The Sun /Interesting Knowledge/

1. How Big is the Sun? How Far is it form us?
Of all the stars that can give out light and heat, the Sun is neither the biggest, nor the smallest. It appears very big because it is the closest star to us. The sun is much bigger than the earth. Its diametr is 1.4 kilometres. If we could put the earth into the sun, the sun could contain 1.3 million earths. If we compare the sun to a basketball, the earth would be only as big as a grain of rice.
The sun is 150 million kilometres from the earth. It is so far away that if we could ever walk to the sun, it would take us 3500 years to get there.
2. What is the Colour of sunlight?
Why does the sun look red at sunrise and sun set? When the sun rises and sets, it goes through a veru thick layer of air and a lot of sunlight is absorbed by air. That's why it looks red. Actually, the white sunlight is formed by the seven colours of red, orange, yellow, green, blue, indigo-blue, and purple. Sometimes a rain-bow might appear in the sky. The seven beautiful colours we see are divided from the white sunlight by the rain drops in the sky. If you paint these seven colours on a disc and turn it real fast. the colours on the disc becomes white.
3. Why does Sunny Sky look blue?
In the sky there is a very thick layer of air which is colourless. So why does the sky look blue? It has something to do with the irradiation of sunlight.
Sunlight is formed by the seven colours of red, orange, yellow, green, blue, indigo-blue, and purple. When the sunlight shines on the air and meets the dust and vapour in the air, the bluelight in the sunlight immediately radiates to all directions, making the sky look blue. It is very easy for the yellow and red colours in the sunlight to go through the thick layer of air and then shine over the earth. Therefore, the sunlight looks yellow the ground.