Ancient Greek and European Astronomers Directions: Read carefully through ALL of the slides presented (total of 18; on a 15 second timer per slide); TAKE BRIEF NOTES on each of the 13 Astronomers presented; When finished, show your notes to the SUB to get a copy of the quiz, STAPLE your PPT notes behind the quiz, and then answer the 13 Matching items on the Quiz provided (YES, open notes!) Then turn your completed quiz in to your class period tray to be graded.

Thales 624-546 B.C. Considered to be the first true “Greek philosopher” Predicted a solar eclipse on May 28, 585 B.C. Known for attempting to find natural explanations for events, rather than supernatural ones

Philolaus 480-385 B.C. The first person to ever think that the Earth was not at the center of the universe. Believed that the Earth and everything else revolved around an object in space called the “Central Fire”

Hipparchus 190-120 B.C. Considered to be the greatest ancient astronomer Developed a very accurate method of predicting eclipses Developed the first catalog of stars, ranking them by brightness, which he called “magnitude”

Pythagoras 575-495 B.C. Mathematician known as “father of numbers” Best known for the Pythagorean Theorem One of the first people to think that Earth was round Said all planets revolved around a central point Thought of the Moon as a planet called “Counter-Earth”

Aristarchus 310-230 B.C. First person to present a heliocentric model of the Solar System, with the Sun at the center This idea was mostly rejected for the next 2,000 years.

Eratosthenes 276-195 B.C. Calculated the circumference of the Earth and the tilt of Earth’s axis with amazing accuracy May have also calculated the distance from Earth to the Sun

Aristotle 384-322 B.C. The teacher of Alexander the Great The most influential of Greek philosophers He believed that the Earth was in the center of the universe, and that the Moon, then the Sun, then the other planets and stars revolved around Earth.

Geocentrism

Ptolemy 90-168 A.D. Roman citizen Changed Aristotle’s geocentric model to include “epicycles” upon which the planets moved This was an attempt to account for the observed “retrograde motion” of planets in the sky

Geocentrism with epicycles

St. Thomas Aquinas 1225-1274 A.D. Italian Catholic priest, considered by many to be the Church’s greatest philosopher Declared in the 1200s A.D. that Ptolemy’s geocentric model with epicycles was a biblical model. Geocentrism became part of Canon Law.

Nicolaus Copernicus 1473-1543 A.D. Polish man who was very religious Astronomy was not his main work, but it is what he is best known for Developed the first comprehensive heliocentric model of the solar system He did this in spite of Canon Law and Ptolemy.

Tycho Brahe 1546-1601 A.D. From Denmark Measured the positions of the planets very accurately for 30 years A popular man with a short temper Brahe never published his work

Johannes Kepler 1571-1630 A.D. German Tycho Brahe’s young assistant When Brahe died, Kepler inherited all of Brahe’s measurements Kepler used the work to provide evidence that firmly supported the heliocentric model of Copernicus

Galileo Galilei 1564-1642 Italian Called the “father of modern astronomy” and “father of modern science” Made significant improvements to telescopes Used telescopes to build scientific support for heliocentrism

Galileo Galilei Galileo’s evidence included: Moons orbit Jupiter—and so not everything orbits Earth There are mountains and craters on the Moon—and so not everything in the heavens is “perfect” Venus goes through “phases” just like the Moon—so it must orbit the Sun

Phases of Venus