Evolution: Why all plumes and jets evolve to round cross sections

This paper uses a common example of natural organization in order to demystify the phenomenon of evolution in nature. The example is inanimate: the evolution of all plumes and jets in one direction in time, from any cross-sectional shapes to round cross sections. The arrow of time points in one direction, and this direction is captured by the constructal law of design evolution in nature.

The prevalent view in science is that evolution is a phenomenon of biology, and that it cannot be witnessed in our lifetime. This paper shows that in plumes and jets we witness evolution in real time. We also see the physics principle of evolution, which also allows us to predict turbulence as a phenomenon of physics.

• A. Bejan, S. Ziaei & S. Lorente, Evolution: Why all plumes and jets evolve to round cross sections, Scientific Reports 4, Article number: 4730, Nature.com