He was born in Cyrene (in modern-day Libya), but worked and died in Ptolemaic Alexandria. He is noted for devising a system of latitude and longitude, and for being the first known to have computed the size of the Earth. Eratosthenes was known under the name β, because he supposedly proved himself to be the second in the world in many fields. He was also reputedly known for his haughty character. Eratosthenes studied at Alexandria and for some years in Athens. In 236 BC he was appointed by Ptolemy III Euergetes I as librarian ...

See also:

Eratosthenes, Eratosthenes - Short summary of Eratosthenes' life, Eratosthenes - Measurement of the Earth, Eratosthenes - Other work, Eratosthenes - The mysterious astronomical distances, Eratosthenes - Named after Eratosthenes

Read more here: » Eratosthenes: Encyclopedia II - Eratosthenes - Short summary of Eratosthenes' life

See also:

Eratosthenes, Eratosthenes - Short summary of Eratosthenes' life, Eratosthenes - Measurement of the Earth, Eratosthenes - Other work, Eratosthenes - The mysterious astronomical distances, Eratosthenes - Named after Eratosthenes

Read more here: » Eratosthenes: Encyclopedia II - Eratosthenes - Other work

Eratosthenes knew that on the summer solstice at local noon on the Tropic of Cancer, the Sun would appear at the zenith, directly overhead — though Syene was in fact slightly north of the tropic. He also knew, from measurement, that in his hometown of Alexandria, the angle of elevation of the Sun would be 7° south of the zenith at the same time. Assuming that Alexandria was due north of Syene- Alexandria is in fact on a more westerly longitude- he concluded that the distance from Alexandria to Syene must be 7/360 of the total circumference of the Earth. The distance between the cities was ...

See also:

Eratosthenes, Eratosthenes - Short summary of Eratosthenes' life, Eratosthenes - Measurement of the Earth, Eratosthenes - Other work, Eratosthenes - The mysterious astronomical distances, Eratosthenes - Named after Eratosthenes

Read more here: » Eratosthenes: Encyclopedia II - Eratosthenes - Measurement of the Earth

Zeno (after Zeno of Elea) is an imperative procedural programming language designed to be easy to learn and user friendly. Zeno is generic in the sense that it contains most of the essential elements used in other languages to develop real applications. The Zeno Interpreter was designed for use in Windows 95 and later Microsoft operating systems. The interpreter comes with built-in debugging tools, a source code text editor, and an on-line language reference. Zeno was created ...

Including:

• Zeno programming language - Example: Sieve of Eratosthenes

Read more here: » Zeno programming language: Encyclopedia - Zeno programming language

Life in Egypt The Culture of Egypt has five thousand years of recorded history. Ancient Egypt was among the earliest civilizations. For millennia, Egypt maintained a strikingly complex and stable culture that had a profound influence on later cultures of Europe, the Middle East and Africa. After the Pharaonic era, Egypt itself came under the influence of Hellenism, for a time Christianity, and later, Arab and Islamic culture. Today, many aspects of Egypt's ancient culture exist in interaction with newer elements, includin ...

Including:

• Culture of Egypt - Language
• Culture of Egypt - Literature
• Culture of Egypt - Religion
• Culture of Egypt - Visual art
• Culture of Egypt - Egyptian art in antiquity
• Culture of Egypt - Egyptian art in modern times
• Culture of Egypt - Science
• Culture of Egypt - Ptolemy
• Culture of Egypt - Eratosthenes
• Culture of Egypt - Library of Alexandria
• Culture of Egypt - Ahmed Hasan Zewail
• Culture of Egypt - Egyptology
• Culture of Egypt - Music and dance
• Culture of Egypt - Cuisine

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An armillary sphere (also known as a spherical astrolabe, armilla, or armil) is a model of the celestial sphere, invented by Eratosthenes in 255 BC. Its name comes from the Latin armilla (circle, bracelet), since it has a skeleton made of graduated metal circles linking the poles and representing the equator, the ecliptic, meridians and parallels. Usually a ball representing the Earth or, later, the Sun is placed in its center. It is used t ...

Including:

• Armillary sphere - Chinese history

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Centuries: 4th century BC - 3rd century BC - 2nd century BC Decades: 270s BC 260s BC 250s BC 240s BC 230s BC - 220s BC - 210s BC 200s BC 190s BC 180s BC 170s BC Years: 225 BC 224 BC 223 BC 222 BC 221 BC - 220 BC - 219 BC 218 BC 217 BC 216 BC 215 BC Events October/November - Pharaoh Ptolemy IV of Egypt marries his sister, who rises to the throne as Arsinoe III of Egypt. Eratosthenes measures the size of the Earth. On the island Crete, the Gortynians occupy Matala. ...

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Centuries: 4th century BC - 3rd century BC - 2nd century BC Decades: 300s BC 290s BC 280s BC 270s BC 260s BC - 250s BC - 240s BC 230s BC 220s BC 210s BC 200s BC Years: 255 BC 254 BC 253 BC 252 BC 251 BC - 250 BC - 249 BC 248 BC 247 BC 246 BC 245 BC Events Greek astronomer Eratosthenes calculates the circumference of Earth. Soghdiana is conquered by the Parthians. Bactria gains its independence from the Seleucid Empire. (approximate date) Antiochus II The ...

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Sieve may mean: a colander, used in cooking goaltender, as taunted among crowds at American college ice hockey games In mathmatics, sieve theory, technique for counting or filtering sets of numbers sieve of Eratosthenes general number field sieve sieve (category theory), a way of writing down how objects ...

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Centuries: 4th century BC - 3rd century BC - 2nd century BC Decades: 270s BC 260s BC 250s BC 240s BC 230s BC - 220s BC - 210s BC 200s BC 190s BC 180s BC 170s BC Years: 230 BC 229 BC 228 BC 227 BC 226 BC - 225 BC - 224 BC 223 BC 222 BC 221 BC 220 BC Events Seleucus III Ceraunus succeeds his father Seleucus II Callinicus as king of the Seleucid dynasty. Battle of Faesulae, Romans are defeated by the Gauls of Northern Italy. Eratosthenes of Cyrene calculates the cir ...

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Aswan (Arabic: محافظة أسوان Aswān ) (24°05′N 32°56′E, population 200,000) is a city in the south of Egypt, the capital of the governorate of the same name. It stands on the east bank of the Nile at the first cataract and is a busy market and tourist center. Aswan is one of the driest inhabited places in the world; as of early 2001, the last rain here was 6 years ago. In Nubian settlements they generally do not both ...

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Centuries: 4th century BC - 3rd century BC - 2nd century BC Decades: 280s BC 270s BC 260s BC 250s BC 240s BC - 230s BC - 220s BC 210s BC 200s BC 190s BC 180s BC Years: 235 BC 234 BC 233 BC 232 BC 231 BC - 230 BC - 229 BC 228 BC 227 BC 226 BC 225 BC Events Sieve of Eratosthenes developed. The Roman Lucius Coruncanius is assaulted and killed while on a diplomatic mission to Queen Teuta, an event leading to the First Illyrian War. Temple of Horus built by Ptolemy II ...

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Centuries: 3rd century BC - 2nd century BC - 1st century BC Decades: 240s BC 230s BC 220s BC 210s BC 200s BC - 190s BC - 180s BC 170s BC 160s BC 150s BC 140s BC Years: 199 BC 198 BC 197 BC 196 BC 195 BC - 194 BC - 193 BC 192 BC 191 BC 190 BC 189 BC Events Battle of Mutina: Romans are victorious over the Gauls. In the Battle of Gythium, Philopoemen of the Achaean League, assisted by the Romans, defeats the Spartans under Nabis. Liternum and Puteoli become Roman co ...

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(2nd millennium BC - 1st millennium BC - 1st millennium) 3rd century BC - Events. The first two Punic Wars between Carthage and Rome over dominance in western Mediterranean Rome conquers Spain Gaulish migration to Macedon, Thrace and Galatia 281 BC Antiochus I Soter, on the assassination of his father Seleucus becomes emperor of the Seleucid empire. 273 BC to 252 BC Ashoka the Great ruled the Mauryan Empire 261 BC Antiochus II Theos, 2nd son, at the death o ...

Including:

• 3rd century BC - Events
• 3rd century BC - Significant persons
• 3rd century BC - Inventions discoveries introductions
• 3rd century BC - Decades and years

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Centuries: 3rd century BC - 2nd century BC - 1st century BC Decades: 250s BC 240s BC 230s BC 220s BC 210s BC - 200s BC - 190s BC 180s BC 170s BC 160s BC 150s BC Years: 205 BC 204 BC 203 BC 202 BC 201 BC - 200 BC - 199 BC 198 BC 197 BC 196 BC 195 BC Events Rome declares war upon Philip V, king of Macedon. Second Macedonian War begins. Roman forces defeat the Gauls of Cisalpine Gaul at Cremona Hannibal becomes Chief Magistrate of Carthage. The Bacchanalia ...

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Aristarchus (310 BC - circa 230 BC) was a Greek astronomer and mathematician, born in Samos, Greece. He is the first recorded person to propose a heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe (hence he is sometimes known as the "Greek Copernicus"). His astronomical ideas were not well-received and were subordinated to those of Aristotle and Ptolemy, until they were successfully revived an ...

Including:

• Aristarchus - Heliocentrism
• Aristarchus - Size of the Moon
• Aristarchus - Distance to the Sun

Read more here: » Aristarchus: Encyclopedia - Aristarchus

Apollonius of Rhodes (Apollonius Rhodius), librarian at Alexandria, was a Greek grammarian and epic poet, who flourished under the Ptolemies Philopator and Epiphanes (222-181 BC). He was the author of Argonautica, a literary epic retelling of ancient material concerning Jason and the Argonauts' quest for the Golden Fleece in the mythic land of Colchis. Born at Alexandria, perhaps about 270 BC, Apollonius was a pupil of Callimachus, with whom he subsequently quarrelled. Callimachus' "Hymn to Apollo", closes with some lines that allude to Apollonius, and dates about 248 or 247 BC, wh ...

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(2nd millennium BC – 1st millennium BC – 1st millennium – other millennia) 1st millennium BC - Events. The Iron Age spread to Western Europe Egypt declined as a major power The Tanakh was written Buddhism was founded by Siddharta Gautama, commonly known as the Buddha (6th century BC) Jainism was founded by Mahavira (6th century BC) Cyrus the Great conquered Babylon and created the Persian Empire (6th century BC) Sparta and Athens fought the P ...

Including:

• 1st millennium BC - Events
• 1st millennium BC - Significant persons
• 1st millennium BC - Inventions Discoveries Introductions
• 1st millennium BC - Cultural landmarks
• 1st millennium BC - Centuries and Decades

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Action! was a programming language, editor and in-memory 6502 compiler created by Clinton Parker working for Optimized Systems Software and running on the Atari 8-bit family of microcomputers. Its syntax was similar to that of ALGOL 68, and it was well-known for its speed. A library was available as a separate product called the Action! Toolkit. It was released in 1983 and officially sold as a cartridge and later "cracked" to disk. "ATR" format files containing a version which may be run on modern systems under emulation are av ...

Including:

• Action programming language - Data Types
• Action programming language - Reserved keywords
• Action programming language - Programming
• Action programming language - Example code

Read more here: » Action programming language: Encyclopedia - Action programming language

First, write three things : The highest factor to check for. It is the square root of the last number you care about, rounded down. A list of primes you've found. It starts empty. A list of numbers that remain to be checked. It starts out filled with all integers from two up to the last number you care about. Then, repeat the following until you've checked all you need : Remove the first remaining number to the primes list. Delete anything that's a multiple of the number you just removed. Finally, remove all remainin ...

See also:

Sieve of Eratosthenes, Sieve of Eratosthenes - Algorithm, Sieve of Eratosthenes - Algorithm implemented in Smalltalk, Sieve of Eratosthenes - Reference

Read more here: » Sieve of Eratosthenes: Encyclopedia II - Sieve of Eratosthenes - Algorithm