Background: Eratosthenes of Cyrene (; Greek: Eratosthenes o Kurenaios, IPA:
Context: Eratosthenes was described by the Suda Lexicon as a Pentathlos (Pentathlos) which can be translated as "All-Rounder", for he was skilled in a variety of things: He was a true polymath. He was nicknamed Beta because he was great at many things and tried to get his hands on every bit of information but never achieved the highest rank in anything; Strabo accounts Eratosthenes as a mathematician among geographers and a geographer among mathematicians. Eusebius of Caesarea in his Preparatio Evangelica includes a brief chapter of three sentences on celestial distances (Book XV, Chapter 53). He states simply that Eratosthenes found the distance to the Sun to be "stadion muriadas tetrakosias kai oktokismurias" (literally "of stadia myriads 400 and 80,000") and the distance to the Moon to be 780,000 stadia. The expression for the distance to the Sun has been translated either as 4,080,000 stadia (1903 translation by E. H. Gifford), or as 804,000,000 stadia (edition of Edouard des Places, dated 1974-1991). The meaning depends on whether Eusebius meant 400 myriad plus 80,000 or "400 and 80,000" myriad. With a stade of 185 m, 804,000,000 stadia is 149,000,000 km, approximately the distance from the Earth to the Sun. Eratosthenes also calculated the Sun's diameter. According to Macrobious, Eratosthenes made the diameter of the Sun to be about 27 times that of the Earth. The actual figure is approximately 109 times. During his time at the Library of Alexandria, Eratosthenes devised a calendar using his predictions about the ecliptic of the Earth. He calculated that there are 365 days in a year and that every fourth year there would be 366 days. He was also very proud of his solution for Doubling the Cube. His motivation was that he wanted to produce catapults. Eratosthenes constructed a mechanical line drawing device to calculate the cube, called the mesolabio. He dedicated his solution to King Ptolemy, presenting a model in bronze with it a letter and an epigram. Archimedes was Eratosthenes' friend and he, too, worked on the war instrument with mathematics. Archimedes dedicated his book The Method to Eratosthenes, knowing his love for learning and mathematics.
Question: Did he think the sun revolves around the Earth?
Answer: The actual figure is approximately 109 times.

Problem: Background: Patrick Michael Rafter (born 28 December 1972) is an Australian former professional tennis player. He reached the Association of Tennis Professionals (ATP) world No. 1 singles ranking on July 26, 1999. His career highlights include consecutive US Open titles in 1997 and 1998 and consecutive runner-up at Wimbledon in 2000 and 2001.
Context: 1998 was a particularly strong year for Rafter, who won the Canadian Open and Cincinnati in a row (only Andre Agassi, in 1995, Andy Roddick, in 2003, and Rafael Nadal, in 2013 also have won both these tournaments in the same year). Rafter defeated ninth ranked Richard Krajicek in the Toronto final and second ranked Pete Sampras in the Cincinnati final. When asked about the difference between himself and Rafter following their titles, Sampras stated "10 grand slams", and that a player has to come back and win a Grand Slam again in order to be considered great. Following his title at Cincinnati, Rafter won a US Open warm-up tournament in Long Island, New York. Entering the US Open as the defending champion, he reached the final again by defeating Hicham Arazi, Hernan Gumy, David Nainkin, Goran Ivanisevic and Jonas Bjorkman before defeating Sampras in a five-set semifinal. Rafter pointedly took issue with Sampras' refusal to show him respect in defeat: "That is what really upsets me about him", Rafter said, "and the reason why I try to piss him off as much as I can." Rafter then defended his U.S. Open title by defeating fellow Australian Mark Philippoussis in four sets, committing only five unforced errors throughout the match. When asked about Sampras' earlier comments about having to win another Grand Slam in order to be considered great, Rafter replied: "Maybe you can ask him that question, if he thinks that now. For me, I won another Slam, and it hasn't sunk in yet. It's very, very exciting for me, especially to repeat it". Altogether, Rafter won six tournaments in 1998, finishing the year #4 in the world.
Question: Important notes about 1998 US open?
Answer:
he reached the final again by defeating Hicham Arazi, Hernan Gumy, David Nainkin, Goran Ivanisevic and Jonas Bjorkman before defeating Sampras in a five-set semifinal.