That’s curious, because from what I remember from school in a metric-since-the 19th-century country is: we basically had only two in-depth units in my whole school career:
in primary school: meters, millimeters, kilometers, grams, kilograms, tonnes and their relationships
early in secondary school: the whole gamut of SI units and prefixes
Afterwards we looked up the more unusual SI prefixes in the ‘reference’ section of the physics/chemistry textbooks (usually inside the front or back cover) or in the logarithm table book as needed; in homework or test problems we converted quantities into powers of ten at the beginning and converted the answer into the appropriately prefixed unit at the end.
Why would you need to have a SI prefixes unit at the beginning of each school year?
The reason you’re having difficulty is that the Angstrom symbol, Å, doesn’t exist in most regional character sets. However, the character does exist in Unicode, the universal character set, and is assigned the code point U+212B. If you tell your e-mail program to use a Unicode character encoding, such as UTF-8, then you should be able to send and receive messages using the Å character without any problems.
(There is a similar character, Å, used in Scandinavian languages. If absolutely necessary, you could use this one instead; it appears in a lot of regional character encodings, including ISO-8859-1, which is often the default for English text.)
You’re not familiar with the American educational system, are you?
I’m being more cynical than serious, but we do tend to repeat from grade to grade with the assumption that students will have forgotten whatever they had learned before. And of course they’re especially conflicted with SI, since we don’t use the system much, and we’re reluctant to explain to kids exactly why. We teach languages the same way: wait until they’ve passed the age for optimal language learning, then repeat the introductory material for two or three years, and then declare that they’ve learned a second language.
What I remember about the “metric chapter” in every lousy year’s math curriculum was night after night of doing 36 or 49 or 53 problems that consisted in their entirety of converting US standard units to metric or metric to US standard.
Hey kids, metric is cool and easy, you’ll love it. Nice elegant round numbers and all that. Now convert 13 feet 7 and a half inches to centimeters, and 14 cc per minute into tablespoons, 4-litre bucket into quarts pints and cups, and the amount of water spilled on the floor after x hours of dripping expressed in both fluid ounces and millilitres. And 74° F as Celsius. Don’t you just love metric?
What’s that? You hate that stuff and prefer inches, miles, quarts, etc? Gee, wonder why that woud be?
We have a large water tank here at work. When asked, I used to tell folks that it contained about half a million gallons of water. From now on, I’m going to say that it only holds 2 Megaliters.
One reason terms like gigameter or petameter aren’t used much is that astronomers seem so wedded to terms like AU and parsec. As an ex-astronomy student I wish they’d join the SI crowd.
A gigabyte is 10^9 bytes exactly. The thing that is 2^18 bytes is a gibibyte. There’s a whole parallel system of prefixes with "b"s in them for binary.
I do heat transfer and other thermal science calculations all the time. The unit strings are so messy in anything other than SI that I have to write a computer program and debug it for a half hour or so to get things to work out the same way twice. Converting units is more or less of a pain - when it gets complex enough, the odds of getting the right answer get too small for practicality.
Come on with me, everybody, and push for a new version of the SI. I want it to be identical to the present system except:
the base unit of mass would be the Einstein and would be the same size as a kg, so the old gram would be a millieinstein.
the prefix meaning 1/1,000,000 would be a “u” instead of a lowercase Greek mu, so you could type it on any keyboard.
The prefix meaning 1000 would be a “K” instead of a “k”. This way all the major prefixes that are bigger than 1 are uppercase, and all those smaller are lowercase.
If you studied astronomy, then I’m sure you’re aware that many astronomical calculations become orders-of-magnitude easier when using those units. AUs, parsecs and solar units were designed to make equations simpler so you can focus on what is important. Meters, kilograms, watts, and other SI units were essentially designed by engineers and bear very little relevance to astronomical phenomena.
It’s the same reason that special relativity uses units of c = 1. Sure, it’s possible to express everything as a multiple of 3*10[SUP]8[/SUP] m/s, but why would you do that to yourself when a much simpler set of units exists?
Nice observation. I’d seen the binary prefixes before and wondered what kind of crack the people were smoking. Maybe they weren’t smoking crack after all. I looked up the prefxes on Wikipedia, which can be found here. I think I’ll use those as well as the really high and really low metric prefixes just to see how many people I can confuse.
