The Shape of Turbulence
Just like artists have been attracted to turbulent flow for centuries, scientists, too, have been studying the flow of liquids for many years, yet even to this day, they can’t make a claim that they fully understand what is happening. While they do have equations that describe the flow, solving these equations and understanding them is different from having them. The most fundamental challenge of the flow of the fluids is that it seems that everything influences everything else at every single point in time. This is very different from other types of equations where it is possible to fix certain variables and study the other ones. This sensitivity and rapid changes of flow make it impossible to predict what happens and to analyze the predictions in the way scientists are able to do so with other equations and processes in nature.
One of the first people to make significant process deciphering the shape of turbulence was Lewis Fry Richardson, the mathematician responsible for the concepts that are now known as the fractal structures. He was interested in the flows of fluids partly because he was curious about predicting the weather. He suggested that flows move in cascades where the previous level moves on to the smaller one until the smaller levels get dissipated somehow. Just like with fractals, the flows of fluids have hidden regularity to them, which means that they do have structure and obey certain rules even though they may seem to act in a completely random way.
At root, the reason for the flow of fluids in nature is the Earth’s atmosphere that is always moving and is never still. It may seem that pressure would be causing the flow, but in reality, the flows have more to do with changes in temperature than they do with changes in pressure.