Stepping on the Water

This study explores various uses of engineering as a tool for solving problems and improving the quality of life. The experiments in the article show that competitive athletes swim with their fingers spread slightly, because this configuration generates greater speed, the research being based on a principle known as constructional law. The constructional law has been applied to predict all the key features of the design of animal locomotion, which includes human running and swimming. In engineering, the discovery expands a domain of constructal-design results that has been growing fast. Bodies that generate heat volumetrically are endowed with maximum heat transfer density when the spacing between the solid surfaces internal to the volume have certain sizes that are smaller in forced convection than in natural convection. The volumetric cooling of future electronics, avionics, and self-cooling materials rests on this class of constructal designs. The swimming with spread fingers is the corresponding design of a body for maximum momentum transfer density.