The Earth's rotation doesn't line up perfectly with our calculation of it, so to keep things consistent, we have to adjust. That's why this weekend will have a leap second. This Saturday, just before midnight Greenwich Mean Time, clocks will count to 60 seconds, instead of 59.
How should you spend that free, unexpected single second? Here are nine ideas.
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.