61. The Copernican Model: A Sun-Centered Solar System natural science. This sequence is commonly called the Copernican Revolution.Been There, Done That aristarchus of samos. There are http://www.pas.rochester.edu/~blackman/ast104/copernican9.html

The Copernican Model: A Sun-Centered Solar System The Earth-centered Universe of Aristotle and Ptolemy held sway on Western thinking for almost 2000 years. Then, in the 16th century a "new" (but remember Aristarchus) idea was proposed by the Polish astronomer Nicolai Copernicus The Heliocentric System In a book called On the Revolutions of the Heavenly Bodies (that was published as Copernicus lay on his deathbed), Copernicus proposed that the Sun, not the Earth, was the center of the Solar System. Such a model is called a heliocentric system . The ordering of the planets known to Copernicus in this new system is illustrated in the following figure, which we recognize as the modern ordering of those planets. The Copernican Universe In this new ordering the Earth is just another planet (the third outward from the Sun), and the Moon is in orbit around the Earth, not the Sun. The stars are distant objects that do not revolve around the Sun. Instead, the Earth is assumed to rotate once in 24 hours, causing the stars to appear to revolve around the Earth in the opposite direction. Retrograde Motion and Varying Brightness of the Planets The Copernican system by banishing the idea that the Earth was the center of the Solar System, immediately led to a simple explanation of both the varying brightness of the planets and retrograde

62. Slide #112 Monograph aristarchus of samos (died 230 BC), has been called the Copernicus of Antiquity because of his early espousal of a heliocentric, rather than geocentric, view http://www.henry-davis.com/MAPS/AncientWebPages/112mono.html

Slide #112 TITLE: World according to Eratosthenes DATE: 194 B.C. AUTHOR: Eratosthenes of Cyrene DESCRIPTION: Slide #111 ). Geographic information that was gathered by Alexander the Great and his successors was the primary source used by Eratosthenes, a scholar with vision large enough to put this information into a logical framework. There can be no doubt that before the time of Eratosthenes the ideas of the learned world on the subject of geography had assumed a more regular and systematic form. And it is certain also that these had been embodied in the form of maps, which, however imperfect, were unquestionably very superior to anything that had preceded them. The first use of world maps by the Greeks had been introduced at a very early period by Anaximander (ca. 610-546 B.C. Slide #107 ), and maps of the world were not uncommon in the time of Herodotus (ca. 489-425 B.C. Slide #109 Slide #109 and Slide #108 Eratosthenes, head of the Library at Alexandria from 240 B.C. until his death, was known as beta to his contemporaries because they considered him second in all his varied academic pursuits. More critical of these accomplishments was Strabo (63 B.C.?- A.D.24, Slide #115 ) to whom we are indebted for much of our knowledge of geography in antiquity, including the work of Eratosthenes whose relevant works, neither of which survived, were

63. Aristarchus Aristarchus aristarchus of samos (c. 310230 BC), Greek astronomer, firstto maintain that the Earth rotates and revolves around the Sun. http://zebu.uoregon.edu/glossary/aristarchus.html

Aristarchus Aristarchus of Samos (c. 310-230 BC), Greek astronomer, first to maintain that the Earth rotates and revolves around the Sun. On this ground, Cleanthes the Stoic declared that he ought to be indicted for impiety. Aristarchus' advanced ideas on the movement of the Earth are known from Archimedes and Plutarch; his only extant work is a short treatise, "On the Sizes and Distances of the Sun and Moon." The values he obtained, by using geometry, are inaccurate, because of faulty observations. Aristarchus found a more precise value for the length of the solar year. A lunar crater is named for him; a peak in its centre is the brightest formation on the Moon.

64. Aristarchus aristarchus of samos believed that the earth was round, not flat, andthat the sun, not the earth, was the center of planetary motion. http://www.math.utah.edu/history/aristarchus.html

Aristarchus (fl 280 - 260 B.C.) Aristarchus of Samos believed that the earth was round, not flat, and that the sun, not the earth, was the center of planetary motion.

65. THOLOS AT EPIDAVROS - The Heliocentric System Inside The Tholos Forty years before the birth of aristarchus of samos who was the first to observethat the earth rotated round the sun, the heliocentric system had already http://users.otenet.gr/~altagr/english/sel3.htm

The Heliocentric System Inside the Tholos (Click on the images to see them larger) Inside the Tholos, the Sun dominated the floor, the mural and the ceiling, with different expressions of its diverse activity. a. Mural The first thing a visitor would see, were he allowed to enter the Monument, would undoubtedly be the superb mural painted by Pausias. The Lyre , the bow and the arrows are the three predominant symbols of the Helios (Sun)/Apollo and through them an allegory is made of the union of the Sun's physical body with Apollo's spiritual entity. It is in the hands of Eros, not Apollo, that the seven-string Lyre harmonized through "Love" the seven orbits of the planets which are depicted on the floor of the Tholos (and which will be interpreted later on). The bow and arrows depicted on the wall-painting are the shooting (bow) of the rays (arrows) of the Sun during its daily course across the sky. It is the bow that is outlined on the celestial vault every day. After its departure, darkness covers the earth. "and thou art the begetter of dawn from the right-hand-side

66. Sir Thomas Little Heath Archimedes Sir Thomas Little Heath Published 1897. aristarchus of samos TheAncient Copernicus Sir Thomas Little Heath Published 1913 by Clarendon Press. http://dspace.dial.pipex.com/ashtead.parish/people/tlh.htm

Sir Thomas Little Heath Sir Thomas Little Heath , 5 Oct 1861, Barnetby le Wold, Lincoln, England - 16 March 1940, Ashtead Sir Thomas Little Heath , short article from School of Mathematics and Statistics University of St Andrews, Scotland Civil servant and authority on ancient mathematics; educated at Clifton and Trinity College, Cambridge; first classes, classical tripos, 1881-3; twelfth wrangler, 1882; passed first into Civil Service, 1884; entered Treasury; assistant secretary, 1907; joint permanent secretary, controlling administrative side, 1913; comptroller-general, National Debt Office, 1919-26; KCB, 1909; KCVO, 1916; a leading authority on Greek mathematics; made accessible in modern notation works of Diophantus Apollonius of Perga Archimedes (1897), and Euclid (1908); other publications include A History of Greek Mathematics (2 vols., 1921) and Greek Astronomy (1932); FRS, 1912; FBA, 1932. Source: Concise Dictionary of National Biography English mathematical historian who specialized in ancient Greece. His History of Greek Mathematics 1921 is regarded as the standard work on the subject in the English language. KCB 1909. Heath was born in Lincolnshire, studied at Cambridge and joined the civil service. He rose through the ranks in the Treasury Office; in 1913 he was appointed joint permanent secretary to the Treasury and auditor of the Civil List, and he was comptroller general and secretary to the Commissioners for the Reduction of the National Debt 1919-26. Between 1885 and 1912, Heath edited the works of Greek mathematicians

67. Ancient Greek Astronomy Earth rotates. aristarchus of samos (310230BC) Worked in Alexandria.Archimedes was his pupil – get most of what we know of him http://www.astunit.com/tutorials/greek.htm

This page last modified 1998 July 16 Ancient Greek Astronomy Making Sense of the Heavens In our understanding of the heavens, we owe a great deal to those who have gone in the centuries before us. Stars and Planets When our ancestors looked at the sky, they saw a dome upon which lights moved. Some of these lights, the stars, remained in the same position in relation to each other. The stars can be divided into two groups: those which rise and set and those which remain above the horizon whilst they appear to circle a fixed point in the sky, the celestial pole. Our ancestors noticed that this fixed point was higher in the sky rose higher if they travelled northwards, and vice versa. This was seen as evidence that the surface of the Earth is curved. The positions of others, including the brightest ones, changed. These were called "wanderers" (in Greek: "planetos") They were often identified with deities. The seven naked-eye wanderers, or planets, were, in order of speed of apparent movement: Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn. The planets' movements are confined to a narrow band of stars a few degrees either side of the path of the Sun, the ecliptic, so called because eclipses can occur when the Moon is on the ecliptic. The constellations of the ecliptic were granted special status as the Zodiac. There are 12, one for each lunation during the course of a year.

68. The Heliocentric Revolution aristarchus of samos also suggested a heliocentric solar system, with stars a tremendousdistance away This would account for their constancy of brightness. http://www.astunit.com/tutorials/heliocentric.htm

This page last modified 1998 July 16 The Heliocentric Revolution The first murmurings of a heliocentric system were those of Heracleides of Pontus , who also taught that the Earth rotates daily on its axis. Aristarchus of Samos also suggested a heliocentric solar system, with stars a tremendous distance away This would account for their constancy of brightness. Cleanthes wanted him condemned for impiety for "putting in motion the Hearth of the Universe". The idea slept until the 16th Century. Mikolaj Kopernigk (Nicolaus Copernicus) (1473-1543) realised that the Ptolemaic system was inadequate and, having read of Aristarchus' theories, became convinced that the solar system was heliocentric. Wrote down some ideas in 1530, De Revolutionibus Orbium Coelestrum Giordano Bruno (1548-1600). Italian monk. Was burned alive at the stake for supporting the Copernican model. Later astronomers must have been aware of, and cautious because of, this. Tycho Brahe (1546-1601) "The first modern astronomer". Saw eclipse at 14. Became fascinated by astronomy. The conjunction of Jupiter and Saturn in 1563 occurred a month earlier than predicted and he realised that the astronomical tables in use were hopelessly inaccurate. In 1566 he fought a duel and had most of his nose cut off . Saw new star (Nova) in Cassiopeia (1572) and began to build accurate instruments for measurement. Was given island of Hven and built observatories (Uraniborg and Stjärneborg). Made extremely accurate measurements. Rejected the idea of a moving Earth. Revived the model of Heracleides. His behaviour forced him to leave and moved to Prague. Left several volumes of accurate observations (

69. Science - Mathematics Aristarchus 2) which is 75. Plato mentioned this approximation of 2^(1/2). Skipping a few steps,FEBH 362 or 181. aristarchus of samos goes on to prove that BA 20BC. http://www.ancientgr.com/archaeonia/science/mathematics/aristarchus.htm

70. Physics 7 Homework Answers #1 Describe how aristarchus of samos' estimates might lead to the conclusionthat the sun rather than the earth is the center of the solar system. http://casswww.ucsd.edu/physics/ph7/hw/hw1_ans.html

Physics 7 Introduction to Astronomy H. E. Smith Winter 2003 Physics 7 - Homework Answers #1 In what ways does the finite speed of light affect our ability to perform astronomical research, both positively and negatively? When we look at an object that is, say 10 billion light years away, we are seeing light that has taken 10 billion years to reach us. That is, the light was emitted 10 billion years ago. This means we are in effect, looking back in time 10 billion years when the universe was relatively young. The ability to use the light travel time effectively as a ``time-machine" to trace the evolution of astronomical objects is a very powerful tool. It can also be negative in that the evolution of objects over the light travel time can make it difficult to compare very distant, thus younger, objects with nearby objects. Also, if we wish to send a light signal to a spacecraft in the vicinity of Saturn, for instance, we must wait about an hour for the signal to travel from the earth to the spacecraft and an additional hour to receive a response from the spacecraft. Obviously, this is a negative aspect. Finally, the finite speed of light, and the fact that light travels at the same speed to all observers regardless of their own motion, is the basis of Einstein's Special Theory of Relativity. This theory profoundly affected our concepts of space and time from Newton's ideas of absolute framework of space and time, uniform throughout the Universe, to one in which space, time, concepts such as simultaneity, etc. are relative, depending on the reference frame of the person making the measurement. Special Relativity will be seen to have some far reaching, often puzzling consequences. It makes travel near the speed of light a very costly proposition, for example.

71. Olivier THILL. Book Review. The Life Of Copernicus. CHAPTER 1. ANCIENT ASTRONOMY Contemplation and Study The Pythagoreans- aristarchus of samos, Copernicus of antiquity - Astronomical Tables. http://members.aol.com/OlivThill/private/copernic.htm

T he L ife of C opernicus by Pierre Gassendi with notes by Olivier Thill A New Biography Timeline Achievements Uncertainties and Errors ... Bibliography Table of contents INTRODUCTION His Real Life, Not a Novel - A 17th Century Text With 21st Century Notes PART I. A WELL-BRED CHILD (1473-1503) CHAPTER 1. BIRTH His Name - Place and Date of Birth - The End of The Middle Ages - His Astrological Theme CHAPTER 2. THE FIRST YEARS His Family - On His Paternal Side - On His Maternal Side - His Childhood in Thorun - The Death of His Father - The Career of Uncle Lucas - At Cracow University - At Bologna University - At Padua University PART 2. CANON IN VARMIA CHAPTER 1. FRAUENBURG Varmia, Borussia - The Years 1503-1509 - The Teutonic Knights - Copernicus' First Published Book in 1509 - The Years 1510-1516 CHAPTER 2. ANOTHER AESCULAPIUS His Books of Medicine - The Consultations of Doctor Copernicus - The Leper of His brother CHAPTER 3. MAPS, COINS, AND BREAD Cartographer - Meditata - The Bread Tariff and The Baking of Bread CHAPTER 4. ADMINISTRATOR

72. SKYLIGHTS In the third century BC, the great Greek astronomer aristarchus of samos tried tomeasure the distance to the Sun (relative to the Moon) by timing the exact http://www.astro.uiuc.edu/~kaler/arc/sk102702.html

SKYLIGHTS Skylights featured on Astronomy Picture of the Day Photo of the Week. . Deepening twilight fills the skies from 35,000 feet. Astronomy news for the short week starting Sunday, October 27, 2002. The Moon approaches its last quarter early in the week, reaching the phase on the night of Monday the 28th, about midnight in the Americas, just about the time of Moonrise. In the third century BC, the great Greek astronomer Aristarchus of Samos tried to measure the distance to the Sun (relative to the Moon) by timing the exact moment of the quarter. The angle between the two would be 90 degrees if the Sun were infinitely far away. If it was not, then the angle would be less. From his estimated angle of 87 degrees, Aristarchus found the Sun to be 20 times farther than the Moon. The experiment is impossible, and the ratio is actually 400. But Aristarchus was on the right track, clearly locating the Sun much farther away than the Moon. The night of Tuesday, the 29th, the Moon will have passed just to the north of bright Jupiter The time to see the two giants of the Solar System , Jupiter and Saturn, is still early morning. At that time

73. [ Link To The Department Of The History Of Science ] [ Link To aristarchus of samos. Aristarchi de magnitvdinibvs et distantiis solis,et lunae, liber cvm Pappi Alexandrini explicationibus quibusdam. http://libraries.ou.edu/depts/HistScience/gala/macro/aristarchus.htm

About the collections Theme of the exhibit Macrocosm Microcosm o The Macrocosm: Most people in the sixteenth and seventeenth centuries who were interested in explaining the motions of the heavenly bodies, accepted the common sense point of view that the earth was the center of the universe and that the planets, including the sun and moon, revolved around a stationary earth in perfect circles. Even though an Alexandrian mathematician, Aristarchus (ca 310-230 B.C.), had proposed an alternative in the third century B.C. (that the sun not the earth was the center), his ideas were never accepted, for both science and common sense seemed to mitigate against it. This book by Aristarchus is a recent acquisition to the Collections' holdings. Aristarchus of Samos.

74. History Of Alexandria: The Ptolemaic Legacy aristarchus of samos, Eratosthenes' coworker in Alexandria, had suggested in thethird century BC the heliocentric hypothesis, which states that the Earth and http://ce.eng.usf.edu/pharos/Alexandria/History/legacy.html

The Ptolemaic Legacy The Mouseion / Library When Ptolemy Soter assumed power, he asked Demitrius Phalerus , a follower of Aristotle , to found a library system at Alexandria that would rival that of Athens. The Alexandrian Mouseion , however, far superseded its Greek prototype to become an intellectual and scientific institution; a university system rather than a bibliotheca. It was here, in the third century BC, that Archimedes invented the pump still in use today and known as Archimedes' screw , and, in the second century BC, that Hypsicles first divided the circle of the zodiac into 360 degrees. Ancient historians claim that the library's 500,000 book collection was so comprehensive that no manuscript was available in any library worldwide that was not available in Alexandria. Mathematics Have you ever heard of Euclidean Geometry? Did you know that Euclid lived, developed his theories, and wrote Elements at the Alexandria Mouseion during the reign of Ptolemy II Philadelphus? In his Elements , Euclid provided a comprehensive analysis of geometry, proportions, and theory of numbers. His other notable contribution

75. Greek Authors On The Web Aristarchus aristarchus of samos Kristen Riley. Aristophanes Aristophanesand Greek Old Comedy - John R. Porter (University of Saskatchewan); http://users.pandora.be/herman.lauvrys/authorsg.htm

Classica Latin and Greek Authors on the Web Greek Authors on the Web Aeschylus Aeschylus - Moonstruck Drama Aeschylus and His Tragedies - TheatreHistory.com Aesop Aesop's Fables - Online Collection - John R. Long Aesop's Fables - Laura Gibbs (University of Oklahoma) Alcman Die Sprache Alkmans: Textgeschichte und Sprachgeschichte - George Hinge (University of Aarhus) Anyte of Tegea Anyte of Tegea - Dorothy Disse Twintig epigrammen van Anyte van Tegea - Ankie Kuyvenhoven Apollodorus Apollodorus - Perseus Project (Tufts University) Apollonius The Argonautica - Douglas B. Killings (OMACL) Apollonius Dyscolus Apollonius Dyscolus - Andreas Schmidhauser Apostolius Michaelis Apostolii Proverborium - Trevor Jennings Archilochus Archilochos on the Web - Martha Gifford Archimedes Archimedes Home Page - Chris Rorres (Drexel University, Philadelphia, Pennsylvania)

76. Untitled Document aristarchus of samos (310250) measured the size and distance of the Moon andSun. Heath, Sir Thomas, aristarchus of samos; the Ancient Copernicus. http://celator.com/cws/marotta.html

Ancient coins show they knew it was round by Michael Marotta The average person in Hellenic and Roman times knew that our world is round. The philosophic inquiries that began with Thales (624-547 BCE), reached a zenith in the works of Aristotle (384-321). Later, hellenistic astronomers made measurements of the size of the Earth and the sizes of and distances to the Sun and Moon. Several schemes for explaining the motions of the planets were invented. Generally, the average person of those times did not believe Earth to be flat any more than the average person of our day believes that we are alone in the galaxy. Philosophic Developments We should not be surprised to learn that various Greek philosophers and mathematicians had clever insights. Empedocles of Akragas (490-430) proved by experiment that air has substance. Democritus of Abdera (460-370) posited the existence of atoms. Pythagoras (569-500) was probably the first to assert that Earth is a sphere. The other candidate for originating this insight is Parmenides of Elea (fl. c. 500 BCE). However, later than them, Anaxagoras of Clazomenae (500-428) said that our world is "cylindrical", i.e., shaped like a drum or a modern coin. Democritus agreed. Aristotle summarized and criticized just about every significant work up to his time. In his books, On The Heavens, he notes the reasons offered by Anaxagoras and Democritus for asserting that Earth is flat. Then he argues against them, and states: "These conditions will be provided, even though the Earth is spherical, if it is of the requisite size..."

77. SCSU CometWatchers aristarchus of samos; Nicolaus Copernicus; Christmas. Cosmology and Evolution;Moving towards DNA; Electronic Universe Project; Stellar Evolution. NASA. http://r2d2.stcloudstate.edu/~cw/links.html

Useful Websites for Astronomical Research Realtime Clock - USNO More USNO links JPl Ephemeris Generator JPL Comet Links ... with small telescopes site -from Apogee CCD LaTeX help Using Aipsview Astronomy History Ancient Cosmology Native American Astronomy History of Space Exploration Ancient Astronomy ... Stellar Evolution NASA Planetary Image Picture of the Day: Archive The Earth's Magnetosphere Sun Centered Physics ... LHEA Physics Craters On the Moon Weighing Jupiter Dark Matter Astrophysical Measurements ... Project CLEA Students for the Exploration and Development of Space Links SEDS Headquarters The Constellation Index Orion The Trapezium ... Apogee Instruments Inc. University Astronomy Astrophysics Data System Astronomical Headlines The Solar System A Sense of the Universe ... Planetary Science US Naval Observatory Naval Observatory Sun or Moon Altitude Azimuth More USNO links Earth's Seasons ... Eclipses Other Alpha Centauri AAVSO Observation Report Form Beta Persei (Algol) ... Current satellite map (Weather Channel) Document Created On: 09/21/2001 Document Last Modified On: 09/21/2001 E-Mail us your comments and/or suggestions.

78. PSIgate - Astronomy Timeline aristarchus of samos (c.320230BC) Greek astronomer Aristarchus challenged the theoryof a geocentric universe, instead putting forth the idea that the Sun was http://www.psigate.ac.uk/newsite/astronomy_timeline.html

79. ARISTARCHUS, OF SAMOS ~n Naxos, but he quarrelled with Megabates, the kersian og mmander, who warned the inhabitants of the island, and the A pedition failed http://64.1911encyclopedia.org/A/AR/ARISTARCHUS_OF_SAMOS.htm

document.write(""); ARISTARCHUS, OF SAMOS ~n Naxos, but he quarrelled with Megabates, the k’ersian og mmander, who warned the inhabitants of the island, and the ‘A pedition failed. Finding himself the object of Persian sus:ion, Aristagoras, instigated by a message from Histiaetls, ~ ised the standard of revolt in Miletus, though it seems likely at this step had been under consideration for some time (see G NSA). After the complete failure of the lonian revolt he iigrated to Myrcinus in Thrace. Here he fell in battle ~ or file attacking Ennea Hodoi (afterwards Amphipolis) on the t rymon, which belonged to the Edonians, a Thracian tribe. se aid given to him by Athens and Eretria, and the burning of ar rdis, were the immediate cause of the invasion. of Greece by PC Irius. cc See Herodotus V. 30-51, 97-126; Thucydides iv. 102; Diodorus bc • 68; for a more favourable view see G. B. Grundy, Great Persian gi ar (London, 1901). se ARISTANDER, of Telmessus in Lycia, was the favourite to othsayer of Alexander the Great, who consulted him on all lii casions. After the death of the monarch, when his body had w n unburied for thirty days, Aristander procured its burial by d retelling that the country in which it was interred would be e most prosperous in the world. He is frequently mentioned af the historians who wrote about Alexander, and was probably hi e author of a work on prodigies, which is referred to by Pliny ra 7~jt. Hist. xvii. 38) and Lucian. cc Philopatris, 21; Arrian, Anabasis, ii. 26, iii. 2, iv. 4; Plutarch, A ‘exander; Curtius iv. 2, 6, 15, vii. 7. T ARISTARCHUS, of Samos, Greek astronomer, flourished about H ~0 BC. He is famous as having been the first to maintain

80. APOD: November 8, 1997 - Aristarchus' Unbelievable Discoveries aristarchus lived on the Greek island of samos, a small island in thecenter of the above picture that can be identified with a good map. http://antwrp.gsfc.nasa.gov/apod/ap971108.html

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. November 8, 1997 Aristarchus' Unbelievable Discoveries Credit: Space Shuttle Columbia NASA Explanation: Here lived one of the greatest thinkers in human history. Aristarchus lived on the Greek island of Samos, a small island in the center of the above picture that can be identified with a good map . Aristarchus, who lived from 310 BC to 230 BC, postulated that the planets orbited the Sun - not the Earth over a thousand years before Copernicus and Galileo made similar arguments. Aristarchus used clear logic to estimate the size of the Earth, the size and distance to our Moon , the size and distance to our Sun, then he even deduced that the points of light we see at night are not dots painted on some celestial sphere but stars like our Sun at enormous distances. Aristarchus' discoveries remained truly unbelievable to the people of his time but stand today as pillars of deductive reasoning. Tomorrow's picture: Surveyor Slides Archive Index Search ... USRA NASA Technical Rep.:

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