“The kilogram has gained weight,” reports Live Science. I had no idea that a “hunk of metal” was in any way involved in defining the weight of a kilogram. Live Science has more:
“The international standard, a cylinder-shaped hunk of metal that defines the fundamental unit of mass, has gained tens of micrograms of mass from surface contamination, according to a new study.”
This may lead to confusion between countries as to the definition of standard mass, the report continues.
“As a result, each country that has one of these standard masses has a slightly different definition of the kilogram, which could throw off science experiments that require very precise weight measurements or international trade in highly restricted items that are restricted by weight, such as radioactive materials.”