who invented magnet

Some people believe that a shepard named Magnes found a rock named magnetite.

The first magnets were not invented, but rather were found from a naturally occurring mineral called magnetite. Traditionally, the ancient Greeks were the discoverers of magnetite. There is a story about a shepherd named Magnes whose shoe nails stuck to a rock containing magnetite. There is an alternate story about a region of Macedonia called Magnesia as the starting point. I remember being taught that the Greeks discovered naturally occurring magnets of magnetite in Turkey. Magnetite occurs all over the world, but there are especially large deposits in Scandinavia. The Vikings invented the first practical magnetic compass and used it extensively in their travels to colonize or in war. This enabled them to cross oceans to reach the new world and to invade England at will, even in the dense fog. The Vikings kept the existence of the magnetic compass a secret. The Chinese also invented the magnetic compass, probably earlier than the Vikings. After commercial trade with China was started by the Italians, especially after Marco Polo's trip, the magnetic compass was introduced to the rest of Europe. This made possible the exploration of the oceans by the Europeans, although the Norsemen had a monopoly for almost 500 years and thus a big head start. Today all ships large and small use magnetic compasses to navigate.

The mineral magnetite is an iron oxide that is easily magnetized when it forms. Magnetite is also known as Lodestone.

The Ancient Greeks first discovered magnets underground

 magnet were descover in greek by a sheperd name magnes

 A magnet (, "Magnesian stone") is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.

A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is arefrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some alloys of rare earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.

Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferritethat are subjected to special processing in a powerful magnetic field during manufacture, to align their internal microcrystalline structure, making them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on coercivity of the respective material. "Hard" materials have high coercivity, whereas "soft" materials have low coercivity.

An electromagnet is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops. Often, the coil is wrapped around a core of "soft" ferromagnetic material such as steel, which greatly enhances the magnetic field produced by the coil.

The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in a material is measured by its magnetization.

Discovery and development

Ancient people learned about magnetism from lodestones, naturally magnetized pieces of iron ore. They are naturally created magnets, which attract pieces of iron. The word magnet in Greek meant "stone from Magnesia", a part of ancient Greece where lodestones were found. Lodestones suspended so they could turn were the first magnetic compasses. The earliest known surviving descriptions of magnets and their properties are from Greece, India, and China around 2500 years ago. The properties of lodestones and their affinity for iron were written of by Pliny the Elder in his encyclopedia Naturalis Historia.

By the 12th to 13th centuries AD, magnetic compasses were used in navigation in China, Europe, and elsewhere.

 force between two magnetic dipoles.