A renewable resource is a natural resource which will replenish to replace the portion depleted by usage and consumption, either through natural reproduction or other recurring processes in a finite amount of time in a human time scale. Renewable resources are a part of Earth's natural environment and the largest components of its ecosphere. A positive life cycle assessment is a key indicator of a resource's sustainability. Definitions of renewable resources may include agricultural production, as in sustainable agriculture and to an extent water resources. In 1962, Paul Alfred Weiss defined Renewable Resources as: "The total range of living organisms providing man with life, etc...". Another type of renewable resources is renewable energy resources. Common sources of renewable energy include solar and wind power, which are all categorised as renewable resources. Water can be considered a renewable material when controlled usage and release are followed. If not, it would become a non-renewable resource at that location.
For example, as is removed from a aquifer at a rate much greater than its slow natural recharge, it is a considered non-renewable resource. Removal of water from the pore spaces in aquifers may cause permanent compaction that cannot be renewed. 97.5% of the water on the Earth is salt water, 3% is fresh water. The remaining unfrozen freshwater is found as groundwater, with only a small fraction present above ground or in the air. Water pollution is one of the main concerns regarding water resources, it is estimated. Major industrial users include hydroelectric dams, thermoelectric power plants and oil refineries and manufacturing plants. Desalination of seawater is considered a renewable source of water, although reducing its dependence on fossil fuel energy is needed for it to be renewable. Food is any substance consumed to provide nutritional support for the body. Most food has its origin in renewable resources. Food is obtained directly from animals. Hunting may not be the first source of meat in the modernised world, but it is still an important and essential source for many rural and remote groups.
It is the sole source of feeding for wild carnivores. The phrase sustainable agriculture was coined by Australian agricultural scientist Gordon McClymont, it has been defined as "an integrated system of plant and animal production practices having a site-specific application that will last over the long term". Expansion of agricultural land contributes to deforestation; the Food and Agriculture Organization of the United Nations estimates that in coming decades, cropland will continue to be lost to industrial and urban development, along with reclamation of wetlands, conversion of forest to cultivation, resulting in the loss of biodiversity and increased soil erosion. Although air and sunlight are available everywhere on Earth, crops depend on soil nutrients and the availability of water. Monoculture is a method of growing only one crop at a time in a given field, which can damage land and cause it to become either unusable or suffer from reduced yields. Monoculture can cause the build-up of pathogens and pests that target one specific species.
The Great Irish Famine is a well-known example of the dangers of monoculture. Crop rotation and long-term crop rotations confer the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops, can improve soil structure and fertility by alternating deep-rooted and shallow-rooted plants. Other methods to combat lost soil nutrients are returning to natural cycles that annually flood cultivated lands such as the Flooding of the Nile, the long-term use of biochar, use of crop and livestock landraces that are adapted to less than ideal conditions such as pests, drought, or lack of nutrients. Agricultural practices are one of the single greatest contributor to the global increase in soil erosion rates, it is estimated that "more than a thousand million tonnes of southern Africa's soil are eroded every year. Experts predict that crop yields will be halved within thirty to fifty years if erosion continues at present rates." The Dust Bowl phenomenon in the 1930s was caused by severe drought combined with farming methods that did not include crop rotation, fallow fields, cover crops, soil terracing and wind-breaking trees to prevent wind erosion.
The tillage of agricultural lands is one of the primary contributing factors to erosion, due to mechanised agricultural equipment that allows for deep plowing, which increases the amount of soil, available for transport by water erosion. The phenomenon called peak soil describes how large-scale factory farming techniques are affecting humanity's ability to grow food in the future. Without efforts to improve soil management practices, the availability of arable soil may become problematic. Methods to combat erosion include no-till farming, using a keyline design, growing wind breaks to hold the soil, widespread use of compost. Fertilizers and pesticides can have an effect of soil erosion, which can contribute to soil salinity and prevent other species from growing. Phosphate is a primary component in the chemical fertiliser applied most in modern agricultural production. However, scientists estimate that rock phosphate reserves will be depleted in 50–100 years and that Peak Phosphate will occur in about 2030.
Industrial processing and logistics have an effect on ag
Wheat is a grass cultivated for its seed, a cereal grain, a worldwide staple food. The many species of wheat together make up the genus Triticum; the archaeological record suggests that wheat was first cultivated in the regions of the Fertile Crescent around 9600 BCE. Botanically, the wheat kernel is a type of fruit called a caryopsis. Wheat is grown on more land area than any other food crop. World trade in wheat is greater than for all other crops combined. In 2016, world production of wheat was 749 million tonnes, making it the second most-produced cereal after maize. Since 1960, world production of wheat and other grain crops has tripled and is expected to grow further through the middle of the 21st century. Global demand for wheat is increasing due to the unique viscoelastic and adhesive properties of gluten proteins, which facilitate the production of processed foods, whose consumption is increasing as a result of the worldwide industrialization process and the westernization of the diet.
Wheat is an important source of carbohydrates. Globally, it is the leading source of vegetal protein in human food, having a protein content of about 13%, high compared to other major cereals but low in protein quality for supplying essential amino acids; when eaten as the whole grain, wheat is a source of dietary fiber. In a small part of the general population, gluten – the major part of wheat protein – can trigger coeliac disease, noncoeliac gluten sensitivity, gluten ataxia, dermatitis herpetiformis. Cultivation and repeated harvesting and sowing of the grains of wild grasses led to the creation of domestic strains, as mutant forms of wheat were preferentially chosen by farmers. In domesticated wheat, grains are larger, the seeds remain attached to the ear by a toughened rachis during harvesting. In wild strains, a more fragile rachis allows the ear to shatter and disperse the spikelets. Selection for these traits by farmers might not have been deliberately intended, but have occurred because these traits made gathering the seeds easier.
As the traits that improve wheat as a food source involve the loss of the plant's natural seed dispersal mechanisms domesticated strains of wheat cannot survive in the wild. Cultivation of wheat began to spread beyond the Fertile Crescent after about 8000 BCE. Jared Diamond traces the spread of cultivated emmer wheat starting in the Fertile Crescent sometime before 8800 BCE. Archaeological analysis of wild emmer indicates that it was first cultivated in the southern Levant, with finds dating back as far as 9600 BCE. Genetic analysis of wild einkorn wheat suggests that it was first grown in the Karacadag Mountains in southeastern Turkey. Dated archeological remains of einkorn wheat in settlement sites near this region, including those at Abu Hureyra in Syria, suggest the domestication of einkorn near the Karacadag Mountain Range. With the anomalous exception of two grains from Iraq ed-Dubb, the earliest carbon-14 date for einkorn wheat remains at Abu Hureyra is 7800 to 7500 years BCE. Remains of harvested emmer from several sites near the Karacadag Range have been dated to between 8600 and 8400 BCE, that is, in the Neolithic period.
With the exception of Iraq ed-Dubb, the earliest carbon-14 dated remains of domesticated emmer wheat were found in the earliest levels of Tell Aswad, in the Damascus basin, near Mount Hermon in Syria. These remains were dated by Willem van Zeist and his assistant Johanna Bakker-Heeres to 8800 BCE, they concluded that the settlers of Tell Aswad did not develop this form of emmer themselves, but brought the domesticated grains with them from an as yet unidentified location elsewhere. The cultivation of emmer reached Greece and Indian subcontinent by 6500 BCE, Egypt shortly after 6000 BCE, Germany and Spain by 5000 BCE. "The early Egyptians were developers of bread and the use of the oven and developed baking into one of the first large-scale food production industries." By 3000 BCE, wheat had reached Scandinavia. A millennium it reached China; the oldest evidence for hexaploid wheat has been confirmed through DNA analysis of wheat seeds, dating to around 6400-6200 BCE, recovered from Çatalhöyük.
The first identifiable bread wheat with sufficient gluten for yeasted breads has been identified using DNA analysis in samples from a granary dating to 1350 BCE at Assiros in Macedonia. From Asia, wheat continued to spread across Europe. In the British Isles, wheat straw was used for roofing in the Bronze Age, was in common use until the late 19th century. Technological advances in soil preparation and seed placement at planting time, use of crop rotation and fertilizers to improve plant growth, advances in harvesting methods have all combined to promote wheat as a viable crop; when the use of seed drills replaced broadcasting sowing of seed in the 18th century, another great increase in productivity occurred. Yields of pure wheat per unit area increased as methods of crop rotation were applied to long cultivated land, the use of fertilizers became widespread. Improved agricultural husbandry has more included threshing machines and reaping machines, tractor-drawn cultivators and planters, better varieties.
Great expansion of wheat production occurred as new arable land was farmed in the Americas and Australia in the 19th and 20th centuries. Leaves emerge from the shoot apical meristem in a telescoping fashion until the transition to reprod
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more they represent problematic species concepts. For example, the boundaries between related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, in a ring species. Among organisms that reproduce only asexually, the concept of a reproductive species breaks down, each clone is a microspecies. All species are given a two-part name, a "binomial"; the first part of a binomial is the genus.
The second part is called the specific epithet. For example, Boa constrictor is one of four species of the genus Boa. None of these is satisfactory definitions, but scientists and conservationists need a species definition which allows them to work, regardless of the theoretical difficulties. If species were fixed and distinct from one another, there would be no problem, but evolutionary processes cause species to change continually, to grade into one another. Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped. Charles Darwin's 1859 book The Origin of Species explained how species could arise by natural selection; that understanding was extended in the 20th century through genetics and population ecology. Genetic variability arises from mutations and recombination, while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures.
Genes can sometimes be exchanged between species by horizontal gene transfer. Viruses are a special case, driven by a balance of mutation and selection, can be treated as quasispecies. Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics. Early taxonomists such as Linnaeus had no option but to describe what they saw: this was formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts, is hard or impossible to test. Biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: agamospecies for asexual organisms biospecies for reproductively isolated sexual organisms ecospecies based on ecological niches evolutionary species based on lineage genetic species based on gene pool morphospecies based on form or phenotype and taxonomic species, a species as determined by a taxonomist.
A typological species is a group of organisms in which individuals conform to certain fixed properties, so that pre-literate people recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens would differentiate the species; this method was used as a "classical" method of determining species, such as with Linnaeus early in evolutionary theory. However, different phenotypes are not different species. Species named in this manner are called morphospecies. In the 1970s, Robert R. Sokal, Theodore J. Crovello and Peter Sneath proposed a variation on this, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms, it differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species is a group of sexually reproducing organisms that recognize one another as potential mates.
Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms. A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology, genes can move even between distantly related bacteria extending to the whole bacterial domain; as a rule of thumb, microbiologists have assumed that kinds of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA-DNA hybridisation to decide if they belong to the same species or not. This concept was narrowed in 2006 to a similarity of 98.7%. DNA-DNA hybri
Economic inequality covers a wide variety of topics. It can refer to the distribution of wealth. Besides economic inequality between countries or states, there are important types of economic inequality between different groups of people. Important types of economic measurements focus on wealth and consumption. There are many methods for measuring economic inequality, with the Gini coefficient being a used one. Another type of measure is the Inequality-adjusted Human Development Index, a statistic composite index that takes inequality into account. Important concepts of equality include equity, equality of outcome, equality of opportunity. Research suggests. Whereas globalization has reduced global inequality, it has increased inequality within nations. In 1820, the ratio between the income of the top and bottom 20 percent of the world's population was three to one. By 1991, it was eighty-six to one. A 2011 study titled "Divided we Stand: Why Inequality Keeps Rising" by the Organisation for Economic Co-operation and Development sought to explain the causes for this rising inequality by investigating economic inequality in OECD countries.
Single-headed households in OECD countries have risen from an average of 15% in the late 1980s to 20% in the mid-2000s, resulting in higher inequality. Assortative mating refers to the phenomenon of people marrying people with similar background, for example doctors marrying doctors rather than nurses. OECD found out that 40% of couples where both partners work belonged to the same or neighbouring earnings deciles compared with 33% some 20 years before. In the bottom percentiles number of hours worked; the main reason for increasing inequality seems to be the difference between the demand for and supply of skills. Income inequality in OECD countries is at its highest level for the past half century; the ratio between the bottom 10 % and the top 10 % has increased to 1:9 in 25 years. There are tentative signs of a possible convergence of inequality levels towards a common and higher average level across OECD countries. With few exceptions, the wages of the 10% best-paid workers have risen relative to those of the 10% lowest paid.
A 2011 OECD study investigated economic inequality in Argentina, China, Indonesia and South Africa. It concluded that key sources of inequality in these countries include "a large, persistent informal sector, widespread regional divides, gaps in access to education, barriers to employment and career progression for women."A study by the World Institute for Development Economics Research at United Nations University reports that the richest 1% of adults alone owned 40% of global assets in the year 2000. The three richest people in the world possess more financial assets than the lowest 48 nations combined; the combined wealth of the "10 million dollar millionaires" grew to nearly $41 trillion in 2008. A January 2014 report by Oxfam claims that the 85 wealthiest individuals in the world have a combined wealth equal to that of the bottom 50% of the world's population, or about 3.5 billion people. According to a Los Angeles Times analysis of the report, the wealthiest 1% owns 46% of the world's wealth.
In January 2015, Oxfam reported that the wealthiest 1 percent will own more than half of the global wealth by 2016. An October 2014 study by Credit Suisse claims that the top 1% now own nearly half of the world's wealth and that the accelerating disparity could trigger a recession. In October 2015, Credit Suisse published a study which shows global inequality continues to increase, that half of the world's wealth is now in the hands of those in the top percentile, whose assets each exceed $759,900. A 2016 report by Oxfam claims that the 62 wealthiest individuals own as much wealth as the poorer half of the global population combined. Oxfam's claims have however been questioned on the basis of the methodology used: by using net wealth, the Oxfam report, for instance, finds that there are more poor people in the United States and Western Europe than in China. Anthony Shorrocks, the lead author of the Credit Suisse report, one of the sources of Oxfam's data, considers the criticism about debt to be a "silly argument" and "a non-issue … a diversion."
Oxfam's 2017 report says the top eight billionaires have as much wealth as the bottom half of the global population, that rising inequality is suppressing wages, as businesses are focused on delivering higher returns to wealthy owners and executives. In 2018, the Oxfam report said that the wealth gap continued to widen in 2017, with 82% of global wealth generated going to the wealthiest 1%; the 2019 Oxfam report said that the poorest half of the human population has been losing wealth at the same time that a billionaire is minted every two days. According to PolitiFact, the top 400 richest Americans "have more wealth than half of all Americans combined." According to The New York Times on July 22, 2014, the "richest 1 percent in the United States now own more wealth than the bottom 90 percent". Inherited wealth may help explain why many Americans who have become rich may have had a "substantial head start". In September 2012, according to the Institute for Policy Studies (I
A forest is a large area dominated by trees. Hundreds of more precise definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing and ecological function. According to the used Food and Agriculture Organization definition, forests covered 4 billion hectares or 30 percent of the world's land area in 2006. Forests are the dominant terrestrial ecosystem of Earth, are distributed around the globe. Forests account for 75% of the gross primary production of the Earth's biosphere, contain 80% of the Earth's plant biomass. Net primary production is estimated at 21.9 gigatonnes carbon per year for tropical forests, 8.1 for temperate forests, 2.6 for boreal forests. Forests at different latitudes and elevations form distinctly different ecozones: boreal forests near the poles, tropical forests near the equator and temperate forests at mid-latitudes. Higher elevation areas tend to support forests similar to those at higher latitudes, amount of precipitation affects forest composition.
Human society and forests influence each other in both negative ways. Forests serve as tourist attractions. Forests can affect people's health. Human activities, including harvesting forest resources, can negatively affect forest ecosystems. Although forest is a term of common parlance, there is no universally recognised precise definition, with more than 800 definitions of forest used around the world. Although a forest is defined by the presence of trees, under many definitions an area lacking trees may still be considered a forest if it grew trees in the past, will grow trees in the future, or was designated as a forest regardless of vegetation type. There are three broad categories of forest definitions in use: administrative, land use, land cover. Administrative definitions are based upon the legal designations of land, bear little relationship to the vegetation growing on the land: land, designated as a forest is defined as a forest if no trees are growing on it. Land use definitions are based upon the primary purpose.
For example, a forest may be defined as any land, used for production of timber. Under such a land use definition, cleared roads or infrastructure within an area used for forestry, or areas within the region that have been cleared by harvesting, disease or fire are still considered forests if they contain no trees. Land cover definitions define forests based upon the type and density of vegetation growing on the land; such definitions define a forest as an area growing trees above some threshold. These thresholds are the number of trees per area, the area of ground under the tree canopy or the section of land, occupied by the cross-section of tree trunks. Under such land cover definitions, an area of land can only be known as forest if it is growing trees. Areas that fail to meet the land cover definition may be still included under while immature trees are establishing if they are expected to meet the definition at maturity. Under land use definitions, there is considerable variation on where the cutoff points are between a forest and savanna.
Under some definitions, forests require high levels of tree canopy cover, from 60% to 100%, excluding savannas and woodlands in which trees have a lower canopy cover. Other definitions consider savannas to be a type of forest, include all areas with tree canopies over 10%; some areas covered in trees are defined as agricultural areas, e.g. Norway spruce plantations in Austrian forest law when the trees are being grown as Christmas trees and below a certain height; the word forest comes from Middle English, from Old French forest "forest, vast expanse covered by trees". A borrowing of the Medieval Latin word foresta "open wood", foresta was first used by Carolingian scribes in the Capitularies of Charlemagne to refer to the king's royal hunting grounds; the term was not endemic to Romance languages. The exact origin of Medieval Latin foresta is obscure; some authorities claim the word derives from the Late Latin phrase forestam silvam, meaning "the outer wood". Frankish *forhist is attested by Old High German forst "forest", Middle Low German vorst "forest", Old English fyrhþ "forest, game preserve, hunting ground", Old Norse fýri "coniferous forest", all of which derive from Proto-Germanic *furhísa-, *furhíþija- "a fir-wood, coniferous forest", from Proto-Indo-European *perkwu- "a coniferous or mountain forest, wooded height".
Uses of the word "forest" in English to denote any uninhabited area of non-enclosure are now considered archaic. The word was introduced by the Norman rulers of England as a legal term denoting an uncultivated area set aside for hunting by feudal nobility; these hunting forests were not neces
Wired is a monthly American magazine, published in print and online editions, that focuses on how emerging technologies affect culture, the economy, politics. Owned by Condé Nast, it is headquartered in San Francisco and has been in publication since March/April 1993. Several spin-offs have been launched, including Wired UK, Wired Italia, Wired Japan, Wired Germany. Condé Nast's parent company Advance Publications is the major shareholder of Reddit, an internet information conglomeration website. In its earliest colophons, Wired credited Canadian media theorist Marshall McLuhan as its "patron saint." From its beginning, the strongest influence on the magazine's editorial outlook came from techno-utopian cofounder Stewart Brand and his associate Kevin Kelly. From 1998 to 2006, Wired magazine and Wired News, which publishes at Wired.com, had separate owners. However, Wired News remained responsible for republishing Wired magazine's content online due to an agreement when Condé Nast purchased the magazine.
In 2006, Condé Nast bought Wired News for $25 million. Wired contributor Chris Anderson is known for popularizing the term "the Long Tail", as a phrase relating to a "power law"-type graph that helps to visualize the 2000s emergent new media business model. Anderson's article for Wired on this paradigm related to research on power law distribution models carried out by Clay Shirky in relation to bloggers. Anderson widened the definition of the term in capitals to describe a specific point of view relating to what he sees as an overlooked aspect of the traditional market space, opened up by new media; the magazine coined the term "crowdsourcing", as well as its annual tradition of handing out Vaporware Awards, which recognize "products and other nerdy tidbits pitched and hyped, but never delivered". The magazine was founded by American journalist Louis Rossetto and his partner Jane Metcalfe, along with Ian Charles Stewart, in 1993 with initial backing from software entrepreneur Charlie Jackson and eclectic academic Nicholas Negroponte of the MIT Media Lab, a regular columnist for six years, wrote the book Being Digital, founded One Laptop per Child.
The founding designers were John Plunkett and Barbara Kuhr, beginning with a 1991 prototype and continuing through the first five years of publication, 1993–98. Wired, which touted itself as "the Rolling Stone of technology", made its debut at the Macworld conference on January 2, 1993. A great success at its launch, it was lauded for its vision, originality and cultural impact. In its first four years, the magazine won two National Magazine Awards for General Excellence and one for Design; the founding executive editor of Wired, Kevin Kelly, was an editor of the Whole Earth Catalog and the Whole Earth Review and brought with him contributing writers from those publications. Six authors of the first Wired issue had written for Whole Earth Review, most notably Bruce Sterling and Stewart Brand. Other contributors to Whole Earth appeared in Wired, including William Gibson, featured on Wired's cover in its first year and whose article "Disneyland with the Death Penalty" in issue 1.4 resulted in the publication being banned in Singapore.
Wired cofounder Louis Rossetto claimed in the magazine's first issue that "the Digital Revolution is whipping through our lives like a Bengali typhoon," yet despite the fact that Kelly was involved in launching the WELL, an early source of public access to the Internet and earlier non-Internet online experience, Wired's first issue de-emphasized the Internet and covered interactive games, cell-phone hacking, digital special effects, military simulations, Japanese otaku. However, the first issue did contain a few references to the Internet, including online dating and Internet sex, a tutorial on how to install a bozo filter; the last page, a column written by Nicholas Negroponte, was written in the style of an email message but contained fake, non-standard email addresses. By the third issue in the fall of 1993, the "Net Surf" column began listing interesting FTP sites, Usenet newsgroups, email addresses, at a time when the numbers of these things were small and this information was still novel to the public.
Wired was among the first magazines to list the email address of its contributors. Associate publisher Kathleen Lyman was brought on board to launch Wired with an advertising base of major technology and consumer advertisers. Lyman, along with Simon Ferguson, introduced revolutionary ad campaigns by a diverse group of industry leaders—such as Apple Computer, Sony, Calvin Klein, Absolut—to the readers of the first technology publication with a lifestyle slant; the magazine was followed by a companion website, a book publishing division, a Japanese edition, a short-lived British edition. Wired UK was relaunched in April 2009. In 1994, John Battelle, cofounding editor, commissioned Jules Marshall to write a piece on the Zippies; the cover story broke records for being one of the most publicized stories of the year and was used to promote Wired's HotWired news service. HotWired spawned websites Webmonkey, the search engine HotBot, a weblog, Suck.com. In June 1998, the magazine launched a stock index, the Wired Index, called the Wired 40 since July 2003.
The fortune of the magazine and allied enterprises corresponded to that of the dot-com bubble. In 1996, Rossetto and the other participants in Wired Ventures attempted to take the company public with an IPO; the initial attempt had to be withdraw
The modern Olympic Games or Olympics are leading international sporting events featuring summer and winter sports competitions in which thousands of athletes from around the world participate in a variety of competitions. The Olympic Games are considered the world's foremost sports competition with more than 200 nations participating; the Olympic Games are held every four years, with the Summer and Winter Games alternating by occurring every four years but two years apart. Their creation was inspired by the ancient Olympic Games, which were held in Olympia, from the 8th century BC to the 4th century AD. Baron Pierre de Coubertin founded the International Olympic Committee in 1894, leading to the first modern Games in Athens in 1896; the IOC is the governing body of the Olympic Movement, with the Olympic Charter defining its structure and authority. The evolution of the Olympic Movement during the 20th and 21st centuries has resulted in several changes to the Olympic Games; some of these adjustments include the creation of the Winter Olympic Games for snow and ice sports, the Paralympic Games for athletes with a disability, the Youth Olympic Games for athletes aged 14 to 18, the five Continental games, the World Games for sports that are not contested in the Olympic Games.
The Deaflympics and Special Olympics are endorsed by the IOC. The IOC has had to adapt to a variety of economic and technological advancements; the abuse of amateur rules by the Eastern Bloc nations prompted the IOC to shift away from pure amateurism, as envisioned by Coubertin, to allowing participation of professional athletes. The growing importance of mass media created the issue of corporate sponsorship and commercialisation of the Games. World wars led to the cancellation of the 1916, 1940, 1944 Games. Large boycotts during the Cold War limited participation in the 1980 and 1984 Games; the Olympic Movement consists of international sports federations, National Olympic Committees, organising committees for each specific Olympic Games. As the decision-making body, the IOC is responsible for choosing the host city for each Games, organises and funds the Games according to the Olympic Charter; the IOC determines the Olympic programme, consisting of the sports to be contested at the Games. There are several Olympic rituals and symbols, such as the Olympic flag and torch, as well as the opening and closing ceremonies.
Over 13,000 athletes compete at the Summer and Winter Olympic Games in 33 different sports and nearly 400 events. The first and third-place finishers in each event receive Olympic medals: gold and bronze, respectively; the Games have grown so much. This growth has created numerous challenges and controversies, including boycotts, bribery, a terrorist attack in 1972; every two years the Olympics and its media exposure provide athletes with the chance to attain national and sometimes international fame. The Games constitute an opportunity for the host city and country to showcase themselves to the world; the Ancient Olympic Games were religious and athletic festivals held every four years at the sanctuary of Zeus in Olympia, Greece. Competition was among representatives of several kingdoms of Ancient Greece; these Games featured athletic but combat sports such as wrestling and the pankration and chariot racing events. It has been written that during the Games, all conflicts among the participating city-states were postponed until the Games were finished.
This cessation of hostilities was known as truce. This idea is a modern myth; the truce did allow those religious pilgrims who were travelling to Olympia to pass through warring territories unmolested because they were protected by Zeus. The origin of the Olympics is shrouded in legend. According to legend, it was Heracles who first called the Games "Olympic" and established the custom of holding them every four years; the myth continues that after Heracles completed his twelve labours, he built the Olympic Stadium as an honour to Zeus. Following its completion, he walked in a straight line for 200 steps and called this distance a "stadion", which became a unit of distance; the most accepted inception date for the Ancient Olympics is 776 BC. The Ancient Games featured running events, a pentathlon, wrestling and equestrian events. Tradition has it that a cook from the city of Elis, was the first Olympic champion; the Olympics were of fundamental religious importance, featuring sporting events alongside ritual sacrifices honouring both Zeus and Pelops, divine hero and mythical king of Olympia.
Pelops was famous for his chariot race with King Oenomaus of Pisatis. The winners of the events were immortalised in poems and statues; the Games were held every four years, this period, known as an Olympiad, was used by Greeks as one of their units of time measurement. The Games were part of a cycle known as the Panhellenic Games, which included the Pythian Games, the Nemean Games, the Isthmian Games; the Olympic Games reached their zenith in the 6th and 5th centuries BC, but gradually declined in importance as the Romans gained power and influence in Gr