Redefining the big 'K': Scientists change rules measuring weight of kilogram
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It may sound like a joke, but the kilogram is believed to have lost weight! Defined by a metal cylinder kept in a highly secured vault in Paris, scientists have now decided to change the rules and peg it to nature's constant rather than to a physical object. The goal is to make it even more accurate. Plus, in Test 24, we tell you more about the booming industry of dockless bike sharing.