Download Galileo and the Heliocentric Solar System

Quaestio: Why did
the Church try to
silence scientific
discoveries?
Nunc Agenda:
Analyze the map of the
solar system and try to
correctly identify each
celestial body
Classical philosophers like
Ptolemy and Aristotle believed
that Earth was center of universe
This model is called the
Geocentric Model of the Universe
The Church supported the Geocentric
model based on passages from the Bible,
insisting that EVERYTHING revolved around
the Earth, which did not move.
1514- Polish
Astronomer Nicolaus
Copernicus realized
that the way
planets appeared to
move in the sky did
not make sense with
the geocentric
model
He proposed the heliocentric model,
with the sun at the center, to explain
why the planets appeared to move as
they did, and found that the
mathematical calculations worked!
Heliocentric Model of the Universe
Copernicus was not the first
to propose the sun-centered
theory:
 200 BCE- Greek Astronomer
Aristarchus suggested the
Sun was unmoving at the
center of the universe
 476-550 CE- Indian
Astronomer Aryabhata
theorized that Earth spins
on its axis
 800s CE- Afghan Muslim
Astronomer Al-Balkhi wrote
that the planets move in
orbits around the sun
Danish Astronomer Tycho Brahe recorded
observations of the movements of heavenly
bodies, and after his death, German
astronomer Johannes Kepler used Brahe’s
data to calculate the orbits of planets
revolving around the sun.
Tycho Brahe
Johannes Kepler
Still, many were not convinced by the
evidence…
Until Italian Astronomer Galileo Galilei used a
telescope (new Dutch invention for sighting
enemy ships) to observe four moons in orbit
around Jupiter, which disproved the
geocentric belief that everything in the
heavens orbited the Earth.
Galileo promoted the Heliocentric Model, which
the Church considered heresy (contradicting
Church teaching), and claimed that the verses in
the Bible that say the Earth cannot move had been
misinterpreted, which violated the Council of Trent
(only Church can interpret). The Roman Inquisition
banned books by Galileo and put him on trial.
Classwork:
Read about the
trial of Galileo, and
the letters written
between Galileo
and Kepler, and
answer the
corresponding
questions
Been there Done that!
Aristarchus of Samos (200 BCE)
Archimedes, wrote: “Aristarchus brought out a book consisting of
certain hypotheses. . . .
the fixed stars and the Sun remain unmoved, and that the
Earth revolves about the Sun in the circumference of a
circle, the Sun lying in the middle of the orbit.”
added that according to Aristarchus in contradiction to “the
common account” of astronomers, the universe is many times
larger than generally assumed by astronomers, and the fixed
stars are at an enormous distance from the Sun and its planets
Been there Done that!
Vedi Sanskrit texts written in ancient India
Yajnavalkya (c. 9th–8th century BC) recognized that
the Earth is spherical and believed that the Sun was
"the centre of the spheres"
"The sun is stationed for all time, in the middle of the
day. [...] Of the sun, which is always in one and the
same place, there is neither setting nor rising."
Indian astronomy - Aryabhata (476–550)
developed planetary model in which the Earth was taken to
be spinning on its axis and the periods of the planets were
given with respect to the Sun.
Been there Done that!
Islamic Astonomy 9th century
Afghan astronomer Ja'far ibn Muhammad Abu Ma'shar alBalkhi developed a planetary model in which his orbital
revolutions of the planets occur only in the heliocentric theory
Nicholas of Cusa (1401 – 1464)
German cardinal of the Roman Catholic Church
suggested Earth revolved around Sun, and each star a
distant sun with its own planets and inhabitants