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How heavy is a kilogram? Merry Christmas 2010

Scientists seek answers

How heavy a kilogram? The question seems silly but some scientists are looking for the answer without losing hope of moving towards a constant value for the kilo, independent of any physical object.

Since 1889, the kilogram is based on a composite cylinder of 90% platinum and 10% iridium , made in London in 1879 and preserved under a bell jar in the Office of Weights and Measures in Sèvres, near Paris.

Measurements for over a hundred years show that the pound has lost. Its changed the equivalent mass of a grain of sand of 0.4 mm in diameter.

enough for scientists around the world consider a definition of the physical object can be passed, as they did with the underground, now defined by the speed of light.

The goal is to redefine all the basic units, mass, distance, time, etc .- stable and universal values. For

kg, scientists suggest the use of Planck's constant, a value that is named after the father of quantum physics, Max Planck. Complex for the neophyte, Planck's constant is defined by a formula called h.

remains to define the relationship between the kilo of life and Planck's constant. For this, experiments are underway around the world. Scientists use the watt balance, a device that converts mechanical power into electrical power and vice versa.

"Our experiments underway, but it is too early to implement the new definition of the kilogram," said Michael Stock, of the Royal Society of London.

"One problem is that we need more of the watt balance we have" to measure reliably the pound when applying the new definition explains.

estimated the change could be approved "reasonably" to the next Conference of Weights and Measures in Paris in 2015.

Source: http://noticias.latam.msn.com/xl/insolito/articulo_afp.aspx?cp-documentid=27401435: