Little Things - What Matters? Units Of Measure

Tags: Little Things

Little things matter a great deal in the world of making, using and achieving. A preposition, angstroms, nanosecond, an octothorpe (ok. 'Hashtag'), or the misplaced click should all bring to mind something we thought was insignificant, but chaos ensued, lessons were learned. It is the grist of stories told, parental warning, legal action, financial consequence.

These are not the little things to which I devote this entry. They are merely the consequences of the little things of which I write. It is the mundane. The routine. The detail that brings creative thought to its knees, or transports one to the world of daydream.

In the spirit of keeping this post short, I will limit this entry to Units of Measure and follow with others such as timing, syntax, order of operation and the like.

There are any number of catastrophic failures traced to a faulty Unit of Measure (UOM), conversion or ambiguity (e.g. Mars Climate Orbiter). These are crucial but trivialized - the cool thing is in focus. They aren’t exciting, the ‘cool nifty stuff’ is and it’s rarely Units. They are something only Engineers (and Scientists) worry about. Relegated to the realm of assumption, transformed into a ‘snake in the grass’ for anyone trying to accomplish something worthwhile.

How was awareness formed? The Unit of Measure concept was foreign in 6th grade, worthy of deduction and gnashing of teeth by 9th, subservient by 12th as Units gave a clue as to solution method; finally beat into our heads as engineers in college, becoming experience when fixing something that should not have occurred (90 degrees IS NOT 90 radians). A tangent thought: Were our educators through High School really taught their significance in their college experience? The practical reality or a hurdle to be overcome when lessons were encountered in the execution of their duty? The older I get the more I appreciate my shop teacher.

By the time I was granted an engineering degree, I concluded that all numbers have Units; dimensions. Anything that is a pure number is explicitly declared as dimensionless and ‘dimensionless’ becomes a Unit with properties similar to the number 1. A tragic fact: You can’t add a dimensionless number to anything with a UOM. Therefore ‘dimensionless’ has properties in common with a UOM. Another tragic fact: Some familiar units are relative, not absolute. Case in point – when told to double the oven temperature, do you go from 200 F to 400 F or take it to 860 F? Ambiguity.

Expected and reasonably known are the different systems of measure: Metric, Imperial, English, SI. Yes, they mean different things: search the internet. Nations also have their own standards. Derived Units add formulaic differences. Particular confusion arises in any discussion involving a secondary or tertiary concept. A simple “How many MMBTU’s are in that cubic meter of propane?” evolves to more questions: “Gas or Liquid?” If gas, “What is the Temperature, Pressure?” “Where was it produced?”, since it probably isn’t a pure cubic meter.

In many tasks and professions, we may safely assume a given set of Units so that when a number is observed in context, the UOM’s are implied. It makes communication efficient and the Units easily overlooked. Not so across regions; not so across professions; especially not so in international concerns. If there is the chance they can be ignored, leadership will stipulate it out of scope. Consequently, there are any number of dramatic and tragic failures attributed to getting the UOM’s, wrong.

Is it even a rational practice to make this assumption when accumulating data or building software and applications that span regions, disciplines and nations? Is a label enough?

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