The world at the bottom of the sea is a quiet place. Whether boats speed around, or storms assault the surface of the sea, the denizens of the deep lead a serene life. Time flows quietly at the bottom of the sea, far from the noisy world of the sea's surface. Water in deep parts of the ocean is heavier than that of shallower parts. This condition is called stable stratification. In the same way, the stratosphere in the atmosphere is also stably stratified. However, the waves from the troposphere are transmitted up through the stratosphere, so things are pretty noisy up there. What makes the depths of the ocean and the stratosphere different?