Early Man -> little recorded information on early man's impression of the heavens, some drawings of eclipses, comets, supernovae such as the Pueblo Petrograph. Early man was frightened/overwhelmed by the sky
Early man also believed that the heavens held power over earthy existence (psychology of the unknown) -> origins of astrology as an attempt to understand, predict and influence events
The earliest written records (i.e. history) were astronomical observations - Babylonians (~1600 B.C.) recorded position of planets, times of eclipses, etc. - also evidence from early Chinese, Central American and North European cultures such as Stonehenge, which is a big computer for calculating the position of planets and the Sun (i.e. when to have that big blowout Solstice thing)
-> thus, Astronomy was the 1st science
The ancient Greeks inherited astronomical records from the Babylonians and applied the data to construct a cosmological framework. Data was not just used for practical goals, such as navigation, but also to think of new experiments = natural philosopher.
Thales (~480 B.C.) used this data to predict eclipses.
Eratosthenes (220 B.C.) - The early Greeks knew the Earth was a sphere based on the shadow of Earth on the Moon during lunar eclipses. Eratosthenes proceeded to use this information to measure circumference of Earth in the following manner; he knew that on a certain date that a stick placed in the ground at Syene cast no shadow. Whereas, a stick at Alexandria has a small shadow. Using simple ratios he showed the following:
Heraclides (330 B.C.) developed the first Solar System model, beginning of the geocentric versus heliocentric debate
Aristarchus (270 B.C.) developed the heliocentric theory
Ptolemy (200 A.D.) was the Librarian of Alexandria who resurrected Heraclides geocentric theory and combined with centuries of data on planetary motions -> formulated complete description of the Solar System that explained/predicted the apparent motions. The Ptolemic system began the 1st paradigm or framework for our understanding of Nature
Unfortunately, the Ptolemy framework was extremely complicated in order to explain retrograde motion.
The solution to retrograde motion was to use a system of circles on circles to explain the orbits of the planets called epicycles and deferents. The main orbit is the deferent, the smaller orbit is the epicycle. Although only one epicycle is shown in the figure below, over 28 were required to explain the actual orbits of the planets.
Alexandria burns, Roman culture collapses, Dark Ages... but the Roman Catholic Church absorbs Aristotle's scientific methods and Ptolemy's model into its own doctrine. Thus, preserving the scientific method and Ptolemy's Solar System until the...
The Renaissance, where new ideas were more important than dogma.
Tycho Brahe (1580's) was astronomy's 1st true observer. He built the Danish Observatory (using sextant's since telescopes had not been invented yet) from which he measured positions of planets and stars to the highest degree of accuracy for that time period (1st modern database). He showed that the Sun was much farther than the Moon from the Earth, using simple trigonometry of the angle between the Moon and the Sun at 1st Quarter.
Tycho's measurements were used to show that there was no detectable parallax with the naked eye, in support of the geocentric theory. So, even though his observations were the best for his time, his result was wrong, a lesson in how science is done.
Kepler (1600's) a student of Tycho who used Brahe's database to formulate the Laws of Planetary Motion which corrects the problems of epicycles in the heliocentric theory by using ellipses instead of circles for orbits of the planets.
The formulation of a highly accurate system of determining the motions of all the planets marks the beginning of the clockwork Universe concept, and another paradigm shift in our philosophy of science.
Galileo (1620's) developed laws of motion (natural versus forced motion, rest versus uniform motion). Then, with a small refracting telescope (3-inches), destroyed the the idea of a "perfect", geocentric Universe with the following 5 discoveries:
spots on the Sun
mountains and "seas" (maria) on the Moon
Milky Way is made of lots of stars
Venus has phases
Jupiter has moons (Galilean moons: Io, Europa, Callisto, Ganymede)
... off to the 18-20th century, with discovery of the outer planets and where astronomy moves towards discoveries in stellar and galactic areas, next paradigm shift occurs in early 1960's with NASA deep space probes