An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to toss people around and destroy whole cities; the seismicity, or seismic activity, of an area is the frequency and size of earthquakes experienced over a period of time. The word tremor is used for non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground; when the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can trigger landslides, volcanic activity. In its most general sense, the word earthquake is used to describe any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused by rupture of geological faults, but by other events such as volcanic activity, mine blasts, nuclear tests.
An earthquake's point of initial rupture is called its hypocenter. The epicenter is the point at ground level directly above the hypocenter. Tectonic earthquakes occur anywhere in the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane; the sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the fault surface that increase the frictional resistance. Most fault surfaces do have such asperities and this leads to a form of stick-slip behavior. Once the fault has locked, continued relative motion between the plates leads to increasing stress and therefore, stored strain energy in the volume around the fault surface; this continues until the stress has risen sufficiently to break through the asperity allowing sliding over the locked portion of the fault, releasing the stored energy. This energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface, cracking of the rock, thus causing an earthquake.
This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth or is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior. There are three main types of fault, all of which may cause an interplate earthquake: normal and strike-slip. Normal and reverse faulting are examples of dip-slip, where the displacement along the fault is in the direction of dip and movement on them involves a vertical component. Normal faults occur in areas where the crust is being extended such as a divergent boundary. Reverse faults occur in areas.
Strike-slip faults are steep structures where the two sides of the fault slip horizontally past each other. Many earthquakes are caused by movement on faults that have components of both dip-slip and strike-slip. Reverse faults those along convergent plate boundaries are associated with the most powerful earthquakes, megathrust earthquakes, including all of those of magnitude 8 or more. Strike-slip faults continental transforms, can produce major earthquakes up to about magnitude 8. Earthquakes associated with normal faults are less than magnitude 7. For every unit increase in magnitude, there is a thirtyfold increase in the energy released. For instance, an earthquake of magnitude 6.0 releases 30 times more energy than a 5.0 magnitude earthquake and a 7.0 magnitude earthquake releases 900 times more energy than a 5.0 magnitude of earthquake. An 8.6 magnitude earthquake releases the same amount of energy as 10,000 atomic bombs like those used in World War II. This is so because the energy released in an earthquake, thus its magnitude, is proportional to the area of the fault that ruptures and the stress drop.
Therefore, the longer the length and the wider the width of the faulted area, the larger the resulting magnitude. The topmost, brittle part of the Earth's crust, the cool slabs of the tectonic plates that are descending down into the hot mantle, are the only parts of our planet which can store elastic energy and release it in fault ruptures. Rocks hotter than about 300 °C flow in response to stress; the maximum observed lengths of ruptures and mapped faults are 1,000 km. Examples are the earthquakes in Chile, 1960; the longest earthquake ruptures on strike-slip faults, like the San Andreas Fault, the North Anatolian Fault in Turkey and the Denali Fault in Alaska, are about half to one third as long as the lengths along subducting plate margins, those along normal faults are shorter. The most important parameter controlling the maximum earthquake magnitude on a fault is however not the maximum available length, but the available width because the latter varies by a factor of 20. Along converging plate margins, the dip angle of the rupture plane is shallow about 10 de
Tobacco is a product prepared from the leaves of the tobacco plant by curing them. The plant is part of the genus Nicotiana and of the Solanaceae family. While more than 70 species of tobacco are known, the chief commercial crop is N. tabacum. The more potent variant N. rustica is used around the world. Tobacco contains the alkaloid nicotine, a stimulant, harmala alkaloids. Dried tobacco leaves are used for smoking in cigarettes, pipe tobacco, flavored shisha tobacco, they can be consumed as snuff, chewing tobacco, dipping tobacco and snus. Tobacco use is a risk factor for many diseases. In 2008, the World Health Organization named tobacco as the world's single greatest preventable cause of death; the English word "tobacco" originates from the Spanish and Portuguese word "tabaco". The precise origin of this word is disputed, but it is thought to have derived at least in part, from Taino, the Arawakan language of the Caribbean. In Taino, it was said to mean either a roll of tobacco leaves or to tabago, a kind of L-shaped pipe used for sniffing tobacco smoke.
However coincidentally, similar words in Spanish and Italian were used from 1410 to define medicinal herbs believed to have originated from the Arabic طُبّاق ṭubbāq, a word dating to the 9th century, as a name for various herbs. Tobacco has long been used in the Americas, with some cultivation sites in Mexico dating back to 1400–1000 BC. Many Native American tribes have traditionally used tobacco. Eastern North American tribes carried tobacco in pouches as a accepted trade item, as well as smoking it, both and ceremonially, such as to seal a peace treaty or trade agreement. In some populations, tobacco is seen as a gift from the Creator, with the ceremonial tobacco smoke carrying one's thoughts and prayers to the Creator. Following the arrival of the Europeans to the Americas, tobacco became popular as a trade item. Hernández de Boncalo, Spanish chronicler of the Indies, was the first European to bring tobacco seeds to the Old World in 1559 following orders of King Philip II of Spain; these seeds were planted in the outskirts of Toledo, more in an area known as "Los Cigarrales" named after the continuous plagues of cicadas.
Before the development of the lighter Virginia and white burley strains of tobacco, the smoke was too harsh to be inhaled. Small quantities were smoked at a time, using a pipe like the midwakh or kiseru or smoking newly invented waterpipes such as the bong or the hookah. Tobacco became so popular that the English colony of Jamestown used it as currency and began exporting it as a cash crop; the alleged benefits of tobacco account for its considerable success. The astronomer Thomas Harriot, who accompanied Sir Richard Grenville on his 1585 expedition to Roanoke Island, explains that the plant "openeth all the pores and passages of the body" so that the natives’ "bodies are notably preserved in health, know not many grievous diseases, wherewithal we in England are times afflicted." Tobacco smoking and snuffing became a major industry in Europe and its colonies by 1700. Tobacco has been a major cash crop in Cuba and in other parts of the Caribbean since the 18th century. Cuban cigars are world-famous.
In the late 19th century, cigarettes became popular. James Bonsack created a machine that automated cigarette production; this increase in production allowed tremendous growth in the tobacco industry until the health revelations of the late-20th century. Following the scientific revelations of the mid-20th century, tobacco became condemned as a health hazard, became encompassed as a cause for cancer, as well as other respiratory and circulatory diseases. In the United States, this led to the Tobacco Master Settlement Agreement, which settled the lawsuit in exchange for a combination of yearly payments to the states and voluntary restrictions on advertising and marketing of tobacco products. In the 1970s, Brown & Williamson cross-bred a strain of tobacco to produce Y1; this strain of tobacco contained an unusually high amount of nicotine, nearly doubling its content from 3.2-3.5% to 6.5%. In the 1990s, this prompted the Food and Drug Administration to use this strain as evidence that tobacco companies were intentionally manipulating the nicotine content of cigarettes.
In 2003, in response to growth of tobacco use in developing countries, the World Health Organization rallied 168 countries to sign the Framework Convention on Tobacco Control. The convention is designed to push for effective legislation and its enforcement in all countries to reduce the harmful effects of tobacco; this led to the development of tobacco cessation products. Many species of tobacco are in the genus of herbs Nicotiana, it is part of the nightshade family indigenous to North and South America, south west Africa, the South Pacific. Most nightshades contain varying amounts of a powerful neurotoxin to insects. However, tobaccos tend to contain a much higher concentration of nicotine than the others. Unlike many other Solanaceae species, they do not contain tropane alkaloids, which are poisonous to humans and other animals. Despite containing enough nicotine and other compounds such as germacrene and anabasine and other piperidine alkaloids to deter most herbivores, a number of such animals have evolved
Battle of Greece
The Battle of Greece is the common name for the invasion of Allied Greece by Fascist Italy and Nazi Germany in April 1941 during World War II. The Italian invasion in October 1940, known as the Greco-Italian War, was followed by the German invasion in April 1941. German landings on the island of Crete came after Allied forces had been defeated in mainland Greece; these battles were part of the greater Balkan Campaign of Germany. Following the Italian invasion on 28 October 1940, Greece repulsed the initial Italian attack and a counter-attack in March 1941; when the German invasion, known as Operation Marita, began on 6 April, the bulk of the Greek Army was on the Greek border with Albania a protectorate of Italy, from which the Italian troops had attacked. German troops invaded from Bulgaria. Greece received a small reinforcement from British and New Zealand forces in anticipation of the German attack; the Greek army found itself outnumbered in its effort to defend against both Italian and German troops.
As a result, the Metaxas defensive line did not receive adequate troop reinforcements and was overrun by the Germans, who outflanked the Greek forces at the Albanian border, forcing their surrender. British and New Zealand forces were overwhelmed and forced to retreat, with the ultimate goal of evacuation. For several days, Allied troops played an important part in containing the German advance on the Thermopylae position, allowing ships to be prepared to evacuate the units defending Greece; the German Army reached the capital, Athens, on 27 April and Greece's southern shore on 30 April, capturing 7,000 British and New Zealand personnel and ending the battle with a decisive victory. The conquest of Greece was completed with the capture of Crete a month later. Following its fall, Greece was occupied by the military forces of Germany and Bulgaria. Hitler blamed the failure of his invasion of the Soviet Union, which had to be delayed, on Mussolini's failed conquest of Greece; the theory that the Battle of Greece delayed the invasion of the Soviet Union has been either refuted or downplayed by the majority of historians, who have accused Hitler of trying to deflect blame from himself to his ally, Italy.
It had serious consequences for the Axis war effort in the North African theatre. Enno von Rintelen, the military attaché in Rome, emphasises from the German point of view, the strategic mistake of not taking Malta. At the outbreak of World War II, Ioannis Metaxas—the fascist-style dictator of Greece and former general—sought to maintain a position of neutrality. Greece was subject to increasing pressure from Italy, culminating in the Italian submarine Delfino sinking the cruiser Elli on 15 August 1940. Italian leader Benito Mussolini was irritated that Nazi leader Adolf Hitler had not consulted him on his war policy and wished to establish his independence, he hoped to match German military success by taking Greece. On 15 October 1940, his closest advisers finalised their decision. In the early hours of 28 October, Italian Ambassador Emanuele Grazzi presented Metaxas with a three-hour ultimatum, demanding free passage for troops to occupy unspecified "strategic sites" within Greek territory.
Metaxas rejected the ultimatum but before it expired, Italian troops had invaded Greece through Albania. The principal Italian thrust was directed toward Epirus. Hostilities with the Greek army began at the Battle of Elaia–Kalamas, where they failed to break the defensive line and were forced to halt. Within three weeks, the Greek army launched a counter-offensive, during which it marched into Albanian territory, capturing significant cities such as Korça and Sarandë. Neither a change in Italian command nor the arrival of substantial reinforcements improved the position of the Italian army. On 13 February, General Papagos, the Commander-in-Chief of the Greek army, opened a new offensive, aiming to take Tepelenë and the port of Vlorë with British air support but the Greek divisions encountered stiff resistance, stalling the offensive that destroyed the Cretan 5th Division. After weeks of inconclusive winter warfare, the Italians launched a counter-offensive on the centre of the front on 9 March 1941, which failed, despite the Italians' superior forces.
After one week and 12,000 casualties, Mussolini called off the counter-offensive and left Albania twelve days later. Modern analysts believe that the Italian campaign failed because Mussolini and his generals allocated insufficient resources to the campaign, failed to reckon with the autumn weather, attacked without the advantage of surprise and without Bulgarian support. Elementary precautions such as issuing winter clothing had not been taken. Mussolini had not considered the warnings of the Italian Commission of War Production, that Italy would not be able to sustain a full year of continuous warfare until 1949. During the six-month fight against Italy, the Hellenic army made territorial gains by eliminating Italian salients. Greece did not have a substantial armaments industry and its equipment and ammunition supplies relied on stocks captured by British forces from defeated Italian armies in North Africa. To man the Albanian battlefront, the Greek command was forced to withdraw forces from Eastern Macedonia and Western Thrace, because Greek forces could not protect Greece's entire border.
The Greek command decided to support its success in Albania, regardless of the risk of a German attack from the Bulgarian border. Hitler intervened on 4 November 1940, four days a
The Rhodopes are a mountain range in Southeastern Europe, with over 83% of its area in southern Bulgaria and the remainder in Greece. Golyam Perelik is its highest peak at 2,191 meters; the mountain range gives its name to the terrestrial ecoregion Rodope montane mixed forests that belongs in the Temperate broadleaf and mixed forests Biome and the Palearctic ecozone. The region is notable for its karst areas with their deep river gorges, large caves and specific sculptured forms, such as the Trigrad Gorge. A significant part of Bulgaria's hydropower resources are located in the western areas of the range. There are a number of hydro-cascades and dams used for electricity production, irrigation and as tourist destinations. In Greece there are the HPPs of Thisavros and Platanovrysi; the Rhodopes have a rich cultural heritage including ancient Thracian sites such as Perperikon and Belintash, medieval castles, churches and picturesque villages with traditional Bulgarian architecture from the 18th and 19th centuries.
The name of the Rhodope mountains has a Thracian provenance. Rhod-ope is interpreted as the first name of a river, meaning "rusty/reddish river", where Rhod- has the same Indo-European root as the Bulgarian "руда", "ръжда", "риж", Latin "rufus", German "rot" and English "red".. In Greek mythology, Queen Rhodope of Thrace, the wife of King Haemus of Thrace, offended the gods, was changed into a mountain by Zeus and Hera as a punishment along with her husband; the mountains are associated with the mythic figure of Orpheus. In geomorphological terms, the Rhodopes are part of the Rilo-Rhodope massif, the oldest landmass on the Balkan peninsula; the Rhodopes are spread over 14,735 square kilometers, of which 12,233 square kilometers are on Bulgarian territory. They have the greatest extent of any single mountain range in Bulgaria; the mountains are about 240 kilometers long and about 100 to 120 kilometres wide, with an average altitude of 785 meters. To the north the mountain slopes descend steeply towards the Upper Thracian Plain.
To the west, the Rhodopes reach the Avram saddle and the valley of the Mesta River. To the south and east they extend to the coastal plains of Greek Thrace; the Rhodopes are a complex system of deep river valleys. Fifteen reserves have been established in the region; the mountains are famous for the largest coniferous woods in the Balkans, their mild relief and the lush vegetation in the western parts as well as the abundance of birds of prey in the eastern areas. The location of the Rhodopes in the southeastern part of the Balkan Peninsula determines the climate in the region to a great extent, it is influenced both by the colder air coming from the north and by the warmer breeze from the Mediterranean. The average annual temperature in the Eastern Rhodopes is 13 °C, the maximum precipitation is in December, the minimum in August. In the Western Rhodopes, the temperature varies from 5 to 9 °C and in the summer rainfalls prevail; the mild climate, combined with some other factors, works in favour of the development of recreation and tourist activities.
The Pamporovo resort, where the microclimate permits a heavy snow cover to be preserved for a long time, is an excellent example. Temperatures as low as −15 °C are common in winter, due to this the Rhodopes are the southernmost place in the Balkans where tree species such as the Norway Spruce and the Silver Birch can be found; the mountains have abundant water reserves with a dense network of mountain rivers. Nearly 80% of the mountain's territory falls within the drainage of the river Maritsa; the natural lakes are few, the most renown of these being the Smolyan lakes situated at several kilometers from the town of the same name. Some of the largest dams in the country are located in the Rhodopes including the Dospat Dam, Batak Dam, Golyam Beglik, Kardzhali Dam, Studen Kladenets, Vacha Dam, Shiroka Polyana and many others, while in Greece there are the dams of Thisavros and Platanovrysi, they are used for hydro-electric power generation and for irrigation. There are many mineral water springs, the most famous being in Velingrad, Devin, Beden and others.
In Greece there are mineral water springs in Thermes, 40 km. north of and in Thermia, 60 km. north of Drama, at 620 m. The Western Rhodopes are the larger, most infrastructurally developed and most visited part of the mountains; the highest and best known peaks are located in the region including the highest one, Golyam Perelik. Among the other popular peaks are Shirokolashki Snezhnik, Golyam Persenk, Batashki Snezhnik, Turla; some of the deepest river gorges in the Rhodopes are located in the western parts, as well as the rock phenomenon Wonderful Bridges. Significant bodies of water include the Chaira lakes and the Dospat, Shiroka Polyana, Golyam Beglik and Tsigov Chark dams; the town of Batak is located in this part of the mountains, as well as the popular tourist centres Smolyan, Devin, the winter resort Pamporovo, the Eastern Orthodox Bachkovo Monastery, the ruins of the Asen dynasty's fortress, the Devil's Throat and Uhlovitsa caves. The highest village in Bulgaria, Manastir, is crouched in the northern foot of Prespa Peak.
World War II
World War II known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries; the major participants threw their entire economic and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China, it included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, the only use of nuclear weapons in war. Japan, which aimed to dominate Asia and the Pacific, was at war with China by 1937, though neither side had declared war on the other. World War II is said to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom.
From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. Following the onset of campaigns in North Africa and East Africa, the fall of France in mid 1940, the war continued between the European Axis powers and the British Empire. War in the Balkans, the aerial Battle of Britain, the Blitz, the long Battle of the Atlantic followed. On 22 June 1941, the European Axis powers launched an invasion of the Soviet Union, opening the largest land theatre of war in history; this Eastern Front trapped most crucially the German Wehrmacht, into a war of attrition. In December 1941, Japan launched a surprise attack on the United States as well as European colonies in the Pacific. Following an immediate U. S. declaration of war against Japan, supported by one from Great Britain, the European Axis powers declared war on the U.
S. in solidarity with their Japanese ally. Rapid Japanese conquests over much of the Western Pacific ensued, perceived by many in Asia as liberation from Western dominance and resulting in the support of several armies from defeated territories; the Axis advance in the Pacific halted in 1942. Key setbacks in 1943, which included a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, Allied victories in the Pacific, cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned toward Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in Central China, South China and Burma, while the Allies crippled the Japanese Navy and captured key Western Pacific islands; the war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the German unconditional surrender on 8 May 1945.
Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings, the Soviet entry into the war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. Tribunals were set up by fiat by the Allies and war crimes trials were conducted in the wake of the war both against the Germans and the Japanese. World War II changed the political social structure of the globe; the United Nations was established to foster international co-operation and prevent future conflicts. The Soviet Union and United States emerged as rival superpowers, setting the stage for the nearly half-century long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia.
Most countries whose industries had been damaged moved towards economic expansion. Political integration in Europe, emerged as an effort to end pre-war enmities and create a common identity; the start of the war in Europe is held to be 1 September 1939, beginning with the German invasion of Poland. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred and the two wars merged in 1941; this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935; the British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the fo
Strabo was a Greek geographer and historian who lived in Asia Minor during the transitional period of the Roman Republic into the Roman Empire. Strabo was born to an affluent family from Amaseia in Pontus in around 64 BC, his family had been involved in politics since at least the reign of Mithridates V. Strabo was related to Dorylaeus on his mother's side. Several other family members, including his paternal grandfather had served Mithridates VI during the Mithridatic Wars; as the war drew to a close, Strabo's grandfather had turned several Pontic fortresses over to the Romans. Strabo wrote that "great promises were made in exchange for these services", as Persian culture endured in Amasia after Mithridates and Tigranes were defeated, scholars have speculated about how the family's support for Rome might have affected their position in the local community, whether they might have been granted Roman citizenship as a reward. Strabo's life was characterized by extensive travels, he journeyed to Egypt and Kush, as far west as coastal Tuscany and as far south as Ethiopia in addition to his travels in Asia Minor and the time he spent in Rome.
Travel throughout the Mediterranean and Near East for scholarly purposes, was popular during this era and was facilitated by the relative peace enjoyed throughout the reign of Augustus. He moved to Rome in 44 BC, stayed there and writing, until at least 31 BC. In 29 BC, on his way to Corinth, he visited the island of Gyaros in the Aegean Sea. Around 25 BC, he sailed up the Nile until reaching Philae, after which point there is little record of his proceedings until AD 17, it is not known when Strabo's Geography was written, though comments within the work itself place the finished version within the reign of Emperor Tiberius. Some place its first drafts around 7 BC, others around AD 17 or 18; the latest passage to which a date can be assigned is his reference to the death in AD 23 of Juba II, king of Maurousia, said to have died "just recently". He worked on the Geography for many years and revised it not always consistently, it is an encyclopaedical chronicle and consists of political, social, geographic description of whole Europe: British Isles, Iberian Peninsula, Germania, The Alps, Greece.
The Geography is the only extant work providing information about both Greek and Roman peoples and countries during the reign of Augustus. On the presumption that "recently" means within a year, Strabo stopped writing that year or the next, when he died, he was influenced by Homer and Aristotle. The first of Strabo's major works, Historical Sketches, written while he was in Rome, is nearly lost. Meant to cover the history of the known world from the conquest of Greece by the Romans, Strabo quotes it himself and other classical authors mention that it existed, although the only surviving document is a fragment of papyrus now in possession of the University of Milan. Strabo studied under several prominent teachers of various specialties throughout his early life at different stops along his Mediterranean travels, his first chapter of education took place in Nysa under the master of rhetoric Aristodemus, who had taught the sons of the same Roman general who had taken over Pontus. Aristodemus was the head of two schools of rhetoric and grammar, one in Nysa and one in Rhodes, the former of the two cities possessing a distinct intellectual curiosity of Homeric literature and the interpretation of epics.
Strabo was an admirer of Homer's poetry a consequence of his time spent in Nysa with Aristodemus. At around the age of 21, Strabo moved to Rome, where he studied philosophy with the Peripatetic Xenarchus, a respected tutor in Augustus's court. Despite Xenarchus's Aristotelian leanings, Strabo gives evidence to have formed his own Stoic inclinations. In Rome, he learned grammar under the rich and famous scholar Tyrannion of Amisus. Although Tyrannion was a Peripatetic, he was more relevantly a respected authority on geography, a fact significant, considering Strabo's future contributions to the field; the final noteworthy mentor to Strabo was Athenodorus Cananites, a philosopher who had spent his life since 44 BC in Rome forging relationships with the Roman elite. Athenodorus endowed to Strabo three important items: his philosophy, his knowledge, his contacts. Unlike the Aristotelian Xenarchus and Tyrannion who preceded him in teaching Strabo, Athenodorus was Stoic in mindset certainly the source of Strabo's diversion from the philosophy of his former mentors.
Moreover, from his own first-hand experience, Athenodorus provided Strabo with information about regions of the empire which he would not otherwise have known. Strabo is most notable for his work Geographica, which presented a descriptive history of people and places from different regions of the world known to his era. Although the Geographica was utilized in its contemporary antiquity, a multitude of copies survived throughout the Byzantine Empire, it first appeared in Western Europe in Rome as a Latin translation issued around 1469. The first Greek edition was published in 1516 in Venice. Isaac Casaubon, classical scholar and editor of Greek texts, provided the first critical edition in 1587. Although Strabo cited the antique Greek astronomers Eratosthenes and Hipparchus, acknowledging their astronomical and mathematical efforts towards geography, he claimed that
The Greeks or Hellenes are an ethnic group native to Greece, southern Albania, Turkey, Egypt and, to a lesser extent, other countries surrounding the Mediterranean Sea. They form a significant diaspora, with Greek communities established around the world. Greek colonies and communities have been established on the shores of the Mediterranean Sea and Black Sea, but the Greek people have always been centered on the Aegean and Ionian seas, where the Greek language has been spoken since the Bronze Age; until the early 20th century, Greeks were distributed between the Greek peninsula, the western coast of Asia Minor, the Black Sea coast, Cappadocia in central Anatolia, the Balkans and Constantinople. Many of these regions coincided to a large extent with the borders of the Byzantine Empire of the late 11th century and the Eastern Mediterranean areas of ancient Greek colonization; the cultural centers of the Greeks have included Athens, Alexandria and Constantinople at various periods. Most ethnic Greeks live nowadays within the borders of Cyprus.
The Greek genocide and population exchange between Greece and Turkey nearly ended the three millennia-old Greek presence in Asia Minor. Other longstanding Greek populations can be found from southern Italy to the Caucasus and southern Russia and Ukraine and in the Greek diaspora communities in a number of other countries. Today, most Greeks are registered as members of the Greek Orthodox Church. Greeks have influenced and contributed to culture, exploration, philosophy, architecture, mathematics and technology, business and sports, both and contemporarily; the Greeks speak the Greek language, which forms its own unique branch within the Indo-European family of languages, the Hellenic. They are part of a group of classical ethnicities, described by Anthony D. Smith as an "archetypal diaspora people"; the Proto-Greeks arrived at the area now called Greece, in the southern tip of the Balkan peninsula, at the end of the 3rd millennium BC. The sequence of migrations into the Greek mainland during the 2nd millennium BC has to be reconstructed on the basis of the ancient Greek dialects, as they presented themselves centuries and are therefore subject to some uncertainties.
There were at least two migrations, the first being the Ionians and Aeolians, which resulted in Mycenaean Greece by the 16th century BC, the second, the Dorian invasion, around the 11th century BC, displacing the Arcadocypriot dialects, which descended from the Mycenaean period. Both migrations occur at incisive periods, the Mycenaean at the transition to the Late Bronze Age and the Doric at the Bronze Age collapse. An alternative hypothesis has been put forth by linguist Vladimir Georgiev, who places Proto-Greek speakers in northwestern Greece by the Early Helladic period, i.e. towards the end of the European Neolithic. Linguists Russell Gray and Quentin Atkinson in a 2003 paper using computational methods on Swadesh lists have arrived at a somewhat earlier estimate, around 5000 BC for Greco-Armenian split and the emergence of Greek as a separate linguistic lineage around 4000 BC. In c. 1600 BC, the Mycenaean Greeks borrowed from the Minoan civilization its syllabic writing system and developed their own syllabic script known as Linear B, providing the first and oldest written evidence of Greek.
The Mycenaeans penetrated the Aegean Sea and, by the 15th century BC, had reached Rhodes, Crete and the shores of Asia Minor. Around 1200 BC, the Dorians, another Greek-speaking people, followed from Epirus. Traditionally, historians have believed that the Dorian invasion caused the collapse of the Mycenaean civilization, but it is the main attack was made by seafaring raiders who sailed into the eastern Mediterranean around 1180 BC; the Dorian invasion was followed by a poorly attested period of migrations, appropriately called the Greek Dark Ages, but by 800 BC the landscape of Archaic and Classical Greece was discernible. The Greeks of classical antiquity idealized their Mycenaean ancestors and the Mycenaean period as a glorious era of heroes, closeness of the gods and material wealth; the Homeric Epics were and accepted as part of the Greek past and it was not until the time of Euhemerism that scholars began to question Homer's historicity. As part of the Mycenaean heritage that survived, the names of the gods and goddesses of Mycenaean Greece became major figures of the Olympian Pantheon of antiquity.
The ethnogenesis of the Greek nation is linked to the development of Pan-Hellenism in the 8th century BC. According to some scholars, the foundational event was the Olympic Games in 776 BC, when the idea of a common Hellenism among the Greek tribes was first translated into a shared cultural experience and Hellenism was a matter of common culture; the works of Homer and Hesiod were written in the 8th century BC, becoming the basis of the national religion, ethos and mythology. The Oracle of Apollo at Delphi was established in this period; the classical period of Greek civilization covers a time spanning from the early 5th century BC to the death of Alexander the Great, in 323 BC. It is so named because it set the standards by which Greek civilization would be judged in eras; the Classical period is described as the "Golden Age" of Greek civilization, and