Search Box

Tuesday, June 28, 2016

The Kilogram May Be Replaced ... By A Calculation, Because The Standard Lump Of Metal Stored In France Is Losing Its Mass

The Kilogram May Be Redefined

The egg-size platinum alloy standard kilo in Paris could be replaced by a calculation 

Tia Ghose | June 27, 2016

One of the most iconic hunks of metal in the world is set to get a demotion.
The official metallic cylinder that defines the mass of a kilogram may soon be set aside in favor of a measurement that is defined by fundamental constants of nature.
The egg-size alloy of platinum and iridium, known as "Le Grand K," has sat inside a hermetically sealed room in Paris since 1879. Le Grand K serves as the benchmark against which all other kilograms are compared. [The 9 Most Massive Numbers in Existence]

"Le Grand K" "The kilogram is the last remaining measurement to be defined by a physical object: a cylinder of platinum and iridium held in a vault under three glass bell jars at the International Bureau of Weights and Measures (BIPM) in the suburbs of Paris. The international prototype, created in the 1880s and known familiarly as “Le Grand K,” is the standard by which all other kilograms are measured. But for all the vault-like protections, Le Grand K is vulnerable. “The big joke is, if someone were to sneeze on the kilogram, there are about 10 fundamental constants that would change, because they’re all tied to its value,” says Jonathan Ellis, an assistant professor of optics and mechanical engineering and a specialist in metrology, or the study of measurements." Source:

<more at; related articles and links: (+Podcast) (Researchers Weigh the Benefits of a New Kilogram Standard. January 24, 2011) and (Kilogram conflict resolved at last. After a fraught few years, experiments to redefine the unit have reached agreement. October 13, 2015)>

No comments:

Post a Comment