This week, the origin and continued preservation of five of our favorite standard units of measure
By Sam KeanPosted 11.02.2010 at 10:56 am 3 Comments
This week, Sam Kean takes a look at some ridiculously precise standards -- the meter, the second, and other international standard units -- and the role that elements have played in defining, redefining, and re-redefining them over the ages.
The definition of the second used to be 1/86,400th of one spin of the earth around its axis (less formally, the number of seconds in one day). But a few pesky facts made that standard inconvenient.