Copyright 2004 Science Enhancement Programme

The Earth Which picture is correct?

A

B

C

Great Britain

Brazil India Great Britain

Great Britain

India

India

Brazil

Brazil

Copyright 2004 Science Enhancement Programme

B

Why? Newton said – GRAVITY!

Gilbert said – MAGNETISM!

What evidence is there ?

Great Britain

BrazilIndia

There is no feeling of movement when you stand still on the Earth.

The stars move across the sky.

The Moon rises in the east, moves across the sky and sets in

the west.

EAST WEST

Some planets change direction as they move across the sky.

Scientists have observed moons going around the planet Jupiter.

The Sun rises in the east, moves across the sky and sets in the

west.

EAST WEST

Other evidence

• The North Star doesn’t move in the sky.• Planets move across the sky from west

to east.• The Moon’s appearance changes each

day (phases of the Moon).• Stars are in patterns (constellations),

which move around the North Star.

Babylonians 2000 BCE• The Universe is made of a number of spheres,

like the layers of an onion.• The Sun, planets and stars are attached to these

spheres and move around the sky as the spheres move around the Earth.

• The Sun and Moon always move eastwards on their sphere.

• Inferior planets move eastwards then reverse direction.

• Superior planets usually move eastwards. They move westwards very rarely.

• Planets change speed and brightness over time, but there is a pattern in these changes.

Aristarchus 250 BCE• The Sun is big and is the only source of light in

the Universe, therefore it must be at the centre of the Universe.

• The Sun is about twenty times bigger than the moon, but it is twenty times further away.

• The stars appear to move across the sky because the Earth is rotating.

• The planets reflect light from the Sun and are further from the Earth than the Sun is from the Earth.

Copernicus 1543 CE• The Sun is at the centre of the Solar

System.• The Earth rotates on its axis once a day.• The Earth travels around the Sun once

every year.• Planets move in circular paths (called

orbits) around the Sun.• The order of planets from the Sun is:

Mercury, Venus, Earth, Mars, Jupiter, Saturn.

Kepler © 1600 AD

• The Sun is at the centre of the Solar System• The Earth rotates on its axis once a day• The Earth travels around the Sun once every

year• Planets move in elliptical paths (called orbits)

around the Sun• The order of the planets from the Sun is:

Mercury, Venus, Earth, Mars, Jupiter, Saturn.

Aristotle/Ptolemy © 150 BC• The Universe is made up of fifty-five crystal

spheres.• The Sun, planets and stars are attached to these

spheres.• The spheres rotate at different speeds.• The Earth is at the centre of the spheres.• Then the order is: Moon, Mercury, Venus, Sun,

Mars, Jupiter, Saturn, stars.• The outermost planet is called the ‘Prime Mover’.

As it rotates it makes the inner spheres rotate.

Bible © 1500 BC• The Universe is made up of a number of spheres, like the

layers of an onion.• The Sun, planets and stars are attached to these spheres

and move around the sky as the spheres move around the Earth.

• The Sun and Moon always move eastwards on their spheres.• Inferior planets move eastwards then reverse direction• Superior planets usually move eastwards. They move

westwards very rarely.• Planets change speed and brightness over time, but there is

a pattern in these changes.

? Questions ?1. What daily observations supported the ancients’

view that the Earth was the centre of their universe?

2. Were the ancients adopting a scientific method?3. Were the people who put forward these ideas

poor scientists, if we know they were wrong? Explain your answer.

4. What other evidence was used to develop the modern view that the Earth orbits the Sun?