The Saga of Seven Suns
The Saga of Seven Suns is a series of seven space opera novels written by Kevin J. Anderson and published between 2002 and 2008; the books are set in a not-too-distant future where humans have colonized a number of other planets across the galaxy, thanks in part to technological assistance from an ancient alien race, the Ildirans. The series chronicles the universe-spanning war that erupts when humans inadvertently ignite the fury of a hidden empire of elemental aliens known as the hydrogues. Internal conflict is sparked within both the human and Ildiran empires as other ancient elemental races reappear to renew their own ancient war with the hydrogues. A sequel trilogy, The Saga of Shadows, so far includes the novels The Dark Between the Stars, Blood of the Cosmos and Eternity's Mind. In the future, the human race has colonized multiple planets in the Spiral Arm, most of which are governed by the powerful Terran Hanseatic League. Though ostensibly ruled by kings, the Hansa is controlled by its Chairman, the puppet monarchs follow orders.
Centuries before, several generation ships had set out from Earth to find new worlds. The Ildirans themselves, psychically linked to their leader the Mage-Imperator, have become stagnant and eschew both expansion and innovation; as the series begins, the arrogant Hansa Chairman Basil Wenceslas begins grooming a replacement for the aging King Frederick. Basil looks to expand the human empire further through the discovery of alien technology from the extinct Klikiss race that will allow scientists to create a new star from a gas giant, turning cold moons into planets ripe for colonization; the most prominent human world aside from Earth is Theroc, a planet covered in semi-sentient worldtrees, independent from the Hansa. Theroc's "green priests" are able to commune with the trees and communicate telepathically across space when touching a treeling, making them indispensable for instantaneous communication across the galaxy; the Roamers are clans of industrious humans living a clandestine existence in the fringes of space, managing a profitable economy centered on the sale of the valuable stardrive fuel ekti and other commodities.
The ignition of the gas giant Oncier reveals the existence of the elemental hydrogues, the inadvertent hydrogue genocide at the hands of the humans incites the ire of the other hidden hydrogue populations across the galaxy. Their brutal retaliation and forced cessation of ekti collection threaten to cripple both the human and Ildiran civilizations, serve as an effective declaration of war; the aggression of the hydrogues reawakens the verdani, the worldtree entities who had fled to Theroc after losing an ancient war with the hydrogues. Meanwhile, the Ildiran Mage-Imperator Cyroc'h struggles to hide his race's secrets and keep the centuries-old plan for ultimate Ildiran survival on track, and the amnesiac black Klikiss robots, left behind after their parent race's mysterious destruction, have secrets of their own. The war escalates simmering rivalries among the human factions and ignites a schism in the Ildiran consciousness; the fire-based faeros and aquatic wentals reappear as the war with their ancient hydrogue enemies escalates.
The long-held secrets of the Ildirans and the Klikiss robots are revealed amidst much destruction, after 10,000 years the Klikiss return to reclaim their own empire at any cost. Hidden Empire is the first book in The Saga of Seven Suns series by Kevin J. Anderson, published on July 24, 2002. Publishers Weekly called it a "stellar launch of a new series" and a "fascinating future epic", praised its "engaging characters." Harriet Klausner of TheBestReviews.com wrote, "The tale grabs the audience from the start as Kevin J. Anderson... blends the players and worlds into the thrilling plot. Thus, the audience does not receive an extended prologue as seen in first novels. Instead readers obtain a powerful futuristic epic that contains a robust stand-alone story line yet provides a puissant cliffhanger that will keep the audience wanting to continue non-stop." However SF Signal described it as "A rather pedestrian space opera that nonetheless has some cool ideas." Having colonized many worlds in the Spiral Arm, humanity is divided into three branches: the Earth-based Terran Hanseatic League and its subordinate planets, the independent world Theroc with its telepathic green priests, the Roamers, interplanetary traders who prefer starships and hidden bases to a conventional planet-based civilization.
The only other known intelligent species in the galaxy are the Ildirans, an ancient civilization at its peak, the long-extinct Klikiss, whose planets remain empty but for their unusual ruins. As the novel begins, the Hansa's test of a discovered ancient Klikiss technology that can convert gas giant planets into suns is a success; the ignition of the planet Oncier will make its satellite moons into habitable worlds perfect for human colonization, but it has murdered millions of hydrogues, a previously-unknown race of gas elementals living in the high-pressure core of the planet. Confined in crystalline globe ships, the hydrogues retaliate by systematically destroying several Roamer skymines, floating factories which harvest the hydrogen used to produce the vital stardrive fuel ekti from the atmosphere of gas giants; the powerful warglobes destroy the moons of Oncier and the scientific space station there before warning the human race to stay away from all gas giants or be destroyed. This ultimatum is punctuated by the murder of the Hansa's puppet king Frederick and everyone in his vicinity.
Arthur C. Clarke
Sir Arthur Charles Clarke was a British science fiction writer, science writer and futurist, undersea explorer, television series host. He is famous for being co-writer of the screenplay for the 1968 film 2001: A Space Odyssey considered to be one of the most influential films of all time. Clarke was a science writer, both an avid populariser of space travel and a futurist of uncanny ability. On these subjects he wrote over a dozen books and many essays, which appeared in various popular magazines. In 1961 he was awarded the Kalinga Prize, an award, given by UNESCO for popularising science; these along with his science fiction writings earned him the moniker "Prophet of the Space Age". His other science fiction writings earned him a number of Hugo and Nebula awards, which along with a large readership made him one of the towering figures of science fiction. For many years Clarke, Robert Heinlein and Isaac Asimov were known as the "Big Three" of science fiction. Clarke was a lifelong proponent of space travel.
In 1934, while still a teenager, he joined the British Interplanetary Society. In 1945, he proposed a satellite communication system using geostationary orbits, he was the chairman of the British Interplanetary Society from 1946–47 and again in 1951–53. Clarke emigrated from England to Sri Lanka in 1956 to pursue his interest in scuba diving; that year he discovered the underwater ruins of the ancient Koneswaram temple in Trincomalee. Clarke augmented his fame on in the 1980s, from being the host of several television shows such as Arthur C. Clarke's Mysterious World, he lived in Sri Lanka until his death. Clarke was appointed Commander of the Order of the British Empire in 1989 "for services to British cultural interests in Sri Lanka", he was knighted in 1998 and was awarded Sri Lanka's highest civil honour, Sri Lankabhimanya, in 2005. Clarke was born in Minehead, Somerset and grew up in nearby Bishops Lydeard; as a boy, he lived on a farm, where he enjoyed stargazing, fossil collecting, reading American science fiction pulp magazines.
He received his secondary education at Huish Grammar school in Taunton. Early influences included dinosaur cigarette cards, which led to an enthusiasm for fossils starting about 1925. Clarke attributed his interest in science fiction to reading three items: the November 1928 issue of Amazing Stories in 1929. In his teens, he joined the Junior Astronomical Association and contributed to Urania, the society's journal, edited in Glasgow by Marion Eadie. At Clarke's request, she added an Astronautics Section, which featured a series of articles by him on spacecraft and space travel. Clarke contributed pieces to the Debates and Discussions Corner, a counterblast to an Urania article offering the case against space travel, his recollections of the Walt Disney film Fantasia, he joined the Board of Education as a pensions auditor. He and some fellow science fiction writers shared a flat in Gray's Inn Road, where he got the nickname "Ego" because of his absorption in subjects that interested him, would name his office filled with memorabilia as his "ego chamber".
During the Second World War from 1941 to 1946 he served in the Royal Air Force as a radar specialist and was involved in the early-warning radar defence system, which contributed to the RAF's success during the Battle of Britain. Clarke spent most of his wartime service working on ground-controlled approach radar, as documented in the semi-autobiographical Glide Path, his only non-science-fiction novel. Although GCA did not see much practical use during the war, it proved vital to the Berlin Airlift of 1948–1949 after several years of development. Clarke served in the ranks, was a corporal instructor on radar at No. 2 Radio School, RAF Yatesbury in Wiltshire. He was commissioned as a pilot officer on 27 May 1943, he was promoted flying officer on 27 November 1943. He was appointed chief training instructor at RAF Honiley in Warwickshire and was demobilised with the rank of flight lieutenant. After the war he attained a first-class degree in mathematics and physics from King's College London. After this he worked as assistant editor at Physics Abstracts.
Clarke served as president of the British Interplanetary Society from 1946 to 1947 and again from 1951 to 1953. Although he was not the originator of the concept of geostationary satellites, one of his most important contributions in this field may be his idea that they would be ideal telecommunications relays, he advanced this idea in a paper circulated among the core technical members of the British Interplanetary Society in 1945. The concept was published in Wireless World in October of that year. Clarke wrote a number of non-fiction books describing the technical details and societal implications of rocketry and space flight; the most notable of these may be Interplanetary Flight: An Introduction to Astronautics, The Exploration of Space and The Promise of Space. In recognition of these contributions, the geostationary orbit 36,000 kilometres above the equator is recognised by the International Astronomical Union as the Clarke Orbit. Following the 1968 release of 2001, Clarke became much in demand as a commentator on science and technology at the time of the Apollo space program.
On 20 July 1969 Clarke appeared as a commentator for CBS for the Apollo 11 moon landing. Clarke lived in Sri Lanka from 1956 until his death in 2008, first in Unawatuna on the south coast, in Colombo, he and his friend Mike Wilson travelled around Sri
A planet is an astronomical body orbiting a star or stellar remnant, massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, has cleared its neighbouring region of planetesimals. The term planet is ancient, with ties to history, science and religion. Five planets in the Solar System are visible to the naked eye; these were regarded by many early cultures as emissaries of deities. As scientific knowledge advanced, human perception of the planets changed, incorporating a number of disparate objects. In 2006, the International Astronomical Union adopted a resolution defining planets within the Solar System; this definition is controversial because it excludes many objects of planetary mass based on where or what they orbit. Although eight of the planetary bodies discovered before 1950 remain "planets" under the modern definition, some celestial bodies, such as Ceres, Pallas and Vesta, Pluto, that were once considered planets by the scientific community, are no longer viewed as such.
The planets were thought by Ptolemy to orbit Earth in epicycle motions. Although the idea that the planets orbited the Sun had been suggested many times, it was not until the 17th century that this view was supported by evidence from the first telescopic astronomical observations, performed by Galileo Galilei. About the same time, by careful analysis of pre-telescopic observational data collected by Tycho Brahe, Johannes Kepler found the planets' orbits were elliptical rather than circular; as observational tools improved, astronomers saw that, like Earth, each of the planets rotated around an axis tilted with respect to its orbital pole, some shared such features as ice caps and seasons. Since the dawn of the Space Age, close observation by space probes has found that Earth and the other planets share characteristics such as volcanism, hurricanes and hydrology. Planets are divided into two main types: large low-density giant planets, smaller rocky terrestrials. There are eight planets in the Solar System.
In order of increasing distance from the Sun, they are the four terrestrials, Venus and Mars the four giant planets, Saturn and Neptune. Six of the planets are orbited by one or more natural satellites. Several thousands of planets around other stars have been discovered in the Milky Way; as of 1 April 2019, 4,023 known extrasolar planets in 3,005 planetary systems, ranging in size from just above the size of the Moon to gas giants about twice as large as Jupiter have been discovered, out of which more than 100 planets are the same size as Earth, nine of which are at the same relative distance from their star as Earth from the Sun, i.e. in the circumstellar habitable zone. On December 20, 2011, the Kepler Space Telescope team reported the discovery of the first Earth-sized extrasolar planets, Kepler-20e and Kepler-20f, orbiting a Sun-like star, Kepler-20. A 2012 study, analyzing gravitational microlensing data, estimates an average of at least 1.6 bound planets for every star in the Milky Way.
Around one in five Sun-like stars is thought to have an Earth-sized planet in its habitable zone. The idea of planets has evolved over its history, from the divine lights of antiquity to the earthly objects of the scientific age; the concept has expanded to include worlds not only in the Solar System, but in hundreds of other extrasolar systems. The ambiguities inherent in defining planets have led to much scientific controversy; the five classical planets, being visible to the naked eye, have been known since ancient times and have had a significant impact on mythology, religious cosmology, ancient astronomy. In ancient times, astronomers noted how certain lights moved across the sky, as opposed to the "fixed stars", which maintained a constant relative position in the sky. Ancient Greeks called these lights πλάνητες ἀστέρες or πλανῆται, from which today's word "planet" was derived. In ancient Greece, China and indeed all pre-modern civilizations, it was universally believed that Earth was the center of the Universe and that all the "planets" circled Earth.
The reasons for this perception were that stars and planets appeared to revolve around Earth each day and the common-sense perceptions that Earth was solid and stable and that it was not moving but at rest. The first civilization known to have a functional theory of the planets were the Babylonians, who lived in Mesopotamia in the first and second millennia BC; the oldest surviving planetary astronomical text is the Babylonian Venus tablet of Ammisaduqa, a 7th-century BC copy of a list of observations of the motions of the planet Venus, that dates as early as the second millennium BC. The MUL. APIN is a pair of cuneiform tablets dating from the 7th century BC that lays out the motions of the Sun and planets over the course of the year; the Babylonian astrologers laid the foundations of what would become Western astrology. The Enuma anu enlil, written during the Neo-Assyrian period in the 7th century BC, comprises a list of omens and their relationships with various celestial phenomena including the motions of the planets.
Venus and the outer planets Mars and Saturn were all identified by Babylonian astronomers. These would remain the only known planets until the invention of the telescope in early modern times; the ancient Greeks did not attach as much significance to the planets as the Babylonians. The Pythagoreans, in the 6th and 5t
The Book of the New Sun
The Book of the New Sun is a series of four science fantasy novels or one four-volume novel written by American author Gene Wolfe. Alternatively, it is a series comprising the original tetralogy, a 1983 collection of essays, a 1987 sequel. Either way, it inaugurated the so-called "Solar Cycle" that Wolfe continued after 1987 by setting other multi-volume works in the same universe. Gene Wolfe had intended the story to be a 40,000-word novella called "The Feast of Saint Catherine", meant to be published in one of the Orbit anthologies, but during the writing it continued to grow in size. Despite being published with a year between each book, all four books were written and completed during his free time without anyone's knowledge when he was still an editor of Plant Engineering, allowing him to write at his own pace and take his time; the tetralogy chronicles the journey of Severian, a disgraced journeyman torturer, exiled and forced to travel to Thrax and beyond. It is a first-person narrative translated by Wolfe into contemporary English, set in the distant future when the Sun has dimmed and Earth is cooler.
Severian claims to have a "perfect memory", but at multiple occasions admits leaving out details and confides in the readers that he may be insane, making him an unreliable narrator. In 1998, Locus magazine ranked the tetralogy number three among 36 all-time best fantasy novels before 1990, based on a poll of subscribers. Since the original four-volume novel, Wolfe has written three short fictions and two book series that are set in Severian's universe; the Internet Speculative Fiction Database catalogues it all as the "Solar Cycle" comprising the short works and three sub-series. The two subseries are The Book of the Long Sun and The Book of the Short Sun. Long Sun is set on a generation ship and Short Sun features the inhabitants of that generation ship after their long journey. Two of the Long Sun books were nominated for Nebula Awards. Severian, an apprentice in the torturers' guild survives a swim in the River Gyoll. On his way back to the Citadel Severian and several other apprentices sneak into a necropolis where Severian first encounters Vodalus, the legendary revolutionary.
Vodalus, along with two others, including a woman named Thea, are robbing a grave. Vodalus and his companions are confronted by volunteer guards. Severian saves Vodalus's life, earning the reward of a single "gold" coin. Shortly before Severian is elevated to journeyman he encounters and falls in love with Thecla, a beautiful aristocratic prisoner. Thecla's crime is never made clear, though it is implied that she is imprisoned for political reasons since Thecla's half-sister is Thea, Vodalus's lover; the Autarch wishes to use Thecla to capture Vodalus. When Thecla is put to torture, Severian takes pity on her and helps her commit suicide, by smuggling a knife into her cell, thus breaking his oath to the guild. Though Severian expects to be tortured and executed, instead the head of the guild is uncharacteristically forgiving and dispatches Severian to Thrax, a distant city which has need of an executioner. Master Palaemon gives Severian a letter of introduction to the archon of the city and Terminus Est, a magnificent executioner's sword.
He departs the guild headquarters. He comes upon an inn, where he forces the innkeeper to take him in despite being full and is asked to share a room with other boarders; this is where he first meets Baldanders and Dr. Talos, travelling as mountebanks, who invite Severian to join them in a play to be performed the same day. During breakfast, Dr. Talos manages to recruit the waitress, for his play and they set out into the streets. Not intending to participate, Severian parts with the group and stops at a rag shop to purchase a mantle to hide his fuligin cloak; the shop is owned by a twin brother and sister, the brother takes interest in Terminus Est. Severian refuses to sell the sword, shortly after which a masked and armoured hipparch enters the shop and challenges Severian to a duel. Severian is forced to accept, he departs with the sister, Agia, to secure an avern, a deadly plant, used for dueling. While on their way, urged by Agia's bet to a passing fiacre, their driver crashes into and destroys the altar of a religious order, where Agia is accused of stealing a precious artifact.
After Agia is searched and released, they continue their journey to the Botanic Gardens, a large landmark of Nessus created by the mysterious Father Inire, right hand to the Autarch. Inside the gardens, Severian falls into a lake used to inter the dead, while pulling himself out he finds a young woman named Dorcas to have come up from the lake as well. Dazed and confused, the woman follows Agia. Severian secures the group proceeds to an inn near the dueling grounds. While eating dinner, Severian receives a mysterious note warning about one of the women. After dinner, Severian meets with his challenger, though stabbed by the avern he miraculously survives and finds that his challenger was the male owner of the rag shop, Agia's brother; when Severian wakes again, he finds himself to be in a lazaret. After finding Dorcas and identifying himself, he is requested to perform an execution; the prisoner turns out to be Agia's brother, whom he executes. Severian and Dorcas return to their travels and while searching his belongings, Severian finds the Claw of the Conciliator.
Agia stole the Claw from the altar they destroyed and placed it in Severian's belongings knowing that she
A gas giant is a giant planet composed of hydrogen and helium. Gas giants are sometimes known as failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System; the term "gas giant" was synonymous with "giant planet", but in the 1990s it became known that Uranus and Neptune are a distinct class of giant planet, being composed of heavier volatile substances. For this reason and Neptune are now classified in the separate category of ice giants. Jupiter and Saturn consist of hydrogen and helium, with heavier elements making up between 3 and 13 percent of the mass, they are thought to consist of an outer layer of molecular hydrogen surrounding a layer of liquid metallic hydrogen, with a molten rocky core. The outermost portion of their hydrogen atmosphere is characterized by many layers of visible clouds that are composed of water and ammonia; the layer of metallic hydrogen makes up the bulk of each planet, is referred to as "metallic" because the large pressure turns hydrogen into an electrical conductor.
The gas giants' cores are thought to consist of heavier elements at such high temperatures and pressures that their properties are poorly understood. The defining differences between a low-mass brown dwarf and a gas giant are debated. One school of thought is based on formation. Part of the debate concerns whether "brown dwarfs" must, by definition, have experienced nuclear fusion at some point in their history; the term gas giant was coined in 1952 by the science fiction writer James Blish and was used to refer to all giant planets. It is, something of a misnomer because throughout most of the volume of all giant planets, the pressure is so high that matter is not in gaseous form. Other than solids in the core and the upper layers of the atmosphere, all matter is above the critical point, where there is no distinction between liquids and gases; the term has caught on, because planetary scientists use "rock", "gas", "ice" as shorthands for classes of elements and compounds found as planetary constituents, irrespective of what phase the matter may appear in.
In the outer Solar System and helium are referred to as "gases". Because Uranus and Neptune are composed of, in this terminology, not gas, they are referred to as ice giants and separated from the gas giants. Gas giants can, theoretically, be divided into five distinct classes according to their modeled physical atmospheric properties, hence their appearance: ammonia clouds, water clouds, alkali-metal clouds, silicate clouds. Jupiter and Saturn are both class I. Hot Jupiters are class IV or V. A cold hydrogen-rich gas giant more massive than Jupiter but less than about 500 M⊕ will only be larger in volume than Jupiter. For masses above 500 M⊕, gravity will cause the planet to shrink. Kelvin–Helmholtz heating can cause a gas giant to radiate more energy than it receives from its host star. Although the words "gas" and "giant" are combined, hydrogen planets need not be as large as the familiar gas giants from the Solar System. However, smaller gas planets and planets closer to their star will lose atmospheric mass more via hydrodynamic escape than larger planets and planets farther out.
A gas dwarf could be defined as a planet with a rocky core that has accumulated a thick envelope of hydrogen and other volatiles, having as result a total radius between 1.7 and 3.9 Earth-radii. The smallest known extrasolar planet, a "gas planet" is Kepler-138d, which has the same mass as Earth but is 60% larger and therefore has a density that indicates a thick gas envelope. A low-mass gas planet can still have a radius resembling that of a gas giant if it has the right temperature. List of gravitationally rounded objects of the Solar System List of planet types Hot Jupiter
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids; this area of civil engineering is intimately related to the design of bridges, channels and levees, to both sanitary and environmental engineering. Hydraulic engineering is the application of the principles of fluid mechanics to problems dealing with the collection, control, regulation and use of water. Before beginning a hydraulic engineering project, one must figure out; the hydraulic engineer is concerned with the transport of sediment by the river, the interaction of the water with its alluvial boundary, the occurrence of scour and deposition. "The hydraulic engineer develops conceptual designs for the various features which interact with water such as spillways and outlet works for dams, culverts for highways and related structures for irrigation projects, cooling-water facilities for thermal power plants."
A few examples of the fundamental principles of hydraulic engineering include fluid mechanics, fluid flow, behavior of real fluids, pipelines, open channel hydraulics, mechanics of sediment transport, physical modeling, hydraulic machines, drainage hydraulics. Fundamentals of Hydraulic Engineering defines hydrostatics as the study of fluids at rest. In a fluid at rest, there exists a force, known as pressure, that acts upon the fluid's surroundings; this pressure, measured in N/m2, is not constant throughout the body of fluid. Pressure, p, in a given body of fluid, increases with an increase in depth. Where the upward force on a body acts on the base and can be found by the equation: p = ρ g y where, ρ = density of water g = specific gravity y = depth of the body of liquidRearranging this equation gives you the pressure head p/ρg = y. Four basic devices for pressure measurement are a piezometer, differential manometer, Bourdon gauge, as well as an inclined manometer; as Prasuhn states: On undisturbed submerged bodies, pressure acts along all surfaces of a body in a liquid, causing equal perpendicular forces in the body to act against the pressure of the liquid.
This reaction is known as equilibrium. More advanced applications of pressure are that on plane surfaces, curved surfaces and quadrant gates, just to name a few; the main difference between an ideal fluid and a real fluid is that for ideal flow p1 = p2 and for real flow p1 > p2. Ideal fluid has no viscosity. Real fluid has viscosity. Ideal fluid is only an imaginary fluid as all fluids. A viscous fluid will deform continuously under to a shear force by the pascles law, whereas an ideal fluid doesn't deform; the various effects of disturbance on a viscous flow are stable and unstable. For an ideal fluid, Bernoulli's equation holds along streamlines. P/ρg + u²/2g = p1/ρg + u1²/2g = p2/ρg + u2²/2g Assuming a flow is bounded on one side only, that a rectilinear flow passing over a stationary flat plate which lies parallel to the flow, the flow just upstream of the plate has a uniform velocity; as the flow comes into contact with the plate, the layer of fluid actually'adheres' to a solid surface. There is a considerable shearing action between the layer of fluid on the plate surface and the second layer of fluid.
The second layer is therefore forced to decelerate, creating a shearing action with the third layer of fluid, so on. As the fluid passes further along the plate, the zone in which shearing action occurs tends to spread further outwards; this zone is known as the'boundary layer'. The flow outside the boundary layer is free of shear and viscous-related forces so it is assumed to act like an ideal fluid; the intermolecular cohesive forces in a fluid are not great enough to hold fluid together. Hence a fluid will flow under the action of the slightest stress and flow will continue as long as the stress is present; the flow inside the layer can be either turbulent, depending on Reynolds number. Common topics of design for hydraulic engineers include hydraulic structures such as dams, water distribution networks, water collection networks, sewage collection networks, storm water management, sediment transport, various other topics related to transportation engineering and geotechnical engineering. Equations developed from the principles of fluid dynamics and fluid mechanics are utilized by other engineering disciplines such as mechanical and traffic engineers.
Related branches include hydrology and rheology while related applications include hydraulic modeling, flood mapping, catchment flood management plans, shoreline management plans, estuarine strategies, coastal protection, flood alleviation. Earliest uses of hydraulic engineering were to irrigate crops and dates back to the Middle East and Africa. Controlling the movement and supply of water for growing food has been used for many thousands of years. One of the earliest hydraulic machines, the water clock was used in the early 2nd millennium BC. Other early examples of using gravity to move water include the Qanat system in ancient Persia and the similar Turpan water system in ancient China as well as irrigation canals in Peru. In ancient China, hydraulic engineering was developed, engineers constructed massive canals with levees and dams to channel the flow of water for irrigation, as well as locks to allow ships to pass through. Sunshu Ao is considered the first Chinese hydraulic engineer. Another important Hyd
Doctor Who is a British science fiction television programme produced by the BBC since 1963. The programme depicts the adventures of a Time Lord called "the Doctor", an extraterrestrial being, to all appearances human, from the planet Gallifrey; the Doctor explores the universe in a time-travelling space ship called the TARDIS. Its exterior appears as a blue British police box, a common sight in Britain in 1963 when the series first aired. Accompanied by a number of companions, the Doctor combats a variety of foes while working to save civilisations and help people in need; the show is a significant part of British popular culture, elsewhere it has gained a cult following. It has influenced generations of British television professionals, many of whom grew up watching the series; the programme ran from 1963 to 1989. There was an unsuccessful attempt to revive regular production in 1996 with a backdoor pilot, in the form of a television film titled Doctor Who; the programme was relaunched in 2005, since has been produced in-house by BBC Wales in Cardiff.
Doctor Who has spawned numerous spin-offs, including comic books, novels, audio dramas, the television series Torchwood, The Sarah Jane Adventures, K-9, Class, has been the subject of many parodies and references in popular culture. Thirteen actors have headlined the series as the Doctor; the transition from one actor to another is written into the plot of the show with the concept of regeneration into a new incarnation, a plot device in which a Time Lord "transforms" into a new body when the current one is too badly harmed to heal normally. Each actor's portrayal is unique. Together, they form a single lifetime with a single narrative; the time-travelling feature of the plot means that different incarnations of the Doctor meet. The Doctor is portrayed by Jodie Whittaker, who took on the role after Peter Capaldi's exit in the 2017 Christmas special "Twice Upon a Time". Doctor Who follows the adventures of the title character, a rogue Time Lord from the planet Gallifrey who goes by the name "the Doctor".
The Doctor fled Gallifrey in a stolen TARDIS, a time machine that travels by materialising into and dematerialising out of the time vortex. The TARDIS has a vast interior but appears smaller on the outside, is equipped with a "chameleon circuit" intended to make the machine take on the appearance of local objects as a disguise. Across time and space, the Doctor's many incarnations find events that pique their curiosity and try to prevent evil forces from harming innocent people or changing history, using only ingenuity and minimal resources, such as the versatile sonic screwdriver; the Doctor travels alone and brings one or more companions to share these adventures. These companions are humans, owing to the Doctor's fascination with planet Earth, which leads to frequent collaborations with the international military task force UNIT when the Earth is threatened; the Doctor is centuries old and, as a Time Lord, has the ability to regenerate in case of mortal damage to the body, taking on a new appearance and personality.
The Doctor has gained numerous reoccurring enemies during their travels, including the Daleks, the Cybermen, the Master, another renegade Time Lord. Doctor Who first appeared on BBC TV at 17:16:20 GMT on Saturday, 23 November 1963, it was to be each episode 25 minutes of transmission length. Discussions and plans for the programme had been in progress for a year; the head of drama Sydney Newman was responsible for developing the programme, with the first format document for the series being written by Newman along with the head of the script department Donald Wilson and staff writer C. E. Webber. Writer Anthony Coburn, story editor David Whitaker and initial producer Verity Lambert heavily contributed to the development of the series; the programme was intended to appeal to a family audience as an educational programme using time travel as a means to explore scientific ideas and famous moments in history. On 31 July 1963, Whitaker commissioned Terry Nation to write a story under the title The Mutants.
As written, the Daleks and Thals were the victims of an alien neutron bomb attack but Nation dropped the aliens and made the Daleks the aggressors. When the script was presented to Newman and Wilson it was rejected as the programme was not permitted to contain any "bug-eyed monsters". According to producer Verity Lambert. We had a bit of a crisis of confidence. Had we had anything else ready we would have made that." Nation's script became the second Doctor. The serial introduced the eponymous aliens that would become the series' most popular monsters, was responsible for the BBC's first merchandising boom; the BBC drama department's serials division produced the programme for 26 seasons, broadcast on BBC 1. Falling viewing numbers, a decline in the public perception of the show and a less-prominent transmission slot saw production suspended in 1989 by Jonathan Powell, controller of BBC 1. Although it was cancelled with the decision not to commission a planned 27th season, which would have been broadcast in 1990, the BBC affirmed, over several ye