
The Milky Way
... Obelisk angle difference = 7 degrees 7/360 = 500/C C = (500 . 360 ) / 7 = 26,000 miles ...
... Obelisk angle difference = 7 degrees 7/360 = 500/C C = (500 . 360 ) / 7 = 26,000 miles ...
Lesson 1- Space
... Understanding of the Solar System • Ptolemy (Claudius Ptolemaeus) 2nd Century C.E. Geocentric Universe: • Earth is the centre of the Universe • Earth doesn’t move and everything else goes around it • Earth is round (well he was right about that!) ...
... Understanding of the Solar System • Ptolemy (Claudius Ptolemaeus) 2nd Century C.E. Geocentric Universe: • Earth is the centre of the Universe • Earth doesn’t move and everything else goes around it • Earth is round (well he was right about that!) ...
Early Observers (The Beginnings of Astronomy)
... Planets traveled in smaller circular paths as they traveled around the Earth (epicycles and deferents) Popular model of universe for 1,500 years. ...
... Planets traveled in smaller circular paths as they traveled around the Earth (epicycles and deferents) Popular model of universe for 1,500 years. ...
How has the model of the solar system changed over time?
... of planet orbits, not the circle. This idea went against the 2,000 years of belief! Kepler had a hard time convincing other scientists of his time that planet orbits are not circles. Even the great scientist, Galileo, ...
... of planet orbits, not the circle. This idea went against the 2,000 years of belief! Kepler had a hard time convincing other scientists of his time that planet orbits are not circles. Even the great scientist, Galileo, ...
Things to do today Terminal, “Astronomy is Fun”
... 2 A planet moves along its orbit with a speed that changes in such a way that a line from the planet to the Sun sweeps out equal areas in equal intervals of time. ...
... 2 A planet moves along its orbit with a speed that changes in such a way that a line from the planet to the Sun sweeps out equal areas in equal intervals of time. ...
Understand Planetary Motion
... Possibly the best observational astronomer… ever Measured stellar and planetary positions with outstanding precision! ...
... Possibly the best observational astronomer… ever Measured stellar and planetary positions with outstanding precision! ...
Astronomical history
... (b) Where did Ptolemy place the stars in his model? In this model Ptolemy places the stars outside of the revolving planets. The sun is an example being the first star in our solar system and being the furthest away eluding to that the stars were placed outside of our solar system. (c) Ptolemy knew ...
... (b) Where did Ptolemy place the stars in his model? In this model Ptolemy places the stars outside of the revolving planets. The sun is an example being the first star in our solar system and being the furthest away eluding to that the stars were placed outside of our solar system. (c) Ptolemy knew ...
proposed another geocentric _ _ _ _ _.
... WORDBANK: rotated, Second, axis, mountains, astronomers, heliocentric, orbited, greater, theory, Sun, centre, orbit, position, motion, distant, planets, elliptical, speed , lunar, longer Copernicus (1473-1543) proposed that the sun is stationary near the _ _ _ _ _ _ of the universe. His _ _ _ _ _ _ ...
... WORDBANK: rotated, Second, axis, mountains, astronomers, heliocentric, orbited, greater, theory, Sun, centre, orbit, position, motion, distant, planets, elliptical, speed , lunar, longer Copernicus (1473-1543) proposed that the sun is stationary near the _ _ _ _ _ _ of the universe. His _ _ _ _ _ _ ...
Chapter3 - The Science of Astronomy-ppt
... their ancient astronomical roots. • 24 hour day – the time it takes the Sun to circle our sky. • Month – comes from the lunar cycle. • Calendar Year – Based on the cycle of the seasons. • Days of the week – named after the seven “naked-eye” objects that appear to move among the constellations. (Sun, ...
... their ancient astronomical roots. • 24 hour day – the time it takes the Sun to circle our sky. • Month – comes from the lunar cycle. • Calendar Year – Based on the cycle of the seasons. • Days of the week – named after the seven “naked-eye” objects that appear to move among the constellations. (Sun, ...
History of Astronomy
... Aristotle’s and Ptolemy’s model of the universe was reintroduced to scholars. 1. The stationary Earth is at the center of the universe. 2. The planets and other celestial bodies travel in perfect circles around it. 3. The heavens are made of a perfect, unchanging substance different from substances ...
... Aristotle’s and Ptolemy’s model of the universe was reintroduced to scholars. 1. The stationary Earth is at the center of the universe. 2. The planets and other celestial bodies travel in perfect circles around it. 3. The heavens are made of a perfect, unchanging substance different from substances ...
The History of Astronomy
... dominated thinking for 1800 years. • Earth is made up of only four elements: earth, water, air, and fire. • The celestial bodies were perfect and divine, and made of a fifth element called Aether. ...
... dominated thinking for 1800 years. • Earth is made up of only four elements: earth, water, air, and fire. • The celestial bodies were perfect and divine, and made of a fifth element called Aether. ...
Ancient Civilizations Ancient Greek Astronomers Ancient Greek
... Models were generally wrong because they were based on wrong “first principles”, believed to be “obvious” and not questioned: 1. Geocentric Universe: Earth at the Center of the Universe. 2. “Perfect Heavens”: Motions of all celestial bodies described by motions involving objects of “perfect” shape, ...
... Models were generally wrong because they were based on wrong “first principles”, believed to be “obvious” and not questioned: 1. Geocentric Universe: Earth at the Center of the Universe. 2. “Perfect Heavens”: Motions of all celestial bodies described by motions involving objects of “perfect” shape, ...
Lesson 4d Models of the Solar System
... small circle (an epicycle) The centre of the epicycle moved on a bigger circle called a deferent. Earth is still at the centre (geocentric) ...
... small circle (an epicycle) The centre of the epicycle moved on a bigger circle called a deferent. Earth is still at the centre (geocentric) ...
Powerpoint
... (356-323 BC) • Much of the knowledge of the world came together as the rule of Alexander spread across Europe, Asia, and Northern Africa. • Founded the city of Alexandria • Library of Alexandria contained the written works and inventions of many great thinkers and scientists. ...
... (356-323 BC) • Much of the knowledge of the world came together as the rule of Alexander spread across Europe, Asia, and Northern Africa. • Founded the city of Alexandria • Library of Alexandria contained the written works and inventions of many great thinkers and scientists. ...
Early Astronomy
... The planets (Mercury, Venus, Mars, Jupiter and Saturn) appeared only as points of light on the sky, like the stars, but unlike the Sun and Moon. These objects received special attention because they: moved against the background of stars, are always located within several degrees of the ecliptic ...
... The planets (Mercury, Venus, Mars, Jupiter and Saturn) appeared only as points of light on the sky, like the stars, but unlike the Sun and Moon. These objects received special attention because they: moved against the background of stars, are always located within several degrees of the ecliptic ...
an object that moves around another object in space
... The movement of any object in orbit, such as Earth moving around the Sun, which takes 365 ¼ days to complete ...
... The movement of any object in orbit, such as Earth moving around the Sun, which takes 365 ¼ days to complete ...
Today`s Powerpoint
... But if you support geocentric model, you must attribute retrograde motion to actual motions of planets, leading to loops called “epicycles”. ...
... But if you support geocentric model, you must attribute retrograde motion to actual motions of planets, leading to loops called “epicycles”. ...
The - Pennsylvania State University
... Reasons for Theories of Geocentricity • Claudius Ptolemy of Alexandria (150 AD) – Utilised the geocentric model, that earth was the center of the universe, to predict with far greater accuracy the motions of known celestial bodies. This reinforced the idea of geocentricity over heliocentricty among ...
... Reasons for Theories of Geocentricity • Claudius Ptolemy of Alexandria (150 AD) – Utilised the geocentric model, that earth was the center of the universe, to predict with far greater accuracy the motions of known celestial bodies. This reinforced the idea of geocentricity over heliocentricty among ...
Introduction
... planets' orbits - solid crystal spheres do not exist • lack of parallax implies large distances to stars in heliocentric model • preferred geocentric model • hybrid model – Earth at centre, Moon and Sun orbit Earth, other planets orbit ...
... planets' orbits - solid crystal spheres do not exist • lack of parallax implies large distances to stars in heliocentric model • preferred geocentric model • hybrid model – Earth at centre, Moon and Sun orbit Earth, other planets orbit ...
1 Timeline 2 Geocentric model
... • Sometimes the eccentric was slightly off center from the center of the Earth Ptolemy’s Geocentric Model • Uniform circular motion could not account for speed of the planets thus Ptolemy used a device called the equant • The equant was placed the same distance from the eccentric as the Earth, but o ...
... • Sometimes the eccentric was slightly off center from the center of the Earth Ptolemy’s Geocentric Model • Uniform circular motion could not account for speed of the planets thus Ptolemy used a device called the equant • The equant was placed the same distance from the eccentric as the Earth, but o ...
Geocentric model

In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a description of the cosmos where Earth is at the orbital center of all celestial bodies. This model served as the predominant cosmological system in many ancient civilizations such as ancient Greece including the noteworthy systems of Aristotle (see Aristotelian physics) and Ptolemy. As such, they believed that the Sun, Moon, stars, and naked eye planets circled Earth.Two commonly made observations supported the idea that Earth was the center of the Universe. The stars, the sun, and planets appear to revolve around Earth each day, making Earth the center of that system. The stars were thought to be on a celestial sphere, with the earth at its center, that rotated each day, using a line through the north and south pole as an axis. The stars closest to the equator appeared to rise and fall the greatest distance, but each star circled back to its rising point each day. The second observation supporting the geocentric model was that the Earth does not seem to move from the perspective of an Earth-bound observer, and that it is solid, stable, and unmoving.Ancient Roman and medieval philosophers usually combined the geocentric model with a spherical Earth. It is not the same as the older flat Earth model implied in some mythology, as was the case with the biblical and postbiblical Latin cosmology. The ancient Jewish Babylonian uranography pictured a flat Earth with a dome-shaped rigid canopy named firmament placed over it. (רקיע- rāqîa').However, the ancient Greeks believed that the motions of the planets were circular and not elliptical, a view that was not challenged in Western culture until the 17th century through the synthesis of theories by Copernicus and Kepler.The astronomical predictions of Ptolemy's geocentric model were used to prepare astrological and astronomical charts for over 1500 years. The geocentric model held sway into the early modern age, but from the late 16th century onward was gradually superseded by the heliocentric model of Copernicus, Galileo and Kepler. There was much resistance to the transition between these two theories. Christian theologians were reluctant to reject a theory that agreed with Bible passages (e.g. ""Sun, stand you still upon Gibeon"", Joshua 10:12 – King James 2000 Bible). Others felt a new, unknown theory could not subvert an accepted consensus for geocentrism.