The genuine sieve of eratosthenes harvey mudd college. He used that information plus some geometry to figure out the angle between the sun and straight up. Eratosthenes was a friend of archimedes, who also lived and worked in alexandria. Roller provides a rich background, including a history of the text and its reception, a biography of eratosthenes, and a comprehensive. Eratosthenes of cyrene 276 194 bc was a 3rd century bc greek mathematician, geographer and astronomer. Man liest, eratosthenes solle einen freund gebeten haben, diese entfernung zu bestimmen. Sieve of eratosthenes, systematic procedure for finding prime numbers that begins by arranging all of the natural numbers 1, 2, 3, in numerical order. You can find prime numbers by using the sieve of eratosthenes. Im sure you guys know which question im talking about. Eratosthenes was the first person to use the word geography and other geographical terms that are still in use today, and his efforts to calculate the circumference of the earth and the distance from the earth to the sun paved the way for our. According to athenian law, if a husband caught his wifes lover in the act of adultery, he could either kill him or demand financial compensation.
Eratosthenes calculated the circumference of the earth to be 250,000 stades for the text of this. Eratosthenes of cyrene biography, birth date, birth place and. This result is widely known, but we can derive this result for ourselves by noting that we perform np crossings o. The sieve of eratosthenes implemented in the usual way requires. Chr 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 19 20. Sieve of eratosthenes the sieve of eratosthenes is a very simple and popular technique for.
The algorithm takes its name from the process of sievingin a simple way we remove multiples of consecutive numbers. Eratosthenes measurement, ptolemys geography, stadion. Eratosthenes was a prominent greek mathematician, astronomer and geographer who lived between 276 bc and 194 bc. This month in physics history aps physics aps home. Eratosthenes, the methods of chartres and singleton precursors to your favored methods, mairsons multiplicative sieve and improvement by dutton et. He was also the first know person to calculate the circumference of the earth. Read and learn for free about the following article. In show math, students will learn how in 200 bc, the greek mathematician eratosthenes calculated the circumference of the earth using simple geometry and a few measurements. Eratosthenes went to the then seat of learning in athens for his education and was taught by the best teachers of the day. On the other hand, pliny in his naturalis historia claims that eratosthenes made 40. Eratosthenes of cyrene how did he measure the circumference. Eratosthenes was an ancient greek scientist born in the town of cyrene in about 276 bc. So, the sieve of eratosthenes, aka that thing where you cross off a bunch of numbers to find the prime numbers.
The sieve of eratosthenes is a simple way to find all the prime numbers up to some number n. Eratosthenes compared the midsummer noontime shadow at syene now aswan, southern egypt to that at alexandria mediterranean coast, northern egypt figure 1. After striking out the number 1, simply strike out every second number following the number 2, every third number following the number 3, and continue in this manner to strike out every nth number following the number n. Map of a facsimile of the world map by eratosthenes around 220 bc. Eratosthenes is the ancient greek mathematician and geographer attributed with devising the first system of latitude and longitude.
Eratosthenes simple english wikipedia, the free encyclopedia. For,each,number,bigger,than,7,if,the,number,is,a,multiple,of,7,mark,it. Sieveoferatosthenes, aaron,weeden,6shodoreducationfoundation,inc. Ptolemys longitudes and eratosthenes measurement of the earths. Eratostenes nasceu em cirene, na grecia, por volta do ano 276 a. He noted that the suns rays fell vertically at noon in syene now aswan, egypt, at the summer solstice. Sieve of eratosthenes worksheet the prime factorisation. Before that time there had been interest in the surface of the earth, its formative processes, and its shape and structure, but it was eratosthenes who brought these divergent streams of thought and experience together to create a new scholarly discipline. The discipline of geography began with eratosthenes of kyrene and the publication of hisgeographikain the last third of the third century bc. I read up on the sieve of eratosthenes while solving a question on project euler. Estudio en alejandria y durante algun tiempo en atenas. Cyrene, then a greek city, is now the town of shahhat in libya. Eratosthenes used the lengths of shadows to figure out how high in the sky the sun was in a certain place on a certain day.
Eratosthenes was educated in philosophy and mathematics in athens. Scientist grandfather of science he determined the circumference of the earth by observing the angles of sunlight as in two towns. This is a facsimile of the map he produced based on his calculations. He was born in what is now libya, to parents who were probably chaldean. At some period during his early manhood he went to athens for the ancient. The works eratosthenes wrote are known to us only indirectly. But they had no idea how big the planet is until about 240 b. Eratosthenes calculation of earths circumference windows. In all probability, the final work of eratosthenes is his biography or. The two earths of eratosthenes sound ideas university of puget. The latter had become the more common type of settlement at athens. Eratosthenes was a greek astronomer in ancient times. He knew of another place where there was no shadow at all on the same day. Eratostenes quien fue, biografia, aportaciones, inventos.
Eratosthenes was born in cyrene presentday libya and became the librarian at alexandria during the second half of the third century b. Eratosthenes biography, facts and pictures famous scientists. The image above is from a painting by bernardo strozzi in the year 1635, nineteen centuries. Eratosthenes biography childhood, life achievements. Life after death experience nde with steve gardipee, vietnam war story one of the best ndes duration. However when i try the same implementation for 2 million its giving me a segmentation fault.
Ignore 1, because it is neither prime or composite. On the summer solstice, the sun shone straight down the well to the very bottom. It forms the western terminus of the montes apenninus mountain range. We will perform the following steps so that all the nonprime numbers will be crossed out, and whats left will be the primes. Lysias 1 on the murder of eratosthenes york university. Sign up for the nature briefing newsletter what matters in science, free to your inbox daily. The multiples of a given prime are generated as a sequence of numbers starting from that prime, with constant difference between them that is. Es ist nach dem griechischen mathematiker eratosthenes benannt. Sieve of eratosthenes simple english wikipedia, the free. Eratosthenes crater is a relatively deep lunar impact crater that lies on the boundary between the mare imbrium and sinus aestuum mare regions. This article is brought to you for free and open access by the faculty. The greek scholar of natural history eratosthenes of cyrene ca. Eratosthenes measured earths circumference mathematically using two surface points to make the calculation. Archimedes was the greatest mathematician and inventor of the age, so perhaps the beta nickname was not unjust.
Eratosthenes is famous for many things, including a mapping method that used latitudes and longitudes, and his accurate computation of the circumference of earth. In mathematics, the sieve of eratosthenes is an ancient algorithm for finding all prime numbers up to any given limit it does so by iteratively marking as composite i. In this activity, students will follow in eratosthenes. Eratosthenes measured the length of the towers shadow on the summer solstice. Before that time there had been interest in the surface of the earth, its formative processes, and its shape and structure, but it was eratosthenes who brought these divergent streams of thought and experience together to. Sieve of eratosthenes a prime number has only two factors. If you had believed that the earth was flat, do you think you would have been. Eratosthenes of cyrene biography, birth date, birth place. Eratostenes e tido tambem como o fundador da disciplina geografia.
Eratosthenes and the circumference of the earth nature. If youre not familiar with it, the process is this. Euphiletos stands accused of the murder of eratosthenes, his wifes lover. Sieve of eratosthenes worksheet the prime factorisation of me. Eratosthenes of cyrene is credited as scholar of natural history, geographer, astronomer and poet, calculate the circumference of the earth. He was head of the library of alexandria from 240 bc until his death. His estimate of the circumference was remarkably accurateto within 2% of the real value. Eratosthenes was born in the year 276 bc to aglaos and his wife. My code manages to show all the primes under 1 million correctly. Write all the numbers from 2 up to n onto a piece of paper, in order. It is named after ancient greek astronomer eratosthenes of cyrene, who estimated the circumference of the earth, and the distance from the earth to the sun. In alexandria, also in egypt, at the same date and time, sunlight fell at an angle of about 7. His estimate of the circumference was remarkably accurateto within 2%.
236 467 568 1233 702 161 1267 917 1387 833 643 964 636 17 571 592 1568 480 1382 1269 1237 1273 934 474 1027 487 1601 614 372 963 450 1270 734 1442 1427 699 45 971 709 577 17 1174 491 1199 16 1177