Page 116 - SST Class 06

G. Answer the questions in detail :
1. What would have happened if the Earth had no motions?
2. What is the difference between summer solstice and winter solstice?
3. Write about the equinox.
4. What is revolution?
5. How are days and nights caused?
6. How do revolution of Earth result in winter and summer seasons?

1. The speed of the Earth’s rotation decreases from the Equator to the poles, why?
2. As you know that the sun is the only source of heat and light on the Earth but it is stationary and
Earth is a sphere. Then how do different parts of the Earth get light?

Nicolaus Copernicus

Nicolaus Copernicus was born in Thorn, Poland on February 19, 1473. He was the son of a wealthy
merchant. Copernicus studied mathematics and astronomy at the University of Krakow.

In Copernicus’ time most astronomers believed the theory the Greek
astronomer Ptolemy had developed more than 1,000 years earlier. Ptolemy said
the Earth was the centre of the universe and was motionless. He believed all
other heavenly bodies moved in complicated patterns around the Earth.
Copernicus felt the Ptolemy’s theory was incorrect. Sometimes between 1507
and 1515, he first circulated the principles of his heliocentric or Sun-centered
astronomy. Copernicus’ observations of the heavens were made with the naked
eye. He died more than fifty years before Galileo became the first person to
study the skies with a telescope. From his observations, Copernicus concluded
that every planet, including Earth, revolved around the Sun. He also determined that the Earth rotated
daily on its axis and that the Earth’s motion affected what people saw in the heavens. Copernicus did
not have the tools to prove his theories. By the 1600s, astronomers such as Galileo would develop the
physics that would prove he was correct. Copernicus died on May 24, 1543.

Contemporary Social Science-6
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