New Delhi, May 19 -- The kilogram, or kilo as it's typically known, is a household term today. But not many people would know that for the last 130 years, a cylinder made of a platinum-iridium alloy has been the internationally-accepted standard for the kilogram. Known as the International Prototype of the Kilogram (IPK), copies of this artifact are used as reference weights by countries across the world to calibrate scales and weights in places like factories, supermarkets and bakeries....