The Evolution of Astronomy: From Ancient Greece to the Copernican Revolution

A collection of vocabulary and definitions related to the historical development of astronomy, focusing on key figures, models, and concepts from ancient Greece through the Copernican Revolution.

Geocentric Model

The astronomical model in which Earth is at the center of the universe, and all celestial bodies orbit around it.

Heliocentric Model

The astronomical model proposed by Copernicus that places the Sun at the center of the universe, with Earth and other planets orbiting around it.

Kepler's Laws of Planetary Motion

Three laws formulated by Johannes Kepler describing the motion of planets around the Sun.

Eccentricity

A measure of how much an orbit deviates from being circular.

Retrograde Motion

The apparent backward motion of a planet as observed from Earth, explained by the relative positions and motions of the Earth and the planet.

Epicycles

Small circular orbits that planets were thought to follow while orbiting the Earth in the Ptolemaic system.

Almagest

A seminal work by Ptolemy that served as the authoritative text on astronomy for centuries.

Perihelion

The point in the orbit of a planet where it is closest to the Sun.

Aphelion

The point in the orbit of a planet where it is farthest from the Sun.

Thales of Miletus

A Greek philosopher known as the first to propose a rational explanation of natural phenomena, laying foundations for scientific thought.

Pythagorean Brotherhood

A group of followers of Pythagoras who viewed mathematics as a language for describing patterns in the universe.

Johannes Kepler

A mathematician and astronomer who formulated the three laws of planetary motion based on Tycho Brahe's observations.

Tycho Brahe

A Danish nobleman and astronomer known for his precise astronomical observations before the invention of the telescope.

Ptolemy

An ancient Greek astronomer who developed the geocentric model and an influential work detailing the motions of celestial bodies.

Copernicus's De Revolutionibus Orbium Coelestium

The work by Nicolaus Copernicus that outlined his heliocentric theory and revolutionized astronomy.

Angular Momentum

The property of a rotating body that is conserved in an isolated system, influencing the motion of planets in their orbits.

Celestial Sphere

An imaginary sphere of arbitrarily large radius, concentric with the Earth, on which all celestial bodies appear to reside from the Earth's perspective.

Stellar Parallax

The apparent shift in the position of a star due to the change in the observer's position, used to measure distances to stars.

The Scientific Method

A systematic approach to research and experimentation that seeks to establish facts and principles.

Renaissance

A period in European history characterized by a renewed interest in classical learning and values, influencing the revival of astronomy.