- Most cultures seem to have had Mythological Explanations for Earth, Moon, Sun, Stars, Planets. Earth was usually feminine, the mother or nurturer. Moon and Sun usually involved some sort of chase. Sun was usually masculine. Stars could be spirits of the dead. Planets were hard to figure out, so they usually got personalities of powerful and eccentric gods.
- Constellations (By April, Val, and April) Not known when constellations were first used. Used long before the rise of Egypt and Mesopotamia, Constellations have been called “man’s oldest picture book”. Some cultures aligned graves with stars. Stonehenge documented the Sun’s solsticial movement
- What did Ancient People think of the Planets?
- Why? Why not?
- Which are missing? Why?
- Why DID they know the 5 (7)?
B. Pre-Helenistic History
- c.6500bc The Ishango tribe (Africa) used a lunar calendar
- c.4500bc Egyptian calendar regulated by sun and moon: 360 days, 12 months/30 days. Babylonians record that Mars moves relative to the other stars
- c.2800bc Beginning of systematic Astronomy in Egypt, Babylonia, India, and China. Egyptians notice Mars' retrograde motion
- 2772bc Egypt uses calendar of 365 days
- 2136bc First record of an eclipse – China
- c.2500bc First manufacture of iron objects, and use of papyrus
- c.2000bc Equinoxes and solstices determined in China. Babylonians use zodiac sign
- c.750bc Babylonian and Chinese Astronomers understand planetary movemen
- c.550bc Sun dial (gnomon) used in Greece and China. Thales predicts solar eclipse
- before 300bc Mayans used the concept of zero
C. Ionians and Greeks
Name Date Significance Who gets credit? Thales of Miletus 640-546BC Thought the Earth's surface could change Alfred Lothar Wegener Anaximander 610-546BC Noticed that species change and suggested evolution Darwin Theodorus Engineer -- lock, smelting, casting, carpenter's square Pythagorus c580-c500bc Mathematical religion. Found sqrt(2) was irrational. Evidence that Earth is round Columbus Empedocles 500-430bc Air has properties like pressure and mass Charles and Boyle Anaxagoras 500-429bc Moon is a place like Earth. Sun is a hot rock Galileo Democritus 460-362bc Suggested things were made of small particles called atoms Galileo Socrates, Plato, Aristotle Universe made of 4 elements. Don't experiment, just think. Euclid of Alexandria c324-264bc Systematized Geometry Archimedes c287-212bc Mathematician and engineer - hydraulics, many machines, including a screw pump Aristarchus 286-264bc Knew order of planets - Heliocentric model Copernicus Eratosthenes 276-195bc Measured circumference of Earth Columbus Christ Eudoxus Created a model involving crystal spheres, to explain motion of stars and planets - Geocentric Ptolemy Improved Eudoxus' model - much more complex and accurate
D. The Dark Ages
- Decline of Roman Empire
- (517) Aryabhata compiles his manual of astronomy - discussed the value of ‘Pi’ and its relationship to the rotation and spherical shape of the earth.
- (595) Decimal used in India
- (610) The Prophet Muhammad was visited by an angel who asked him to read from the Holy Qur'an.
- (963) “The Book of Fixed Stars” by Al Sufi mentions “nebula” and named many stars (see 1612)
- Ibn al-Haytham (965-c. 1040) a critic of Ptolemy, hypothesized that there is no empty space and that celestial bodies are in constant, individual motion
- During the European Dark Ages, China flourished, inventing paper, the compass, and movable type
- 1054 record of a supernova , not recorded by Europeans (still visible as the Crab Nebula):
- "In the 1st year of the period Chih-ho, the 5th moon, the day chi-ch'ou, a guest star appeared... After more than a year it gradually became invisible..."
- 1054 record of a supernova , not recorded by Europeans (still visible as the Crab Nebula):
- (1066) Battle of Hastings - Bayeux Tapestry records battle and the passing of a specific comet.
- (1231) Pope Gregory IX creates special court to investigate heretics (Inquisition)
- (1327) Edward III, becomes king, later to begin the “100 years war”
- Several "Plagues"... "The Black Death"
- (1300s-1600s) Renaissance
- (1492) Columbo
- (1517) Martin Luthor begins Protestant Reformation in Germany
- (1542) Congregation of the Holy Office controls the Inquisition, run by Dominican and Franciscan friars
- Europe is slowly Coming out of the Dark Ages
E. Renaissance and the Age of Discovery
- Italian Renaissance begins in late 1300's (Much later in the rest of Europe)
- Leonardo DaVinci (1452-1519): Inventor, Painter, Philosopher. Explained Earthshine. Died 24 years before Copernicus' theory was published.
- Niccolò Machiavelli (1469-1527): Political philosopher, musician, poet, and playwright. A key figure of the Italian Renaissance and a central figure of its political component, best known for his treatise on political theory, The Prince.
- Nicolas Copernicus [Mikolaj Kopernik from Torun] (1473-1543): Polish monk, published De Revolutionibus, giving evidence that the Sun is the center of the universe, Earth is one of 6 planets-- heliocentric theory.
- Tycho Brahe (1546-1601): His model of the universe put the Earth #at the center, w/ the sun and moon orbiting it, planets orbited the sun. (Court astrologer of Denmark, advised the Duke, his “patron.”) Made very accurate observations w/out telescopes.
- Giordano Bruno (1548-1600): Traveled through Europe teaching Copernicus' ideas. Tended to be rude and confrontational. Charged with heresy and burned at the stake. “Martyr of science”--historical precedent that kept his contemporaries scared.
- William Shakespeare (1564-1616) England
- Galileo Galilei (1564-1642) Italy, Musician parents, Eventually ordained. Sometimes given credit for inventing the telescope. Using his telescopes, he made money, pissed people off, and explored the universe. He also reintroduced Democritus' concept of atoms, and figured out a lot about motion that Newton gets credit for. Thought that the moon affected tides. Invented water clock - most accurate yet. Published heretical books despite Inquisition threats. His works were added to the Index of Prohibited Books, and he was sentenced to confinement in his home, for the last 10 years of his life.
- Johannes Kepler (1571-1630): Created 3 laws of planetary motion, did research in optics, worked to prove that his ideas were right but also published the truth when he was wrong. He, more than Galileo, improved on the telescope. Published Astronomia nova in 1609. He was the “last Scientific Astrologer” and the first true Astronomer.
- In 1610, Galileo used his 20X telescope to observe the heavens. He saw Lunar imperfections, found 4 Jovian moons, and basically proved Copernicus right. His drawings of Saturn showed what appeared to be ears or handles attached to the planet. Galileo concluded that there were 2 large moons near Saturn. However, while observing 2 years later, the moons had disappeared. In 1616, they were back, but now his drawing showed them as half ellipses. It wasn't until almost 50 years after Galileo's original observation that Christian Huygens suggested that Saturn could be surrounded by a “thin, flat ring, nowhere touching”, and that every 15 years, the Earth passes through the plane of the ring.
F. Scientific Revolution
- Giovanni Alfonso Borelli AKA Giovanni Francesco Antonio Alonso (1608-1679): Italian - mathematician, astronomer, and physician (truly a renaissance man), suggested that comets return
- Jan Heweliusz/Hevelius (1611-1687): Polish - lawyer, brewer, and mayor. Studied Mira, hunted comets, mapped Luna, and built large refracting telescopes.
- G. D. Cassini (1625-1712): Italian - used advances (telescopes) of Kepler and Newton to find a spot on Jupiter and that there are gaps in Saturn's ring (Cassini Division).
- Christiaan Huygens (1629-1695): Dutch - Improved system of measuring brightness of stars, found 4th moon around Saturn and identified its “ears” as rings. Patented “The Pendulum Clock”. Was involved in the development of calculus light theory.
- Isaac Newton (1643-1727): Wrote papers explaining gravitational effects, but didn't define it. He added to Galileo and Kepler's thoughts and explained it in mathematical terms. Newton's 3 laws of motion. Invented reflecting telescope.
- John Flamsteed (1646-1719): First royal astronomer of England―scientific arm of the govt. Leader of Royal Society: Map-making was a major issue during his time, so the Royal Society offered a prize for the person who could “solve the Longitude problem”. Rival of Newton.
- Halley (1656-1742): Took works of Kepler and Newton, made careful observations, charted paths of comets, and proved that some comets return. Made Newton publish his books. Some say we wouldn't know about Newton w/out Halley.
- John Harrison (1693-1776): “Solved” the longitude problem. Clock-maker.
- Sir Frederick William Herschel (1738-1822): German-born English Astronomer well-known for discovering Uranus (1781)
G. Technology Takes Over
- 19th century: Discovery of more Planets (Asteroids – 1801, Neptune - 1846), Telescopes got even bigger, Time Zones (1884)
- 20th century: Daylight Saving Time (1916), Theory of Relativity, space flight, nuclear power, and computers ... lead to interplanetary exploration, mostly by remote (robots).
- 21st century and beyond: Internationalization and Privatization of space exploration, FTL, colonies, et cetera