A spear is a pole weapon consisting of a shaft, usually of wood, with a pointed head. The most common design for hunting or combat spears since ancient times has incorporated a metal spearhead shaped like a triangle, the heads of fishing spears usually feature barbs or serrated edges. The word spear comes from the Old English spere, from the Proto-Germanic speri, from a Proto-Indo-European root *sper- spear, Spears can be divided into two broad categories, those designed for thrusting in melee combat and those designed for throwing. The spear has been used throughout history both as a hunting and fishing tool and as a weapon. Along with the axe and club, it is one of the earliest and most important tools developed by early humans, as a weapon, it may be wielded with either one hand or two. It was used in every conflict up until the modern era, where even it continues on in the form of the bayonet. Spear manufacture and use is not confined to human beings and it is practiced by the western chimpanzee.
Chimpanzees near Kédougou, Senegal have been observed to create spears by breaking straight limbs off trees, stripping them of their bark and side branches and they used the weapons to hunt galagos sleeping in hollows. Orangutans have used spears to fish, presumably after observing humans fishing in a similar manner, neanderthals were constructing stone spear heads from as early as 300,000 BP and by 250,000 years ago, wooden spears were made with fire-hardened points. From 200,000 BP onwards, Middle Paleolithic humans began to make stone blades with flaked edges which were used as spear heads. These stone heads could be fixed to the shaft by gum or resin or by bindings made of animal sinew. During this period, a clear difference remained between spears designed to be thrown and those designed to be used in hand-to-hand combat, by the Magdalenian period, spear-throwers similar to the atlatl were in use. Spears were one of the most common weapons used in the Stone Age. They may be seen as the ancestor of such weapons as the lance, the pilum, the halberd, the naginata, the glaive, the bill.
Spears may be used as both a projectile and melee weapons, Spears used primarily for thrusting may be used with either one or two hands and tend to have heavier and sturdier designs than those intended exclusively for throwing. From the atlatl dart, the arrow for use with bows eventually developed, one-handed spears featuring socketed metal heads were used in conjunction with a shield by the earliest Bronze Age cultures. They were wielded in either combat or in large troop formations. This tradition continued from the first Mesopotamian cultures, through the various ancient Egyptian dynasties, during this time the spear was used by cavalry
Radiocarbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed by Willard Libby in the late 1940s, Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with oxygen to form radioactive carbon dioxide. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to decrease as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained.
Research has been ongoing since the 1960s to determine what the proportion of 14C in the atmosphere has been over the past fifty thousand years. The resulting data, in the form of a curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the samples calendar age. Other corrections must be made to account for the proportion of 14C in different types of organisms, additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s. Conversely, nuclear testing increased the amount of 14C in the atmosphere, measurement of radiocarbon was originally done by beta-counting devices, which counted the amount of beta radiation emitted by decaying 14C atoms in a sample. The development of dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than previous methods, histories of archaeology often refer to its impact as the radiocarbon revolution.
Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice age, and they synthesized 14C using the laboratorys cyclotron accelerator and soon discovered that the atoms half-life was far longer than had been previously thought. This was followed by a prediction by Serge A. Korff, employed at the Franklin Institute in Philadelphia and it had previously been thought that 14C would be more likely to be created by deuterons interacting with 13C. At some time during World War II, Willard Libby, who was at Berkeley, learned of Korffs research, in 1945, Libby moved to the University of Chicago where he began his work on radiocarbon dating. He published a paper in 1946 in which he proposed that the carbon in living matter might include 14C as well as non-radioactive carbon, by contrast, methane created from petroleum showed no radiocarbon activity because of its age. The results were summarized in a paper in Science in 1947, Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages
Archaeology, or archeology, is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, biofacts or ecofacts, Archaeology can be considered both a social science and a branch of the humanities. In North America, archaeology is considered a sub-field of anthropology, archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. Archaeology as a field is distinct from the discipline of palaeontology, Archaeology is particularly important for learning about prehistoric societies, for whom there may be no written records to study. Prehistory includes over 99% of the human past, from the Paleolithic until the advent of literacy in societies across the world, Archaeology has various goals, which range from understanding culture history to reconstructing past lifeways to documenting and explaining changes in human societies through time.
The discipline involves surveying and eventually analysis of data collected to learn more about the past, in broad scope, archaeology relies on cross-disciplinary research. Archaeology developed out of antiquarianism in Europe during the 19th century, Archaeology has been used by nation-states to create particular visions of the past. Nonetheless, archaeologists face many problems, such as dealing with pseudoarchaeology, the looting of artifacts, a lack of public interest, the science of archaeology grew out of the older multi-disciplinary study known as antiquarianism. Antiquarians studied history with attention to ancient artifacts and manuscripts. Tentative steps towards the systematization of archaeology as a science took place during the Enlightenment era in Europe in the 17th and 18th centuries, in Europe, philosophical interest in the remains of Greco-Roman civilization and the rediscovery of classical culture began in the late Middle Age. Antiquarians, including John Leland and William Camden, conducted surveys of the English countryside, one of the first sites to undergo archaeological excavation was Stonehenge and other megalithic monuments in England.
John Aubrey was a pioneer archaeologist who recorded numerous megalithic and other monuments in southern England. He was ahead of his time in the analysis of his findings and he attempted to chart the chronological stylistic evolution of handwriting, medieval architecture and shield-shapes. Excavations were carried out in the ancient towns of Pompeii and Herculaneum and these excavations began in 1748 in Pompeii, while in Herculaneum they began in 1738. The discovery of entire towns, complete with utensils and even human shapes, prior to the development of modern techniques, excavations tended to be haphazard, the importance of concepts such as stratification and context were overlooked. The father of archaeological excavation was William Cunnington and he undertook excavations in Wiltshire from around 1798, funded by Sir Richard Colt Hoare. Cunnington made meticulous recordings of neolithic and Bronze Age barrows, one of the major achievements of 19th century archaeology was the development of stratigraphy.
The idea of overlapping strata tracing back to successive periods was borrowed from the new geological and paleontological work of scholars like William Smith, James Hutton, the application of stratigraphy to archaeology first took place with the excavations of prehistorical and Bronze Age sites
Japan is a sovereign island nation in Eastern Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asia Mainland and stretches from the Sea of Okhotsk in the north to the East China Sea, the kanji that make up Japans name mean sun origin. 日 can be read as ni and means sun while 本 can be read as hon, or pon, Japan is often referred to by the famous epithet Land of the Rising Sun in reference to its Japanese name. Japan is an archipelago consisting of about 6,852 islands. The four largest are Honshu, Hokkaido and Shikoku, the country is divided into 47 prefectures in eight regions. Hokkaido being the northernmost prefecture and Okinawa being the southernmost one, the population of 127 million is the worlds tenth largest. Japanese people make up 98. 5% of Japans total population, approximately 9.1 million people live in the city of Tokyo, the capital of Japan. Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period, the first written mention of Japan is in Chinese history texts from the 1st century AD.
Influence from other regions, mainly China, followed by periods of isolation, from the 12th century until 1868, Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor. Japan entered into a period of isolation in the early 17th century. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the bombings of Hiroshima and Nagasaki. Japan is a member of the UN, the OECD, the G7, the G8, the country has the worlds third-largest economy by nominal GDP and the worlds fourth-largest economy by purchasing power parity. It is the worlds fourth-largest exporter and fourth-largest importer, although Japan has officially renounced its right to declare war, it maintains a modern military with the worlds eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a country with a very high standard of living. Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world, in ancient China, Japan was called Wo 倭.
It was mentioned in the third century Chinese historical text Records of the Three Kingdoms in the section for the Wei kingdom, Wa became disliked because it has the connotation of the character 矮, meaning dwarf. The 倭 kanji has been replaced with the homophone Wa, meaning harmony, the Japanese word for Japan is 日本, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, at the start of the seventh century, a delegation from Japan introduced their country as Nihon
Travertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, cream-colored and it is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, and it is frequently used in Italy and elsewhere as a building material. Travertine is a sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters. Similar deposits formed from water are known as tufa. The word travertine is derived from the Italian travertino, itself a derivation of the Latin tiburtinus ‘of Tibur’ and its namesake is the origin of Tivoli, a district near Rome. Modern travertine is formed from geothermally heated supersaturated alkaline waters, with raised pCO2, on emergence, waters degas CO2 due to the lower atmospheric pCO2, resulting in an increase in pH. Since carbonate solubility decreases with increased pH, precipitation is induced, precipitation may be enhanced by factors leading to a reduction in pCO2, for example increased air-water interactions at waterfalls may be important, as may photosynthesis.
Precipitation may be enhanced by evaporation in some springs, both calcite and aragonite are found in hot spring travertines, aragonite is preferentially precipitated when temperatures are hot, while calcite dominates when temperatures are cooler. When pure and fine, travertine is white, but often it is brown to yellow due to impurities, travertine may precipitate out directly onto rock and other inert materials as in Pamukkale or Yellowstone for example. The latter has a historic value, because it was one of the quarries that Gian Lorenzo Bernini selected material from to build the famous Colonnade of St. Peters Square in Rome in 1656-1667. Michaelangelo chose travertine as the material for the ribs of the dome of St Peters Basilica. Travertine derives its name from the town, known as Tibur in ancient Roman times. The ancient name for the stone was lapis tiburtinus, meaning tibur stone, detailed studies of the Tivoli and Guidonia travertine deposits revealed diurnal and annual rhythmic banding and laminae, which have potential use in geochronology.
Cascades of natural lakes formed behind travertine dams can be seen in Pamukkale, Turkey, in Central Europes last post-glacial palaeoclimatic optimum, huge deposits of tufa formed from karst springs. On a smaller scale, these karst processes are still working, travertine has been an important building material since the Middle Ages. Travertine has formed sixteen huge, natural dams in a valley in Croatia known as Plitvice Lakes National Park, clinging to moss and rocks in the water, the travertine has built up over several millennia to form waterfalls up to 70 m in height. In the U. S. the most well-known place for travertine formation is Yellowstone National Park, Oklahoma has two parks dedicated to this natural wonder
Tokyo, officially Tokyo Metropolis, is the capital of Japan and one of its 47 prefectures. The Greater Tokyo Area is the most populous area in the world. It is the seat of the Emperor of Japan and the Japanese government, Tokyo is in the Kantō region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands. Formerly known as Edo, it has been the de facto seat of government since 1603 when Shogun Tokugawa Ieyasu made the city his headquarters. It officially became the capital after Emperor Meiji moved his seat to the city from the old capital of Kyoto in 1868, Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture and the city of Tokyo. The Tokyo metropolitan government administers the 23 Special Wards of Tokyo, the metropolitan government administers 39 municipalities in the western part of the prefecture and the two outlying island chains. The population of the wards is over 9 million people. The prefecture is part of the worlds most populous metropolitan area with upwards of 37.8 million people, the city hosts 51 of the Fortune Global 500 companies, the highest number of any city in the world.
Tokyo ranked third in the International Financial Centres Development IndexEdit, the city is home to various television networks such as Fuji TV, Tokyo MX, TV Tokyo, TV Asahi, Nippon Television, NHK and the Tokyo Broadcasting System. Tokyo ranked first in the Global Economic Power Index and fourth in the Global Cities Index. The city is considered a world city – as listed by the GaWCs 2008 inventory – and in 2014. In 2015, Tokyo was named the Most Liveable City in the world by the magazine Monocle, the Michelin Guide has awarded Tokyo by far the most Michelin stars of any city in the world. Tokyo ranked first in the world in the Safe Cities Index, the 2016 edition of QS Best Student Cities ranked Tokyo as the 3rd-best city in the world to be a university student. Tokyo hosted the 1964 Summer Olympics, the 1979 G-7 summit, the 1986 G-7 summit, and the 1993 G-7 summit, and will host the 2020 Summer Olympics, Tokyo was originally known as Edo, which means estuary. During the early Meiji period, the city was called Tōkei, some surviving official English documents use the spelling Tokei.
However, this pronunciation is now obsolete, the name Tokyo was first suggested in 1813 in the book Kondō Hisaku, written by Satō Nobuhiro. When Ōkubo Toshimichi proposed the renaming to the government during the Meiji Restoration, according to Oda Kanshi, Tokyo was originally a small fishing village named Edo, in what was formerly part of the old Musashi Province. Edo was first fortified by the Edo clan, in the twelfth century
A tooth is a hard, calcified structure found in the jaws of many vertebrates and used to break down food. Some animals, particularly carnivores, use teeth for hunting or for defensive purposes, the roots of teeth are covered by gums. Teeth are not made of bone, but rather of tissues of varying density. The cellular tissues that ultimately become teeth originate from the germ layer. The general structure of teeth is similar across the vertebrates, although there is variation in their form. The teeth of mammals have deep roots, and this pattern is found in some fish. In most teleost fish, the teeth are attached to the surface of the bone. In cartilaginous fish, such as sharks, the teeth are attached by tough ligaments to the hoops of cartilage that form the jaw, some animals develop only one set of teeth while others develop many sets. Sharks, for example, grow a new set of every two weeks to replace worn teeth. Rodent incisors grow and wear away continually through gnawing, which helps maintain relatively constant length, the industry of the beaver is due in part to this qualification.
Many rodents such as voles and guinea pigs, but not mice, Teeth are not always attached to the jaw, as they are in mammals. In many reptiles and fish, teeth are attached to the palate or to the floor of the mouth, some teleosts even have teeth in the pharynx. While not true teeth in the sense, the dermal denticles of sharks are almost identical in structure and are likely to have the same evolutionary origin. Though modern teeth-like structures with dentine and enamel have been found in late conodonts, living amphibians typically have small teeth, or none at all, since they commonly feed only on soft foods. In reptiles, teeth are simple and conical in shape. The pattern of incisors, canines and molars is found only in mammals, the numbers of these types of teeth vary greatly between species, zoologists use a standardised dental formula to describe the precise pattern in any given group. The genes governing tooth development in mammals are homologous to these involved in the development of fish scales, Teeth are among the most distinctive features of mammal species.
Paleontologists use teeth to identify species and determine their relationships
Naha is the capital city of Okinawa Prefecture, the most southern prefecture of Japan. As of December 2012, the city has an population of 321,467. The total area is 38.99 km², Naha is a city on the East China Sea coast of the southern part of Okinawa Island, the largest of Okinawa Prefecture. The modern city was founded on May 20,1921. Before that Naha had been for one of the most important. Naha is the political and education center of Okinawa Prefecture, in the medieval and early modern periods, it was the commercial center of the Ryūkyū Kingdom. Kokusai-dōri boasts a 1.6 kilometre long stretch of stores, Kokusai-dōri ends at the main bus terminal in Okinawa and is served by several stations along the Okinawa Monorail, the only train system in the prefecture. Just outside the area is the neighborhood of Tsuboya, which was once a major center of ceramic production. Northeast of Kokusai-dōri is a new commercial district called Shintoshin. The area, formerly United States military housing, was released to Okinawa in 1987, frequented by young people, the area boasts large stores such as Toys R Us and Best Denki, a co-op market, many restaurants and a movie theater.
The Okinawa Prefectural Museum, containing sections devoted to the art, according to the Irosetsuden, the name of Naha comes from its original name, which was the name of a large, mushroom-shaped stone in the city. Gradually, the stone away and became buried, and the names pronunciation. In Naha, some relics of the Stone Age were found. From a Jōmon period kaizuka, ancient Chinese coins were found, pottery found by archaeologists indicates that the area was an active site of trade with the Japanese archipelago and Korean peninsula at least as early as the 11th century. Though it is not known just when the area first became organized as a port city. Medieval Naha was on an island called Ukishima, connected to the mainland of Okinawa Island by a narrow causeway called Chōkōtei which led on to Shuri. The main port area for trade, Naha proper, was divided into the East and West districts and was on the southwestern portion of Ukishima. A large open-air marketplace was active in front of the government trading center
Charcoal is a lightweight, black residue, consisting of carbon and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis- the heating of wood or other substances in the absence of oxygen, the whole pile is covered with turf or moistened clay. The firing is begun at the bottom of the flue, the success of the operation depends upon the rate of the combustion. The operation is so delicate that it was left to colliers. They often lived alone in small huts in order to tend their wood piles, for example, in the Harz Mountains of Germany, charcoal burners lived in conical huts called Köten which are still much in evidence today. The massive production of charcoal was a cause of deforestation. The increasing scarcity of easily harvested wood was a factor behind the switch to fossil fuel equivalents, mainly coal. Charcoal made at 300 °C is brown and friable, and readily inflames at 380 °C, made at higher temperatures it is hard and brittle, in Finland and Scandinavia, the charcoal was considered the by-product of wood tar production.
The best tar came from pine, thus pinewoods were cut down for tar pyrolysis, the residual charcoal was widely used as substitute for metallurgical coke in blast furnaces for smelting. Tar production led to deforestation, it has been estimated all Finnish forests are younger than 300 years. The end of tar production at the end of the 19th century resulted in rapid re-forestation, the charcoal briquette was first invented and patented by Ellsworth B. A. Zwoyer of Pennsylvania in 1897 and was produced by the Zwoyer Fuel Company. The process was popularized by Henry Ford, who used wood. Ford Charcoal went on to become the Kingsford Company, Charcoal has been made by various methods. The traditional method in Britain used a clamp and this is essentially a pile of wooden logs leaning against a chimney. The chimney consists of 4 wooden stakes held up by some rope, the logs are completely covered with soil and straw allowing no air to enter. It must be lit by introducing some burning fuel into the chimney, if the soil covering gets torn by the fire, additional soil is placed on the cracks.
Once the burn is complete, the chimney is plugged to prevent air from entering, the true art of this production method is in managing the sufficient generation of heat, and its transfer to wood parts in the process of being carbonised. A strong disadvantage of this method is the huge amount of emissions that are harmful to human health
In zoology, cannibalism is the act of one individual of a species consuming all or part of another individual of the same species as food. To consume the same species or show cannibalism is an ecological interaction in the animal kingdom and has been recorded for more than 1,500 species. It does not, as believed, occur only as a result of extreme food shortages or artificial conditions. Cannibalism seems to be prevalent in aquatic communities, in which up to approximately 90% of the organisms engage in cannibalism at some point of the life cycle. Cannibalism is not restricted to species, but is commonly found in herbivores and detritivores. Sexual cannibalism is a case of cannibalism in which a female organism kills and consumes a conspecific male before, during. Sexual cannibalism has been recorded in the female spider, black widow spider, praying mantis. Size-structured cannibalism is cannibalism in which older, more mature individuals consume smaller, younger conspecifics, in size-structured populations, cannibalism can be responsible for 8% to 95% of the total mortality, making it a significant and important factor for population and community dynamics.
Size-structured cannibalism has commonly been observed in the wild for a variety of taxa, vertebrate examples include chimpanzees, where groups of adult males have been observed to attack and consume infants. Filial cannibalism is a type of size-structured cannibalism in which adults eat their own offspring. Though most often thought of as parents eating live young, filial cannibalism includes parental consumption of stillborn infants and miscarried fetuses as well as infertile, vertebrate examples include pigs, where savaging accounts for a sizable percentage of total piglet deaths, and cats. Filial cannibalism is common in teleost fishes, appearing in at least seventeen different families of teleosts. Within this diverse group of fish, there have been many, one of these is the energy-based hypothesis, which suggests that fish eat their offspring when they are low on energy as an investment in future reproductive success. In other words, when males of a species are low on energy, it might sometimes be beneficial for them to feed on their own offspring to survive.
Another hypothesis as to the value of filial cannibalism in teleosts is that it increases density-dependent egg survivorship. In other words, filial cannibalism simply increases overall reproductive success by helping the other eggs make it to maturity by thinning out the numbers. Possible explanations as to why this is so include increasing oxygen availability to the eggs, the negative effects of accumulating embryo waste. In some species of wasps, such as P. chinensis