なぜ指先が水に長く浸かるとしわしわになるの？
When your fingertips stay in water for a long time, they wrinkle not just because the skin soaks up water. It is actually a response controlled by your brain. The brain sends signals to make the blood vessels shrink, causing the skin to form wrinkles. Scientists believe this helps us grip objects better in wet conditions. It's an amazing feature of the human body!
