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Do these platinum-iridium cylinders make my kilogram look fat?

When is a kilogram not a kilogram? When it puts on weight while hanging out in the lab!

From the Stuff That Makes You Go Hmmm Once You Find Out About It File — there are about 40 of these platinum-iridium cylinders, which were created in 1875, and distributed to countries who signed on to the Convention of the Meter. The problem is, over time the cylinders became slightly different due to disparities in how they're handled and cleaned.

To clean them, a skilled technician will rub the cylinders with chamois leather dipped in alcohol. But because every country cleans their kilograms differently and at different times, each kilogram in the world is off by a different, unknown amount.

To solve the cleaning problem scientists developed a nifty new gadget that uses ozone and ultraviolet light to really get those cylinders shiny and bright. It also has the added bonus of providing a uniform cleaning procedure, so the fundamental unit of mass could soon be more consistent.

Long-term though the world needs to get away from defining the kilogram based on what is essentially a glorified beer can. What happens if the cleaning guy drops it? You can't really order a new one from Amazon...

One possibility is to use a fundamental law of nature instead. A precision electromagnetic device could be created to produce a uniform amount of force, from which mass can then be calculated. Of course adopting such a procedure will entail years of international negotiations so we're pretty much stuck for now.

So… The next time your scale says you've packed on a few pounds, you can probably get away with blaming it on "inconsistencies" in the international definition of a kilogram. I mean, if Real Scientists say they aren't sure, how can that el-cheapo bathroom scale possibly be right!

Posted at 18:14 by Chris Wysocki   [/tech]   Comments | Perm Link |
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