Magnetism
Essay by review • December 15, 2010 • Essay • 348 Words (2 Pages) • 1,336 Views
History of magnetism
Early Discoveries
In the early discoveries people of ancient greece and china discovered a lodestone (the natural form of a magnet). Through experiments they found out that a lodestone would always point in a north-south direction if it was allowed to rotate freely. They applied this charistic of the lodestones to navigation, fortune telling, and a guide for building.
North and south poles
In 1263 Pierre de maricourt a french solidure mapped the magnetic field of a lodestone with a compass. He discovered that a magnet had two magnetic poles North and South poles.
In the 1600's Willam Gilbert concluded that the earth itself is a giant magnet with north and south poles.
Magnets and Electricity
In 1820 a danish physicist and chemist Hans Christian discovered that when an electric current flows through a wire it causes the compass needle to rotate. This proved that magnetism and electricity were related.
Also in 1820 Andre Marie a french physicist worked out the mathematical relationship between the current of electricity and the strength of th magnetic field. He also had a theory that the electric current in atoms had a magnetic field.
In 1830 Micheal Faraday an english scientist and Joseph henery an american ohysicist discovered that a changing magnetic field produced a current in a coil of wire.
Modern research onMagnets Today
Pierre curie discovered that magnets loose their magnetism above a certain temperature which became known as the Curie point.
In the early 1900's a lot of physicists began exploring the behaivor of electrons and other particles in a magnet which became known as quantum mechanics. Also the understanding of magnetic properties of atoms and molecues.
In the 1900's Edward M Purcell and flix Bloch both american physicists developed a way to measure the magnetic field of the nuclei. This discovery led to MRI also known as Magnetic Renosance Imaging.
In the 1960's and 1970's scientists developed superconducting materials. Only when the magnet is cooled to absolute
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