Crossword clues for eratosthenes
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Eratosthenes of Cyrene (; , ; – ) was a Greek mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. He invented the discipline of geography, including the terminology used today.
He is best known for being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, a standard unit of measure during that time period. His calculation was remarkably accurate. He was also the first to calculate the tilt of the Earth's axis (again with remarkable accuracy). Additionally, he may have accurately calculated the distance from the Earth to the Sun and invented the leap day. He created the first map of the world, incorporating parallels and meridians based on the available geographic knowledge of his era.
Eratosthenes was the founder of scientific chronology; he endeavored to revise the dates of the chief literary and political events from the conquest of Troy. In number theory, he introduced the sieve of Eratosthenes, an efficient method of identifying prime numbers.
He was a figure of influence in many fields. According to an entry in the Suda (a 10th-century reference), his critics scorned him, calling him Beta (the second letter of the Greek alphabet) because he always came in second in all his endeavors. Nonetheless, his devotees nicknamed him Pentathlos after the Olympians who were well rounded competitors for he had proven himself to be knowledgeable in every area of learning. Eratosthenes yearned to understand the complexities of the entire world.
Eratosthenes is a relatively deep lunar impact crater that lies on the boundary between the Mare Imbrium and Sinus Aestuum mare regions. It forms the western terminus of the Montes Apenninus mountain range. The crater has a well-defined circular rim, terraced inner wall, central mountain peaks, an irregular floor, and an outer rampart of ejecta. It lacks a ray system of its own, but is overlain by rays from the prominent crater Copernicus to the south-west.
It is named after ancient Greek astronomer Eratosthenes of Cyrene, who estimated the diameter of the earth, and the distance to the moon and sun.
The Eratosthenian period in the lunar geological timescale is named after this crater, though it does not define the start of this time period. The crater is believed to have been formed about 3.2 billion years ago.
At low Sun-angles, this crater is prominent due to the shadow cast by the rim. When the Sun is directly overhead, however, Eratosthenes visually blends into the surroundings, and it becomes more difficult for an observer to locate it. The rays from Copernicus lie across this area, and their higher albedo serves as a form of camouflage.
In 1851 Shropshire Astronomer Henry Blunt constructed a model of the moon's surface showing Eratosthenes. The model is based on observations made by Blunt with a reflecting telescope from his home in Shrewsbury and was displayed in the same year at the Great Exhibition, London.
In 1910–1920th, William H. Pickering noted dark patches in the crater that varied in a regular manner over each lunar day. He put forward the speculative idea that these patches appeared to migrate across the surface, suggestive of herds of small life forms. The idea received a degree of attention primarily due to Pickering's reputation.
Eratosthenes of Athens was one of the Thirty Tyrants elected to rule the city of Athens after the Peloponnesian War (431–404 BC).
Having lost the war to the Spartans, the citizens of Athens elected thirty men as oligarchs. The Thirty instituted oppressive and highly exclusionary laws and instituted a political purge against Athenians who had been Spartan informers and collaborators during the long war. Eventually open hostilities between the Thirty and disenfranchised or disaffected Athenian citizens led to a coup d'etat in 403 BC that deposed them.
He is the subject of a legal oration by the orator Lysias, entitled Against Eratosthenes (Speech 12). According to some critics he is also the subject of another of Lysias' speech, On the Murder of Eratosthenes (Speech 1). However, the age of the Tyrant does not fit with the context of the latter speech: he must have been aged at least 18 in 411 BC to have served as a trierarch, and at least 30 by the time of the Thirty Tyrants period in 403/2 BC. But On the Murder of Eratosthenes suggests that the Eratosthenes referred to in that speech was younger than 30 at the time of his death – he is described as 'neaniskos', a word which Lysias elsewhere uses to refer to younger men.
Eratosthenes may refer to:
- Eratosthenes, a Greek mathematician, geographer, poet, astronomer, and music theorist.
- Eratosthenes (statesman)
- Eratosthenes Seamount
- Eratosthenes of Croton
- Eratosthenes (crater), a lunar impact crater.
Usage examples of "eratosthenes".
I envy those who will succeed in circling the two hundred and fifty thousand Greek stadia so ably calculated by Eratosthenes, the round of which would bring us back to our point of departure.
The base held an inscription in Greek, which Eratosthenes verified by reading slowly to himself.
No chart will ever say to you, Eratosthenes, you will die at sunup tomorrow.
At most your chart will say, Eratosthenes, you will be presented with the possibility of dying on such and such a day, and perhaps at such and such an hour.
One thing was certain: the fates of Eratosthenes and Hor-ent-yotf were inextricably interwoven, like designs into a funerary shroud.
An hour later Khor, Eratosthenes, and Ne-tiy had wound the last of the linen strips around the hydraulic tubes, refilled the depleted oil surge tank, and secured the amphora of natron in the storage locker.
I have read widely in your Library, Eratosthenes, and I can cite your own laws and applicable cases.
She glanced once at Eratosthenes, then followed the hawk-priest away from the group.
He had followed closely the negotiations between Eratosthenes and Hor-ent-yotf.
Even Eratosthenes, who had suspected something like this would happen, was stunned.
He held the priest with one hand and tossed something to Eratosthenes with the other.
Ne-tiy watched with uneasy curiosity as Eratosthenes opened the chest and carefully removed the little statue of Atlas, his back and arms still bent to receive his as yet invisible burden.
Khor, Eratosthenes, and Ne-tiy had wound the last of the linen strips around the hydraulic tubes, refilled the depleted oil surge tank, and secured the amphora of natron in the storage locker.
For I loved the Moon, and now I knew that the creeping moss of Aristarchus and Eratosthenes was not the only life she had brought forth in her youth.
The last sentence may be interpreted by the notice of Suidas, who informs us that Apollonius was a contemporary of Eratosthenes, Euphorion and Timarchus, in the time of Ptolemy Euergetes, and that he succeeded Eratosthenes in the headship of the Alexandrian Library.