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Ancient Greece From Wikipedia, the free encyclopedia Jump to navigationJump to search The Parthenon, a temple dedicated to Athena, located on the Acropolis in Athens, is one of the most representative symbols of the culture and sophistication of the ancient Greeks. Part of a series on the History of Greece This map of the island Crete before the coast of Greece was published after 1681 by Nicolaes Visscher II (1649-1702). Visscher based this map on a map by the Danish cartographer Johann Lauremberg (1590-1658) Neolithic Greece[show] Greek Bronze Age[show] Ancient Greece[show] Medieval Greece[show] Early modern Greece[show] Modern Greece[show] History by topic[show] Flag of Greece.svg Greece portal vte Ancient history Preceded by prehistory Near East Sumer · Egypt · Elam · Akkad · Assyria · Babylonia · Mitanni · Hittites · Sea Peoples · Anatolia · Israel and Judah · Arabia · Berbers · Phoenicia · Persia Europe Minoans · Greece · Nuragic · Tartessos · Celts · Germanics · Etruscans · Rome · Slavs Eurasian Steppe Proto-Indo-Europeans · Afanasievo · Indo-Iranians · Scythians · Sarmatians · Saka · Xiongnu · Huns · Xionites · Turks East Asia China · Japan · Korea · Mongolia South Asia Indus Valley Civilisation · Vedic period · Mahajanapadas · Nanda Empire · Maurya Empire · Sangam period · Middle Kingdoms · Gupta Empire Mississippi and Oasisamerica Adena · Hopewell · Mississippian · Puebloans Mesoamerica Olmecs · Epi-Olmec · Zapotec · Mixtec · Maya · Teotihuacan · Toltec Empire Andes Norte Chico · Sechin · Chavín · Paracas · Nazca · Moche · Lima · Tiwanaku · Wari West Africa Dhar Tichitt · Oualata · Nok · Senegambia · Djenné-Djenno · Bantu · Ghana Empire Southeast Asia and Oceania Vietnam · Austronesians · Australia · Polynesia · Funan · Tarumanagara See also History of the world · Ancient maritime history Protohistory · Axial Age · Iron Age Historiography · Ancient literature Ancient warfare · Cradle of civilization Category Category Followed by Post-classical history vte Ancient Greece (Greek: Ἑλλάς, romanized: Hellás) was a civilization belonging to a period of Greek history from the Greek Dark Ages of the 12th–9th centuries BC to the end of antiquity (c. AD 600). Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era.[1] Roughly three centuries after the Late Bronze Age collapse of Mycenaean Greece, Greek urban poleis began to form in the 8th century BC, ushering in the Archaic period and colonization of the Mediterranean Basin. This was followed by the period of Classical Greece, an era that began with the Greco-Persian Wars, lasting from the 5th to 4th centuries BC. Due to the conquests by Alexander the Great of Macedon, Hellenistic civilization flourished from Central Asia to the western end of the Mediterranean Sea. The Hellenistic period came to an end with the conquests and annexations of the eastern Mediterranean world by the Roman Republic, which established the Roman province of Macedonia in Roman Greece, and later the province of Achaea during the Roman Empire. Classical Greek culture, especially philosophy, had a powerful influence on ancient Rome, which carried a version of it to many parts of the Mediterranean Basin and Europe. For this reason, Classical Greece is generally considered to be the seminal culture which provided the foundation of modern Western culture and is considered the cradle of Western civilization.[2][3][4] Classical Greek culture gave great importance to knowledge. Science and religion were not separate and getting closer to the truth meant getting closer to the gods. In this context, they understood the importance of mathematics as an instrument for obtaining more reliable ("divine") knowledge.[5] Greek culture, in a few centuries and with a limited population, managed to explore and make progress in many fields of science, mathematics, philosophy and knowledge in general. Contents 1 Chronology 2 Historiography 3 History 3.1 Archaic period 3.2 Classical Greece 3.3 Hellenistic Greece 3.4 Roman Greece 4 Geography 4.1 Regions 4.2 Colonies 5 Politics and society 5.1 Political structure 5.2 Government and law 5.3 Social structure 5.3.1 Slavery 5.4 Education 5.5 Economy 5.6 Warfare 6 Culture 6.1 Philosophy 6.2 Literature and theatre 6.3 Music and dance 6.4 Science and technology 6.5 Art and architecture 6.6 Religion 7 Legacy 8 See also 9 References 10 Further reading 11 External links Chronology Further information: Timeline of ancient Greece Classical antiquity in the Mediterranean region is commonly considered to have begun in the 8th century BC[6] (around the time of the earliest recorded poetry of Homer) and ended in the 6th century AD. Classical antiquity in Greece was preceded by the Greek Dark Ages (c. 1200 – c. 800 BC), archaeologically characterised by the protogeometric and geometric styles of designs on pottery. Following the Dark Ages was the Archaic Period, beginning around the 8th century BC. The Archaic Period saw early developments in Greek culture and society which formed the basis for the Classical Period.[7] After the Archaic Period, the Classical Period in Greece is conventionally considered to have lasted from the Persian invasion of Greece in 480 until the death of Alexander the Great in 323.[8] The period is characterized by a style which was considered by later observers to be exemplary, i.e., "classical", as shown in the Parthenon, for instance. Politically, the Classical Period was dominated by Athens and the Delian League during the 5th century, but displaced by Spartan hegemony during the early 4th century BC, before power shifted to Thebes and the Boeotian League and finally to the League of Corinth led by Macedon. This period saw the Greco-Persian Wars and the Rise of Macedon. Following the Classical period was the Hellenistic period (323–146 BC), during which Greek culture and power expanded into the Near and Middle East. This period begins with the death of Alexander and ends with the Roman conquest. Roman Greece is usually considered to be the period between Roman victory over the Corinthians at the Battle of Corinth in 146 BC and the establishment of Byzantium by Constantine as the capital of the Roman Empire in AD 330. Finally, Late Antiquity refers to the period of Christianization during the later 4th to early 6th centuries AD, sometimes taken to be complete with the closure of the Academy of Athens by Justinian I in 529.[9] Historiography Main article: Greek historiographers The Victorious Youth (c. 310 BC), is a rare, water-preserved bronze sculpture from ancient Greece. The historical period of ancient Greece is unique in world history as the first period attested directly in proper historiography, while earlier ancient history or proto-history is known by much more circumstantial evidence, such as annals or king lists, and pragmatic epigraphy. Herodotus is widely known as the "father of history": his Histories are eponymous of the entire field. Written between the 450s and 420s BC, Herodotus' work reaches about a century into the past, discussing 6th century historical figures such as Darius I of Persia, Cambyses II and Psamtik III, and alluding to some 8th century ones such as Candaules. Herodotus was succeeded by authors such as Thucydides, Xenophon, Demosthenes, Plato and Aristotle. Most of these authors were either Athenian or pro-Athenian, which is why far more is known about the history and politics of Athens than those of many other cities. Their scope is further limited by a focus on political, military and diplomatic history, ignoring economic and social history.[10] History Further information: History of Greece Archaic period Main article: Archaic period in Greece Dipylon Vase of the late Geometric period, or the beginning of the Archaic period, c. 750 BC. In the 8th century BC, Greece began to emerge from the Dark Ages which followed the fall of the Mycenaean civilization. Literacy had been lost and Mycenaean script forgotten, but the Greeks adopted the Phoenician alphabet, modifying it to create the Greek alphabet. Objects with Phoenician writing on them may have been available in Greece from the 9th century BC, but the earliest evidence of Greek writing comes from graffiti on Greek pottery from the mid-8th century.[11] Greece was divided into many small self-governing communities, a pattern largely dictated by Greek geography: every island, valley and plain is cut off from its neighbors by the sea or mountain ranges.[12] The Lelantine War (c. 710 – c. 650 BC) is the earliest documented war of the ancient Greek period. It was fought between the important poleis (city-states) of Chalcis and Eretria over the fertile Lelantine plain of Euboea. Both cities seem to have suffered a decline as result of the long war, though Chalcis was the nominal victor. A mercantile class arose in the first half of the 7th century BC, shown by the introduction of coinage in about 680 BC.[13] This seems to have introduced tension to many city-states. The aristocratic regimes which generally governed the poleis were threatened by the new-found wealth of merchants, who in turn desired political power. From 650 BC onwards, the aristocracies had to fight not to be overthrown and replaced by populist tyrants. This word derives from the non-pejorative Greek τύραννος tyrannos, meaning 'illegitimate ruler', and was applicable to both good and bad leaders alike.[14][15] A growing population and a shortage of land also seem to have created internal strife between the poor and the rich in many city-states. In Sparta, the Messenian Wars resulted in the conquest of Messenia and enserfment of the Messenians, beginning in the latter half of the 8th century BC, an act without precedent in ancient Greece. This practice allowed a social revolution to occur.[16] The subjugated population, thenceforth known as helots, farmed and labored for Sparta, whilst every Spartan male citizen became a soldier of the Spartan Army in a permanently militarized state. Even the elite were obliged to live and train as soldiers; this commonality between rich and poor citizens served to defuse the social conflict. These reforms, attributed to Lycurgus of Sparta, were probably complete by 650 BC. Political geography of ancient Greece in the Archaic and Classical periods Athens suffered a land and agrarian crisis in the late 7th century BC, again resulting in civil strife. The Archon (chief magistrate) Draco made severe reforms to the law code in 621 BC (hence "draconian"), but these failed to quell the conflict. Eventually the moderate reforms of Solon (594 BC), improving the lot of the poor but firmly entrenching the aristocracy in power, gave Athens some stability. By the 6th century BC several cities had emerged as dominant in Greek affairs: Athens, Sparta, Corinth, and Thebes. Each of them had brought the surrounding rural areas and smaller towns under their control, and Athens and Corinth had become major maritime and mercantile powers as well. Rapidly increasing population in the 8th and 7th centuries BC had resulted in emigration of many Greeks to form colonies in Magna Graecia (Southern Italy and Sicily), Asia Minor and further afield. The emigration effectively ceased in the 6th century BC by which time the Greek world had, culturally and linguistically, become much larger than the area of present-day Greece. Greek colonies were not politically controlled by their founding cities, although they often retained religious and commercial links with them. The emigration process also determined a long series of conflicts between the Greek cities of Sicily, especially Syracuse, and the Carthaginians. These conflicts lasted from 600 BC to 265 BC when the Roman Republic entered into an alliance with the Mamertines to fend off the hostilities by the new tyrant of Syracuse, Hiero II and then the Carthaginians. This way Rome became the new dominant power against the fading strength of the Sicilian Greek cities and the Carthaginian supremacy in the region. One year later the First Punic War erupted. In this period, there was huge economic development in Greece, and also in its overseas colonies which experienced a growth in commerce and manufacturing. There was a great improvement in the living standards of the population. Some studies estimate that the average size of the Greek household, in the period from 800 BC to 300 BC, increased five times, which indicates[citation needed] a large increase in the average income of the population. In the second half of the 6th century BC, Athens fell under the tyranny of Peisistratos and then of his sons Hippias and Hipparchos. However, in 510 BC, at the instigation of the Athenian aristocrat Cleisthenes, the Spartan king Cleomenes I helped the Athenians overthrow the tyranny. Afterwards, Sparta and Athens promptly turned on each other, at which point Cleomenes I installed Isagoras as a pro-Spartan archon. Eager to prevent Athens from becoming a Spartan puppet, Cleisthenes responded by proposing to his fellow citizens that Athens undergo a revolution: that all citizens share in political power, regardless of status: that Athens become a "democracy". So enthusiastically did the Athenians take to this idea that, having overthrown Isagoras and implemented Cleisthenes's reforms, they were easily able to repel a Spartan-led three-pronged invasion aimed at restoring Isagoras.[17] The advent of the democracy cured many of the ills of Athens and led to a 'golden age' for the Athenians. Classical Greece Main article: Classical Greece Early Athenian coin, depicting the head of Athena on the obverse and her owl on the reverse – 5th century BC In 499 BC, the Ionian city states under Persian rule rebelled against the Persian-supported tyrants that ruled them.[18] Supported by troops sent from Athens and Eretria, they advanced as far as Sardis and burnt the city down, before being driven back by a Persian counterattack.[19] The revolt continued until 494, when the rebelling Ionians were defeated.[20] Darius did not forget that the Athenians had assisted the Ionian revolt, however, and in 490 he assembled an armada to conquer Athens.[21] Despite being heavily outnumbered, the Athenians—supported by their Plataean allies—defeated the Persian forces at the Battle of Marathon, and the Persian fleet withdrew.[22] Map showing events of the first phases of the Greco-Persian Wars. Delian League ("Athenian Empire"), immediately before the Peloponnesian War in 431 BC Ten years later, a second invasion was launched by Darius' son Xerxes.[23] The city-states of northern and central Greece submitted to the Persian forces without resistance, but a coalition of 31 Greek city states, including Athens and Sparta, determined to resist the Persian invaders.[24] At the same time, Greek Sicily was invaded by a Carthaginian force.[25] In 480 BC, the first major battle of the invasion was fought at Thermopylae, where a small force of Greeks, led by three hundred Spartans, held a crucial pass into the heart of Greece for several days; at the same time Gelon, tyrant of Syracuse, defeated the Carthaginian invasion at the Battle of Himera.[26] The Persians were defeated by a primarily Athenian naval force at the Battle of Salamis, and in 479 defeated on land at the Battle of Plataea.[27] The alliance against Persia continued, initially led by the Spartan Pausanias but from 477 by Athens,[28] and by 460 Persia had been driven out of the Aegean.[29] During this period of campaigning, the Delian league gradually transformed from a defensive alliance of Greek states into an Athenian empire, as Athens' growing naval power enabled it to compel other league states to comply with its policies.[30] Athens ended its campaigns against Persia in 450 BC, after a disastrous defeat in Egypt in 454 BC, and the death of Cimon in action against the Persians on Cyprus in 450.[31] While Athenian activity against the Persian empire was ending, however, conflict between Sparta and Athens was increasing. Sparta was suspicious of the increasing Athenian power funded by the Delian League, and tensions rose when Sparta offered aid to reluctant members of the League to rebel against Athenian domination. These tensions were exacerbated in 462, when Athens sent a force to aid Sparta in overcoming a helot revolt, but their aid was rejected by the Spartans.[32] In the 450s, Athens took control of Boeotia, and won victories over Aegina and Corinth.[33] However, Athens failed to win a decisive victory, and in 447 lost Boeotia again.[34] Athens and Sparta signed the Thirty Years' Peace in the winter of 446/5, ending the conflict.[35] Despite the peace of 446/5, Athenian relations with Sparta declined again in the 430s, and in 431 war broke out once again.[36] The first phase of the war is traditionally seen as a series of annual invasions of Attica by Sparta, which made little progress, while Athens were successful against the Corinthian empire in the north-west of Greece, and in defending their own empire, despite suffering from plague and Spartan invasion.[37] The turning point of this phase of the war usually seen as the Athenian victories at Pylos and Sphakteria.[38] Sparta sued for peace, but the Athenians rejected the proposal.[39] The Athenian failure to regain control at Boeotia at Delium and Brasidas' successes in the north of Greece in 424, improved Sparta's position after Sphakteria.[40] After the deaths of Cleon and Brasidas, the strongest objectors to peace on the Athenian and Spartan sides respectively, a peace treaty was agreed in 421.[41] The peace did not last, however. In 418 an alliance between Athens and Argos was defeated by Sparta at Mantinea.[42] In 415 Athens launched a naval expedition against Sicily;[43] the expedition ended in disaster with almost the entire army killed.[44] Soon after the Athenian defeat in Syracuse, Athens' Ionian allies began to rebel against the Delian league, while at the same time Persia began to once again involve itself in Greek affairs on the Spartan side.[45] Initially the Athenian position continued to be relatively strong, winning important battles such as those at Cyzicus in 410 and Arginusae in 406.[46] However, in 405 the Spartans defeated Athens in the Battle of Aegospotami, and began to blockade Athens' harbour;[47] with no grain supply and in danger of starvation, Athens sued for peace, agreeing to surrender their fleet and join the Spartan-led Peloponnesian League.[48] Greece thus entered the 4th century BC under a Spartan hegemony, but it was clear from the start that this was weak. A demographic crisis meant Sparta was overstretched, and by 395 BC Athens, Argos, Thebes, and Corinth felt able to challenge Spartan dominance, resulting in the Corinthian War (395–387 BC). Another war of stalemates, it ended with the status quo restored, after the threat of Persian intervention on behalf of the Spartans. The Spartan hegemony lasted another 16 years, until, when attempting to impose their will on the Thebans, the Spartans were defeated at Leuctra in 371 BC. The Theban general Epaminondas then led Theban troops into the Peloponnese, whereupon other city-states defected from the Spartan cause. The Thebans were thus able to march into Messenia and free the population. 4th century BC Greek gold and bronze rhyton with head of Dionysus, Tamoikin Art Fund Deprived of land and its serfs, Sparta declined to a second-rank power. The Theban hegemony thus established was short-lived; at the Battle of Mantinea in 362 BC, Thebes lost its key leader, Epaminondas, and much of its manpower, even though they were victorious in battle. In fact such were the losses to all the great city-states at Mantinea that none could establish dominance in the aftermath. The weakened state of the heartland of Greece coincided with the Rise of Macedon, led by Philip II. In twenty years, Philip had unified his kingdom, expanded it north and west at the expense of Illyrian tribes, and then conquered Thessaly and Thrace. His success stemmed from his innovative reforms to the Macedonian army. Phillip intervened repeatedly in the affairs of the southern city-states, culminating in his invasion of 338 BC. Decisively defeating an allied army of Thebes and Athens at the Battle of Chaeronea (338 BC), he became de facto hegemon of all of Greece, except Sparta. He compelled the majority of the city-states to join the League of Corinth, allying them to him, and preventing them from warring with each other. Philip then entered into war against the Achaemenid Empire but was assassinated by Pausanias of Orestis early on in the conflict. Alexander the Great, son and successor of Philip, continued the war. Alexander defeated Darius III of Persia and completely destroyed the Achaemenid Empire, annexing it to Macedon and earning himself the epithet 'the Great'. When Alexander died in 323 BC, Greek power and influence was at its zenith. However, there had been a fundamental shift away from the fierce independence and classical culture of the poleis—and instead towards the developing Hellenistic culture. Hellenistic Greece Main articles: Wars of Alexander the Great and Hellenistic period Alexander Mosaic, National Archaeological Museum, Naples. The Hellenistic period lasted from 323 BC, which marked the end of the wars of Alexander the Great, to the annexation of Greece by the Roman Republic in 146 BC. Although the establishment of Roman rule did not break the continuity of Hellenistic society and culture, which remained essentially unchanged until the advent of Christianity, it did mark the end of Greek political independence. The major Hellenistic realms included the Diadochi kingdoms: Kingdom of Ptolemy I Soter Kingdom of Cassander Kingdom of Lysimachus Kingdom of Seleucus I Nicator Epirus Also shown on the map: Greek colonies Carthage (non-Greek) Rome (non-Greek) The orange areas were often in dispute after 281 BC. The Attalid dynasty occupied some of this area. Not shown: Indo-Greek Kingdom. After the death of Alexander, his empire was, after quite some conflict, divided among his generals, resulting in the Ptolemaic Kingdom (Egypt and adjoining North Africa), the Seleucid Empire (the Levant, Mesopotamia and Persia) and the Antigonid dynasty (Macedonia). In the intervening period, the poleis of Greece were able to wrest back some of their freedom, although still nominally subject to the Macedonian Kingdom. During the Hellenistic period, the importance of "Greece proper" (that is, the territory of modern Greece) within the Greek-speaking world declined sharply. The great centers of Hellenistic culture were Alexandria and Antioch, capitals of the Ptolemaic Kingdom and the Seleucid Empire, respectively. The conquests of Alexander had numerous consequences for the Greek city-states. It greatly widened the horizons of the Greeks and led to a steady emigration, particularly of the young and ambitious, to the new Greek empires in the east.[49] Many Greeks migrated to Alexandria, Antioch and the many other new Hellenistic cities founded in Alexander's wake, as far away as what are now Afghanistan and Pakistan, where the Greco-Bactrian Kingdom and the Indo-Greek Kingdom survived until the end of the first century BC. The city-states within Greece formed themselves into two leagues; the Achaean League (including Thebes, Corinth and Argos) and the Aetolian League (including Sparta and Athens). For much of the period until the Roman conquest, these leagues were usually at war with each other, and/or allied to different sides in the conflicts between the Diadochi (the successor states to Alexander's empire). The Antigonid Kingdom became involved in a war with the Roman Republic in the late 3rd century. Although the First Macedonian War was inconclusive, the Romans, in typical fashion, continued to make war on Macedon until it was completely absorbed into the Roman Republic (by 149 BC). In the east the unwieldy Seleucid Empire gradually disintegrated, although a rump survived until 64 BC, whilst the Ptolemaic Kingdom continued in Egypt until 30 BC, when it too was conquered by the Romans. The Aetolian league grew wary of Roman involvement in Greece, and sided with the Seleucids in the Roman–Seleucid War; when the Romans were victorious, the league was effectively absorbed into the Republic. Although the Achaean league outlasted both the Aetolian league and Macedon, it was also soon defeated and absorbed by the Romans in 146 BC, bringing an end to the independence of all of Greece. Roman Greece Main article: Roman Greece Further information: Byzantine Greece The Greek peninsula came under Roman rule during the 146 BC conquest of Greece after the Battle of Corinth. Macedonia became a Roman province while southern Greece came under the surveillance of Macedonia's prefect; however, some Greek poleis managed to maintain a partial independence and avoid taxation. The Aegean islands were added to this territory in 133 BC. Athens and other Greek cities revolted in 88 BC, and the peninsula was crushed by the Roman general Sulla. The Roman civil wars devastated the land even further, until Augustus organized the peninsula as the province of Achaea in 27 BC. Greece was a key eastern province of the Roman Empire, as the Roman culture had long been in fact Greco-Roman. The Greek language served as a lingua franca in the East and in Italy, and many Greek intellectuals such as Galen would perform most of their work in Rome. Geography Regions Main article: Regions of ancient Greece Map showing the major regions of mainland ancient Greece and adjacent "barbarian" lands. The territory of Greece is mountainous, and as a result, ancient Greece consisted of many smaller regions each with its own dialect, cultural peculiarities, and identity. Regionalism and regional conflicts were a prominent feature of ancient Greece. Cities tended to be located in valleys between mountains, or on coastal plains, and dominated a certain area around them. In the south lay the Peloponnese, itself consisting of the regions of Laconia (southeast), Messenia (southwest), Elis (west), Achaia (north), Korinthia (northeast), Argolis (east), and Arcadia (center). These names survive to the present day as regional units of modern Greece, though with somewhat different boundaries. Mainland Greece to the north, nowadays known as Central Greece, consisted of Aetolia and Acarnania in the west, Locris, Doris, and Phocis in the center, while in the east lay Boeotia, Attica, and Megaris. Northeast lay Thessaly, while Epirus lay to the northwest. Epirus stretched from the Ambracian Gulf in the south to the Ceraunian mountains and the Aoos river in the north, and consisted of Chaonia (north), Molossia (center), and Thesprotia (south). In the northeast corner was Macedonia,[50] originally consisting Lower Macedonia and its regions, such as Elimeia, Pieria, and Orestis. Around the time of Alexander I of Macedon, the Argead kings of Macedon started to expand into Upper Macedonia, lands inhabited by independent Macedonian tribes like the Lyncestae and the Elmiotae and to the West, beyond the Axius river, into Eordaia, Bottiaea, Mygdonia, and Almopia, regions settled by Thracian tribes.[51] To the north of Macedonia lay various non-Greek peoples such as the Paeonians due north, the Thracians to the northeast, and the Illyrians, with whom the Macedonians were frequently in conflict, to the northwest. Chalcidice was settled early on by southern Greek colonists and was considered part of the Greek world, while from the late 2nd millennium BC substantial Greek settlement also occurred on the eastern shores of the Aegean, in Anatolia. Colonies See also: Greeks in pre-Roman Gaul, Magna Graecia, and List of ancient cities in Thrace and Dacia § Greek Greek cities & colonies c. 550 BC. During the Archaic period, the population of Greece grew beyond the capacity of its limited arable land (according to one estimate, the population of ancient Greece increased by a factor larger than ten during the period from 800 BC to 400 BC, increasing from a population of 800,000 to a total estimated population of 10 to 13 million).[52] From about 750 BC the Greeks began 250 years of expansion, settling colonies in all directions. To the east, the Aegean coast of Asia Minor was colonized first, followed by Cyprus and the coasts of Thrace, the Sea of Marmara and south coast of the Black Sea. Eventually Greek colonization reached as far northeast as present day Ukraine and Russia (Taganrog). To the west the coasts of Illyria, Sicily and Southern Italy were settled, followed by Southern France, Corsica, and even northeastern Spain. Greek colonies were also founded in Egypt and Libya. Modern Syracuse, Naples, Marseille and Istanbul had their beginnings as the Greek colonies Syracusae (Συράκουσαι), Neapolis (Νεάπολις), Massalia (Μασσαλία) and Byzantion (Βυζάντιον). These colonies played an important role in the spread of Greek influence throughout Europe and also aided in the establishment of long-distance trading networks between the Greek city-states, boosting the economy of ancient Greece. Politics and society Political structure Further information: History of citizenship § Ancient Greece Marble bust of Pericles with a Corinthian helmet, Roman copy of a Greek original, Museo Chiaramonti, Vatican Museums; Pericles was a key populist political figure in the development of the radical Athenian democracy.[53] Ancient Greece consisted of several hundred relatively independent city-states (poleis). This was a situation unlike that in most other contemporary societies, which were either tribal or kingdoms ruling over relatively large territories. Undoubtedly the geography of Greece—divided and sub-divided by hills, mountains, and rivers—contributed to the fragmentary nature of ancient Greece. On the one hand, the ancient Greeks had no doubt that they were "one people"; they had the same religion, same basic culture, and same language. Furthermore, the Greeks were very aware of their tribal origins; Herodotus was able to extensively categorise the city-states by tribe. Yet, although these higher-level relationships existed, they seem to have rarely had a major role in Greek politics. The independence of the poleis was fiercely defended; unification was something rarely contemplated by the ancient Greeks. Even when, during the second Persian invasion of Greece, a group of city-states allied themselves to defend Greece, the vast majority of poleis remained neutral, and after the Persian defeat, the allies quickly returned to infighting.[54] Thus, the major peculiarities of the ancient Greek political system were its fragmentary nature (and that this does not particularly seem to have tribal origin), and the particular focus on urban centers within otherwise tiny states. The peculiarities of the Greek system are further evidenced by the colonies that they set up throughout the Mediterranean Sea, which, though they might count a certain Greek polis as their 'mother' (and remain sympathetic to her), were completely independent of the founding city. Inevitably smaller poleis might be dominated by larger neighbors, but conquest or direct rule by another city-state appears to have been quite rare. Instead the poleis grouped themselves into leagues, membership of which was in a constant state of flux. Later in the Classical period, the leagues would become fewer and larger, be dominated by one city (particularly Athens, Sparta and Thebes); and often poleis would be compelled to join under threat of war (or as part of a peace treaty). Even after Philip II of Macedon "conquered" the heartlands of ancient Greece, he did not attempt to annex the territory, or unify it into a new province, but simply compelled most of the poleis to join his own Corinthian League. Government and law Main article: Ancient Greek law Inheritance law, part of the Law Code of Gortyn, Crete, fragment of the 11th column. Limestone, 5th century BC Initially many Greek city-states seem to have been petty kingdoms; there was often a city official carrying some residual, ceremonial functions of the king (basileus), e.g., the archon basileus in Athens.[55] However, by the Archaic period and the first historical consciousness, most had already become aristocratic oligarchies. It is unclear exactly how this change occurred. For instance, in Athens, the kingship had been reduced to a hereditary, lifelong chief magistracy (archon) by c. 1050 BC; by 753 BC this had become a decennial, elected archonship; and finally by 683 BC an annually elected archonship. Through each stage more power would have been transferred to the aristocracy as a whole, and away from a single individual. Inevitably, the domination of politics and concomitant aggregation of wealth by small groups of families was apt to cause social unrest in many poleis. In many cities a tyrant (not in the modern sense of repressive autocracies), would at some point seize control and govern according to their own will; often a populist agenda would help sustain them in power. In a system wracked with class conflict, government by a 'strongman' was often the best solution. Athens fell under a tyranny in the second half of the 6th century. When this tyranny was ended, the Athenians founded the world's first democracy as a radical solution to prevent the aristocracy regaining power. A citizens' assembly (the Ecclesia), for the discussion of city policy, had existed since the reforms of Draco in 621 BC; all citizens were permitted to attend after the reforms of Solon (early 6th century), but the poorest citizens could not address the assembly or run for office. With the establishment of the democracy, the assembly became the de jure mechanism of government; all citizens had equal privileges in the assembly. However, non-citizens, such as metics (foreigners living in Athens) or slaves, had no political rights at all. After the rise of the democracy in Athens, other city-states founded democracies. However, many retained more traditional forms of government. As so often in other matters, Sparta was a notable exception to the rest of Greece, ruled through the whole period by not one, but two hereditary monarchs. This was a form of diarchy. The Kings of Sparta belonged to the Agiads and the Eurypontids, descendants respectively of Eurysthenes and Procles. Both dynasties' founders were believed to be twin sons of Aristodemus, a Heraclid ruler. However, the powers of these kings were held in check by both a council of elders (the Gerousia) and magistrates specifically appointed to watch over the kings (the Ephors). Social structure Fresco of dancing Peucetian women in the Tomb of the Dancers in Ruvo di Puglia, 4th–5th century BC Only free, land owning, native-born men could be citizens entitled to the full protection of the law in a city-state. In most city-states, unlike the situation in Rome, social prominence did not allow special rights. Sometimes families controlled public religious functions, but this ordinarily did not give any extra power in the government. In Athens, the population was divided into four social classes based on wealth. People could change classes if they made more money. In Sparta, all male citizens were called homoioi, meaning "peers". However, Spartan kings, who served as the city-state's dual military and religious leaders, came from two families.[citation needed] Slavery Main article: Slavery in ancient Greece Gravestone of a woman with her slave child-attendant, c. 100 BC Slaves had no power or status. They had the right to have a family and own property, subject to their master's goodwill and permission, but they had no political rights. By 600 BC chattel slavery had spread in Greece. By the 5th century BC slaves made up one-third of the total population in some city-states. Between forty and eighty per cent of the population of Classical Athens were slaves.[56] Slaves outside of Sparta almost never revolted because they were made up of too many nationalities and were too scattered to organize. However, unlike later Western culture, the Ancient Greeks did not think in terms of race.[57] Most families owned slaves as household servants and laborers, and even poor families might have owned a few slaves. Owners were not allowed to beat or kill their slaves. Owners often promised to free slaves in the future to encourage slaves to work hard. Unlike in Rome, freedmen did not become citizens. Instead, they were mixed into the population of metics, which included people from foreign countries or other city-states who were officially allowed to live in the state. City-states legally owned slaves. These public slaves had a larger measure of independence than slaves owned by families, living on their own and performing specialized tasks. In Athens, public slaves were trained to look out for counterfeit coinage, while temple slaves acted as servants of the temple's deity and Scythian slaves were employed in Athens as a police force corralling citizens to political functions. Sparta had a special type of slaves called helots. Helots were Messenians enslaved during the Messenian Wars by the state and assigned to families where they were forced to stay. Helots raised food and did household chores so that women could concentrate on raising strong children while men could devote their time to training as hoplites. Their masters treated them harshly, and helots revolted against their masters several times before in 370/69 they won their freedom.[58] Education Main article: Education in ancient Greece Mosaic from Pompeii depicting Plato's academy For most of Greek history, education was private, except in Sparta. During the Hellenistic period, some city-states established public schools. Only wealthy families could afford a teacher. Boys learned how to read, write and quote literature. They also learned to sing and play one musical instrument and were trained as athletes for military service. They studied not for a job but to become an effective citizen. Girls also learned to read, write and do simple arithmetic so they could manage the household. They almost never received education after childhood. Boys went to school at the age of seven, or went to the barracks, if they lived in Sparta. The three types of teachings were: grammatistes for arithmetic, kitharistes for music and dancing, and Paedotribae for sports. Boys from wealthy families attending the private school lessons were taken care of by a paidagogos, a household slave selected for this task who accompanied the boy during the day. Classes were held in teachers' private houses and included reading, writing, mathematics, singing, and playing the lyre and flute. When the boy became 12 years old the schooling started to include sports such as wrestling, running, and throwing discus and javelin. In Athens some older youths attended academy for the finer disciplines such as culture, sciences, music, and the arts. The schooling ended at age 18, followed by military training in the army usually for one or two years.[59] Only a small number of boys continued their education after childhood, as in the Spartan agoge. A crucial part of a wealthy teenager's education was a mentorship with an elder, which in a few places and times may have included pederastic love. The teenager learned by watching his mentor talking about politics in the agora, helping him perform his public duties, exercising with him in the gymnasium and attending symposia with him. The richest students continued their education by studying with famous teachers. Some of Athens' greatest such schools included the Lyceum (the so-called Peripatetic school founded by Aristotle of Stageira) and the Platonic Academy (founded by Plato of Athens). The education system of the wealthy ancient Greeks is also called Paideia. Economy Main articles: Economy of ancient Greece, Agriculture of ancient Greece, and Slavery in ancient Greece At its economic height, in the 5th and 4th centuries BC, ancient Greece was the most advanced economy in the world. According to some economic historians, it was one of the most advanced pre-industrial economies. This is demonstrated by the average daily wage of the Greek worker which was, in terms of wheat, about 12 kg. This was more than 3 times the average daily wage of an Egyptian worker during the Roman period, about 3.75 kg.[60] Warfare Main articles: Ancient Greek warfare and Army of Macedon Greek hoplite and Persian warrior depicted fighting, on an ancient kylix, 5th century BC At least in the Archaic Period, the fragmentary nature of ancient Greece, with many competing city-states, increased the frequency of conflict but conversely limited the scale of warfare. Unable to maintain professional armies, the city-states relied on their own citizens to fight. This inevitably reduced the potential duration of campaigns, as citizens would need to return to their own professions (especially in the case of, for example, farmers). Campaigns would therefore often be restricted to summer. When battles occurred, they were usually set piece and intended to be decisive. Casualties were slight compared to later battles, rarely amounting to more than 5% of the losing side, but the slain often included the most prominent citizens and generals who led from the front. The scale and scope of warfare in ancient Greece changed dramatically as a result of the Greco-Persian Wars. To fight the enormous armies of the Achaemenid Empire was effectively beyond the capabilities of a single city-state. The eventual triumph of the Greeks was achieved by alliances of city-states (the exact composition changing over time), allowing the pooling of resources and division of labor. Although alliances between city-states occurred before this time, nothing on this scale had been seen before. The rise of Athens and Sparta as pre-eminent powers during this conflict led directly to the Peloponnesian War, which saw further development of the nature of warfare, strategy and tactics. Fought between leagues of cities dominated by Athens and Sparta, the increased manpower and financial resources increased the scale, and allowed the diversification of warfare. Set-piece battles during the Peloponnesian war proved indecisive and instead there was increased reliance on attritionary strategies, naval battle and blockades and sieges. These changes greatly increased the number of casualties and the disruption of Greek society. Athens owned one of the largest war fleets in ancient Greece. It had over 200 triremes each powered by 170 oarsmen who were seated in 3 rows on each side of the ship. The city could afford such a large fleet—it had over 34,000 oars men—because it owned a lot of silver mines that were worked by slaves. Culture The stadium of ancient Olympia, home of the Ancient Olympic Games Philosophy Main article: Ancient Greek philosophy Ancient Greek philosophy focused on the role of reason and inquiry. In many ways, it had an important influence on modern philosophy, as well as modern science. Clear unbroken lines of influence lead from ancient Greek and Hellenistic philosophers, to medieval Muslim philosophers and Islamic scientists, to the European Renaissance and Enlightenment, to the secular sciences of the modern day. Neither reason nor inquiry began with the Greeks. Defining the difference between the Greek quest for knowledge and the quests of the elder civilizations, such as the ancient Egyptians and Babylonians, has long been a topic of study by theorists of civilization. Some of the well-known philosophers of ancient Greece were Plato and Socrates, among others. They have aided in information about ancient Greek society through writings such as The Republic, by Plato. Literature and theatre Main articles: Ancient Greek literature, Ancient Greek comedy, and Theatre of ancient Greece The theatre of Epidauros, 4th century BC The earliest Greek literature was poetry, and was composed for performance rather than private consumption.[61] The earliest Greek poet known is Homer, although he was certainly part of an existing tradition of oral poetry.[62] Homer's poetry, though it was developed around the same time that the Greeks developed writing, would have been composed orally; the first poet to certainly compose their work in writing was Archilochus, a lyric poet from the mid-seventh century BC.[63] tragedy developed, around the end of the archaic period, taking elements from across the pre-existing genres of late archaic poetry.[64] Towards the beginning of the classical period, comedy began to develop—the earliest date associated with the genre is 486 BC, when a competition for comedy became an official event at the City Dionysia in Athens, though the first preserved ancient comedy is Aristophanes' Acharnians, produced in 425.[65] A scene from the Iliad: Hypnos and Thanatos carrying the body of Sarpedon from the battlefield of Troy; detail from an Attic white-ground lekythos, c. 440 BC. Like poetry, Greek prose had its origins in the archaic period, and the earliest writers of Greek philosophy, history, and medical literature all date to the sixth century BC.[66] Prose first emerged as the writing style adopted by the presocratic philosophers Anaximander and Anaximenes—though Thales of Miletus, considered the first Greek philosopher, apparently wrote nothing.[67] Prose as a genre reached maturity in the classical era,[68] and the major Greek prose genres—philosophy, history, rhetoric, and dialogue—developed in this period.[69] The Hellenistic period saw the literary epicentre of the Greek world move from Athens, where it had been in the classical period, to Alexandria. At the same time, other Hellenistic kings such as the Antigonids and the Attalids were patrons of scholarship and literature, turning Pella and Pergamon respectively into cultural centres.[70] It was thanks to this cultural patronage by Hellenistic kings, and especially the Museum at Alexandria, which ensured that so much ancient Greek literature has survived.[71] The Library of Alexandria, part of the Museum, had the previously-unenvisaged aim of collecting together copies of all known authors in Greek. Almost all of the surviving non-technical Hellenistic literature is poetry,[72] and Hellenistic poetry tended to be highly intellectual,[73] blending different genres and traditions, and avoiding linear narratives.[74] The Hellenistic period also saw a shift in the ways literature was consumed—while in the archaic and classical periods literature had typically been experienced in public performance, in the Hellenistic period it was more commonly read privately.[75] At the same time, Hellenistic poets began to write for private, rather than public, consumption.[76] With Octavian's victory at Actium in 31 BC, Rome began to become a major centre of Greek literature, as important Greek authors such as Strabo and Dionysius of Halicarnassus came to Rome.[77] The period of greatest innovation in Greek literature under Rome was the "long second century" from approximately AD 80 to around AD 230.[78] This innovation was especially marked in prose, with the development of the novel and a revival of prominence for display oratory both dating to this period.[79] Music and dance Main article: Music of ancient Greece Music was present almost universally in Greek society, from marriages and funerals to religious ceremonies, theatre, folk music and the ballad-like reciting of epic poetry. There are significant fragments of actual Greek musical notation as well as many literary references to ancient Greek music. Greek art depicts musical instruments and dance. The word music derives from the name of the Muses, the daughters of Zeus who were patron goddesses of the arts. Science and technology Main articles: List of Graeco-Roman geographers, Greek astronomy, Greek mathematics, Ancient Greek medicine, and Ancient Greek technology The Antikythera mechanism was an analog computer from 150–100 BC designed to calculate the positions of astronomical objects. Ancient Greek mathematics contributed many important developments to the field of mathematics, including the basic rules of geometry, the idea of formal mathematical proof, and discoveries in number theory, mathematical analysis, applied mathematics, and approached close to establishing integral calculus. The discoveries of several Greek mathematicians, including Pythagoras, Euclid, and Archimedes, are still used in mathematical teaching today. The Greeks developed astronomy, which they treated as a branch of mathematics, to a highly sophisticated level. The first geometrical, three-dimensional models to explain the apparent motion of the planets were developed in the 4th century BC by Eudoxus of Cnidus and Callippus of Cyzicus. Their younger contemporary Heraclides Ponticus proposed that the Earth rotates around its axis. In the 3rd century BC Aristarchus of Samos was the first to suggest a heliocentric system. Archimedes in his treatise The Sand Reckoner revives Aristarchus' hypothesis that "the fixed stars and the Sun remain unmoved, while the Earth revolves about the Sun on the circumference of a circle". Otherwise, only fragmentary descriptions of Aristarchus' idea survive.[80] Eratosthenes, using the angles of shadows created at widely separated regions, estimated the circumference of the Earth with great accuracy.[81] In the 2nd century BC Hipparchus of Nicea made a number of contributions, including the first measurement of precession and the compilation of the first star catalog in which he proposed the modern system of apparent magnitudes. The Antikythera mechanism, a device for calculating the movements of planets, dates from about 80 BC, and was the first ancestor of the astronomical computer. It was discovered in an ancient shipwreck off the Greek island of Antikythera, between Kythera and Crete. The device became famous for its use of a differential gear, previously believed to have been invented in the 16th century, and the miniaturization and complexity of its parts, comparable to a clock made in the 18th century. The original mechanism is displayed in the Bronze collection of the National Archaeological Museum of Athens, accompanied by a replica. The ancient Greeks also made important discoveries in the medical field. Hippocrates was a physician of the Classical period, and is considered one of the most outstanding figures in the history of medicine. He is referred to as the "father of medicine"[82][83] in recognition of his lasting contributions to the field as the founder of the Hippocratic school of medicine. This intellectual school revolutionized medicine in ancient Greece, establishing it as a discipline distinct from other fields that it had traditionally been associated with (notably theurgy and philosophy), thus making medicine a profession.[84][85] Art and architecture Main articles: Ancient Greek art and Ancient Greek architecture The Temple of Hera at Selinunte, Sicily The art of ancient Greece has exercised an enormous influence on the culture of many countries from ancient times to the present day, particularly in the areas of sculpture and architecture. In the West, the art of the Roman Empire was largely derived from Greek models. In the East, Alexander the Great's conquests initiated several centuries of exchange between Greek, Central Asian and Indian cultures, resulting in Greco-Buddhist art, with ramifications as far as Japan. Following the Renaissance in Europe, the humanist aesthetic and the high technical standards of Greek art inspired generations of European artists. Well into the 19th century, the classical tradition derived from Greece dominated the art of the western world. Religion Main article: Ancient Greek religion Mount Olympus, home of the Twelve Olympians Religion was a central part of ancient Greek life.[86] Though the Greeks of different cities and tribes worshipped similar gods, religious practices were not uniform and the gods were thought of differently in different places.[87] The Greeks were polytheistic, worshipping many gods, but as early as the sixth century BC a pantheon of twelve Olympians began to develop.[87] Greek religion was influenced by the practices of the Greeks' near eastern neighbours at least as early as the archaic period, and by the Hellenistic period this influence was seen in both directions.[88] The most important religious act in ancient Greece was animal sacrifice, most commonly of sheep and goats.[89] Sacrifice was accompanied by public prayer,[90] and prayer and hymns were themselves a major part of ancient Greek religious life.[91] Legacy Further information: Classics The civilization of ancient Greece has been immensely influential on language, politics, educational systems, philosophy, science, and the arts. It became the Leitkultur of the Roman Empire to the point of marginalizing native Italic traditions. As Horace put it, Graecia capta ferum victorem cepit et artis / intulit agresti Latio (Epistulae 2.1.156f.) "Captive Greece took captive her uncivilised conqueror and instilled her arts in rustic Latium." Via the Roman Empire, Greek culture came to be foundational to Western culture in general. The Byzantine Empire inherited Classical Greek culture directly, without Latin intermediation, and the preservation of classical Greek learning in medieval Byzantine tradition further exerted strong influence on the Slavs and later on the Islamic Golden Age and the Western European Renaissance. A modern revival of Classical Greek learning took place in the Neoclassicism movement in 18th- and 19th-century Europe and the Americas. See also Ancient Greece portal Outline of ancient Greece Regions of ancient Greece Outline of ancient Rome Outline of ancient Egypt Outline of classical studies Regions in Greco-Roman antiquity Classical demography History of science in classical antiquity Numerical control From Wikipedia, the free encyclopedia (Redirected from CNC machine) Jump to navigationJump to search "CNC" redirects here. For other uses, see CNC (disambiguation). "Numerics" redirects here. For the field of computer science, see Numerical analysis. A CNC machine that operates on wood Numerical control (also computer numerical control, and commonly called CNC) is the automated control of machining tools (drills, boring tools, lathes) and 3D printers by means of a computer. A CNC machine processes a piece of material (metal, plastic, wood, ceramic, or composite) to meet specifications by following a coded programmed instruction and without a manual operator. A CNC machine is a motorized maneuverable tool and often a motorized maneuverable platform, which are both controlled by a computer, according to specific input instructions. Instructions are delivered to a CNC machine in the form of a sequential program of machine control instructions such as G-code and then executed. The program can be written by a person or, far more often this century, generated by graphical computer-aided design (CAD) software. In the case of 3D Printers, the part to be printed is "sliced", before the instructions (or the program) is generated. 3D printers also use G-Code. CNC is a vast improvement over non-computerized machining that must be manually controlled (e.g., using devices such as hand wheels or levers) or mechanically controlled by pre-fabricated pattern guides (cams). In modern CNC systems, the design of a mechanical part and its manufacturing program is highly automated. The part's mechanical dimensions are defined using CAD software, and then translated into manufacturing directives by computer-aided manufacturing (CAM) software. The resulting directives are transformed (by "post processor" software) into the specific commands necessary for a particular machine to produce the component, and then are loaded into the CNC machine. Since any particular component might require the use of a number of different tools – drills, saws, etc. – modern machines often combine multiple tools into a single "cell". In other installations, a number of different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case, the series of steps needed to produce any part is highly automated and produces a part that closely matches the original CAD. Contents 1 History 2 Description 3 Parts Description 4 Examples of CNC machines 4.1 Other CNC tools 5 Tool / machine crashing 6 Numerical precision and equipment backlash 7 Positioning control system 8 M-codes 9 G-codes 10 Coding 11 See also 12 References 13 Further reading 14 External links History Main article: History of numerical control The first NC machines were built in the 1940s and 1950s, based on existing tools that were modified with motors that moved the tool or part to follow points fed into the system on punched tape. These early servomechanisms were rapidly augmented with analog and digital computers, creating the modern CNC machine tools that have revolutionized machining processes. Description Motion is controlling multiple axes, normally at least two (X and Y),[1] and a tool spindle that moves in the Z (depth). The position of the tool is driven by direct-drive stepper motors or servo motors in order to provide highly accurate movements, or in older designs, motors through a series of step-down gears. Open-loop control works as long as the forces are kept small enough and speeds are not too great. On commercial metalworking machines, closed loop controls are standard and required in order to provide the accuracy, speed, and repeatability demanded. Parts Description As the controller hardware evolved, the mills themselves also evolved. One change has been to enclose the entire mechanism in a large box as a safety measure, often with additional safety interlocks to ensure the operator is far enough from the working piece for safe operation. Most new CNC systems built today are 100% electronically controlled. CNC-like systems are used for any process that can be described as movements and operations. These include laser cutting, welding, friction stir welding, ultrasonic welding, flame and plasma cutting, bending, spinning, hole-punching, pinning, gluing, fabric cutting, sewing, tape and fiber placement, routing, picking and placing, and sawing. Examples of CNC machines CNC Machine Description Image Mill Translates programs consisting of specific numbers and letters to move the spindle (or workpiece) to various locations and depths. Many use G-code. Functions include: face milling, shoulder milling, tapping, drilling and some even offer turning. Today, CNC mills can have 3 to 6 axes. Most CNC mills require placing your workpiece on or in them and must be at least as big as your workpiece, but new 3-axis machines are being produced that you can put on your workpiece, and can be much smaller.[2] Lathe Cuts workpieces while they are rotated. Makes fast, precision cuts, generally using indexable tools and drills. Effective for complicated programs designed to make parts that would be infeasible to make on manual lathes. Similar control specifications to CNC mills and can often read G-code. Generally have two axes (X and Z), but newer models have more axes, allowing for more advanced jobs to be machined. Plasma cutter Involves cutting a material using a plasma torch. Commonly used to cut steel and other metals, but can be used on a variety of materials. In this process, gas (such as compressed air) is blown at high speed out of a nozzle; at the same time, an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma. The plasma is sufficiently hot to melt the material being cut and moves sufficiently fast to blow molten metal away from the cut. File:CNC Plasma Cutting.ogv CNC plasma cutting Electric discharge machining (EDM), also known as spark machining, spark eroding, burning, die sinking, or wire erosion, is a manufacturing process in which a desired shape is obtained using electrical discharges (sparks). Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric fluid and subject to an electric voltage. One of the electrodes is called the tool electrode, or simply the "tool" or "electrode," while the other is called the workpiece electrode, or "workpiece." Master at top, badge die workpiece at bottom, oil jets at left (oil has been drained). Initial flat stamping will be "dapped" to give a curved surface. Multi spindle machine Type of screw machine used in mass production. Considered to be highly efficient by increasing productivity through automation. Can efficiently cut materials into small pieces while simultaneously utilizing a diversified set of tooling. Multi-spindle machines have multiple spindles on a drum that rotates on a horizontal or vertical axis. The drum contains a drill head which consists of a number of spindles that are mounted on ball bearings and driven by gears. There are two types of attachments for these drill heads, fixed or adjustable, depending on whether the centre distance of the drilling spindle needs to be varied.[3] Wire EDM Also known as wire cutting EDM, wire burning EDM, or traveling wire EDM, this process uses spark erosion to machine or remove material from any electrically conductive material, using a traveling wire electrode. The wire electrode usually consists of brass- or zinc-coated brass material. Wire EDM allows for near 90 degree corners and applies very little pressure on the material.[4] Since the wire is eroded in this process, a wire EDM machine feeds fresh wire from a spool while chopping up the used wire and leaving it in a bin for recycling.[5] Sinker EDM Also called cavity type EDM or volume EDM, a sinker EDM consists of an electrode and workpiece submerged in oil or another dielectric fluid. The electrode and workpiece are connected to a suitable power supply, which generates an electrical potential between the two parts. As the electrode approaches the workpiece, dielectric breakdown occurs in the fluid forming a plasma channel and small spark jumps. Production dies and moulds are often made with sinker EDM. Some materials, such as soft ferrite materials and epoxy-rich bonded magnetic materials are not compatible with sinker EDM as they are not electrically conductive.[6] Water jet cutter Also known as a "waterjet", is a tool capable of slicing into metal or other materials (such as granite) by using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance, such as sand. It is often used during fabrication or manufacture of parts for machinery and other devices. Waterjet is the preferred method when the materials being cut are sensitive to the high temperatures generated by other methods. It has found applications in a diverse number of industries from mining to aerospace where it is used for operations such as cutting, shaping, carving, and reaming. Other CNC tools Many other tools have CNC variants, including: Drills EDMs Embroidery machines Lathes Milling machine Canned cycle Wood routers Sheet metal works (Turret punch) Tube, pipe and wire bending machines Hot-wire foam cutters Plasma cutters Water jet cutters Laser cutting Oxy-fuel Surface grinder Cylindrical grinders 3D printing Induction hardening machines Submerged arc welding Glass cutting CNC router Tool / machine crashing In CNC, a "crash" occurs when the machine moves in such a way that is harmful to the machine, tools, or parts being machined, sometimes resulting in bending or breakage of cutting tools, accessory clamps, vises, and fixtures, or causing damage to the machine itself by bending guide rails, breaking drive screws, or causing structural components to crack or deform under strain. A mild crash may not damage the machine or tools, but may damage the part being machined so that it must be scrapped. Many CNC tools have no inherent sense of the absolute position of the table or tools when turned on. They must be manually "homed" or "zeroed" to have any reference to work from, and these limits are just for figuring out the location of the part to work with it, and aren't really any sort of hard motion limit on the mechanism. It is often possible to drive the machine outside the physical bounds of its drive mechanism, resulting in a collision with itself or damage to the drive mechanism. Many machines implement control parameters limiting axis motion past a certain limit in addition to physic