1. Infants have more bones than adults.

A newborn baby has about 300 bones, but as the baby grows, some of these bones gradually fuse together. In adulthood, the human body has 206 bones.

2. Stomach acid can corrode metals.

Human stomach acid is extremely acidic (pH value of about 1.5-3.5), and can even corrode metallic iron. However, the stomach lining is constantly renewed to prevent stomach acid from "digesting" itself.

3. Fingerprints are for preventing slippage, not for identity verification.

The evolutionary significance of fingerprints lies in increasing friction, which helps with gripping objects. It wasn't until recent times that people discovered their unique characteristics could be used for identification.

4. The eye has over 500 million "pixels".

The human eye has approximately 120 million photoreceptor cells (rod cells) + 7 million (cone cells). If we compare it to a camera, it is equivalent to about 576 million pixels—far exceeding most cameras!

5. Your DNA could travel to and from the moon thousands of times.

If all the DNA in the human body were unfolded and laid end to end, the length would be enough to travel between the Earth and the Moon about 6,000 times (about 30 billion kilometers).

6. Yawning is contagious, but it may only be effective on people with strong empathy.

Being "caught" by someone yawning may be related to mirror neurons in the brain, reflecting your empathy. People with autism or those who are withdrawn may not be easily affected.

7. The idea that the tongue has a "taste map" is incorrect.

Traditionally, it is believed that different areas of the tongue are responsible for different tastes (such as sweet at the tip of the tongue and bitter at the back of the tongue), but in reality, all areas can perceive all tastes, only with slight differences in sensitivity.

8. A sneeze can travel faster than a typhoon.

When you sneeze, the droplets can be ejected at speeds of up to 160 kilometers per hour (about 45 meters per second), which is equivalent to the speed of a typhoon, and can even be ejected up to 3 meters away in an instant!

9. The appendix may not be entirely useless.

The appendix was previously thought to be a vestigial organ, but research has found that it may store beneficial gut bacteria, helping to restore gut microbiota balance after diarrhea or infection.

10. Humans are the only animals that shed tears because of emotions.

Animals shed tears mostly due to physiological stimuli (such as foreign objects entering the eyes), while humans are the only species that shed tears due to emotions such as sadness and being moved.