SESSION 3. THE EARTH IN MOTION

UNIT 1. PLANET EARTH

SESSION 3. THE EARTH IN MOTION

The  Earth’s rotation and its consequences

·         You have to Know…

The earth is not static, it moves steadily through space, following two movements: rotation and orbiting around the Sun.

Rotation movement: It is the movement that the Earth describes spinning around an imaginary axis.

Rotation movement

The axis of rotation is tilted respect to the plane of the orbit that describes the Earth around the sun.

The day, the night and the hours

The rotary motion produces a succession of day and night. Also, the rotary movement produces the time difference between some areas of the Earth.

As the Earth is spherical it is only illuminated on the face opposite to the sun. As it is turning on itself, the lighted face is not always the same. So the illuminated part (day) and the dark part (night) are constantly changing..

Principal consequences of the rotation movement:

·         Day and  night

·         The movement of the Sun on the horizon

·         The existence of the hours of the day

·        Aditional information

The movement of the Sun. The cardinal points and getting your bearings.

The cardinal points allow us to get our bearings. To do this, we have to hold our arms out like a cross. Then we point with our right arm to the East or the place where the Sun rises in the morning.

·        Vocabulary

-       Static: When somebody or something doesn’t move.

-       Steadily: When something happens in regular way.

-       Spinning: If you spin around, or someone spins you around, your body turns quickly to face the opposite direction

-       Axis: It is an imaginary central line. The Earth goes around the axis.

-       Tilted: to move into a position where one end or side is higher than the other, or to make something move into this position

-       Allow: to give someone permission for something

-       Bearings: to find out where you are.

·        Exercises:

1.    Explain how night follows day by using a tennis ball and a torch.

2.    How many hours takes the Earth in it’s rotation movement? Which are the consequences of this rotation movements?

·        Investigator’s corner

-       Imagine that the Earth did not rotate in it’s axis. What would happen?

-      In 1851, Jean Bernard Leon Foucault conducted an experiment that scientifically proved the Earth’s rotation. Find out something about it and write it down in a short summary.