We all have conducted tests where 2 glass jars were connected by a thin pipe, we fill one jar with water above the level of that pipe and the other jar will start filling due to gravitational force. It's a normal phenomenon and we probably don't even think much of it even if this property of liquid and gas is essential for a number of life sustaining processes.
But today we will talk about another fascinating property that sustains life on earth. The capillary action.
Ever wondered how trees pull water from the soil and send it up, may be several feet up, to every part of their body? It's capillary action. Water molecules are sticky. They stick themselves to other objects such as cotton, soil etc. They also attract each other. So the moment trees use up some of the water in their body, a vacuum gets created and water molecules, due to their mutual attractions, fill that vacuum and move up.
It has always fascinated me to think how perfect nature is. Even the seemingly simple properties that we so easily take for granted, could be the difference between life and no life on earth. Without this property, trees wouldn't have survived, and without trees, we never would have existed.