We’ve long known that there were some issues with France’s ‘Le Grand K’, the international prototype for what a kilogram really is. Made in 1879 from platinum and iridium alloy, it is the perfect standard for what a kilogram weighs. The problem is it’s losing weight.
Mental Floss takes a look at what the lost weight of the official kilogram means and the flaws of using a physical standard for such important purposes — it’s all so fascinating. For example, scientists are scrambling to redefine what a kilogram is like how they changed the definition of a meter from once being a metal rod stored next to ‘Le Grand K’ to the distance light travels in a vacuum during 1/299,792,458 of a second.
But why does it matter whether or not ‘Le Grand K’ is the perfect kilogram? Because the standard needs to be standardised. Mental Floss says, the little changes can add up to be a big problem. Specifically:
The kilogram is also used as a building block in other measurements. The joule, for instance, is the amount of energy required to move a one-kilogram weight one meter. The candela, a measure of the brightness of light, is measured in joules per second.
These links mean that if the kilogram is flawed, so are the joule and candela, which could eventually cause problems in an array of industries, particularly in technology. As microchips process more information at higher speeds, even tiny deviations will lead to catastrophes. Le Grand K’s unreliability “will start to be noticeable in the next decade or two in the electronics industry,” warns NIST physicist Richard Steiner.
Read more about the flawed perfect kilogram at Mental Floss. [Mental Floss]