Sound Waves on Pitara Kids Network

Why do We Cup Our Hands When We Shout?

Wed, 21 Aug 2002 23:23:05 +0000

“Go on Sanjay, go on,” we shouted. It was the annual sports meet in our school and the 100 metres sprint was on. The White House runner Deepak was giving our Blue House sprinter, Sanjay, tough competition.

As the sprinters neared the finishing line, and the shouts turned into screams, I noticed something remarkable. Everyone had cupped their hands around their mouths while shouting.

The gesture caught my attention. I had seen that kind of a hand movement in plays and folk dances. What is the reason behind this theatrical gesture?

What does a Train Whistle tell us about the Universe?

Tue, 26 Nov 2002 15:33:03 +0000

I remember my first visit to the railway station as a child of five. The excitement of the approaching train was an experience I have never quite forgotten. At first I heard a train whistle far away, low and distant. As the train got closer, the sound of the whistle not only increased, it became shriller, and difficult to bear. So much so that I covered my ears in alarm!

Once the excitement had passed, I discovered a secret – even with my eyes closed and by just hearing the whistle, I could tell whether a train was approaching or moving away.