Discovery of Magnets

History of Magnets

The history of magnets goes back to 600 B.C. but it was only in the 20th century that scientists began to understand it and the discovery of magnets applications began.

Magnetism was most likely first discovered in a type of magnetite called lodestone, which is made up of iron oxide, a chemical compound made up of iron and oxygen. The first known users of this mineral, which they called a magnet because of its ability to attract other pieces of the same material and iron, were the ancient Greeks.

William Gilbert (1540-1603), an Englishman, was the first to use scientific methods to investigate the phenomenon of magnetism. He also found that the Earth is a weak magnet in and of itself. Carl Friedrich Gauss, a German, conducted the first theoretical studies into the nature of the Earth's magnetism (1777-1855).

The inverse square law of force states that the attractive force between two magnetized objects is directly proportional to the product of their fields and inversely proportional to the square of the distance between them.

Quantitative studies of the history of magnetism and magnetic phenomena began in the 18th century with Frenchman Charles Coulomb (1736-1806), who developed the inverse square law of force, which states that “the attractive force between two magnetized objects is directly proportional to the product of their individual fields and inversely proportional to the square of the distance”.

Hans Christian Oersted (1777-1851), a Danish physicist, was the first to propose a link between electricity and magnetism. Experiments on the interactions of magnetic and electric fields were carried out by Frenchman Andre Marie Ampere (1775-1836) and Englishman Michael Faraday (1791-1869), but it was the Scotsman James Clerk Maxwell (1831-1879) who laid the theoretical foundation for electromagnetism in the 19th century by demonstrating that electricity and magnetism are the same things.

The work and theoretical models of two Germans, Ernest Ising (1900- ) and Werner Heisenberg (1900- ), are responsible for our current understanding of magnetism, which is based on the theory of electron motion and interactions in atoms (known as quantum electrodynamics) (1901-1976). Werner Heisenberg was a key figure in the development of modern quantum mechanics.


Origin of Magnets

Magnetism is caused by two kinds of electron motions in atoms: one is the motion of electrons in an orbit around the nucleus, which is similar to the motion of planets in our solar system around the sun, and the other is the spin of electrons around their axis, which is similar to the rotation of the Earth around its axis.

Each electron acquires a magnetic moment as a result of its orbital and spin motions, causing it to behave like a tiny magnet. The rotational force experienced by a magnet in a magnetic field of unit strength acting perpendicular to its magnetic axis defines its magnetic moment.

Because of the Pauli exclusion principle, which states that each electronic orbit can only be occupied by two electrons of opposite spin, the magnetic moment of the electrons cancels out in a large fraction of the elements. However, several so-called transition metal atoms, such as iron, cobalt, and nickel, have magnetic moments that are not cancelled, making them common magnetic materials. The magnetic moment in these transition metal elements is derived solely from the spin of the electrons.

The effect of electron orbital motion is not cancelled in the rare earth elements (which start with lanthanum in the sixth row of the Periodic Table of Elements), so both spin and orbital motion contribute to the magnetic moment. Cerium, neodymium, samarium, and europium are examples of magnetic rare earth elements.

Magnetic moments can be found in a wide range of chemical compounds containing transition and rare earth elements, in addition to metals and alloys. Metal oxides, which are chemically bonded compositions of metals with oxygen, are among the most common magnetic compounds.

According to a fundamental law of electromagnetism, a magnetic field is created by the passage of an electric current, the Earth's geomagnetic field is the result of electric currents produced by the slow convective motion of its liquid core.

The Earth's core, according to this model, should be electrically conductive enough to allow for the generation and transmission of an electric current. The resulting geomagnetic field will be dipolar, similar to the magnetic field produced by a conventional magnet, with lines of magnetic force lying in approximate planes passing through the geomagnetic axis.


Who was the Founder of Magnet?

Magnets make the world go-’round, and tales of their discovery and application appear to come from all corners of the globe.


Greece

Magnes, a Greek shepherd, is said to have been tending his sheep in Magnesia, a region of northern Greece, around 4,000 years ago. When he took a step forward, the nails holding his shoe together and the metal tip of his staff became stuck to the rock he was standing on! He began digging, intrigued, and found the first known lodestone. Magnesia or Magnesia was probably the inspiration for the name "magnetite" given to lodestones.


Rome

Pliny the Elder, a Roman author, and naturalist who undertook important scientific research for the then-Roman Emperor Vespasian in the early AD years described a hill made of a stone that attracted iron. Pliny attributed magnetite's powers to magic, igniting a flurry of superstitious theories about the material, including the possibility that ships that had gone missing at sea had been drawn to magnetic islands. Pliny died in the eruption of Pompeii, which is unrelated but curious.


Scandinavia

With a large lodestone deposit in Scandinavia and insufficient light to navigate ships by during the winter, the Vikings had every incentive to put lodestone's magnetic properties to good use. The Vikings are believed to have used a compass-like tool made of lodestone and iron as early as 1,000 B.C. Viking sailors used a magnetized iron needle inserted into a piece of straw and float in a bowl of water to signify north and south, according to legend.


China

The Chinese may have invented a mariner's compass that was similar in construction to the Vikings'. As early as 800 A.D., the Chinese used a splinter of lodestone floating on water to navigate. Explorers such as Marco Polo brought the magnetic compass back to Italy, allowing Europeans to finally explore the oceans that the Vikings had been navigating for at least 500 years using their version of the compass.


France

One of the first written accounts of the scientific properties of magnets was authored by French scholar Petrus Peregrinus in the 1200s. The freely pivoting compass needle–a key component of the first dry compass–is depicted and discussed in his report. Peregrinus is said to have composed these works while taking part in a papal-sanctioned crusade/attack on the Italian city of Lucera.


England

William Gilbert, a physician from the United Kingdom, was the first scientist to create a magnet. He found in 1600 that magnets could be forged out of iron and that their magnetic properties could be lost when that iron was heated.


Denmark

Hans Christian Oersted began studying the relationship between electricity and magnetism two hundred years later, in 1820. He proved his theory by placing a magnetic compass near an electrical wire, which caused the compass's accuracy to be thrown off.


A Brief History of Electromagnets/Electromagnetism

1770-90: Cavendish and Coulomb establish foundations of electrostatics

1820: Oersted makes the connection between flowing charge and magnetism.

1820s: Ampere identifies currents as the source of all magnetism (even permanent magnets)

1831: Faraday (also Henry) discovers that time-varying magnetic fields serve as sources for electric fields

1864: Maxwell puts it all together.

1887: Hertz demonstrates the existence of electromagnetic radiation.


History of Electromagnets

Hans Christian Orsted made an unexpected observation while preparing for an evening lecture on April 21, 1820. When the electric current from the battery he was using was turned on and off while he was setting up his materials, he noticed a compass needle deflected away from magnetic north.

This deflection convinced him that magnetic fields, like light and heat, radiate from all sides of a wire carrying an electric current, confirming the existence of a direct relationship between electricity and magnetism.

Orsted did not provide a satisfactory explanation for the phenomenon at the time of its discovery, nor did he attempt to represent it mathematically.

His discoveries sparked a wave of electrodynamics studies across the scientific community. They influenced the development of a single mathematical form to represent the magnetic forces between current-carrying conductors by French physicist André-Marie Ampère. Orsted's discovery was also a significant step toward a unified energy concept.

One of the most important achievements of 19th-century mathematical physics is the unification, which was observed by Michael Faraday, expanded by James Clerk Maxwell, and partially reformulated by Oliver Heaviside and Heinrich Hertz. It had far-reaching implications, one of which was a better understanding of light's nature.

William Sturgeon, an Englishman, was the first person to invent an electromagnet in 1826. It was made up of a coil that created a magnetic field when the current passed through it. There was an iron core in the coil, which increased the magnetic field and led. The magnetic field lines, in this case, are concentrated in the interior of the coil, which has the highest magnetic flux density. With a larger distance outside the coil, it decreases quickly; we can also argue that electromagnets have a large effect when used over short distances.

FAQs (Frequently Asked Questions)

Q1. State the Different Types of Magnetism.

Ans: On the basis of the magnetic behaviour of materials in response to magnetic fields at various temperatures, five fundamental types of magnetism have been observed and classified.

  1. Ferromagnetism

  2. Ferrimagnetism

  3. Antiferromagnetism

  4. Paramagnetism

  5. Dimagnetism

Q2. Mention the Contemporary Applications of Magnetism.

Ans: Electromagnets are used in motors and generators, as well as in power supplies that convert electrical energy from a wall outlet into direct current energy for a wide range of electronic devices. In MRI (magnetic resonance imaging) devices that are now widely used in hospitals and medical centers, high field superconducting magnets (where superconducting coils produce the magnetic field) provide the magnetic field.


Magnetic recording and storage devices in computers, as well as audio and video systems, are some of the more esoteric applications of magnetism.

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