I love this stuff.. The jiffy, the microfortnight, a zeptosecond (10^-21 of a second), etc.. It all started with an inquiry and discussion into the number of gallons of water in an olympic-sized swimming pool!
For example, Nines..
Numbers very close to, but below one are often expressed in nines (N – not to be confused with the unit newton), that is in the number of nines following the decimal separator in writing the number in question.
For example, “three nines” or “3N” indicates 0.999 or 99.9%, “four nines five” or “4N5” is the expression for the number 0.99995 or 99.995%.
Typical areas of usage are: the reliability of computer systems (the ratio of uptime to the sum of uptime and downtime); “Five nines” reliability in a continuously operated system means an average downtime of no more than approximately five minutes per year. Also, the purity of materials, such as gases and metals.
So, is this where the phrase “dressed to the nines” comes from? If the goal is to be dressed-up 100%, then being dressed to the nines would be approaching perfection in ones attire…?
. . . Plot thickens.