Japanese folklore encompasses the folk traditions of Japan and the Japanese people. In Japanese, the term minkan denshō is used to describe folklore. Folklorists employ the term minzoku shiryō or "folklore material" to refer to objects and arts they study. Men dressed as namahage, wearing ogre-like masks and traditional straw capes make rounds of homes, in an annual ritual of the Oga Peninsula area of the Northeast region; these ogre-men masquerade as kami looking to instill fear in the children who are lazily idling around the fire. This is a colorful example of folk practice still kept alive. A parallel custom is the secretive Akamata-Kuromata ritual of the Yaeyama Islands, Okinawa which does not allow itself to be photographed. Many, though fewer households maintain a kamidana or a small Shinto altar shelf; the Shinto version of the kitchen god is the Kamado kami, the syncretic Buddhist version is the Kōjin, a deity of the hearth enshrined in the kitchen. Japanese popular cults or kō are sometimes devoted to particular deities and buddhas, e.g. the angry Fudō Myōō or the healer Yakushi Nyorai.
But many cults centered around paying respects to sacred sites such as the Ise Mount Fuji. Pilgrimage to these meccas declined after the Edo period, but the Shikoku Pilgrimage of the eighty-eight temple sites has become fashionable. Popular media and cottage industries now extoll a number of shrines and sacred natural sites as power spots. There is a long list of practices performed to expel evil, e.g. sounding the drums. In some areas it is common to place a small mound of salt outside the house. Salt-scattering is considered purifying. A stock routine in period or contemporary drama involves a master of the house telling his wife to scatter salt after an undesirable visitor has just left. Contrarily, lighting sparks with flint. No one now engages in the silent vigil required by the Kōshin cult, but it might be noted that this cult has been associated with the iconic three See no evil, hear no evil, speak no evil monkeys. There are certain vestiges of geomancy introduced into Japan from China through Onmyōdō.
The word kimon, "ogre's gate", colloquially refers to anything that a person may have constant ill luck with, but in the original sense designates the northeasterly direction, considered to be unlucky or dangerously inviting of ill-intended spirits. There is a Japanese version of Feng Shui known as kasō or "house physiognomy". Connected is the Yin-yang path or Onmyōdō, its concepts such as katatagae known as kataimi, practiced by nobles in the Heian period. A known taboo advises against sleeping with your head faced north, though it is doubtful if anyone now heeds this prohibition; as in most developed nations, it is difficult to find living storytellers of oral tradition. But there is a wealth of folktales collected through the ages; the name mukashi-banashi has been applied to the common folktale, since they open with the formula "Mukashi...". They close with some set phrase like "dotto harai"; these tales had been told in their local dialects, which may be difficult to understand to outsiders, both because of intonation and pronunciation differences and vocabulary.
Many folktales collected from the field are "translations" into standard Japanese. Classic folktales such as Momotarō, which most Japanese today are familiarized through pictured children's storybooks, manga, or other popularizations, can be traced to picture-books printed in the Edo period, though their prototypical stories may go back much further; the versions retold by children's story author Sazanami Iwaya had a strong hand in establishing the forms known today. Two creatures are known for their abilities to transform into humans or other beings and objects, the kitsune and tanuki, they occur in folktales of humorous nature. Marriages between humans and non-humans comprise a major motif in Japanese folklore. Japanese heterotype examples such as the crane story describes a sustained period of married life between the interspecies couple, in contrast to Western examples like Frog Prince or the Leda myth where the supernatural encounter is brief. An unusual pairing occurs in the story of the Hamaguri nyōbo, which exist in both a politer written version and in a more rustic and vulgar oral tale.
The gender is reversed in the tale of Tanishi chōja. A number of folktales were adapted for stage performance by playwright Junji Kinoshita, notably Yūzuru, based on the folktale Tsuru no Ongaeshi or "a crane who repaid its gratitude". In the American television series called The Yokai King, starring by Shin Koyamada, the characters are based on the Japanese folklore creatures. A great deal of interest gravitates towards Japanese monsters taken from traditional Japanese sources; some of the yōkai or strange beings are the stuff of folklore, orally
Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is one joule per second. Electric power is produced by electric generators, but can be supplied by sources such as electric batteries, it is supplied to businesses and homes by the electric power industry through an electric power grid. Electric power is sold by the kilowatt hour, the product of the power in kilowatts multiplied by running time in hours. Electric utilities measure power using an electricity meter, which keeps a running total of the electric energy delivered to a customer. Electrical power provides a low entropy form of energy and can be carried long distances and converted into other forms of energy such as motion, light or heat with high energy efficiency. Electric power, like mechanical power, is the rate of doing work, measured in watts, represented by the letter P; the term wattage is used colloquially to mean "electric power in watts." The electric power in watts produced by an electric current I consisting of a charge of Q coulombs every t seconds passing through an electric potential difference of V is P = work done per unit time = V Q t = V I where Q is electric charge in coulombs t is time in seconds I is electric current in amperes V is electric potential or voltage in volts Electric power is transformed to other forms of energy when electric charges move through an electric potential difference, which occurs in electrical components in electric circuits.
From the standpoint of electric power, components in an electric circuit can be divided into two categories: Passive devices or loads: When electric charges move through a potential difference from a higher to a lower voltage, when conventional current moves from the positive terminal to the negative terminal, work is done by the charges on the device. The potential energy of the charges due to the voltage between the terminals is converted to kinetic energy in the device; these devices are called passive loads. Examples are electrical appliances, such as light bulbs, electric motors, electric heaters. In alternating current circuits the direction of the voltage periodically reverses, but the current always flows from the higher potential to the lower potential side. Active devices or power sources: If the charges are moved by an'exterior force' through the device in the direction from the lower electric potential to the higher, work will be done on the charges, energy is being converted to electric potential energy from some other type of energy, such as mechanical energy or chemical energy.
Devices in which this occurs are called active devices or power sources. Some devices can current through them. For example, a rechargeable battery acts as a source when it provides power to a circuit, but as a load when it is connected to a battery charger and is being recharged, or a generator as a power source and a motor as a load. Since electric power can flow either into or out of a component, a convention is needed for which direction represents positive power flow. Electric power flowing out of a circuit into a component is arbitrarily defined to have a positive sign, while power flowing into a circuit from a component is defined to have a negative sign, thus passive components have positive power consumption, while power sources have negative power consumption. This is called the passive sign convention. In the case of resistive loads, Joule's law can be combined with Ohm's law to produce alternative expressions for the amount of power, dissipated: P = I V = I 2 R = V 2 R, where R is the electrical resistance.
In alternating current circuits, energy storage elements such as inductance and capacitance may result in periodic reversals of the direction of energy flow. The portion of power flow that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as real power; that portion of power flow due to stored energy, that returns to the source in each cycle, is known as reactive power. The real power P in watts consumed by a device is given by P = 1 2 V p I p cos θ = V r m s I r m s cos θ where Vp is the peak voltage in volts Ip is the peak current in amperes Vrms is the root-mean-square voltage in volts Irms is the root-mean-square current in amperes θ is the phase angle between the current and voltage sine waves The relationship between real power, reactive power and apparent power can be expressed by representing the quantities as vectors. Real power is represented as a horizontal vector and reactive power is represented as a vertical vector.
The apparent power vector is the hypotenuse o
The silkworm is the larva or caterpillar of the domestic silkmoth, Bombyx mori. It is an economically important insect. A silkworm's preferred food is white mulberry leaves, though they may eat other mulberry species and osage orange. Domestic silkmoths are dependent on humans for reproduction, as a result of millennia of selective breeding. Wild silkmoths are different from their domestic cousins. Sericulture, the practice of breeding silkworms for the production of raw silk, has been under way for at least 5,000 years in China, whence it spread to India, Korea and the West; the silkworm was domesticated from the wild silkmoth Bombyx mandarina, which has a range from northern India to northern China, Korea and the far eastern regions of Russia. The domesticated silkworm derives from Chinese rather than Korean stock. Silkworms were unlikely to have been domestically bred before the Neolithic age. Before the tools to manufacture quantities of silk thread had not been developed; the domesticated B. mori and the wild B. mandarina can still sometimes produce hybrids.
Domestic silkmoths are different from most members in the genus Bombyx. Mulberry silkworms can be categorized into types; the major groups of silkworms fall under the bivoltine categories. The univoltine breed is linked with the geographical area within greater Europe; the eggs of this type hibernate during winter due to the cold climate, cross-fertilize only by spring, generating silk only once annually. The second type is called bivoltine and is found in China and Korea; the breeding process of this type takes place twice annually, a feat made possible through the warmer climates and the resulting two life cycles. The polyvoltine type of mulberry silkworm can only be found in the tropics; the eggs are laid by female moths and hatch within nine to 12 days, so the resulting type can have up to eight separate life cycles throughout the year. Eggs take about 14 days to hatch into larvae, they have a preference for white mulberry. They are not monophagous since they can eat other species of Morus, as well as some other Moraceae Osage orange.
They are covered with tiny black hairs. When the color of their heads turns darker, it indicates. After molting, the larval phase of the silkworms emerge white and with little horns on their backs. After they have molted four times, their bodies become yellow and the skin becomes tighter; the larvae prepare to enter the pupal phase of their lifecycle, enclose themselves in a cocoon made up of raw silk produced by the salivary glands. The final molt from larva to pupa takes place within the cocoon, which provides a vital layer of protection during the vulnerable motionless pupal state. Many other Lepidoptera produce cocoons, but only a few—the Bombycidae, in particular the genus Bombyx, the Saturniidae, in particular the genus Antheraea—have been exploited for fabric production. If the animal is allowed to survive after spinning its cocoon and through the pupal phase of its lifecycle, it releases proteolytic enzymes to make a hole in the cocoon so it can emerge as an adult moth; these enzymes are destructive to the silk and can cause the silk fibers to break down from over a mile in length to segments of random length, which reduces the value of the silk threads, but not silk cocoons used as "stuffing" available in China and elsewhere for doonas, jackets etc.
To prevent this, silkworm cocoons are boiled. The heat kills the water makes the cocoons easier to unravel; the silkworm itself is eaten. As the process of harvesting the silk from the cocoon kills the larva, sericulture has been criticized by animal welfare and rights activists. Mahatma Gandhi was critical of silk production based on the Ahimsa philosophy "not to hurt any living thing"; this led to Gandhi's promotion of cotton spinning machines, an example of which can be seen at the Gandhi Institute. He promoted Ahimsa silk, wild silk made from the cocoons of wild and semiwild silkmoths; the moth – the adult phase of the lifecycle – is not capable of functional flight, in contrast to the wild B. mandarina and other Bombyx species, whose males fly to meet females and for evasion from predators. Some may emerge with the ability to lift off and stay airborne, but sustained flight cannot be achieved; this is because their bodies are too heavy for their small wings. However, some silkmoths can still fly.
Silkmoths have a wingspan of 3 -- a white, hairy body. Females are about two to three times bulkier than males, but are colored. Adult Bombycidae do not feed, though a human caretaker can feed them; the cocoon is made of a thread of raw silk from 300 to about 900 m long. The fibers are fine and lustrous, about 10 μm in diameter. About 2,000 to 3,000 cocoons are required to make a pound of silk. At least 70 million pounds of raw silk are produced each year. Due to its small size and ease of culture, the silkworm has become a model organism in the study of lepidopteran and arthropod biology. Fundamental findings on pheromones, brain structures, physiology have been made with the silkworm. One example of this was the m
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results
Orb-weaver spiders or araneids are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs found in gardens and forests. "Orb" was used in English to mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, no stridulating organs; the family is cosmopolitan, including brightly colored garden spiders. With 3122 species in 172 genera worldwide, Araneidae is the third-largest family of spiders. Araneid webs are constructed in a stereotyped fashion. A framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets. Orb-webs are produced by members of other spider families; the long-jawed orb weavers were included in the Araneidae. The family Arkyidae has been split off from the Araneidae; the cribellate or hackled orb-weavers belong to a different group of spiders. Their webs use a different kind of sticky silk. Orb-weaving spiders are three-clawed builders of flat webs with sticky spiral capture silk.
The building of a web is an engineering feat, begun when the spider floats a line on the wind to another surface. The spider secures the line and drops another line from the center, making a "Y"; the rest of the scaffolding follows with many radii of nonsticky silk being constructed before a final spiral of sticky capture silk. The third claw is used to walk on the nonsticky part of the web. Characteristically, the prey insect that blunders into the sticky lines is stunned by a quick bite, wrapped in silk. If the prey is a venomous insect, such as a wasp, wrapping stinging. Many orb-weavers build a new web each day. Most orb-weavers tend to be active during the evening hours. Towards evening, the spider will consume the old web, rest for an hour spin a new web in the same general location. Thus, the webs of orb-weavers are free of the accumulation of detritus common to other species, such as black widow spiders; some orb-weavers do not build webs at all. Members of the genera Mastophora in the Americas, Cladomelea in Africa, Ordgarius in Australia produce sticky globules, which contain a pheromone analog.
The globule is hung from a silken thread dangled by the spider from its front legs. The pheromone analog attracts male moths of only a few species; these are reeled in to be eaten. Both types of bolas spiders are camouflaged and difficult to locate; the spiny orb-weaving spiders in the genera Gasteracantha and Micrathena look like plant seeds or thorns hanging in their orb-webs. Some species of Gasteracantha have long, horn-like spines protruding from their abdomens. One feature of the webs of some orb-weavers is the stabilimentum, a crisscross band of silk through the center of the web, it is found in several genera, but Argiope – the yellow and banded garden spiders of North America – is a prime example. As orb-weavers age, they tend to have less production of their silk, many adult orb-weavers can depend on their coloration to attract more of their prey; the band may be a lure for prey, a marker to warn birds away from the web, a camouflage for the spider when it sits in the web. The stabilimentum may decrease the visibility of the silk to insects, thus making it harder for prey to avoid the web.
The orb-web consists of a frame and supporting radii overlaid with a sticky capture spiral, the silks used by orb-weaver spiders have exceptional mechanical properties to withstand the impact of flying prey. During the Cretaceous, a radiation of angiosperm plants and their insect pollinators occurred. Fossil evidence shows that the orb web was in existence at this time, which permitted a concurrent radiation of the spider predators along with their insect prey; the capacity of orb–webs to absorb the impact of flying prey led orbicularian spiders to become the dominant predators of aerial insects in many ecosystems. Insects and spiders have comparable rates of diversification, suggesting they co-radiated, the peak of this radiation occurred 100 Mya before the origin of angiosperms. Vollrath and Selden make the bold proposition that insect evolution was driven less by flowering plants than by spider predation – through orb webs – as a major selective force. Most arachnid webs are vertical and the spiders hang with their head downward.
A few webs, such as those of orb-weavers in the genus Metepeira have the orb hidden within a tangled space of web. Some Metepiera are live in communal webs. In Mexico, such communal webs have been used for living fly paper. In 2009, workers at a Baltimore Wastewater Treatment Plant called for help to deal with over 100 million orb-weaver spiders, living in a community that managed to spin a phenomenal web that covered some 4 acres of a building with spider densities in some areas reaching 35,176 spiders per cubic meter; the oldest known true orb-weaver is Mesozygiella dunlopi, from the Lower Cretaceous. Several fossils provide direct evidence that the three major orb-weaving families, namely Araneidae and Uloboridae, had evolved by this time, about 140 million years ago, they originated during the Jurassic. Based on new molecular evidence in silk genes, all three families are to have a common origin; the two families and Araneoidea, have similar behavioral sequences and spinning apparatuses to produce architecturally similar webs.
The Araneidae weave true viscid
Golden silk orb-weaver
The golden silk orb-weavers are a genus of araneomorph spiders noted for the impressive webs they weave. Nephila consists of numerous species found in warmer regions around the world, they are commonly called golden orb-weavers, giant wood spiders, or banana spiders. The genus name Nephila is derived from Ancient Greek, meaning "fond of spinning", from the words νεῖν = to spin + φίλος = "love". Nephila spiders vary from reddish to greenish yellow in color with distinctive whiteness on the cephalothorax and the beginning of the abdomen. Like many species of the superfamily Araneoidea, most of them have striped legs specialized for weaving, their contrast of dark brown/black and green/yellow allows warning and repelling of potential predators to which their venom might be of little danger. Golden orb-weavers reach sizes of 4.8–5.1 cm in females, not including legspan, with males being two-thirds smaller. The largest specimen recorded was a 6.9-cm female N. plumipes from Queensland, able to catch and feed on a small finch.
In 2012, a large individual was photographed killing and consuming a 0.5-m-long brown tree snake in Freshwater, Queensland. Species from Taiwan have been known to reach over 130 mm, legspan included, in mountainous country. In 2014, a study discovered that golden orb-weavers living in urban areas areas of a high socioeconomic status, grew larger and carried more eggs than those in their native habitats. A number of possible explanations were suggested, such as increased food supplies due to artificial light or lack of predators and parasites; as of May 2017, the World Spider Catalog accepted these species: Golden silk orb-weavers are widespread in warmer regions throughout the world, with species in Australia, Asia and the Americas. One species, N. clavipes, occurs in the United States of America, where it ranges throughout the coastal southeast and inland, from North Carolina to Texas. Spiderlings can be carried by the wind over long distances, each year, a small number of golden orb web spiders are found in New Zealand after having been blown across the Tasman Sea.
Whilst the geographic distribution of Nephila is large, many habitat similarities are seen between these locations. A warm and reasonably wet climate is preferred, as these are some of the environmental cues that induce spiderling hatching. Locally, spiders look for dense vegetation where webs can be set up in areas that insects will fly through. Urban environments are attractive due to the large prey concentrations and lower levels of predation. Nephila spiders produce large asymmetric orb webs up to 1.5 m in diameter. The hub of the web is in the upper section, while most of the sticky capture strands are found in the lower web. Nephila species remain in their webs permanently. A barrier web structure on either side of the main web helps mitigate this risk; the golden silk orb-weaver is named for the yellow color of the spider silk used to construct these webs. Yellow threads of their web shine like gold in sunlight. Carotenoids are the main contributors to this yellow color, but xanthurenic acid, two quinones, an unknown compound may aid in the color.
Experimental evidence suggests that the silk's color may serve a dual purpose: sunlit webs ensnare bees that are attracted to the bright yellow strands, whereas in shady spots, the yellow blends in with background foliage to act as a camouflage. The spider is able to adjust pigment intensity relative to color; the webs of most Nephila spiders are complex, with a fine-meshed orb suspended in a maze of non-sticky barrier webs. As with many weavers of sticky spirals, the orb is renewed if not daily because the stickiness of the orb declines with age; when weather is good and adults rebuild only a portion of the web. The spider removes and consumes the portion to be replaced, builds new radial elements spins the new spirals; this partial orb renewal is distinct from other orb-weaving spiders that replace the entire orb web. The web of Nephila antipodiana contains ant-repellent chemicals to protect the web; the golden orb-weaver first weaves a nonsticky spiral with space for two to 20 more spirals in between.
When she has completed the coarse weaving, she fills in the gaps. Whereas most orb-weaving spiders remove the nonsticky spiral when spinning the sticky spiral, Nephila spiders leave it; this produces a "manuscript paper" effect when the orb is seen in the sun: groups of sticky spirals reflecting light with "gaps" where the nonsticky spiral does not reflect the light. The circular-orb portion of a mature N. clavipes web can be more than 1 m across, with support strands extending several more meters away. In relation to the ground, the webs of adults may be woven from eye-level upwards high into the tree canopy; the orb web is truncated by a top horizontal support strand, giving it an incomplete look. Adjacent to one face of the main orb, a rather extensive and haphazard-looking network of guard-strands may be suspended a few cm distant across a free space; this network is decorated with a lumpy string or two of plant detritus
Yōkai are a class of supernatural monsters and demons in Japanese folklore. The word yōkai is made up of the kanji for "bewitching, they can be called ayakashi, mononoke, or mamono. Yōkai range diversely from the malevolent to the mischievous, or bring good fortune to those who encounter them. Yōkai possess animal features, yet others appear human; some yōkai look like inanimate objects. Yōkai have spiritual or supernatural abilities, with shapeshifting being the most common. Yōkai that shapeshift are called bakemono / obake. Japanese folklorists and historians explain yōkai as personifications of "supernatural or unaccountable phenomena to their informants". In the Edo period, many artists, such as Toriyama Sekien, invented new yōkai taking inspiration from folk tales or purely from their own imagination. Today, several such fabricated yōkai are mistaken to originate in more traditional folklore. Yurei are called yuree in Okinawa, yokai are called majimun マジムン, evil spirits are called yanamun ヤナムン.
What is thought of as "supernatural" depends on the time period. According to Japanese ideas of animism, spirit-like entities called mononoke were believed to reside in all things; such spirits possessed personalities. If the spirit were peaceful, it was a nigi-mitama. Violent spirits, ara-mitama, brought ill fortune -- including natural disasters. One's ancestors and particularly-respected departed elders could be deemed nigi-mitama, accruing status as protective gods and receiving worship. Animals and natural features or phenomena were venerated as nigi-mitama or propitiated as ara-mitama—depending on the area; the ritual for converting ara-mitama into nigi-mitama was called the chinkon. Chinkon rituals were performed to quell maleficent spirits, prevent misfortune and alleviate fear from events and circumstances that could not otherwise be explained. Ara-mitama that failed to achieve deification due to lack of sufficient veneration, or who lost their divinity following attrition of worshipers, became yōkai.
Over time, those things thought to be supernatural became fewer. Meanwhile, depictions of yōkai in emaki and paintings began to standardize, turning into caricatures and softening their fearsome natures. Elements from tales of yōkai were mined for public entertainment. Use of yōkai in popular media began as early as the middle ages. However, the mythology and lore of yōkai became more defined and formalized during the Edo period and after; the folkloricist Tsutomu Ema studied the literature and paintings depicting yōkai and henge and divided them into categories, as presented in the Nihon Yōkai Henge Shi and the Obake no Rekishi. Five categories based on the yōkai's "true form": human, plant, object, or natural phenomenon. Four categories depending on source of mutation: this-world related, spiritual/mental related, reincarnation/next-world related, or material related. Seven categories based on external appearance: human, plant, structure/building, natural object or phenomenon, miscellaneous—as well as compound classifications for yōkai falling into more than one category.
In traditional Japanese folkloristics, yōkai are classified by location or phenomenon associated with their manifestation. Yōkai are indexed in the book Sogo Nihon Minzoku Goi as follows: Yama no ke, michi no ke, ki no ke, mizu no ke, umi no ke, yuki no ke, oto no ke, doubutsu no ke First century: there is a book from what is now China titled 循史伝 with the statement "the spectre was in the imperial court for a long time; the king asked Tui for the reason. He answered that there was great anxiety and he gave a recommendation to empty the imperial room", thus using "妖恠" to mean "phenomenon that surpasses human knowledge." Houki 8: in the Shoku Nihongi, there is the statement "shinto purification is performed because yōkai appear often in the imperial court," using the word "yōkai" to mean not anything in particular, but strange phenomena in general. Middle of the Heian era: In The Pillow Book by Sei Shōnagon, there is the statement "there are tenacious mononoke" as well as a statement by Murasaki Shikibu that "the mononoke have become quite dreadful," which are the first appearances of the word "mononoke."
Koubu 3: In the Taiheiki, in the fifth volume, there is the statement, "Sagami no Nyudo was not at all frightened by yōkai." The ancient times were a period abundant in literature and folktales mentioning and explaining yōkai. Literature such as the Kojiki, the Nihon Shoki, various Fudoki expositioned on legends from the ancient past, mentions of oni, among other kinds of mysterious phenomena can be seen in them. In the Heian period, collections of stories about yōkai and other supernatural phenomena were published in multiple volumes, starting with publications such as the Nihon Ryōiki and the Konjaku Monogatarishū, in these publications, mentions of