HERON OF ALEXANDRIA: BIOGRAPHY, CONTRIBUTIONS AND INVENTIONS - ARTE - 2025

Heron of Alexandria (10 AD-70 AD) was an inventor, mathematician and engineer, considered one of the most important inventors of his time. The steam engine, also called aeolipile and baptized as Heron's machine or fountain, is perhaps his most important work, but not the only one.

Many original designs as well as some of his writing were lost. His work is said to have been greatly influenced by the ideas of Ctesibius, also an inventor and mathematician from Alexandria.

Image of Heron of Alexandria. Source:, via Wikimedia Commons.

He also excelled in his facet as a mathematician by establishing a method to calculate the square root of a number and create Heron's Formula, which is the one used to calculate the area of ​​a triangle.

Biography

Many elements of the life of Heron of Alexandria are unknown. It has not even been possible to determine exactly what was the period in which he lived. On this several hypotheses were created.

One of them states that Heron's life passed around 150 BC and others claimed that he lived around 250 AD.

The first group based their theory on the fact that Heron of Alexandria did not cite any work that was later than Archimedes, a famous physicist, engineer and inventor who lived between 287 and 212 BC.

On the other hand, the second group used Ptolemy and Pappus to establish the period of life of Herón since they affirmed that he lived before Pappus; this refers to the works of Heron in his writings.

But, both theories have been disproved over time. There is a third hypothesis, which is also the most accepted, in which it was stated that Herón de Alejandría is contemporary with Columella. Lucius Junius Moderatus Columella was a soldier and renowned writer and farmer of the Roman Empire.

This third theory was supported by the discovery in 1938 by Otto Neugebauer. The Austrian-born mathematician and astronomer managed to identify that Heron referred to an eclipse that occurred in the year 62 in Alexandria as something recent for him. Thanks to this, today it is stated that Heron of Alexandria was born in the year 10 after Christ.

Education

Based on his manuscripts, some historians went so far as to affirm that as he grew up, Heron spent much of his time in the library of the University of Alexandria, a work of Alexander the Great.

After completing his studies, Heron began to teach at the Museum of Alexandria, where the famous Library of Alexandria was located, which in its time represented the largest library in the world, with about a million works.

Many of the manuscripts that were used to analyze his life refer to notes for courses in physics, mathematics, and even mechanics. Hence it is stated that he had a role as a teacher.

Contributions

The contributions of Herón de Alejandría were many and in different areas of study. Heron's formula, Heron's method or the inventions of automated machines were some of his contributions.

Today the impact of Heron's discoveries or inventions can still be seen. His principles in the area of ​​geometry have allowed the formulation of calculations of more exact forms.

In addition, he gained much fame for his inventions of automated machines. Those devices are considered the first studies on cybernetics. Although cybernetics was not formalized as an area of ​​study until the 20th century.

Also for some of his inventions, which have to do mainly with automation, he is known as one of the forerunners of robotics.

Heron's formula is widely used to calculate the area of ​​a triangle. This formula was found in his book Metrics and for that it is credited. Some critics argue that Meter is only a collection of knowledge available during the time of Heron and that Archimedes was already using that formula two centuries earlier.

In modern mathematics, the formula for calculating the square root of a number is known as Heron's method (or also the Babylonian method). This contribution by Herón was also reflected in his book Métrica.

He was one of the pioneers in geometric symbols, he even coined many of its terms. And he mastered an area of ​​study known as geodesy, which is currently used to understand the geometry of planet earth, among other elements.

Inventions and works

The best known and most famous invention of Heron of Alexandria is the aeolipila. He described this machine in the Roman province of Egypt, during the first century after Christ.

Marcus Vitruvius Pollio described a similar machine a century earlier, but made no mention of rotating parts, as did Heron. Furthermore, it is said that Ctesibius inspired Heron, as he was the first to write (between 285 and 222 BC) on the uses of compressed air.

At first the aeolipila was not studied in depth and was considered a simple toy, but it was the invention that laid the foundations for the steam engine to be created between the 17th and 18th centuries.

Windmills

Another important invention of Heron was the wind wheel. It acquires greater value since it was the first machine in history, of which there is record, to take advantage of the energy produced by the wind.

At first this wind wheel was used to operate a musical instrument, since it created an organ that worked thanks to the presence of a pump that introduced air to the instrument. Years later, this invention was used for the creation of windmills.

Vending machines

Heron was also the creator of what is known as one of the earliest forms of dispensing machine, although this was not officially invented until 1833.

Heron's machine was used to give water or wine and had a slot to deposit a coin. The weight of the coin was driven by the apparatus, as it lowered a tray until the coin fell from the tray.

Hydraulic machines

Known as the Heron's fountain, it is a device that is still present today. It can be found very easily in physics classrooms. It is used, as in the past, to study the essential principles of hydraulics and pneumatics.

The syringe and hydraulic fire pump are also attributed to him.

Automatisms

His inventions even affected the theater, since he devised machines suitable for presenting ten-minute plays. These machines were made up of strings, springs and could even reproduce thunder-like sounds thanks to the use of metal spheres.

He managed to open and close the doors of the temples thanks to the use of water tanks that were under the ground and pulleys.

Published works

As with his life, his works have not been fully defined either. A large part of Heron's works have survived over the years, but the authorship of some works has been questioned.

The works he published span different areas of study and categories. Some works were on technical matters, other works have to do with mechanics and there are others in the field of mathematics.

Among the most important books authored by Herón de Alejandría are:

Pneumatics

In this book Herón dealt with the operation of mechanical devices and toys such as dolls, coin-operated machines or the water organ. This book was basically a compilation of descriptions of devices that took advantage of the power given by air, steam or water.

Mechanics

Here Heron dealt with a great many principles in this area. He presented a method for lifting and carrying heavy objects and a theory of motion, or a method for calculating the center of gravity of simple shapes. In this case, the original book was lost, but the Arabic translation is still preserved.

Automaton

In this work he described the machines that were present in the temples and that were invented to create magical effects. It referred to machines that allowed to open or close doors or statues that poured wine.

Metrics

Finally he did his work Metrica. A series of three books that were found in 1896, in Istanbul. This is the most famous work of Heron of Alexandria. In it he wrote about how to calculate area and volume.

Similarly, there are his works Dioptra, Belopoeica and Catóptrica.

In dispute

Some works were credited with Heron's authorship, but most likely someone else wrote them. Among them are:

• Geometry, which for many is based on the first chapter of his work Metrics. There is also Stereometrica, based on the second chapter of the same book.
• Other works whose authorship is not fully recognized are: Measurement, Quirobalist and Definitions.

Partial

Geodesia and Geoopónica are two manuscripts of Herón de Alejandría of which only fragments exist, reason why his complete contributions on these subjects are not known.

References

1. Greenwood, J., & Woodcroft, B. (1851). The Pneumatics of Hero of Alexandria, from the original Greek.. London.
2. Heron of Alexandria - Greek mathematician. Recovered from britannica.com
3. Maynard, J. (2005). The Light of Alexandria (1st ed.). New Hampshire.
4. McKenzie, J. (2010). The architecture of Alexandria and Egypt, c. 300 BC to AD 700. New Haven, Conn.: Yale University Press.
5. Rao, J. (1996). Kinematics of Machinery Through HyperWorks. India: One World.