Tuesday, February 10, 2015

Anusha in wonderland Part – 20

Anusha’s mom had taught about the directions.

She knew that Sun rises in the East and goes to West in the evening. If she stood facing east, spread her hands both sides, right hand shows South and left hand shows North.

In the night while walking with her dad, she told that she had learned the directions from mom. Dad asked her, "Tell me which is East?"

 Anusha got confused as there was no sun in the sky but all stars.

Dad told that we can find the directions by looking at stars also. He told her how earth rotates and but we don’t know about  it as we are also rotating with earth. However, we feel that stars in the sky move. Sun is a star and very near to us so we see its movement in the daytime. At night we can see that stars also move.
 Anusha looked in the sky in amazement. “Is it so? Then how to find direction in the night if there is no sun?”

Dad showed her Star Polaris on the north side in the sky and told her that it does not move like other stars? He explained that earth rotates keeping her north and south poles in line with north star.

He told her the story of Dhruva who got blessing from god and gave him such a position in the sky that nobody can move him from there. Dhruva is that north pole star.

Dad asked “If we stand facing  Star Polaris (North pole star) , the direction in front of us is north. Can you now tell me other directions?”

Anusha was clever. She knew that if she is facing rising sun her  left hand side was north. She spread her hands and slowly turned such that her left hand was in the direction of north pole star. Now she could tell all directions as in her front side was east, right side was south and backside was west.
 
Dad was happy. “Good. This is how ancient people were determining direction  in the sea at night. Now we can use magnetic compass which shows north direction in any place without looking to sky.”

He told her that all maps are drawn on paper with North direction facing top.Anusha was proud about her line girls who help all people to find direction and locations on map.

He showed him world map and the north arrow on it. He told that when the north is pointing towards top we can recognise the shapes of continents.  
 Anusha decided to  draw similar map of her magic math school and show classrooms, playground, trees, roads and hills, river and sea with prominent North arrow.


Anusha realised that all these directions are nothing but invisible straight line girls.She spread her hands wide and turned about herself. Now she was a fixed point her hands were like line girls showing different directions. It was like hour, minute and second hands in the clock.

She decided to make clock with circle, point and three line girls in her magic math school. She would ask the line girls to move at different speeds keeping their one end fixed at center point. She now understood that each line becomes horizontal, slant and vertical as time changes .


 Her dad told her that  turning round is measured in terms of angles. But the measurement is not done in the way, clock hands move, but in the opposite way also called as anticlockwise rotation.