Yes, it’s from a book called “Uncle John’s Bathroom Reader” and that book was resting on a closed toilet seat in a nation that only kind of uses the metric system in certain situations… however, you’d be surprised how much you can learn after a single visit to any local fast-food joint!
The metric prefix system is a fantastic invention, akin to the arabic number system. Honestly it’s surprising no one came up with it sooner… but (and I’m sure I’ll catch some flak for this) the metre is an awkward length - it’s too big for human scale measurements. The decimetre is not as bad but still not very good, and it’s also not commonly used. The centimetre has the opposite problem - it’s too small for the human scale but too big for precision work.
Don’t get me wrong, the horrible conversions between imperial units make the system unusable for me, but the unit lengths themselves are scaled to humans because they weren’t initially defined arbitrarily by some committee (why should the distance from the pole to the equator be used as the baseline for a measurement used by humans?). I think the inch and foot are great lengths to use on a daily basis, they feel quite natural.
What annoys me the most is that we could have had the best of both, since the foot and inch are only a factor of 12 apart, so we could have had a metre measuring about one foot and a decimetre measuring about an inch.
You clearly haven’t been a kid measuring a 7m penalty kick on some random field. It works perfectly fine.
I would rather walk-measure the side of a field than tiptoe-measure it.
If you want to be more precise, you need to know your body’s measures. Like the span of my hand from thumb to middle finger is 21cm. 20 if I’m not that concerned about accuracy. I can measure quite a lot with that. Or 170cm for my arms spread apart (wingspan).
You’re right, I have no interest in sports. Though in that case under this modified metric a decametre would be approximately on the same scale as the previous metre.
Don’t get me wrong, imperial sucks, but the scale of the typical measurements with typical units lands nicely in what the human brain is good at visualising - small groups of up to about 10 (see my comments to other people in this thread). I think most people would prefer when the common measurements they make with common units end up in the range of 0.2 to 10-ish. Centimetres are too small for that and you measure using dozens or hundreds of them, which starts to lose semantic meaning, which makes visual estimation a bit trickier, especially with comparative distances. You start thinking in terms of tens or hundreds of cm visually to keep it under control which is just another layer of cognitive load. I think the perfect unit system would avoid this as much as practical. The existing metric metre is fine for outdoor activities, but I would argue most people aren’t out measuring fields all day, they’re looking at things on the same scale as their own body for the most part. Metres are a bit big for that.
What? The whole idea of the prefix system is that it’s granular enough that you can describe any size as up to 100s (or 10s of common sizes) of any prefix.
Think of it as scales: Metres is the unit for things people sized (including kids), decimeters for things hand sized, centimeters for grit sized, etc.
Other scales are mostly an extension of the system: Kilometers is “away” sized, millimeters are tiny sized, and following the convention of 10s makes for easy to remember and translate conversions, although I’ll admit that they aren’t inherently more convenient than other measures.
Similarily: foot is stick sized, an inch is pebble sized, but the imperial system then doesn’t easily convert between other common human experiences. Talking of things seed sized becomes weird fractional math, figuring out how many steps it is to the next town (miles I’d argue is “trip” sized) gets weird. And when you need higher precision you end up in fractions of a larger unit rather than convenient ones.
The size of an atom is about 100 pikometers (10e-12 metres) and a molecule about a nanometer (10x the size). In US customary an atom is about 1/262144 (2^18) thou of an inch, and molecules about 1/2048 (2^11) thou of an inch. And if we want it compared to miles or feet, we’ll have to redo the calculations from scratch with loads of danger of messing up conversion numbers.
Besides, most of the benefit of the metric system is that the standardised scale prefixes makes it very easy to correlate all other physical constants. Speed of light is just under 300 km/s, which is about 300 m/ms or 300 mm/ns, or 200 miles/second which is about 1000 ft/ms or 10 in/ns (not to mention that rounding errors are larger in customary)
EtA: I do wish we had a base 12 math system though
Don’t misunderstand me, imperial sucks. I just wish the metric system had defined the metre to be smaller, that’s all.
See my other comments in this thread. I think most people would prefer if the common measurements they made with common units landed in the number range of about 0.2-10-ish. The human brain is good at visually estimating small groups so any unit system should try to lean into that and put the scale of commonly measured values in that range. Obviously as things get bigger you end up with tens or hundreds of units which start to lose semantic meaning, especially for quick estimations or relative comparisons, so you should start thinking of switching units at this point. Likewise when values get below about 0.1 they get hard to visualise, so most people switch units here.
My point being - I think the base unit of one metre is too large for most daily tasks - most things that are around a human scale end up being less than one metre, and I think the centimetre is too small - most things on the human scale end up being dozens of centimetres at least. Both fall outside that ideal range of ‘a small handful’ which the brain is good intuitively and subconsciously working with.
Why don’t you use the decimeter then? It’s 10 cm and sounds like it solves all your issues.
The decimeter is certainly an overlooked unit, and it’s a shame it’s relegated to relative obscurity - I use it occasionally even if people give me weird looks. Ideally I think something in the range of 20-30cm would make for a nice base unit - about the length of a forearm. Deci-units around the length of a finger segment, and centi-units being a slightly larger millimetre-equivalent. A deca-unit would be about the height of a doorframe.