WHY DOES IT SEEMS THAT THE SUN IS MOVING?

HAVE YOU EVER WONDER IF THE SUN IS MOVING OR NOT?- We used to believe that the sun is

moving as it rises from the east & sets from the west.

-But the fact is the sun is not moving at all, the earth is the one that is moving.

HOW IS THE EARTH MOVING?

- The earth rotate “spins” around itself “its axis”

every day “24 hours”.

- And this rotation causes “the day & night” on earth ,because as the earth is rotating around itself, one side will be facing the sun so it will have day, while the other side will be far from the sun so it will have night .

- The Earth rotates around its axis “itself” every 24 hours “day”.

- This rotation causes the “day & night” on earth.

The Earth’s motion

“ When something appears to be moving”

The Apparent motion

Examples

-The sun appears to move , it appears to rise from the east & set to the west.

-The stars too appears to be moving in the sky at night

Earth’s rotation causes apparent motion, but the sun and stars are not moving in real/

Take a look at this pictureHave you

ever wonder what is this dark area standing beside you?

It’s your shadow

- It’s the dark area that is formed when the light is blocked by an object.

What is the shadow?

But some times I saw my shadow at different positions,

How this happens?

- This depends on the position of the sun, as the earth move around its axis, the position of the sun changes, that causes the shadow to be found at different positions.

Example

During the early

morning

Shadow is long

During the Mid day

Shadow is short

During the sunset

Shadow is long

- During the sun rise & the sunset:The sun is at the sides of the tree, so a

large part of the tree blocks the sun light, so the shadow is long.

-During the mid day:The sun is above the tree, so only a small part blocks the sun light, so the shadow is short.

- The earth revolves around the sun.- The earth completes one orbit around

the sun in 365 ¼ days.

The sun & the Earth

Revolution: When an object travels around another object.Orbit: It’s the path of the revolving object.

Earth

Orbit

- The axis of the earth is not straight.- It’s titled to an angle of 23.5˚ .

- Earth’s tilt cause the sunlight to strike the earth at different angles .

- (At any given time, each half of the earth gets more or less sunlight, that causes the different seasons)

The Earth’s axis

What causes the seasons to happen on Earth?

- The Earth’s tilted axis & the revolving of the Earth around the sun causes the four seasons to happen on Earth.

The Four seasons

How?

In June: The northern hemisphere is tilted towards the sun. The light strikes at steep angles, so it will have summer

In Dec.: The northern hemisphere is tilted away from the sun. The light strikes at low angles, So it will have winter

-During summer daylight hours are longer than winter and nighttime hours are shorter.

- At the equator the temperature and day hours stay almost the same throughout the year