Getting my students to complete an online lesson about the water cycle inspired this write-up. I’m quite proud of myself for digesting the information and coming up with something that has a Sensei spin.
Air. You probably know that we need it, together with food and water, to survive. But did you know that there are other interesting facts about air?
For example, air is a poor conductor of heat. Many aquatic insects, such as beetles, trap air in bubbles to breathe underwater. This enables them to survive in hot weather. Since air is a poor conductor of heat, the beetle gains heat from the surroundings at a slower rate, which aids in it withstanding high temperatures.
On the other hand, mammals like the polar bear have thick fur to help them survive in cold places. Since air is trapped within the thick fur, the heat transfer from the polar bear’s body to the surroundings is slowed down. This also explains why winter clothing typically consists of thick layers of cotton that trap air. Fashion designers might have gotten their inspiration from this adaptation!
Another interesting property of air is that it allows certain pond plants to float on water. The water hyacinth can float on water due to the air spaces trapped in its swollen leaf stalks. Similarly, the tiny hairs on the leaves of the water fern trap air, allow it to stay afloat. Such buoyancy is important for water plants to trap sunlight to make food during photosynthesis.
There is no doubt that air provides us with a variety of benefits. We should endeavour to cultivate eco-friendly habits that prevent air pollution.
Air
- Aquatic plants contain air pockets that trap air which enables the plant to float on water
- Air is a poor conductor of heat, so it slows down heat loss to the surroundings. This is why winter clothing is made of a thick layer of cotton. This layer of cotton traps air, so our body will lose heat to the surroundings slower.
- Water is a better conductor of heat than air.
- We should never leave any animal locked inside a car in an open car park. The car absorbs heat from the sun and the temperature inside the car increases. This causes the living thing inside the car to perspire and breathe more. The oxygen level decreases more rapidly and eventually the living thing will be deprived of oxygen to stay alive.
- Human body temperature is regulated by the brain. When it gets too cold for the body, the brain sends nerve impulses to the skin, causing the hair muscles to contract and make hair stand on end. Hair on the skin will trap more warm air if they are erect and so help to reduce heat loss from the body.
- Dry air loses heat quicker than wet air, so deserts get cold at night-time, especially in the winter.