as well as the strong influence of his Catholic faith, to which he converted after marrying into the religion. He is a prolific short story writer and novelist and has won many science fiction and fantasy literary awards (below).
Wolfe is most famous for The Book of the New Sun (1980ff), the first part of his Solar Cycle. In 1998, Locus magazine ranked it third-best fantasy novel before 1990, based on a poll of subscribers that considered it and several other series as single entries.
Wolfe was born in New York. He had polio as a small child. While attending Texas A&M University, he published his first speculative fiction in The Commentator, a student literary journal. Wolfe dropped out during his junior year, and was drafted to fight in the Korean War. After returning to the United States he earned a degree from the University of Houston and became an industrial engineer. He edited the journal Plant Engineering for many years before retiring to write full-time, but his most famous professional engineering achievement is a contribution to the machine used to make Pringles potato chips. He now lives in Barrington, Illinois, a suburb of Chicago, with his wife Rosemary.