Discovery Magnets

It tells the story of Magnes, a shepherd who lived in ancient Greece. He used to take his flock of sheep and goats to graze in the nearby mountains. He’d bring a stick with him to keep his herd under control.

A small piece of iron was attached to one end of the stick. In the morning, he had to work hard on his stick to take out his stick to a rock on the edge of the mountain and this incident was surprising for him. It appeared as if the stick was being drawn to the rock. The rock was a natural magnet that drew the iron tip of the shepherd’s stick to it. This is said to be how natural magnets were discovered.

Who first discovered magnets?

The first magnets were discovered in a naturally occurring mineral called magnetite, rather than invented. Magnetite was traditionally discovered by the ancient Greeks.

There is an alternate story that uses Magnesia, a region of Macedonia, as the starting point. 

It is also said that the Greeks discovered naturally occurring magnetite magnets in Turkey. Magnetite is found all over the world, but large deposits are concentrated in Scandinavia. 

The Vikings invented the first practical magnetic compass and used it extensively in their colonisation and war travels. This allowed them to cross oceans to reach the new world and invade England at their leisure, even in dense fog. 

The Vikings kept the magnetic compass a closely guarded secret. The magnetic compass was also invented by the Chinese, most likely before the Vikings. The magnetic compass was introduced to the rest of Europe after the Italians began commercial trade with China, particularly after Marco Polo’s trip. 

This enabled Europeans to explore the oceans, despite the fact that the Norsemen had a monopoly for nearly 500 years and thus a significant head start. Magnetic compasses are now used to navigate all ships, large and small.

What were early natural magnets known as?

The first written record of these accredits the discovery to the Idaean Dactyls (sometimes known as Curetes) that guarded caves on Crete in Minoan times, where precious things were likely stored; they are considered to be the Minoans, who developed many early metal processes. Previously dismissed as mythology, there appears to be archaeological evidence to support the view that magnets were used in Crete as early as 1900 BCE, with a land-based example shown below, 1700 BCE.

Skyros had magnetite (naturally occurring iron), which needed to be struck by lightning to become magnetised. The Minoans were generally very good metal workers, and there have been some surprising complex things discovered in the Caves (lenses and prisms), so perhaps we should not dismiss compasses. 

I do note that this artefact appears to embed magnetic declination to true north using sub markers, 1/total giving the angle as a fraction, the main marker being West, indicating declination rather than inclination, there are large changes in the magnetic field at this time and possibly indicating (at this time).

What is a permanent magnet?

A permanent magnet is an object made of magnetised material that generates its own persistent magnetic field. A refrigerator magnet, for example, is commonly used to hold notes on a refrigerator door. 

Ferromagnetic materials are those that can be magnetised and are also strongly attracted to a magnet (or ferrimagnetic). These include the elements iron, nickel, and cobalt, as well as their alloys, some rare-earth metal alloys, and naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones that are strongly attracted to a magnet and are commonly thought to be magnetic, all other substances respond weakly to a magnetic field via one of several other types of magnetism.

Magnetization process

William Thomson (Lord Kelvin) defined and named the quantities now used to characterise magnetization in 1850. The symbol B represents the magnitude of magnetic flux density within a magnetised body, while the symbol H represents the magnitude of magnetising force, or magnetic field, that produces it. T

The two are represented by the equation B = H, where the Greek letter mu, represents the material’s permeability and is a measure of the intensity of magnetization that can be produced in it through a given magnetic field. The modern International Standard (SI) units for B are teslas (T) or webers per square metre (Wb/m2), and amperes per metre (A/m) for H. Previously, the units were known as gauss and oersted.

Conclusion 

The first magnets were discovered in a naturally occurring mineral called magnetite, rather than invented. It is also said that the Greeks discovered naturally occurring magnetite magnets in Turkey. The Vikings invented the first practical magnetic compass and used it extensively in their colonisation and war travels. This enabled Europeans to explore the oceans, despite the fact that the Norsemen had a monopoly for nearly 500 years and thus a significant head start.