Cha!

We were babysitting our grandson, Ian, on a rainy day. Since we were stuck indoors, we spent the day playing on his bedroom floor. While building a castle with blocks we heard a sharp crack of thunder overhead. Ian looked up with concern on his face and said, "Cha!"

I said, "That's thunder! You'll sometimes hear it when it's raining." He nodded his head and placed another block on the castle. A few minutes later there was another rumble. He pointed up and again said, "Cha!" You see, he was just learning to talk and sometimes had a hard time expressing himself with words.

I told him the noise is called thunder and added that it's created by lightning in the sky. The lightning is caused by an electric discharge between water drops in the clouds. The electrical buildup on each drop is very small but the huge number of water drops creates a large electrical difference between different portions of the cloud. Then a reaction happens to balance the electrical build-up, either within the cloud or between the cloud and the ground. When lightning moves through the air it increases the temperature of the air. The air then cools rapidly. This rapid expansion and contraction of the air gives off the sound wave that we hear as thunder. Think of a balloon popping. There is a sudden release of noise due to the rapid expansion of air.

He gave me a dismissive look as though I was crazy and placed another block on the castle. Chris rolled her eyes at my explanation before adding another block to the structure.

When the third rumble of thunder came. Ian looked squarely at me and with determined emphasis declared, "Cha!" Chris and I shrugged as we put the last block on top of our castle. Ian summarily knocked the whole thing down and said, "Again!"

Driving home that night we saw a bright streak of lightning in the sky up ahead. We glanced at each other and with resignation said, "Cha!"