Drop a rock into the middle of a pond and this action takes place.
Hitting the water that is non-compressible the water comes up the sides
of the rock and is pushed away in all directions. It creates a circular
wave that is moving up and down,and the circle gets bigger and bigger as
it moves towards the shore. Bigger makes the wave lose energy,much like
big light waves(radio) have far less energy as gamma rays. The pond
wave comes to shore as a tiny ripple,and rubbing against the sandy shore
bottom its energy is converted to heat. The pond wave obeys the
square law,and reality is no matter how big the pond is the wave will
never lose all its energy. It will reach the shore. Like a light wave
can go to infinity Bert