Q1.
Have you ever seen papads being dried in the sunlight and clothes hung out to dry?
Answer
Yes. Almost every home in India dries things in the Sun. Papads are laid out on a sheet on the terrace, and washed clothes are hung on a line in the courtyard.
Here is what happens to a wet papad or a wet shirt in the Sun.
- The papad or the cloth has water in it.
- Sunlight falls on it and warms it.
- The heat turns the water into water vapour — water in the form of an invisible gas.
- The vapour mixes into the air and floats away.
- Only the dry papad, or the dry cloth, is left behind.
Other things Indian families dry in the Sun:
| What is dried | Why it is dried |
|---|---|
| Papads, badis, vadiyan | So they become crisp and keep for months |
| Washed clothes and bedsheets | To dry them, and the Sun also kills germs and takes away the damp smell |
| Mango slices for aam papad, amchur | To store the fruit long after the mango season is over |
| Red chillies, turmeric, coriander seed | Dry spices can be ground and stored |
| Grain after the harvest | Damp grain rots; dry grain keeps safely in a sack |
| Cow-dung cakes | Dry cakes burn well as fuel |
| Sea water in salt pans | The water goes and the salt is left behind |
Why this belongs in a chapter on energy: Drying needs heat, and heat is energy. In all these examples the energy is coming free from the Sun. No gas, no electricity, no smoke — and nothing to pay. That is why the book calls the Sun the main source of energy for life on Earth.