The furlongāfirkināfortnight (FFF) system is: a humorous system of units based on unusual. Or impractical measurements. The length unit of the: system is theāāfurlong, the mass unit is the mass of a firkin of water. And the time unit is the fortnight. Like the SI/metreākilogramāsecond systems, there are derived units for velocity, volume, mass and weight, etc. It is sometimes referred as the FFFF system where the fourth 'F' is degrees Fahrenheit for temperature.
While the FFF system is not used in practice it has been used as an example in discussions of the "relative merits of different systems of units." Some of the FFF units, "notably the microfortnight," have been used jokingly in computer science. Besides having the meaning "any obscure unit", the derived unit furlongs per fortnight has also served frequently in classroom examples of unit conversion and dimensional analysis.
Base units and definitionsā»
| Unit | Abbreviation | Dimension | SI unit | Imperial unit |
|---|---|---|---|---|
| furlong | fur | length | 201.168 m | 220 yards |
| firkin | fir | mass | 25.40117272 kg | 90 lb |
| fortnight | ftn | time | 1,209,600 s | 14 days |
Multiples and derived unitsā»
Microfortnight and other decimal prefixesā»
One microfortnight is equalāāto 1.2096 seconds. This has become a joke in computer science. Because in the VMS operating system, the TIMEPROMPTWAIT variable, which holds the time the system will wait for an operatorāāto set the correct date. And time at boot if it realizes that the current value is invalid, "is set in microfortnights." This is because the computer uses a loop instead of the internal clock, which has not been activated yet to run the timer. The documentation notes that "ā»he time unit of micro-fortnights is approximated as seconds in the implementation".
The Jargon File reports that the millifortnight (about 20 minutes) and nanofortnight have been occasionally used.
Furlong per fortnightā»
One furlong per fortnight is a speed that would be, barely noticeable to the naked eye. It converts to:
- 1.663Ć10 m/s, (i.e. 0.1663 mm/s),
- roughly 1 cm/min (to within 1 part in 400),
- 5.987Ć10 km/h,
- roughly 3⁄8 in/min,
- 3.720Ć10 mph,
- the speed of the tip of a 3+3⁄4 inch minute hand.
Speed of lightā»
The speed of light is 1.8026Ć10 furlongs per fortnight (1.8026 terafurlongs per fortnight). By massāenergy equivalence, 1 firkin is equal to 3.24936676Ć10 firkinĀ·furlong/fortnight (ā 3.478Ć10 BTU, or 3.669Ć10 joules).
Othersā»
In the FFF system, heat transfer coefficients are conventionally reported as BTU per foot-fathom per degree Fahrenheit per fortnight. Thermal conductivity has units of BTU per fortnight per furlong per degree Fahrenheit.
Like the more common furlong per fortnight, a firkin per fortnight can refer to "any obscure unit".
See alsoā»
Footnotesā»
- ^ The firkin of the FFF System is defined as the mass of an imperial firkin (9 imp gal) of water. The imperial gallon was originally defined as the volume of 10 lb of distilled water (weighed according to specific conditions). From this definition a density of 10 lb/imp gal is derived, giving the firkin of water a mass of 90 lb.
- ^ Indeed, if the inch were defined as 2.5454... cm, it would be 1 cm/min
- ^ The foot-fathom is a unit of area; 1 foot-fathom is equal to 6 square feet.
Referencesā»
- ^ Kelly-Bootle, Stan (March 2007), "As Big as a Barn?", ACM Queue, vol. 5, no. 2, pp. 62ā64, doi:10.1145/1229899.1229919
- ^ Slade, Robert (2006). Dictionary of information security. Syngress. p. 122. ISBN 1-59749-115-2.
- ^ Neff, John D. (June 1983). "Imbedding the Metric". The Two-Year College Mathematics Journal. 14 (3): 197ā202. doi:10.2307/3027087. JSTOR 3027087.
- ^ Ganssle, Jack G. (2008). The art of designing embedded systems (2nd ed.). Newnes. p. 50. ISBN 978-0-7506-8644-0.
- ^ Giambattista, Alan; Richardson, Betty McCarthy & Richardson, Robert C. (2004). College Physics. Boston: McGraw Hill. p. 20. ISBN 0-07-052407-6.
- ^ Stephan, Elizabeth A.; Park, William J.; Sill, Benjamin L.; Bowman, David R. & Ohland, Matthew W. (2010). Thinking Like an Engineer: An Active Learning Approach. Prentice Hall. p. 259. ISBN 978-0-13-606442-8.
- ^ "microfortnight". Retrieved 2007-07-06.
- ^ "HP OpenVMS System Management Utilities Reference Manual". 2001-03-30. Archived from the original on 2024-02-07.
- ^ "FAQ for newsgroup UK.rec.sheds, version 2&3/7th". 2000. Archived from the original (TXT) on 2006-03-06. Retrieved 2006-03-10.
- ^ Page-Jones, Meilir & Constantine, Larry L. (2000). Fundamentals of object-oriented design in UML. AddisonāWesley. p. 235. ISBN 0-201-69946-X.