A Profile of Greek Mathematician Eratosthenes

A Profile of Greek Mathematician Eratosthenes Eratosthenes (c.276-194 B.C.), a mathematician, is known for his mathematical calculations and geometry. Eratosthenes was called Beta (the second letter of the Greek alphabet) because he was never first, but he is more famous than his Alpha teachers because his discoveries are still used today. Chief among these are the calculation of the circumference of the earth (note: the Greeks did know the earth was spherical) and the development of a mathematical sieve named after him. He made a calendar with leap years, a 675-star catalog, and maps. He recognized the Niles source was a lake, and that rains in the lake region caused the Nile to flood. Eratosthenes - Life and Career Facts Eratosthenes was the third librarian at the famous Library of Alexandria. He studied under the Stoic philosopher Zeno, Ariston, Lysanias, and the poet-philosopher Callimachus. Eratosthenes wrote a Geographica based on his calculations of the circumference of the earth. Eratosthenes is reported to have starved himself to death at Alexandria in 194 B.C. Writing of Eratosthenes Much of what Eratosthenes wrote is now lost, including a geometrical treatise, On Means, and one on the mathematics behind Platos philosophy, Platonicus. He also wrote the fundamentals of astronomy in a poem called Hermes. His most famous calculation, in the now lost treatise On the Measurement of the Earth, explains how he compared the shadow of the sun at Summer Solstice noon in two places, Alexandria and Syene. Eratosthenes Calculates the Circumference of the Earth By comparing the shadow of the sun at Summer Solstice noon at Alexandria and Syene, and knowing the distance between the two, Eratosthenes calculated the circumference of the earth.The sun shone directly into a well at Syene at noon. At Alexandria, the angle of inclination of the sun was about 7 degrees. With this information, and knowing that Syene was 787 km due south of Alexandrian  Eratosthenes calculated the circumference of the earth to be 250,000 stadia (about 24,662 miles).

Bad Writing Assignment(Intentional) Essays

Bad Writing Assignment(Intentional) Essays Bad Writing Assignment(Intentional) Essay Bad Writing Assignment(Intentional) Essay An Indiana supermarket has started the next trend in do-it-yourself grocery shopping – allowing customers not only to check themselves out. But also to let themselves in. On Thanksgiving night in Goshen, the locking mechanism on its front door was not checked by someone at the store. That resulted in a dozen customers entering the store and trying to shop despite a complete absence of store employees. Normally open 24 hours a day, the doors of the store were shut at 6 p. m. on Thanksgiving evening. Store manager, Sheila Donley, said. It seems the locks on the front doors must have failed, and instead of actually sleeping off their turkey dinners or getting an early head start on Black Friday, some loyal Kroger customers decided to pick up a few extra items. † Since the locking mechanism had failed the doors were not easy to slide open, Donley said, that may have deterred others who came earlier in the evening. About 10:15 p. m. , though, one customer decided the store lo oked open. And pulled the sliding front doors apart just as several other shoppers arrived. When I arrived at the store I could see a little space between the doors, because all the lights were on inside, I just assumed the automatic opener had stopped working but I could still shop,† said, Goshen resident, Bill Terrell. â€Å"I looked for an employee to alert, I found no one and decided just to buy what I needed. † Several other late-night shoppers gathered items and went to the self-checkout lanes, seemingly oblivious to the utter lack of employees. They realized something was wrong after seeing all registers closed, Terrell said. At some point, police were called. Puzzled by the situation, a call came from a customer or a neighbor concerned about the sudden activity. Police spokeswoman, Christy Samms said, â€Å"There were definitely no signs of forced entry at all and apparently no one stole any items from the business. † She said it appeared the door’s locking mechanism had not completely engaged. At this point in time, Donley, called in by police, secured all of the entrances and sent the confused customers on their way – each with a voucher for $20 worth of Kroger-brand items on a upcoming future visit. The customers, taking it in stride, left without incident, Terrell said. â€Å"As foolish as we probably were to be out on Thanksgiving night, I guess it’s hard to complain about free food on our next trip,† he said. 1a. Original: Donley, called in by police†¦. 1b. Revision: At this point in time, Donley, called in by police†¦ (Concise Wording) 2a. Original: â€Å"There were no signs of forced entry and apparently†¦. 2b. Revision: â€Å"There were no signs of forced entry at all and apparently†¦ (Unnecessary Filler) 3a. Original: †¦and apparently no one stole from the business. † 3b. Revision: †¦and apparently no one stole any items from the business. † (Unnecessary Filler) 4a. Original: â€Å"It seems the locks on the front doors failed†¦ 4b. Revision: â€Å"It seems the locks on the front doors must have stopped working†¦ (Concise wording) 5a. Original: â€Å"I could see a little space between the doors†¦ 5b. Revision: â€Å"When I arrived at the store I could see a little space between the doors†¦ (Long Lead Ins) 6a. The doors were not easy to slide open,†¦. 6b. Since the locking mechanism had failed the doors were not easy to slide open,.. (Long Lead Ins) 7a. †¦and instead of sleeping off†¦. 7b. †¦and instead of actually sleeping off†¦ (Needless Adverb) 8a. †¦brand items on a future visit. 8b. †¦brand items on a upcoming future visit. (Redundant Words) 9a. â€Å"There were no signs of forced entry†¦ 9b. â€Å"There were definitely no signs of forced entry†¦ (Needless Adverb) 10a. †¦or getting an early start on Black Friday†¦ 10b. †¦or getting an early head start on Black Friday†¦ (Redundant Words)