Chronos vs. the Federal Agency.

The current Harper's (December 2006) features a good article that details the debate in the U.S. between astronomers and physicist about who should control time. In this article, Clash of the Time Lords, Michelle Stacey elucidates by talking with folks at the USNO and NIST, the literal keepers of the time, who are in favor of moving to a purely atomic (perfect) clock, and the opposition.

Basically the argument comes down to whether or not Time should be an exact unwavering measure, or whether things should remain the same with 'perfect' Time being altered periodically so that Time reflects observable phenomena.

While this issue is potentially vexing, it is tackled with the swagger of the popular-science writing that periodically dominate the Times best seller list, and couples that with the 'journalistic balance and integrity' that a lazy public demands from their news writers.

Ultimately though, this is an issue that has real world consequences: air planes could literally fall from the sky and noon could occur well after sunset. For a more down to earth, though benign, example read the excerpt.

The deeper problem that haunts Levine is what might be considered the underlying gap between the two ways of counting time, a gap that cannot be remedied by inserting leap seconds. He explains this dilemma with a real-world analogy: our physical age, counted by seconds and days lived, and our age counted by birthdays. Someone who is, say, twenty years old could be considered, on his birthday, to have ben alive for 7,300 days (365 times 20). But this self-evident fact is not actually true. Because of the every-four-year leap year, he has in real-life (what Levine calls "heartbeat") terms been alive 7,305 days (including the five leap days that have occurred since his birth). On his birthday he is twenty years old, but depending on how you count time--by a calendar or by the actual moments that have passed--he is either twenty, or he is twenty years and five days. It's a mathematical conundrum with no true answer that results from our ability (or our decision) to count time in two different ways.

Surprise -- you are older than you thought.