HERON

Alexandrian. Greek mathematician, physicist and mathematician. The place and time of his birth and death are unknown. It is considered by many to have flourished in the middle of the 1st century BC, while according to others its peak is placed in the 1st century AD. What is certain is that he lived and worked in Alexandria, where he directed the Higher Technical Greek School.

An important work of Heron is the Mirrors, which contains several propositions which also respond to the homonymous work attributed to Euclid. In Mirrors, Heron explains the rectilinear propagation of light and the well-known law of the equality of the angle of incidence and the angle of reflection.

Heron is the first Greek writer to mention the sources he uses. Among his inventions and theories are the following: He emphasizes that in nature there is no absolute vacuum and that air has great elasticity and can exert great pressure. It interprets the expansion of air after heating and the hydrostatic pressure on both the walls and the bottom of a container. He uses the parallelogram of velocities, examines the inclined plane, and introduces the experimental determination of the center of gravity of a solid body. Uses the levers in different ways, describes how the screw works. It also looks at the stress that the lever and screw can apply. The dioptra of Heron is, according to Hope, an excellent creation of the Greek spirit.