WHAT ? WHY? HOW?

1. Why do roads look wet on hot days?

Generally, the light rays from the sun travel towards the earth after suffering the atmospheric refraction, but on a hot day the roads heat up the air to a very high temperature due to which the air right above the roads becomes less dense. Thus, the light rays on reaching the ground suffer further refraction, as a result of which, our brain senses that the light has reached us straight through the atmosphere and we see the image of sky on the ground. Hence the roads appear wet on hot days.

2. Why do mosquito bites itch?

When a female mosquito pierces our skin with its proboscis to suck our blood, it injects some of its saliva into our blood stream, which acts as anti-coagulant and helps the mosquito to draw the blood easily. In response to the presence of this foreign agent, our immune system triggers the release of histamine, which causes the blood vessels near the site of the bite to swell up. The nerves in this area get irritated by the swollen blood vessels. This irritation leads to the itchy sensation.

3. Why do we get tears when we laugh a lot?

When we laugh a lot, our face twists up so much that it puts a lot of pressure on our tear glands thus forcing the tears out. Also, shedding out tears is a body’s way to return to a stable and normal state after the state of high excitement.

4. Why do some of our body parts fall asleep?

There is a vast network of nerves in our body which carries the information in the form of electrical impulses from different body parts to the brain. If a nerve in a certain part of our body gets pressed for a long time, the communication from that body part to the brain gets cut off temporarily. As a result, that part of body doesn’t feel anything due to the lack of communication with brain and goes numb.