Shift-Flag = turbo. Adjust sliders. Simulates wood burning fractals by having dots stick to previously stuck dots. Dots are between min & max size, adjustable. Turn off moving dots to look more like the wood burning. That also shows electric terminals.
Using thousands of volts to send electrons through wood coated with electrolytic solution burns a fractal branching pattern, branched discharge trees, resulting from insulator breakdown ("dielectric breakdown"). This isn't something possible in real life because it would kill you, but we can simulate it. Electrons are temporarily trapped resulting in a powerful electric field. When the electric field’s strength exceeds the insulating strength of the wood (acrylic works well too as an insulator) it discharges, creating a "Lichtenberg" tree, similar at various scales (fractal). It happens when electrical charges rush out in a river-like torrent where the insulator breaks down. All insulating materials undergo breakdown when the electric field caused by an applied voltage exceeds the material's dielectric strength. The model here is a remake of my earlier DLA models, this time to simulate lightning-like, tree-like patterns, called "Lichtenberg figures," in wood. The main process in my model is Diffusion Limited Aggregation, a simple model of a common growth process in nature. Particles start at a random position on a circle, move randomly, and stick to other stationary particles. At the start there's only one stationary particle, a dark brown "seed" in the center, and a tan sprite that makes clones of itself and moves. When a clone touches any dark brown, it stops. The main approach to simulating these patterns combines a model of dielectric breakdown with Diffusion Limited Aggregation. Particles randomly move until touching a stationary particle. This combined with dielectric collapse forms a tree-like fractal shape much like Lichtenberg patterns. The dielectric breakdown model (DBM) combines DLA with electric field (Niemeyer, Pietronero, and Weismann 1984). It describes the patterns of dielectric breakdown of solids, liquids, and even gases, resulting in Lichtenberg trees. Charge wants to get from A to B while avoiding itself. This forms electrically conducting regions in an insulating material exposed to a strong electric field. For example, the intense electric fields during thunderstorms produce a conducting path in the air along which many electrons flow, "lightning." The result is a fractal pattern of electron flow. The mathematics that describes dielectric breakdown are the same as those describing DLA. We can thus model dielectric breakdown using DLA. Electric current is a flow of electrically charged particles caused by an electric field, usually created by a voltage. The mobile charged particles are charge carriers. In metals and some other solids some of the outer electrons of each atom (conduction electrons) are mobile; in electrolytes and plasma it is ions, electrically charged atoms or molecules, and electrons that are charge carriers. A material with few charge carriers, such as glass or ceramic, conducts very little current with a given electric field and has a high resistivity; this is called an electrical insulator or dielectric. All matter is composed of charged particles, but the common property of insulators is that the negative charges, the orbital electrons, are tightly bound to the positive charges, the atomic nuclei, and cannot easily be freed to become mobile. However, when a large enough electric field is applied to any insulating substance, at a certain field strength the number of charge carriers in the material suddenly increases by many orders of magnitude, so its resistance drops and it becomes a conductor, a breakdown. The physical mechanism causing breakdown differs in different substances. In a solid, it usually occurs when the electric field becomes strong enough to pull outer valence electrons away from their atoms, so they become mobile, and the heat created by their collisions with other atoms releases additional electrons.
