🔥 Wildfire Elliptical Spread: Length-to-Breadth, Huygens Wavelets, Backing Fire and Firebreaks

Ignite a hillside and watch the fire front grow as an ellipse: Anderson length-to-breadth from wind and slope, Huygens wavelets solved as arrival times, Byram flame length, a lake and a firebreak that holds only if it is wider than the spotting distance.