The kilogram has been measured the same way for the past 130 years, based on a cylinder constructed from a platinum-iridium alloy (proportionately 90 prevent platinum and 10 percent iridium). This ...
This story is a part of Science Friday’s end of year celebrations. Explore staff stories of the year, read the best science books of 2019, geek out over a roundup of science board games, and join the ...
In early 2017, the two of us, along with a few others, refreshed the debate on the definition of planet in scientific nomenclature. The International Astronomical Union’s (IAU) historic definitional ...