Western astronomymotion

A Brief History of Western Astronomy and Motion

King City Astronomy 1Class 2

Zoe Buck

The Most Important Things about WESTERN ASTRONOMY

• Aristotle provided proof that the Earth was round using a lunar eclipse

• People used to think the Sun and planets went around the Earth, this is called the geocentric model , and Ptolemy’s version was the most popular

• Copernicus suggested that the Earth went around the Sun, the heliocentric model, and Galileo provided proof thorugh his telescope

• Kepler came up with three laws of planetary motion• Newton came up with three basic laws of motion,

which explain Kepler’s laws using the concept of FORCE

• Newton saw a connection between a falling apple and the Moon

Aristotle  (384 BC-322 BC)

• Presented observational proof that the Earth is round

Lunar eclipse

The Geocentric Model

Ptolemy (AD 90-AD 168)

• Improved on the geocentric model by proposing that planets have their own spheres that move around the bog spheres – called “epicycles”

• Still had Earth in the center; his model was prominent for more than 100 years

Copernicus (1473-1543)

• Proposed a heliocentric model of the cosmos, rather than a geocentric model

Galileo (1564-1642)

• First to use a refracting telescope to look at the skies

• Considered the “Father of Modern Science”

• All objects fall at the same rate• Confirmed Copernicus’s heliocentric theory using observations

Phases of Venus

• Only explanation was that Venus moved around the Sun

Galileo (1564-1642)

• Confirmed Copernicus’s heliocentric theory using observations1. Phases of Venus2. Sunspots3. Moons of Jupiter

Sunspots

• Proved the Sun was not a “perfect” sphere, that there are imperfections in the heavens

Galileo (1564-1642)

• Confirmed Copernicus’s heliocentric theory using observations1. Phases of Venus2. Sunspots3. Moons of Jupiter

Moons of Jupiter

• Proved that there are objects rotating around other bodies, not everything rotates around the Earth

Kepler (1571 - 1630)

• Used careful observations to establish three laws of planetary motion:1. The orbit of every planet is an ellipse with

the Sun at one of the two foci.2. A line joining a planet and the Sun sweeps

out equal areas during equal intervals of time.

3. The square of the orbital period of a planet is directly proportional to the  cube of the semi-major axis of its orbit.

Kepler’s First Law

Kepler’s Second Law

Kepler’s Third Law

Newton (1642-1727)

• Invented the reflecting telescope• Invented calculus• Founded modern mechanics by

establishing three basic laws of motion1. An object’s velocity will not change

unless acted on by an external force2. Force on an object is

determined by the acceleration of the object, and the mass of that object (F=ma)

3. Every action has an equal and opposite reaction

Newton’s 1st Law

• An object’s velocity will not change unless acted on by an external force

• Velocity: the speed of an object, including what direction it is moving

• Force: something that causes a change in the velocity of an object

Newton’s 2nd Law

• Force on an object is determined by the acceleration of the object, and the mass of that object (F=ma)

• Force: something that causes a change in the velocity of an object

• Acceleration: a change in the velocity of an object

• Force: something that causes an acceleration

Newton’s 3rd Law

• Every action has an equal and opposite reaction

Newton and the Apple

The Most Important Things about WESTERN ASTRONOMY

• Aristotle provided proof that the Earth was round using a lunar eclipse

• People used to think the Sun and planets went around the Earth, this is called the geocentric model , and Ptolemy’s version was the most popular

• Copernicus suggested that the Earth went around the Sun, the heliocentric model, and Galileo provided proof through his telescope

• Kepler came up with three laws of planetary motion• Newton came up with three basic laws of motion,

which explain Kepler’s laws using the concept of FORCE

• Newton saw a connection between a falling apple and the Moon