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Old 05-07-2014, 05:55 PM   #563
lightgiver
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The process by which lodestone is created has long been an open question in geology.. Only a small amount of the magnetite on Earth is found magnetized as lodestone.. Ordinary magnetite is attracted to a magnetic field like iron and steel is, but does not tend to become magnetized itself.. Recent research has found that only a variety of magnetite with a particular crystalline structure, a mixture of magnetite and maghemite, has sufficient coercivity to remain magnetized and thus be a permanent magnet.. One theory suggests that lodestones are magnetized by the strong magnetic fields surrounding lightning bolts.. This is supported by the observation that they are mostly found at the surface of the Earth; not buried at great depth..Among the first references to lodestone's magnetic properties is by 6th century BCE Greek philosopher Thales of Miletus, whom the ancient Greeks credited with discovering lodestone's attraction to iron and other lodestones.. The name "magnet" may come from lodestones found in Magnesia...The earliest Chinese literary reference to magnetism is in a 4th-century BC book called Book of the Devil Valley Master (鬼谷子): "The lodestone makes iron come or it attracts it.."The earliest mention of a needle's attraction appears in a work composed between 20 and 100 AD (論衡): "A lodestone attracts a needle"..Medieval Chinese navigators were by the 12th century using lodestone compasses..The American astronomer John Carlson based on his finding an Olmec hematite artifact in Central America suggests that "the Olmec may have discovered and used the geomagnetic lodestone compass earlier than 1000 BC," thereby predating "the Chinese discovery of the geomagnetic lodestone compass by more than a millennium"..The bulk of Jupiter's magnetic field, like Earth's, is generated by an internal dynamo supported by the circulation of a conducting fluid in its outer core. But whereas Earth's core is made of molten iron and nickel, Jupiter's is composed of metallic hydrogen.. As with Earth's, Jupiter's magnetic field is mostly a dipole, with north and south magnetic poles at the ends of a single magnetic axis..Metallic hydrogen is a phase of hydrogen in which it behaves as an electrical conductor..Liquid metallic hydrogen is thought to be present in large amounts in the gravitationally compressed interiors of Jupiter, Saturn, and in some of the newly discovered extrasolar planets...

Quote:
A magnetic field is the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude (or strength); as such it is a vector field..The term is used for two distinct but closely related fields denoted by the symbols B and H, which are measured in units of tesla and amp per meter respectively in the SI.. B is most commonly defined in terms of the Lorentz force it exerts on moving electric charges..Hibernia is the Classical Latin name for the island of Ireland.. The name Hibernia was taken from Greek geographical accounts.. During his exploration of NorthWest Europe (c. 320 BC), Pytheas of Massilia called the island Iérnē (written Ἰέρνη). In his book Geographia (c. 150 AD), Claudius Ptolemaeus ("Ptolemy") called the island Iouerníā (written Ἰουερνία, where "ου"-ou stands for w). The Roman historian Tacitus, in his book Agricola (c. 98 AD), uses the name Hibernia. The Romans also sometimes used Scotia, "land of the Scoti", as a geographical term for Ireland in general, as well as just the part inhabited by those people..Iouerníā was a Greek alteration of the Q-Celtic name *Īweriū from which eventually arose the Irish names Ériu and Éire. The original meaning of the name is thought to be "abundant land"...
http://en.wikipedia.org/wiki/Alnico
http://en.wikipedia.org/wiki/Lodestone
http://www.davidicke.com/forum/showp...1&postcount=12Did you have an affair with her..Whatever resentment she's feeling, she probably got it out of her system..What if she didn't get it out of her system?. What then..Do I need to introduce myself... http://www.davidicke.com/forum/showp...&postcount=183

Last edited by lightgiver; 05-07-2014 at 05:56 PM.
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