Fire has been around for a long time. It’s been with us even before we knew what it was, and has been with us much longer than any of our scientific research. Fire has never changed: we all know what it does and what is for, but what we didn’t know is why they have the same general shape. Until now. This new discovery is thanks to Adrian Benjan, mechanical engineering professor at Duke University.
A little background about Benjan: he discovered the Constructal Law, a law that states “For a finite-size flow system to persist in time (to survive) its configuration must evolve (morph) in time in such a way that it provides easier flow access.”
What this essentially means when applied to fire is that fires burn it hottest when what you’re burning is as tall as it is wide.
According to Benjan, at Duke University “Our bonfires are shaped as cones and pyramids, as tall as they are wide at the base. They look the same in all sizes, from the firewood in the chimney, to the tree logs and wooden benches in the center of the university campus after the big game.” “They look the same as the pile of charcoal we make to grill meat. And now we know why.”
“Humans from all eras have been relying on this design.” “The reason is that this shape is the most efficient for air and heat flow. Our success in building fires in turn made it possible for humans to migrate and spread across the globe heat flow from fire facilitates the movement and spreading of human mass on the globe, which is a direct prediction of the Constructal Law.”