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Helliconia
The Helliconia trilogy is a series of science fiction books by British writer Brian W. Aldiss, set on the Earth-like planet Helliconia. It is an epic chronicling the rise and fall of a civilisation over more than a thousand years as the planet progresses through its incredibly long seasons, which last for centuries. The trilogy consists of the books ''Helliconia Spring'' (published in 1982), '' Helliconia Summer'' (1983), and '' Helliconia Winter'' (1985). Synopsis In one sense, the central character is not any person (though some families are focused on, such as Yuli the Priest's line, which dominates ''Helliconia Spring'') but the planet itself and its science, particularly in the light of James Lovelock's Gaia Hypothesis. The books describe realistic and credible details of the planet from the perspectives of a great variety of fields of study – astronomy, geology, climatology, geobiology, microbiology, religion, society, and many others – for which Aldiss gained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helliconia Summer
''Helliconia Summer'' is a novel by Brian Aldiss published in 1983. Plot summary ''Helliconia Summer'' is a novel in which the world of Helliconia experiences its intensely hot summer. Reception David Langford, Dave Langford reviewed ''Helliconia Summer'' for ''White Dwarf (magazine), White Dwarf'' #50, and stated that "Fine writing, unforgettable images: and hanging over it all, the doomy awareness of Helliconia-watchers in the orbiting Earth Station Avernus, who know and remind us that all this differs only in detail from the summer of the last Great Year." Neil Gaiman reviewed ''Helliconia Summer'' for ''Imagine (game magazine), Imagine'' magazine, and stated that "Rich and romantic, the story of the world of Helliconia where the seasons take two thousand years to turn, and humans and the horned and shaggy phagor are locked in continual struggle, is one that continues to echo through the mind long after the last page of the book is finished." Reviews *Review by Faren Miller (19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helliconia Winter
''Helliconia Winter'' is a novel by Brian W. Aldiss published in 1985. Plot summary The third part of the trilogy, ''Helliconia Winter'' is set during late autumn in the northern continent, Sibornal. The book's protagonist, Luterin Shokerandit, is the son of the Keeper of the Wheel of Kharnabar, located above the far north of Helliconia. The Wheel is an extraordinary revolving monastery/prison built into a ring-shaped tunnel with a single entrance and exit, powered entirely by the efforts of the prisoners pulling it along by means of chains set into the outer wall. Once a prisoner enters a cell of the Wheel, it is impossible for him to leave until its full ten-year rotation has passed. Luterin joins the army, where he gains renown by killing the commandant of an enemy battalion, taking his widow Toress Lahl as a slave. Soon, however, the first cases of Fat Death begin to appear in the Sibornalese army. The Oligarch, autocratic ruler of Sibornal, orders other troops to destroy this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helliconia Spring
''Helliconia Spring'' is a novel by Brian W. Aldiss published in 1982, set in a world with two suns and where each year is incredibly long. Dave Pringle reviewed ''Helliconia Spring'' for ''Imagine'' magazine, and stated that "it seems the hour of the blockbuster has arrived and there is little we can do but submit". Reviews *Review by Faren Miller (1982) in ''Locus'', #253 February 1982 *Review by Fritz R. Leiber (1982) in '' Interzone'', #2 Summer 1982 *Review by Roger C. Schlobin (1982) in ''Fantasy Newsletter'', #48 June 1982 *Review by Mary Gentle (1982) in ''Vector'' 109 *Review by Darrell Schweitzer (1982) in ''Science Fiction Review'', Fall 1982 *Review by Baird Searles (1982) in ''Isaac Asimov's Science Fiction Magazine'', September 1982 *Review by Tom Easton (1982) in ''Analog Science Fiction/Science Fact'', November 1982 *Review by John Clute (1983) in '' Omni'', March 1983 *Review by Don D'Ammassa (1984) in ''Science Fiction Chronicle DNA Publications was an America ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periastron
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellipse
In mathematics, an ellipse is a plane curve surrounding two focus (geometry), focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special type of ellipse in which the two focal points are the same. The elongation of an ellipse is measured by its eccentricity (mathematics), eccentricity e, a number ranging from e = 0 (the Limiting case (mathematics), limiting case of a circle) to e = 1 (the limiting case of infinite elongation, no longer an ellipse but a parabola). An ellipse has a simple algebraic solution for its area, but only approximations for its perimeter (also known as circumference), for which integration is required to obtain an exact solution. Analytic geometry, Analytically, the equation of a standard ellipse centered at the origin with width 2a and height 2b is: : \frac+\frac = 1 . Assuming a \ge b, the foci are (\pm c, 0) for c = \sqrt. The standard parametric e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and understanding of the exact mechanics of orbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolf 1061c
Wolf 1061c is an exoplanet orbiting within the habitable zone of the red dwarf star Wolf 1061 in the constellation Ophiuchus, about 13.8 light years from Earth, making it the fifth closest known, potentially habitable, and confirmed exoplanet to Earth (after Proxima Centauri b, Ross 128 b, Luyten b and Tau Ceti e), yielding interest from astronomers. It is the second planet in order from its host star in a triple planetary system, and has an orbital period of 17.9 days. Wolf 1061c is classified as a super-Earth exoplanet as its estimated radius is greater than 1.5 . Characteristics Mass, radius and temperature Wolf 1061c is thought to be a rocky planet estimated to be a super-Earth exoplanet as its mass is about 4.3 times that of Earth and radius is over 1.5 which would give it a density either near or possibly higher than Earth. It has an estimated surface gravity of 1.6 times that on Earth. In astronomical terms, the Wolf 1061 system is relatively close to Earth, at only 13. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Years
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. Defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiuchus
Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. An old alternative name for the constellation was Serpentarius (). Location Ophiuchus lies between Aquila, Serpens, Scorpius, Sagittarius, and Hercules, northwest of the center of the Milky Way. The southern part lies between Scorpius to the west and Sagittarius to the east. In the northern hemisphere, it is best visible in summer. It is opposite of Orion. Ophiuchus is depicted as a man grasping a serpent; the interposition of his body divides the snake constellation Serpens into two parts, Serpens Caput and Serpens Cauda. Ophiuchus straddles the equator with the majority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Class
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coolest (''M'' type). Each letter class is then subdivided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough they can gravitationally distort their mutual outer stellar atmospheres. In some cases, thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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