astronomy: the greeks

what 4 big things in society originated from the greeks

scientific thought

philosophy

politics

the arts

what were the 3 main periods of time in ancient greeks

archaic

classical

hellenistic

who were the 3 big guys in the archaic period

Thales, Anaximander, Pythagoras

who were the 3 big guys in the classical period

Socrates, Plato, Aristotle

who were the 3 big guys in the hellenistic period

Aristarchus, Archimedes, Eratosthenes

what event ended the classical period

death of alexander the great

what event ended the hellenistic period

battle of actium and rise of the roman empire

ancient greece was a loose connection of ____________ ____-_______

independent city-states

what were 3 pros of ancient greece being a loose collection of city-states

freedom of thought

active trade

interchange of ideas

what were 2 cons of ancient greece being a collection of city-states

frequent wars

travel was hard

the ancient greeks weren’t special because they were the first astronomers or mathematicians, rather, they were special because they were the first to look for ________ _________ for these phenomena in a systematic way

rational explanations

name the dude:

• founder of greek philosophy

• first to use scientific philosophy

• orderly universe

• diverse natural phenomena could have a common cause

• “all things are water”

• predicted solar eclipse of 585 BC

thales of miletus

name the dude:

• student of thales

• lived in miletus

• gnomon as sundial

• concept of infinity (apeiron)

• mechanical model of universe

• inhabited portion of earth is flat

• the sun and moon are really hollow holes that let fire shine through

anaximander

name the dude:

• founder of geometry

• “all is number”

• cosmos

• venus = morning/evening stars

• earth is a sphere

• discovered 5 regular solids

pythagoras

name the dude:

• moon = sphere made of ordinary matter

• sun = hot sone

• convicted of impeity

anaxagoras

name the dude:

• air = finely divided matter

• four elements = earth, water, air, fire

Empedocles

name the dude:

• atomic theory: all matter made of particles

• milky way is the light from a collection of indistinguishable stars

Leucippus and Democritus

name the dude:

• student of socrates

• dialect method: truth established through dialogue and argument

• 30 “dialogues” laid out his worldview

• metaphysics

• founded academy of athens

• universe is circular motion

plato

name the dude:

• assign the 5 regular solids with building blocks of the universe

  • ex: tetrahedron = fire; octahedron = air

timaeus

name the dude:

• student of plato

• math theory for motion of planets

eudoxus

name the dude:

• student of plato

• recorded sum of human knowledge at the time

• tutored alexander the great

• “on the heavens” book

• transit of venus in front of sun

• order of spheres (planets)

• prime mover

• stars made of 5th element called aether

• first detailed arguments for spherical earth

  • shadow of earth on the moon during a lunar eclipse is round

aristotle

name the dude:

• sun center of universe

• geometry to measure distances to sun and moon

• parallax

  • change in object’s position compared to background

  • 
    

aristarchus

name the dude:

• the word geography

• angle of sun with respect to zenith —> circumference of earth calculation

  • position of sun in syene (egypt) vs alexandria

• 
  

eratosthenes

name the dude:

• length of year to within 6.5 minutes of real value

• cataloged stars

• precession of earth’s rotation axis

• magnitude system to compare brightness of stars

• used epicycles to explain retrograde motion

• 
  

hipparchus

name the dude:

• wrote about all astronomy in books

• refined the geocentric model of the universe

  • deferents, eccentrics, epicycles, equant

• cartographer

• almagest book

ptolemy

what was found in a shipwreck in 1901 off a greek island that modeled the sun, moon, lunar phases, and eclipses, and was probably designed by hipparchus?

• Antikythera mechanism

what is the Antikythera mechanism commonly referred to as? (the world’s first what?)

analog computer

what is made of aether, and therefore was considered “perfect and immutable”

the heavens

what evidence did Aristotle use to determine that the earth is a sphere?

the earth’s shadow during a lunar eclipse is round

which two quarter phases of the moon did aristarchus use to estimate the relative distance of the sun and moon from earth

first and third

what was the basis for the math aristarchus used to calculate the relative distance of the moon and sun from earth

triangle

what did aristarchus specifically measure?

the angle between the sun and moon

what did aristarchus use to measure the relative sizes of the earth, moon, and sun?

size of earth’s shadow during a lunar eclipse

aristarchus, using the size of earth’s shadow during a lunar eclipse, inferred that the sun is how many times larger than the earth? (which was wrong)

20

aristarchus may have got the measurements wrong, but his methods were correct. what two geometric concepts did his methods use?

angles and triangles

Although his model had flaws, he is credited with developing the first well-thought-out geocentric model of the Universe that persisted until the 1500s.

aristotle

He was the pupil of Socrates and Aristotle's teacher. He emphasized the importance of the circle in models.

plato

The primary purpose of describing planetary orbits in terms of epicycles and deferents was to account for the

pattern of direct and retrograde motion of a planet as it moved slowly against the background of stars.

Retrograde motion of a planet when viewed from Earth is caused by

the relative motions of Earth and planet.

In the geocentric model for the solar system developed by Ptolemy, to what does the word “epicycle” refer?

a small circle around which a planet moves while the center of this circle moves around Earth

To determine the actual diameter (in km) of the Moon one can

determine the actual diameter (in km) of the Earth and then use information on the relative size of the Moon with respect to the Earth to deduce the answer.

What observation did Aristarchus use to determine the size of the Moon relative to that of the Earth?

He completed the circle of the Earth's shadow on the Moon during a lunar eclipse and compared it to the observed size of the Moon.