History of Astronomy: From Ancient Times

• The module aims to trace historical accounts from the Golden Age of Astronomy and differentiate between geocentric and heliocentric models of the Solar System.
• Caracol, Stonehenge, Karnak Temple Complex, and Angkor Wat are associated with archaeoastronomy.
• Structures serve purposes beyond being edifices, aiding in understanding ancient civilizations through archaeoastronomy.
• Humanity's fascination with celestial objects dates back to ancient civilizations, inspiring scientific discoveries in astronomy.
• The lesson outlines the timeline of astronomy's milestones as one of the oldest and most prolific scientific disciplines.

Prehistoric Astronomy

• The earliest written astronomical records come from ancient Babylonians around 1600 BCE.
• Babylonians kept diaries of daily, annual, and other astronomical events, observing the sky.
• Ancient civilizations tracked the movement of heavenly bodies like the Sun and Moon, including annual events like equinoxes and solstices.
• Tracking heavenly bodies was crucial for timekeeping.
• Ancient societies studied celestial movements to inform agricultural and cultural cycles, timing rains and flooding seasons.
• Polynesians used star positions and ocean currents for navigation.

Classical Astronomy

• Natural philosophers and thinkers from 500 BCE to 1400 CE contemplated the structure and workings of the heavens.
• Ancient Greeks, including Pythagoras (560-480 BCE) and Aristotle (382-322 BCE), argued the Earth was spherical.
• Eratosthenes (276-195 BCE) calculated the Earth's circumference using shadows and geometry.
• Eratosthenes and Aristarchus provided insights into the relative sizes and distances of the Moon and Earth.
• Most philosophers supported the geocentric model with Earth at the center of concentric spheres containing heavenly bodies.
• Ptolemy compiled astronomical knowledge of ancient Greek and Roman civilizations in "The Almagest."
• Arab, Chinese, Korean, and Japanese civilizations also kept detailed astronomical records.
• These collective works significantly influenced the Renaissance, known as the Golden Age of Astronomy.

Renaissance Astronomy

• The Renaissance marked a renewed interest in astronomical observation and thought.
• The Ptolemaic geocentric model was challenged by data on planetary positions.
• Nicolas Copernicus (1473-1543) proposed a heliocentric model in De Revolutionibus Orbium Coelestium, placing the Sun at the center.
• Copernicus's heliocentric model closely aligned with planetary position data and explained the retrograde motion of Mars.
• Tycho Brahe (1546-1601) made accurate astronomical records, aiding Johannes Kepler (1571-1630) in formulating the Three Laws of Planetary Motion:
• Planets follow elliptical orbits with the Sun at one focus.
• A planet's speed varies, sweeping equal areas in equal times.
• The period (T) of a planet's orbit is proportional to the cube of its distance from the Sun (d³).
• The invention of telescopes allowed scientists like Galileo Galilei (1564-1642) to make new observations.
• Galileo observed sunspots and the moons of Jupiter, challenging the geocentric model and supporting heliocentrism.

Modern Astronomy

• Sir Isaac Newton (1642-1727) developed physical laws governing celestial objects, including the Laws of Motion and Universal Gravitation.
• Newton's work provided a basis for Kepler's Laws and refined planetary orbit calculations, leading to the growth of astrophysics.
• Technological advancements led to telescopes that observe beyond visible light, revealing more about the solar system and stellar universe.
• Nicholas-Claude Peiresc (1580-1637), Jacques Cassegrain (1652-1712), Edmond Halley (1656-1742), and William Herschel (1738-1822) contributed to understanding the Solar System and galaxies.
• Knowledge of motion, gravitation, and orbits enabled space exploration programs from the 1980s onward, gathering information on planets and the solar system's structure.
• Albert Einstein (1879-1955) revolutionized the understanding of gravity with his theory of general relativity.
• Measurement and detection of gravitational waves have validated Einstein's theory.
• Astronomy remains a prolific field, with ongoing research into the cosmos.