| Intro | Metre | Kilogram | kelvin | candela | mole | second | helen(joke) | Bibliography |
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The kilogram was initially based on the weight of pure water at 4 degrees celsius(the temperature that water's density is most stable.) The volume of water used was 1 cubic decimeter. Modern measurements have determined that a cubic decimeter of water has a mass of 28 ppm less than the standard we currently use.
The future of the kilogram is in question, over the last 100 years a strange thing has occured, that is "relative to the other replicas of the kilogram produced for various countries the kilogram standard in france has lost 30 micrograms." This fact amongst other things is the reason for some physicists wanting to base the kilogram on a constant that can be replicated in a laboratory.