Resources for Teachers

History of Astronomy

Eratosthenes (c.276 BC - c.194 BC)
Source BBC Homepage - History
Eratosthenes was born in Cyrene on the north coast of Africa but educated in Athens, and came to Egypt in his thirties. He was a contemporary of Archimedes who would send him mathematical problems to solve and send the solutions later in case of difficulties. Eratosthenes was a skilled geographer, astronomer, poet and literary critic. He drew a map of the world as it was then known and calculated the angle of tilt of the earth in space. For forty years he served as a librarian at the famous library of Alexandria and as a renowned mathematician he invented a way of finding prime numbers known as the Sieve of Eratosthenes. Possibly his greatest feat was to measure the size of the Earth.

The Eratosthenes Project
Source - Department of Physics & Astronomy - Sonoma Sate University - USA.
Eratosthenes was a Greek scholar who lived and worked in Cyrene and Alexandria. He was director of the famous library in Alexandria and is known for numerous important contributions to mathematics, geography, and astronomy. He is remembered in particular for a technique he introduced which enabled him to compute the first reliable determination of the true size of the earth. See how he did it!

Ptolemy
Source - School of Mathematics & Statistics - University of St Andrews - Scotland
Claudius Ptolemy Born: about 85 in Egypt, Died: about 165 in Alexandria, Egypt. Ptolemy was one of the most influential Greek astronomers and geographers of his time and propounded the geocentric theory in a form that prevailed for 1400 years. Of all the ancient Greek mathematicians his work has generated more discussion and argument than any other.

Copernicus
Source - School of Mathematics & Statistics - University of St Andrews - Scotland
Nicolaus Copernicus. Born: 19 Feb 1473, Died: 24 May 1543, Poland. Copernicus's cosmology placed a motionless sun close to the centre of the earth and also involved giving several distinct motions to the Earth. Copernicus assumed all motion was circular so, like Ptolemy, he was forced into using epicycles. His theories were considered implausible by the most of his contemporaries and by most astronomers and natural philosophers until the middle of the seventeenth century and Copernicus was fully aware of the criticisms his work would attract. Notable defenders included Kepler and Galileo while theoretical evidence for the Copernican theory was provided by Newton's theory of universal gravitation around 150 years later.

Aristotle
Source - School of Mathematics & Statistics - University of St Andrews - Scotland
Aristotle. Born: 384 BC, Died: 322 BC in Greece. Aristotle determined the orientation and the content of Western intellectual history more than any other thinker. He was the author of a philosophical and scientific system that through the centuries became the support and vehicle for both medieval Christian and Islamic scholastic thought until the end of the 17th century, Western culture was Aristotelian. Even after the intellectual revolutions of centuries to follow, Aristotelian concepts and ideas remain embedded in Western thinking.

Galileo Galilei (1564 - 1642)
Source BBC Homepage - History
Aristotle's earth-centred view of the universe was the view at the time of Galileo but Galileo the mathematician gradually realised that it didn't make sense - and he set out to prove it. Galileo is supposed to have gathered a group of students then climbed the leaning tower of Pisa and dropped two balls of differing weight off the top.Galileo's experiments into gravity refuted Aristotle - Galileo found that the light weight did not take ten times as long to hit the ground, it didn't take five times as long - it hit the ground at exactly the same time as the heavy weight. Not only had Galileo disproved one of the ancient laws of the universe, he had done it by experiment and hoped that experiment rather than beliefs passed down through the generations would always be used to determine the truth. But if Galileo hoped that the supporters of Aristotle were about to give up, he was seriously mistaken.

The Galileo Project
Source - Rice University - USA
This is an amazingly detailed and well-documented site that provides great detail about every aspect of the life and work of one of the most influential thinkers in all history. The aim is to provide hypertextual information about Galileo and the science of his time to viewers of all ages and levels of expertise.

Catalogue of the Scientific Community in the 16th and 17th Centuries
Source Rice University - USA
This catalogue is a collection of 631 detailed biographies on members of the scientific community during the 16th and 17th centuries with vital facts about each individual and their contributions to science. The information is concise and very well organized. All individuals in the catalogue are systematically described by ten categories using twenty searchable fields.

Kepler
Source - School of Mathematics & Statistics - University of St Andrews - Scotland
Johannes Kepler is now chiefly remembered for discovering the three laws of planetary motion that bear his name published in 1609 and 1619). He also did important work in optics (1604, 1611), discovered two new regular polyhedra (1619), gave the first mathematical treatment of close packing of equal spheres (leading to an explanation of the shape of the cells of a honeycomb, 1611), gave the first proof of how logarithms worked (1624), and devised a method of finding the volumes of solids of revolution that (with hindsight!) can be seen as contributing to the development of calculus (1615, 1616). Moreover, he calculated the most exact astronomical tables hitherto known, whose continued accuracy did much to establish the truth of heliocentric astronomy.

Newton
Source - School of Mathematics & Statistics - University of St Andrews - Scotland
Isaac Newton's greatest achievement was his work in physics and celestial mechanics, which culminated in the theory of universal gravitation. By 1666 Newton had early versions of his three laws of motion. He had also discovered the law giving the centrifugal force on a body moving uniformly in a circular path.Isaac Newton's life can be divided into three quite distinct periods:
1. His boyhood days from 1643 up to his appointment to a chair in 1669;
2. The second period from 1669 to 1687 was the highly productive period in which he was Lucasian Professor at Cambridge;
3. The third period (nearly as long as the other two combined) saw Newton as a highly paid government official in London with little further interest in mathematical research.

The Newton Project
The Newton Project was formed in 1998 to make all Newton's texts, both 'scientific' and 'non-scientific' (including those papers relevant to his three decades service at the Royal Mint), available to a broad readership in a form that is at once scholarly and accessible. Isaac Newton (1642-1727) is universally acknowledged as one of the two or three most influential scientists in history. The Project aims to create a printed edition of Newton's theological, alchemical and administrative writings and an electronic edition of all his writings, including his correspondence.

Sir Isaac Newton (1643 - 1727)
Source - BBC Homepage - History
Sir Isaac Newton was born on 4 January 1643 in the manor house in Woolsthorpe, three months after his father's death. He was so tiny that no one expected him to survive. When Newton was three years old, his mother remarried, an event which improved her situation and led to three more children but which deprived Isaac of a mother. His stepfather, the Reverend Mr Smith, would not take the three-year-old Newton along with his mother, and he was left at Woolsthorpe with his grandparents. This is a highly readable account of his life.

Edmond Halley (1656 - 1742)
Source - BBC Homepage - History
This BBCi site offers a short summary of the work of the English astronomer and mathematician who was the first to calculate the orbit of the comet later named after him. He also played a central role in the publication of Newton's Principia. Halley recorded the celestial longitudes and latitudes of 341 stars and observed a transit of Mercury across the Sun's disk. Halley's star catalogue, published in 1678, was the first to contain telescopically determined locations of southern stars and that year he was elected a fellow of the Royal Society.

Edmond Halley
Source - School of Mathematics & Statistics - University of St Andrews - Scotland
Born: 8 Nov 1656, Died: 14 Jan 1742 Greenwich, England. Halley proposed using transits of Mercury (and even better of Venus) to determine the distance of the Sun and therefore the scale of the solar system using Kepler's third law. From around 1695 Halley made a careful study of the orbits of comets. Using his theory of cometary orbits he calculated that the comet of 1682 (now called Halley's comet) was periodic and was the same object as the comet of 1531, and 1607. He later also identified this comet with one which appeared in 1305, 1380, and 1456. In 1705 he published his prediction that it would return in 76 years, claiming that it would appear in December 1758. Although Halley had been dead for fifteen years by 1758, he achieved lasting fame when the comet was observed on 25 December 1758 (very slightly later than Halley expected).

Jeremiah Horrocks - 1619 -1641
Source - Department of Physics, Astronomy & Mathematics - University of Central Lancashire - UK
Basic background on Jeremiah Horrocks, his observing device, and a later painting of Horrocks observing 1639 transit of Venus, by Eyre Crowe. From Paul Marston's chapter on Horrocks from the University Certificate in the History of Astronomy: "Presently on loan from the Walker Gallery and hanging in the Liverpool Museum Planetarium is a famous painting by Eyre Crowe BA. The painter said he modeled the room on that in Carr House, which he claimed in 1891 to have visited, though the Puritan outfit seems unlikely and elaborate equatorial telescopic apparatus unhistorical. The painting is now very dark, and is unclear without computer enhancement."

Jeremiah Horrocks 1619-1641
Detailed background on Jeremiah Horrocks and William Crabtree, from Allen Chapman.

History of Jeremiah Horrocks
Extracted from Great Astronomers in History, Centre for Astrophysics, �University of Central Lancashire. "Jeremiah Horrox[1] possessed one of the most original minds of the seventeenth century. A follower of Tycho, Horrox combined a gift for instrumentation with a theoretical genius that later won the acclaim of Hevelius and Flamsteed. His contributions to the lunar theory were the first significant advances on the subject since antiquity, and earned the praise of Newton himself in the pages of Principia."