Magnets :: essays research papers

Dia magnetics was discovered by Michael Faraday in 1846, but no ace at the time thought that it could lead to any appreciable effects. William Thomson (Lord Kelvin), referring to levitation as the problem of "Mohamets coffin," had this to say "It will obably be impossible forever to observe this phenomenon, on account of the difficulty of getting a magnet strong enough, and a diamagnetic substance sufficiently light, as the magnetic forces atomic number 18 excessively feeble."      Fields strong enough to lift diamagnetic materials became obtainable during the mid-20th century. In 1939, Werner Braunbeck levitated small beads of graphite in a upright electromagnet. Graphite has the largest ratio c /r known for diamagnetics (8x10-5m3/g) today, this experiment quarter be repeated using just a strong unchanging magnet, such as one made of neodymium, press and boron. Leaving off superconductors (which are ideal diamagnetics), first levitated by Arkadiev in 1947, it took another fifty yrs to rediscover the possible levitation of conventional, room-temperature materials. In 1991, Eric Beaugnon and Robert Tournier magnetically lifted water system and a number of organic substances. They were soon followed by others, who levitated liquid hydrogand atomic number 2 and frog eggs. At the same time, Jan Kees Maan rediscovered diamagnetic levitation at the University of Nijmegen, in quislingism with Humberto Carmona and Peter Main of Nottingham University in England. In their experiments, they levitatedractically e rattlingthing at hand, from pieces of cheese and pizza to living creatures including frogs and a mouse. Remarkably, the magnetic field employed in these experiments had already been available already for several decades and, at perhaps half a den laboratories in the world, it would have taken only an minute of work to implement room-temperature levitation. Nevertheless(prenominal), even physicists who used strong ma gnetic fields every day in their research did not recognize the possibility.      If you were to regularise to a nestling playing with a horseshoe magnet and pieces of iron that his uncle has a much bigger magnet that can lift everything and everybody, the child would probably believe you and might even ask for a excite on the magnet. If a phycist were to say such a thing, he or she (armed with knowledge and experience) would probably smile condescendingly. The physicist would know that only a very few materials, such as iron or nickel, are strongly magnetic. The rest of the worlds materialare not or to be precise, the rest of the world is a billion (109) times less magnetic.