All but one unit of the metric system can be scientifically derived. For instance, anyone anywhere can currently define a meter with the right equipment. This is important because any measurement standard that relies on a physical tool (think yardstick in this country and a meterstick elsewhere) means it is vulnerable to variability based on the material it’s made from—and every material is subject to change. Such differences can come from use (some of it gets worn off, making it shorter or lighter or accumulates dirt, making it longer or heavier) or even temperature. Optimally, you want a measurement standard that never changes under any circumstances.
The international standard for the length of the meter (for instance) is 1/299,792,458 of the distance traveled by light in a vacuum in one second.
If you can measure that (and laboratories around the world can), you can define the meter without any other external reference.
The outlier within the metric system is the kilogram. By definition, a kilogram is the weight of a piece of special metal kept at the International Bureau of Weights and Measures located outside of Paris called the International Prototype of the Kilogram. (It is equal to 2.20462 lbs for those still using U.S. customary units.) Periodically kilogram standards held by metrology centers from around the world are brought together to ensure their consistency against this single cylinder of metal kept carefully preserved for that purpose.
Work is currently underway for the development of a scientifically derived kilogram and while it’s not quite there, it’s getting close. When that happens, the kilogram will no longer require a physical standard or be subject to environmental fluctuations. This is a good thing.
It is this history and ongoing scientific work that is the subject of a documentary called State of the Unit: The Kilogram. Amy Young, who has been working on this project for two years, needs help raising completion funds for her project and I’m asking you to help.
To learn more about the documentary, its background, the people involved and for your chance to contribute, go to http://www.kickstarter.com/projects/52746223/the-state-of-the-unit-the-kilogram-documentary-fil.
This is the sort of project that will help raise awareness of the metric system in this country (though not the direct purpose of Amy’s efforts) and for that reason, I’m putting my support behind it.
How much support? While my own project has certainly taken its fair share of my resources, I’m contributing to the project. I ask you to consider doing the same.
The Kickstarter campaign for State of the Unit ends on Friday, May 17 at 5:33pm EDT. Amy’s goal is to raise a modest $26,800 to help her complete the project that she already has spent so much of time and money on. Unless she raises the full amount, she’ll get none of it. She’s close but the deadline is looming fast.
Please consider helping her further this important work.
I thank you in advance for contributing to metric system understanding and education in whatever ways you can.
(Note: Revised on 5/12 at 8:20 p.m. to correct a typographical error.)
The kilogram is about the get an update (along with the rest of the system):