NCERT Solutions Curiosity Chapter 1 Chapter opening — In-text Questions

Yes. In the Preparatory Stage (Classes 3, 4 and 5) we learnt through Our Wonderful World and The World Around Us — and almost all of it was discovery rather than memorising.

• We observed — the shapes of leaves, the ants marching in a line, the Moon changing shape night after night.
• We collected and sorted — seeds, pebbles, feathers, pictures of animals and birds.
• We did things with our hands — grew gram seeds on wet cotton, made a paper windmill, floated and sank things in a bucket of water.
• We talked to people — asked grandparents about the games and food of their childhood, visited the market and the post office.

In the words of the textbook:

So science is not a fat book of facts to be learnt by heart. It is a way of working. Break the definition into its three parts:

• Thinking — asking questions, making guesses, reasoning about what the answer could be.
• Observing — looking carefully at things around you and noticing what actually happens.
• Doing — trying things out, experimenting, testing whether your guess is right.

The book compares science to two things:

• A big adventure — we ask questions, explore and try to understand how things work.
• A giant, unending jigsaw puzzle — every discovery adds one more piece. Sometimes we find a piece was put in the wrong place and has to be moved. That is why new discoveries keep changing our understanding of the world.

Yes — and this is a perfect example of a question that begins with simple observation.

What you observe: on a clear, dark night, away from street lights, thousands of tiny points of light are seen. They twinkle, and some look brighter than others. The Moon, by contrast, does not twinkle.

Why it happens:

• A star gives out its own light. Deep inside a star, matter is packed so tightly and is so hot that it releases enormous amounts of heat and light. Our Sun is also a star — the nearest one — which is why it looks like a huge ball of fire and the others look like pinpricks.
• Stars look tiny only because they are unimaginably far away.
• They seem to twinkle because their light passes through the moving layers of air around the Earth, which bend the light a little this way and a little that way. The Moon and planets are much closer and look like small discs rather than points, so their twinkling is not noticed.

Yes — flowers really do open and close at fixed times, and it is not an accident.

What you observe: a lotus and a sunflower open in the morning sunlight and close by evening. Raat ki rani and the brahma kamal do the opposite — they open after dark. Tamarind and rain-tree leaflets fold up at night.

Why it happens: a plant has no eyes or brain, but it can still sense its surroundings.

• The petals respond to light and darkness, and to the rise and fall of temperature between day and night. One side of the petal grows or swells with water a little faster than the other, so the petal bends outward and the flower opens.
• Plants also have an inner “body clock” of roughly 24 hours, so they begin to open a little before the sunlight actually arrives.
• The timing is useful to the plant. Day-blooming flowers open when bees and butterflies are active; night-blooming flowers open when moths and bats are about, and they are usually white and strongly scented so that these visitors can find them in the dark.