Before 1980 it was considered that the chemical reaction of combustion can only occur if three elements are combined: a fuel, an oxidizer, and an activation energy in sufficient quantities. This is why we used to speak of the “triangle of fire”.
Since the 1980s it has been discovered that one of the essential stages of the chemical reaction is the production of free radicals; this step is necessary so that the combustion is maintained and that one can speak of fire. This is the reason why we speak since of “tetrahedron of fire”.
The disappearance of one of the four elements is enough to stop combustion.
The discovery of combustion by dioxygen is attributable to the French chemist Lavoisier, in 1775, because it is generally considered that Joseph Priestley, who isolated for the first time (impure) dioxygen in 1774 did not, however, discover the role of oxidizer of oxygen. Indeed, insofar as it was based on the theory of phlogiston, this prevented it from conceiving the role of dioxygen in combustion.
According to the philosopher of science Thomas Samuel Kuhn, the discovery of combustion by dioxygen constitutes a major scientific revolution in the history of science. It constituted a paradigm shift, replacing the old paradigm of phlogiston.
Modèle : Nelly Rack Framboise
Technique utilisé : Photographie sous canons UV (395 nm) . Photos brutes non retouchées.
Canon 5DSr / Lightroom