Why don’t things floating on the surface of the water float out?
Standing by the river, we can see the water carrying things floating on the water. But in ponds and lakes, the ripples of water spreading in circles, spreading out, could not carry a small fallen leaf on the water. The leaves only bob up and down in place according to the water waves. What is that for?
The cause is simple. Water is made up of molecules. Where waves arrive, each water molecule is forced to move. First, they rise to a certain height and then move down. During the descent, the water molecule moves forward and backward. Once it has dropped to a certain height, the water molecule changes to emerge again. During the emergence, the water molecule moves back and forth and returns to its original starting point. Just like that, the water molecule moves the circle in a vertical section. At first glance, the water seemed to follow the waves. Water molecules are only local oscillations. Therefore, when the water wave spreads out, it is impossible to carry things floating on the water surface. That is a bit like a wave caused by the wind blowing into a rice field. At first glance, it seems that the rice grains follow the rice wave, but in fact, they do not move; just under the influence of the wind, the rice flower “nods its back” in turn.