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Tree-of-Life
Pak Breeders and Pak Protectors are two developmental stages of fictional life in Larry Niven's Known Space universe. The Pak first appeared in "The Adults", which appeared in ''Galaxy'' in 1967; this story was expanded into the novel ''Protector'' by Larry Niven (1973). The Pak also appear in several of Niven's later novels, notably those set in the Ringworld. '' Destroyer of Worlds'' depicts a confrontation between the Pak and the Puppeteers. Narrative purpose Niven has written that he invented the Protectors as a thought experiment to explain the common effects of aging on humans and to create a fictional evolutionary explanation for humans' long lives after females have passed reproductive age. Accordingly, most of the positive attributes of Protectors are based on negative human aging effects: swollen joints, decreased muscle-fat ratio, weakening heart, invariant diet, decreasing height, facial atrophy, leathery skin, hair loss, lack of sex drive, and tooth loss are all t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amalgamated Regional Militia
Known Space is the fictional setting of about a dozen science fiction novels and several collections of short stories written by Larry Niven. It has also become a shared universe in the spin-off ''Man-Kzin Wars'' anthologies. The Internet Speculative Fiction Database (ISFDB) catalogs all works set in the fictional universe that includes Known Space under the series name Tales of Known Space, which was the title of a 1975 collection of Niven's short stories. The first-published work in the series, which was Niven's first published piece was "The Coldest Place", in the December 1964 issue of '' If'' magazine, edited by Frederik Pohl. This was the first-published work in the 1975 collection. The stories span approximately one thousand years of future history, from the first human explorations of the Solar System to the colonization of dozens of nearby systems. Late in the series, Known Space is an irregularly shaped "bubble" about 60 light-years across. The epithet "Known Space" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protector (novel)
''Protector'' is a 1973 science fiction novel by American writer Larry Niven, set in his Known Space universe. It was nominated for the Hugo in 1974, and placed fourth in the annual Locus poll for that year. The work fleshes out a species called the Pak, originally introduced in a 1967 story called "The Adults", which forms the first half of the novel (there titled ''Phssthpok''); the second half is titled ''Vandervecken''. The Pak also appear in several of Niven's later works, including the later volumes of the ''Ringworld'' series and the novel '' Destroyer of Worlds'' which serves as a semi-sequel to ''Protector''. Plot summary The novel comprises two phases in the same space that are separated by 220 years of time. Its central conceit is that Humans evolved from the juvenile stage of the Pak, a species with a distinct adult form ("Protectors") that has immense strength and intelligence and cares only about younger Pak of their bloodline. A key plot point is that trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coconut
The coconut tree (''Cocos nucifera'') is a member of the palm tree family (Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, the seed, or the fruit, which botanically is a drupe, not a nut. The name comes from the old Portuguese word '' coco'', meaning "head" or "skull", after the three indentations on the coconut shell that resemble facial features. They are ubiquitous in coastal tropical regions and are a cultural icon of the tropics. The coconut tree provides food, fuel, cosmetics, folk medicine and building materials, among many other uses. The inner flesh of the mature seed, as well as the coconut milk extracted from it, form a regular part of the diets of many people in the tropics and subtropics. Coconuts are distinct from other fruits because their endosperm contains a large quantity of clear liquid, called '' coconut water'' or ''coconut juice''. Mature, ripe co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moment (physics)
In physics, a moment is a mathematical expression involving the product of a distance and physical quantity. Moments are usually defined with respect to a fixed reference point and refer to physical quantities located some distance from the reference point. In this way, the moment accounts for the quantity's location or arrangement. For example, the moment of force, often called torque, is the product of a force on an object and the distance from the reference point to the object. In principle, any physical quantity can be multiplied by a distance to produce a moment. Commonly used quantities include forces, masses, and electric charge distributions. Elaboration In its most basic form, a moment is the product of the distance to a point, raised to a power, and a physical quantity (such as force or electrical charge) at that point: : \mu_n = r^n\,Q, where Q is the physical quantity such as a force applied at a point, or a point charge, or a point mass, etc. If the quantity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femoral Vein
In the human body, the femoral vein is a blood vessel that accompanies the femoral artery in the femoral sheath. It begins at the adductor hiatus (an opening in the adductor magnus muscle) as the continuation of the popliteal vein. It ends at the inferior margin of the inguinal ligament where it becomes the external iliac vein. The femoral vein bears valves which are mostly bicuspid and whose number is variable between individuals and often between left and right leg. Structure Segments *The common femoral vein is the segment of the femoral vein between the branching point of the deep femoral vein and the inferior margin of the inguinal ligament.Page 590 in: *The subsartorial vein or superficial femoral vein are designat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genocide
Genocide is the intentional destruction of a people—usually defined as an ethnic, national, racial, or religious group—in whole or in part. Raphael Lemkin coined the term in 1944, combining the Greek word (, "race, people") with the Latin suffix ("act of killing").. In 1948, the United Nations Genocide Convention defined genocide as any of five "acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group." These five acts were: killing members of the group, causing them serious bodily or mental harm, imposing living conditions intended to destroy the group, preventing births, and forcibly transferring children out of the group. Victims are targeted because of their real or perceived membership of a group, not randomly. The Political Instability Task Force estimated that 43 genocides occurred between 1956 and 2016, resulting in about 50 million deaths. The UNHCR estimated that a further 50 million had been d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thallium Oxide
Thallium has several oxides: *Thallium(I) oxide Tl2O *Thallium(III) oxide Thallium(III) oxide, also known as thallic oxide, is a chemical compound of thallium and oxygen. It occurs in nature as the rare mineral avicennite. Its structure is related to that of Mn2O3 which has a bixbyite like structure. Tl2O3 is metallic ... Tl2O3 * Thallium(I) superoxide or thallium dioxide TlO2 * Tl4O3 {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abundance Of Elements In Earth's Crust
The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each chemical element shown as mg/kg, or parts per million (ppm) by mass (10,000 ppm = 1%). Estimates of elemental abundance are difficult because (a) the composition of the upper and lower crust are quite different, and (b) the composition of the continental crust can vary drastically by locality. David KringComposition of Earth's continental crust as inferred from the compositions of impact melt sheets Lunar and Planetary Science XXVIII List of abundance by element See also * Abundances of the elements (data page) * Atmospheric chemistry * Clarke number — lists of historical data and terminology * List of chemical elements This is a list of the 118 chemical elements which have been identified as of 2022. A chemical element, often simply called an element, is a type of atom which has the same number of protons in its atomic nucleus (i.e., the same atomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
