Science Tips Chapter 1

1. Rabbits use their legs to pat the ground to convey information. Most of the rabbits that pat the ground with their hind legs are male rabbits. This is a way for them to express their emotions to female rabbits.

2. The largest monkey in the world is the baboon, and the smallest monkey is the pygmy marmoset.

3. Why does ice cream emit steam? Ice cream emits steam because there is a lot of invisible water vapor in the outside air. When it touches the very cold ice cream, it liquefies into mist droplets surrounding the ice cream, and it looks like the ice cream is "steaming".

4. Why do sunflowers always face the sun? The stems of sunflowers contain a wonderful plant growth hormone. This growth hormone is very afraid of light. Once exposed to light, it will go to the backlit side, and at the same time it stimulates the cells on the backlit side to reproduce rapidly. Therefore, the backlit side grows faster than the light-facing side, causing the sunflower to bend towards the light.

5. Why do cicadas shed their skin? The shell (exoskeleton) of cicadas is hard and cannot expand as the cicada grows. When the cicada grows to a certain stage, the exoskeleton of the cicada restricts the growth of the cicada. The cicada removes the original exoskeleton, which is the cicada molt.

6. How do bees make honey? The bees first spit the sweet juice collected from the flowers into an empty beehive. At night, they suck the sweet juice into their honey stomachs for mixing, then spit it out and swallow it again. This cycle of swallowing and spitting should be repeated 100 to 240 times before sweet honey is finally brewed.

7. Why do the stars twinkle? We see the stars twinkling, not because the brightness of the stars themselves changes, but because of the obstruction of the atmosphere. The atmosphere separates us from the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent, and its transparency will change according to the density. So when we look at the stars through it on the ground, we will see that the stars seem to be flashing.

8. Why do people yawn? When we feel tired, a lot of carbon dioxide is produced in the body. When there is too much carbon dioxide, oxygen must be added to balance the body's needs. Because these residual carbon dioxide will affect our body's functional activities, the body will then respond with a protective response, so yawning. Yawning is a deep breathing action, which allows us to inhale more oxygen and expel more carbon dioxide than usual, and also has the effect of eliminating fatigue.

9. Why can snakes walk without feet? Snakes have many scales on their bodies, which is the outermost layer of armor on their bodies. Scales are not only used to protect the body, but also can be their "feet". When a snake crawls forward, its body will be S-shaped. And each scale outside the S shape will be raised to help the snake grasp the uneven road surface when it moves forward. These scales cooperate with the snake's muscles and can push the body forward to crawl, so snakes can walk without feet!

10. Why does a person's hair turn white when he gets old? There is a substance called "melanin" in our hair. The more melanin there is, the darker the hair color will be. If there is less melanin, the hair will turn yellow or white. When humans reach old age, the various functions of the body will gradually decline, and the formation of pigments will also become less and less, so the hair will gradually turn white!

11. Why do fireflies glow? Fireflies glow because they have a light organ at the end of their abdomen. The light organ is full of many phosphorus-containing luminescent substances and luminescent enzymes, which enable fireflies to emit flashing light. In addition to lighting, fireflies also have the purpose of courtship, warning, trapping, etc. This is also a tool for them to communicate. Different types of fireflies have different ways of emitting light, frequency of light emission, and color, and they use this to convey different messages.

12. Why does the stomach growl when hungry? The stomach will growl when hungry. This is because the food eaten before is almost digested. Although the stomach is empty, the gastric juice in the stomach will continue to be secreted. At this time, the stomach will gradually expand as it contracts, and the liquid and gas inside will churn, causing a gurgling sound. Don't be embarrassed by your stomach gurgling next time! This is a normal physiological action.