In August, scappuccino reported on a BBC radio story about the changing weight of the kilogram. That is, THE kilogram: an apple-sized mass of platinum-iridium protected behind glass that defines how much a kilogram weighs. There are replica masses all over the world, but this is the queen bee. If she loses weight, everyone feels it. And she has been. Over the past few decades her weight has fluctuated. It's also possible that the comparison weights have been gaining mass, but no one can be sure because the change is happening on such a small scale. It's only by a few micrograms - nothing that would affect general consumers like you and me - but enough to affect precision measurements done by scientists. Needless to say, there's a bit of a panic to come up with a solution so that the weight of the world, so to speak, won't continue to rest on Le Grand K's shoulders. There are currently two key efforts to successfully redefine the kilogram in a way that would not re
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