### Key Points

**Greek mathematician and engineer Hero of Alexandria was active in his native city of Alexandria.****Hero of Alexandria was born in 10 AD.****Heron’s works demonstrate his genius as an inventor, but he also made important contributions to mathematics.**

## Who Was Heron (Hero) of Alexandria?

Greek mathematician and engineer Hero of Alexandria was active in his native city of Alexandria, a part of the Roman Empire. His work is representative of Hellenistic-era science.

The aeolipile and other devices, such as the Hero engine, were powered by steam. One of his most famous inventions was an experiment done as part of the earliest instance of harnessing wind energy on land.

He is said to have philosophies related to atomists, which he discussed in his work Mechanics. He also described pantographs.

Heron is mostly remembered for devising a formula to calculate the area of a triangle.

Much of the original writings and designs attributed to Hero, including in manuscripts from the Eastern Roman Empire, have been lost including works detailing an automatic door. However, some of his works were preserved to a lesser extent in Latin or Arabic translations.

## Early Life

Hero of Alexandria was born in 10 AD. As a boy, he spent most of his time at the University of Alexandria – an institution that housed the famous Library of Alexandria. Very little is known about his family

Hero’s teaching career is lauded by the historian, who believes it is Hero’s work at the Museum that supports this. She ascribes to his writings lectures in physics, pneumatics, mathematics and mechanics – though he was famous for inventions of devices later automated.

Some of his devices represent the first formal research into cybernetics. Cybernetics, originally spelled ‘cybernetique’ (from Greek: κυβερνητικος), was not recognized as a field of study until the 20th century.

## Career

Heron’s works demonstrate his genius as an inventor, but he also made important contributions to mathematics. He won acclaim for devising a practical approach that would be used today. In addition to formulating approximations of square roots and the area of triangles, Heron contributed to geometer development with his treatise.

These three books written by Heron in Istanbul, focus on calculating areas and volumes of bodies like pyramids, cones, cylinders, prisms etc.

The book, Geometria et Almagestum Vtiqui Aliique OPuscula was the first work to have come up with the famous ‘Heron’s formula. Other geometrical works include Definition which lists out different geometrer-related terms and Geometrica that is a list of geometries.

His mathematics focused primarily on practical uses such as determining the capacity of a stadium or how many jars could be stored on a ship. He was the pioneer of geometrical terms and symbols.

Heron pioneered procedures for finding numerical square roots and cube roots, as well as other areas of mathematics like geodesy. He studied the size and shape of the earth while also exploring locations on it.

It is not certain that Baroulkos existed, but we know without a doubt that his book on heavy-lifting machines was lost. Archimedes also worked with mirrors and building vaults. He made some treatises in surveying as well.

His breadth of understanding was not limited to just mechanics and mathematics. Heron also mastered other disciplines, including Cheirobalistra, Belopoeica, Automatic Poietica and Pneumatica.

## What Was Heron of Alexandria Known For?

Aside from his theorems and works detailing an automatic door, Heron had several other contributions.

### Contributions To Mathematics

Heron’s formula, a widely respected tool for computing the area of triangles, bears his name due to its appearance in his book ‘Metrica.’ However, theorists believe that Hero was not the only person to know about this equation as Archimedes from Syracuse is said to have discovered this formula centuries earlier.

Hero developed an iterative method that calculated square roots. This system was first detailed in Metrica, by Hero. Now we refer to it as the ‘Babylonian Method’ or the ‘Heron’s Method.’ He also discovered a way to calculate cube roots with iteration.

He was quite knowledgeable in calculating seating capacity for stadiums and estimating the number of jars that could be stored in containers or ships. He also coined many terms about geometry, such as “geodesy” which is now used to measure the Earth’s geometric shape.

### Aeolipile

Hero lived in Roman Egypt during the 1st century, and his description of a steam-powered device called an ‘aeolipile’ is considered to be the first recorded mention of a steam turbine.

Though Hero does not mention rotating parts in his description, Vitruvius (active 1st century BC) who first mentioned this device in his work, is said to have been inspired by the earlier work of Ctesibius (285-222 BC).

### Windwheel

Hero is credited with inventing the first wind-powered musical instrument, a form of organ that used the power of the wind to generate sounds.

### Vending Machine

Although the modern vending machine first appeared in 1883, it was not invented by inventor, Percival Everett. Instead, Hero is credited with being the inventor of the earliest known vending machine that dispensed holy water. His inventions only accepted coins and had a slot to insert them into.

Holy water would flow from a spigot until the coin fell into a pan at the bottom. The weight of the coin caused it to tilt on an attached lever which tilted the pan and continued flowing holy water.

### Field of Optics

Hero’s contribution to the field of optics is invaluable. His principle of least time, which was first formulated by French mathematician Pierre de Fermat is now known as Fermat’s principle and it has been expanded on by Alhacen (who lived in what is now called Syria), who worked on reflection and refraction based on Heron’s work

### Greek Theater

Hero used the laws of mechanics to orchestrate a ten-minute play with almost no human intervention, using ropes and simple machines behind the stage. The spectacle is so enchanting because people in ancient times were captivated by its theatrical tricks but couldn’t work out how it was done.

### Hydraulic Machine

This machine is commonly known as Heron’s fountain, and was invented by him. It demonstrates the principles of pneumatics and hydraulics, so it is often used in physics classes for demonstrations.

## Heron of Alexandria: Marriage, Divorce, Children, and Personal Life

Heron, whose personal life is virtually unknown, makes a living in Alexandria among the scientists and writers of the late-Ptolemaic rule and Roman era. He was brilliant at theoretical sciences and wrote with clarity and insight. His family life remains a mystery.

His knowledge was saved in writings of medieval Byzantine scholars as well as those from Arabic countries.

## Heron of Alexandria: Published Works and Books

- Hero of Alexandria is credited with writing myriad books that include mechanical devices and toys. ‘Pneumatica’ includes descriptions of machines that harness the power of air, steam, and water such as an aeolipile (scroll through to know more), water organ, coin operated machine etc.
- Hero’s book ‘Mechanica’ details a wide range of principles, including a way to lift and transport heavy objects, the theory of motion, and how to calculate the center of gravity for simple shapes. Unfortunately, an Arabic translation is all that remains from the original texts.
- The book,
*Automata*, gives detailed descriptions of several mechanical statues that filled wine goblets at specific intervals or when queried — particularly of an automatic door. - Hero wrote three books about geometry that were found in Istanbul in 1896. They were “Metrica”, containing Hero’s calculation of volumes and surface areas, the “Geometrica” with equations based on those from Metrica’s first chapter, and a third book called the ‘Hoard’ with measurements.