Towards a just, equitable, humane and sustainable society

Social Science - Rotation and Revolution


Our Earth is the only planet in the solar system that supports life. All living beings - from unicellular organisms to complex organisms derive energy from the sun. Half the world sleeps in the dark while the other half is busy in bright sunlight. Have you ever wondered how night and day happen? We enjoy the warmth of the sun in winter while we yearn for milder temperatures during summer. Why do we have different seasons? The following videos provide the scientific explanation for the questions mentioned above. 

Rotation and Revolution of the Earth

The video describes the rotation and revolution of the earth.  It explains why we have 24 hours in a day and 365 days a year.  The axis of the earth and its role in the occurrence of day and night are also explained.

Title of the video: Rotation and Revolution of Earth | Educational Video for Kids

https://www.youtube.com/watch?v=cDed5eXmngE

Activities on Rotation and Revolution

Materials: 60 watts bulb (yellow), globe, balls of different sizes.

The activity needs to be done in a dark room.

Hang the yellow bulb at the center of the room which depicts the Sun.

  • Hang 7 balls at appropriate distances from the light bulb. These depict the 7 planets in the solar system other than the earth.
  • Place a globe marked with names of continents, tilted at 23.5° at the third position from the light bulb.
  • This set up models the solar system.
  • Switch on the yellow bulb and rotate the globe slowly in the anti-clockwise direction.
  • The light from the bulb falls on the globe. It can be explained that the side of the globe which is illuminated by light experiences day and the other half experiences  night.
  • The teacher can explain to students that the alternating experience of day and night is due to the rotation of earth and not all parts of the globe receive sunlight at the same time.   

Seasons on Earth

This video explains why there are different seasons like summer, winter, autumn experienced  in different places in the earth at a given time. The reason why a few countries have short summers / winters is also described.

Why Do We Have Different Seasons? | California Academy of Sciences

https://www.youtube.com/watch?v=WgHmqv_-UbQ

Activity for Revolution (Seasons)

Revolution and the formation of seasons are correlated. Seasons occur due to revolution of earth around the sun.

  • Move the globe in an elliptical path around the light bulb without stopping the rotation of the globe.
  • Since the earth is tilted at 23.5°, the angle of impact of the sun’s rays on the earth differs at different places.
  • When the earth is farthest from the sun in the elliptical orbit, (month of July) and the tilt of the earth causes the north pole to face the sun; the northern hemisphere and north pole experiences summer.
  • When the earth is near the sun in the elliptical orbit, (month of january) and the tilt of the earth causes the south pole to face the sun; the south pole and the southern hemisphere experience summer.
  • The teacher can explain that the other seasons occur as the earth moves along the eliptical path  orbiting the sun.

Phases of Moon

This animated video explains the phases of moon. It shows the position of the moon at different times and how it is viewed from the earth. Phases like the new moon, first quarter and full moon are clearly explained.

Phases of the Moon Explanation for kids -Animation Lesson Unit

https://www.youtube.com/watch?v=bWeaQctUp1c

Activity for the phases of Moon

  • Place a ball on the holder and the light bulb is fixed in the center.
  • The completed setup should be like - you (earth), holding of the ball  (moon) and light bulb (sun)
  • Switch on the light and hold the ball between you and the light. In this phase we cannot see the moon or it can said that the moon is dark. This phase is called the newmoon.
  • Now hold the ball at 30° where you can see a thin crescent.
  • Gradually increase the angle and observe the variances.
  • When the moon is placed at 180° from the starting point, we can see the full moon.
  • The teacher can tell students that it takes around 15 days to see the full moon from the day of the new moon.

Eclipses

Solar eclipse and lunar eclipse are explained in detail in videos mentioned below.

Title of the video: Solar Eclipse | The Dr. Binocs Show | Educational Videos For Kids

https://www.youtube.com/watch?v=E6OtLfszaVI

Title of the video: Lunar Eclipse | The Dr. Binocs Show | Educational Videos For Kids

https://www.youtube.com/watch?v=LH-aSizsx1o

Activity on Eclipses

  • The teacher explains that eclipses occur when the sun, the earth and the moon are in a straight line.
  • The ball is placed in between globe and light in a straight line. This is solar eclipse. The sun is bigger in size so the moon cannot hide it completely. From the earth we can see the outer ring of sun.
  • Place the globe between the ball and the light bulb. Now the earth shadows the moon. This is called lunar eclipse.

Grade: 
6

Term: Term 1

Subject: 
Science