Kilo’s weight in the balance
LONDON: For those who still have trouble converting between metric and imperial, take some comfort. Even eminent scientists get confused over such matters – and are currently arguing over the “weight” of a kilogram.
Since measurements are man-made units, the only accurate way to measure a kilogram is to compare it with one of 40 platinum and iridium casts made in France in 1879.
Unfortunately, each time the cast is handled, some atoms come away – making it slightly lighter. So scientists are talking about an alternative.
Measurements have been changed before. In the 18th century it took the French seven years to decide that a metre should be one ten-millionth of the distance from the North Pole to the Equator. – Daily Mail