is a number without it’s way.
Every test or quiz I grade as a High School Physics Teacher, the easiest thing to take off for is units. My professors taught me well. Units are essential to the meaning of a number. Imagine needing to bail off of a multi-pitch unexpectedly…one of those times where rapping the route isn’t an option…maybe because of choss…or simply the angle of the climb. Straight down is the way to go, into the unknown on a route you’ve never climbed. Clearly, there is a huge difference between a 60 meter rappel versus a 60 foot rappel to a climber, and not just in convenience. We are talking the difference between needing a second rope (not always feasible). The alternative is needing to build an additional anchor to get down which may or may not include sacrificial gear, but also is not always an option depending on the wall and features that are present. The worst case often fatal scenario is rapping off a rope end. These types of rappel accidents are an all too common an event even when climbers know how far they are rapping.
A number is almost meaningless without units. 1 second? 1 day? 1 year? 1 decade?
One has an infinite number of implications depending on the usage of the word, and it matters. It matters to students, to teachers, to doctors, to engineers, to homebodies, to any member of this society, and yes, even to a climber. Anyone with the ability to read this article is living in a world constructed upon precise units of measurements. Everyone drives (or bikes) and has some perception of speed. It always entertains to see the 100 km/hr signs in in BC, vastly different than what 100 (mph) would feel like in the ole’ US.
Imagine reading a guidebook and seeing the number 13 next to a climb. Are we talking…. Yosemite Decimal?… and they were just too lazy to write the “5”? (Eek…kind of hard for me personally…) Is it Australian? (I got this!!..) French? (uhhhh….??)
So yes, climbing grades are unit-less…and perhaps a bad example, but the system and context we use these numbers (and letters) within is still important. Without it, these grades lose their meaning. (Though many would argue that grades have very little meaning, but this argument and climbing grade subjectivity will have to wait for another day.)
One of the most classic and costly physics examples of units gone wrong took place in September of ’99 resulting in the failed mission of the Mars Climate Orbiter.
“The ‘root cause’ of the loss of the spacecraft was the failed translation of English units into metric units in a segment of ground-based, navigation-related mission software, as NASA has previously announced,” said Arthur Stephenson, chairman of the Mars Climate Orbiter Mission Failure Investigation Board.
The aforementioned multi-million dollar Orbiter began its descent to Mars a touch early, lost radio contact, and soon disintegrated in the Mars atmosphere. I’ll leave further investigation of this for the interested parties…
Which leaves me with the great debate: International System vs. United States Customary Units and which one should I use here?
The development of standardized units of measurement is an interesting research topic in its own right, one which I am not going to delve too far into (on this fine Valentine Day late evening). A few interesting tidbits in regards to choice unit systems:
Metric System: (SI units)
– World embraced favorite. There is a great graphic showing the “metrication” of the world here.
– Physics Class = Metric System all the way – the standard for scientists and engineers
– That whole pre-fix system the metric system has is pretty effective….
US Customary Units: (Similar to the Imperial System, based on English Units)
– The US is only one of three countries that have not officially adopted the metric system for weights and measures….ha…
– US Customary Units have small divergences from the Imperial system – very confusing
-To make matters worse..states are given a choice on what conversion system to use for the foot: some use the US Survey Foot, some use the International Foot (again – slightly different), some states have not even decided which conversion to use…
– In favor of English based units….I’m American – yea!!
– You’re probably American, too- yea! (thus familiar and relatable).
Thus, from here out I will include all numbers and complete all calculations using the International System of Measurement or SI Units, the modern day metric system. In deference to us American Folk…I will include English Units as well for reference in parenthesis, because its nice.
Example:
I led a 40 meter pitch (131 feet).
Side-note: I do find it ironic…that in the high school classroom and even while teaching undergrads, I constantly reminded students to remember their units. It’s a clue…a hint to figuring out those type of problems, and a way to check that your answer is in the ballpark of correct. However in graduate school, I never personally remember using units….mainly because the problems in homework sets were so difficult on their own, that we only solved for variables and rarely numbers. We did use a handy tool…dimensional analysis to look to see if our answers made sense…occasionally. (Imagine algebra on drugs.) Truth be told, dimensional analysis at that level felt less helpful at the time, but feels truly essential in retrospect.