orthogon wrote: CharlieP wrote:
quolnok wrote:A few hundred yards? that doesn't seem very precise. For a start, are we talking about front yards, back yards or grave yards?
My first thought was "why yards, and not feet?". As somebody who prefers SI measurements, I'm yet to figure out what the rule is.
Length of a tapered drinking vessel with a bulb at one end: 1 yard
Height of a tall person: 6 feet
Length of a football field: 100 yards
Length of a Nimitz-class aircraft carrier: 1,092 feet
Length of a two-lap running race: 880 yards
Altitude of Alan Eustace's recent jump: 135,906 feet
I speculated about this in another thread, but there's definitely a tendency to use different units
for quantities that have the same dimensions
when those physical quantities are felt to be qualitatively different; even the most rigid adherent of SI would hesitate to use the Joule as a unit of torque, for example.
Orientation is one distinguishing factor. For human beings living in a strong gravitational field, vertical distances are completely different to horizontal distances. I would generally (when in an imperial frame of mind) only use yards and miles for horizontal distances in the context of travel; vertical distances are measured in feet. Yards of Ale and the Mile High Club are interesting examples: the former is probably partly because it's held horizontally and partly to emphasize the extraordinary size of the vessel by deliberately using the "wrong" unit; the Mile High Club is probably another example of the "wrong unit".
Objects, natural or man-made, are generally measured in feet rather than yards, hence the aircraft carrier. I guess a football pitch is conceived more in terms of distances that the players have to travel marked out on the ground, rather than as an artefact or object.
I don't expect to come up with a definitive set of rules - many of these things are probably arbitrary convention - but it isn't completely random either.
One final point is that yards aren't very useful when you want to provide a fractional part: you can say 6ft 4ins, but 2yds 4ins? 2 yds 0 ft 4 ins?
I think there are several factors involved orientation, convenience, precision, tradition, and connotation, to name a few.
- Length of a tapered drinking vessel with a bulb at one end: 1 yard From a yardstick, the traditional ruler for more than 1 foot.
- Height of a tall person: 6 feet When people are very young, they are measured in inches. That changes at some point...see belo.
- Length of a football field: 100 yards 100 has a nice connotation, I expect.
- Length of a Nimitz-class aircraft carrier: 1,092 feet Yard is too inaccurate, even at that length; off by 1 yard is off by 0.3%
- Length of a two-lap running race: 880 yards Many races are much shorter and came to be denoted in yards. 880? Exactly half a mile, of course.
- Altitude of Alan Eustace's recent jump: 135,906 feet I'll buy your speculation on vertical distance for this. But I note that altitudes such as the space station are often given in miles.
Essentially, a lot of this thinking derives from some software I worked out that translates age to human terms. Every human age can be translated to days, but for example when have you last hear it said that someone is 21,204 days old? What I was trying to do was come up with rules to specify which unit should be used for "common nomenclature", and this is what I came up with:
- 1 day old to 6 days old
- 1 week old
- 7 days old to 10 days old (when did you ever hear of a 15-day-old or 21 day old baby?)
- 2 weeks, 3 weeks
- 1 month old
- 4 weeks to 7 weeks old
- 2 months old
- 9 weeks old to 11 weeks old
- 3 months old to 11 months old
- 1 year old
- 13 months to 17 months, approximately
- 1½ years old, 2, 2½, 3, 3½, 4, 4½
- ...but then the halves are dropped; I've heard 4½, but not 5½; after that it just goes by year: 5, 6, 7, 8...
...and I'm not sure I got it right (it was never actually implemented) because I'm quite sure someone could dispute these. In summary, the rules are highly arcane and human...not necessarily making straightforward logical sense. And, like so many things a balance of human factors: number of syllables (convience); listener needs to know (accuracy); how does it make me feel to say it (21,204 days is just silly); what sounds good (connotation); what have I heard other people use (tradition).
If you want a real reason, expect to spend a lot of time on research...