The International Bureau of Weights and Measures (BIPM) is planning to review four units of measure, including the crucial kilogram, at a meeting that's currently ongoing from October 16 to 20. Afterwards, these recommendations go before the General Conference on Weights and Measures in November 2018, with the potential to take effect in May 2019.
The review concerns a potential redefinition of the ampere (a unit of electricity), the kelvin (temperature), the mole (measurement of atoms and or molecules) and the kilogram. The four units would, starting in 2019, be defined by "relationships to fundamental constants, rather than abstract or arbitrary definitions" according to Nature.
The problem is one of use. While current measurements are fine for conventional, civilian purposes, they're not up to snuff for scientific testing. A kilogram, for example, is presently defined as the mass of a chunk of metal in a vault in Paris and even the slightest speck of dust could change the weight. "The problem with the kilogram in Paris is that it's so precious that people don't want to use it," said Stephan Schlamminger, a physicist with the National Institute of Standards and Technology, in a press release from the American Institute of Physics in 2014.
Using fundamental constants of nature will allow scientists to decrease the levels of uncertainty within measurements. These will have no bearing on day-to-day activities, but will allow scientific measurements to catch up to the latest levels of universal certainty, which track the physical quantities that are universal in nature.
It's complicated stuff, but one that Schlamminger believes can go smoothly. "If you do your job right," he said in 2015, "nobody should notice."
David Grossman is a staff writer for PopularMechanics.com. He's previously written for The Verge, Rolling Stone, The New Republic and several other publications. He's based out of Brooklyn.
