The eight-year-old Sharada asked, “What is gravity, Thatha?” I was not prepared for this seemingly simple question, knowing her tenacity to probe deeper. I dropped the pencil I was holding and asked her, “Why does it go down?” “Because you dropped it.”
Then I took the pencil and threw it up and said, “See, I have to throw it up with hand movement for it to go up, but all I have to do is free my hand from the pencil and it drops down”. That held her for a while, but not long. She asked, “Why?” “Because the earth is huge and attracts things”.
She was thoroughly bored discussing the obvious and went away. But I had no intention of letting her or the subject of gravitation slip by, having started a train of thought.
After a short while, she was playing skipping rope but was hardly able to raise her feet beyond one foot. I challenged her to jump up higher which she couldn’t. I told her, “This is because the earth is pulling you down. But if you go to the moon, you can go up as much as that six-storey building”. She looked at me with utter disbelief.
I said, “That is because the moon is much smaller and hence gravitation is very low”. In the evening, she googled and showed me videos of astronauts and objects floating in space ships. I was amazed, not so much because of her ability to google, but the sheer fact she had sustained interest in the subject.
I told her that they are so far away from earth or the moon, they experience very little gravitation. With total adoration, she said, “you are great, Thatha”. I said it was not me, the credit goes to Sir Isaac Newton. I didn’t yet tell her about warped space-time and the bending of light due to gravitation.
It was time for Sharada and her parents to go back to the US, and we accompanied them with a stop in London. there, we had several choices to spend the day. While shopping in Bond Street and a visit to Harrods was the popular choice, I preferred to visit Cambridge.
Not surprisingly, Sharada wanted to join me. Well, it was glorious, walking through the Hall of Fame, a ride in River Cam, Grasshopper clock at the Corpus Christie college in honour of Stephen Hawking,and lunch in Eagle pub where Watson and Crick announced their work on DNA which later won them the Nobel.
The highlight was the well-preserved tree where Newton got a clue on gravitation by a falling apple.
Sharada was lost in thought looking at the tree. A budding physicist?
The visit to Cambridge was worthwhile. And I saved a hole in my pocket too.
Watch latest videos by DH here: