Download geocentric - Hewlett

Models of the Solar System
1. Geocentric Model of the Solar System
 Geo- Greek word for Earth
 Centric-Greek word for center
In a Geocentric Model of the Solar System,
Earth is at the center of the Universe. So
the Sun, Moon, Stars and Planets are all
revolving around Earth.
In the Geocentric Model, Earth does not
move, it doesn’t even rotate.
Who was the first scientist to say that the
Earth is not the center of the Solar System,
but the Sun?
 Copernicus was first and then Galileo
gave more evidence.
What was Galileo’s evidence?
1. Galileo was the first to use the
telescope to study the nighttime sky.
He noticed that Jupiter had Moons
that revolved around Jupiter and
not Earth.
2. Galileo also observed the different
phases of Venus- which demonstrates
that Venus is revolving around the
Sun
2. Heliocentric Model of the Solar System
 Helio- Greek word for Sun
 Centric- Greek word for Center
So in a Heliocentric Model of the Solar
System the Sun is in the center and all the
planets are revolving around the Sun.
 In this model the Earth Rotates
Which model is accepted today?
How can you prove that Earth rotates?
1. Coriolis Effect
2. Foucault Pendulum
3. Star Trails
4. Day & Night
Which of these 4 could not be explained by
the Geocentric Model?
Coriolis Effect- this phenomenon causes winds
and other moving objects to get curved to the
right in the Northern hemisphere and get curved
to the left in the Southern hemisphere.
- this is caused by Earth’s rotation
Foucault Pendulum- a freely swinging
pendulum will appear to move in a circle
throughout the course of a day
- It is not the pendulum that is really moving
in a circle, it is actually the Earth moving in
a circle beneath it.