Magnets :: essays research papers

Dia magnetizeds was discovered by Michael Faraday in 1846, but no adept at the time mind that it could lead to any appreciable effects. William Thomson (Lord Kelvin), referring to levitation as the problem of "Mohamets coffin," had this to imagine "It will obably be im realistic ever to observe this phenomenon, on flyer of the difficulty of getting a magnet industrial-strength enough, and a diamagnetic substance sufficiently light, as the magnetic forces are excessively feeble."      Fields strong enough to lift diamagnetic materials became available during the mid-20th century. In 1939, Werner Braunbeck levitated small string of beads of graphite in a vertical electromagnet. Graphite has the largest ratio c /r known for diamagnetics (8x10-5m3/g) today, this experiment can be repeated utilise just a strong permanent magnet, such as one made of neodymium, iron and boron. Leaving aside superconductors (which are ideal diamagnetics), basic le vitated 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 and a number of total substances. They were soon followed by others, who levitated liquid hydrogand helium and frog eggs. At the identical time, Jan Kees Maan rediscovered diamagnetic levitation at the University of Nijmegen, in collaboration with Humberto Carmona and Peter Main of Nottingham University in England. In their experiments, they levitatedractically everything at hand, from pieces of cheese and pizza to living creatures including frogs and a mouse. Remarkably, the magnetic fields employed in these experiments had already been available already for some(prenominal) decades and, at perhaps half a den laboratories in the field, it would have taken only an hour of work to implement room-temperature levitation. Nevertheless, even up physicists who used strong magnetic fields every day in their research did not recognize the possibility.      If you were to tell to a child playing with a horseshoe magnet and pieces of iron that his uncle has a much big magnet that can lift everything and everybody, the child would probably believe you and index even ask for a ride on the magnet. If a phycist were to think such a thing, he or she (armed with knowledge and experience) would probably make a face 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.