A brief history of Astronomy
Or, a few thousand years
of European History in a
• Lived 384-322 BCE
• Born and lived in Greece.
• Studied with PLATO.
• Established his own
• He was an expert on many topics.
• His academy laid the basis of LOGIC,
PHILOSOPHY and NATURAL SCIENCE.
• Many of their theories later proved FALSE!
• Lived about 100-190 CE
• Probably lived in Egypt, nobody knows for sure.
• Was a prominent Astronomer, Geographer and
• Developed the theory of EPICYCLES.
• Promoted the GEOCENTRIC theory of the
This is one of Ptolemy’s famous
diagrams, showing his
conceptualization of the universe.
Here’s a drawing he made showing
his idea of an “epicycle” for Mars.
Here’s an image of Ptolemy making
What do you
think he is
• Lived 1473-1543
• Born and lived in Poland.
• Initiated a scientific revolution but didn’t
live to see it. His first book was published
the year he died.
• Proposed a simpler, Heliocentric model.
• Model still flawed because orbits
considered perfectly Circular.
• Lived 1546 – 1601
• Born to a prominent family.
• Loved learning and studying.
• Invested his own money to
build the best observation
• Became the Royal
Astronomer to the King of
Denmark. Got his own island
for this! Lived and studied
there for 20 years.
• Tyco was very eccentric.
• Eventually fell out of favor with the King
and moved to Prague.
• He is said to have had his nose cut off in a
• Invented many observation tools used by
• On his death, he passed all his data to his
• Lived 1564-1642
• Lived in various places in Italy.
• Manufactured the best telescopes yet!
• Turned the telescope to the heavens and
observed things that had never been seen.
• Galileo devised many experiments that
disproved Aristotle’s worldview.
• Galileo is considered the “father” of
• Galileo believed that people could learn
about nature by observing nature, not just
by studying scripture.
• That view put him at odds with the
• Galileo had to “recant” his writings and
spent his later years under house arrest.
• Lived 1571-1630
• Was Tyco Brahe’s assistant!
• Believed in the Copernican model.
• Used Tyco’s data to support his belief.
• Proposed three “Laws” of planetary
• These laws were among the first “Natural
Kepler was deeply
religious but he was a
Protestant so he did not
feel bound by the
Catholic Church. His
theory moved Earth
from the center of the
Universe and Solar
System, thus putting
him at odds with Rome.
• Invented many more observing techniques
• First to Propose the idea that planetary
orbits are ELLIPTICAL, not CIRCULAR.
Sir Isaac Newton
• Lived 1643-1727
• Lived in England
• Was a genius! Solved many
of the important problems of
• Made important discoveries
in Optics, Fluid physics,
Mechanics, and Astronomy.
Sir Isaac Newton
• Newton’s three Laws of Motion are
taught in Physics classes to this day.
• Law of Gravitation finally provided an
explanation of the motions of planets,
not just a description.
• He came up with important theories
during an extended break from school.
(Universities were closed due to the