Friday, April 29, 2011
Is this April 1?
The one-size-fits-all strictness of the SI measurement system is annoying. It gets especially annoying when scientists write everything in the LaTeX system of typography using SI units. When this format gets shoehorned into plain old HTML web text, the results range from ambiguous to incomprehensible.
Example: cost of electric power, typically given in cents / kilowatt-hour.
How would this show up in SI? You can't have a cent because that's a hundredth, and only powers of 10 that are multiples of 3 are allowed. Have to use milliDollars instead. The kilowatt and the hour are both in the denominator, so each must be written with an exponent of negative 1 to keep the expression on one line, as SI idiotically requires.
Thus "5 cents / kilowatt-hour" must be "50 mDkW-1H-1" in LaTex reformatted to HTML.
But wait! The hour isn't SI-legal at all. Have to use seconds. So we divide the 50 by 3600, to get the nice legal form:
0.013888888 mDkW-1s-1
Completely unreadable! And as an extra bonus, it's much less exact than the primitive old-fashioned 5 cents / kilowatt-hour. Just the way we like it in SI!
Now this article in New Superstitionist shows a new example of SI-lliness.
Well, at least that corresponds to the real world. Most people who find the annus interesting would rather use KY than kilo-annus.
Oh, the author of the article is Celeste Biever. Now I'm convinced it's April 1.
Example: cost of electric power, typically given in cents / kilowatt-hour.
How would this show up in SI? You can't have a cent because that's a hundredth, and only powers of 10 that are multiples of 3 are allowed. Have to use milliDollars instead. The kilowatt and the hour are both in the denominator, so each must be written with an exponent of negative 1 to keep the expression on one line, as SI idiotically requires.
Thus "5 cents / kilowatt-hour" must be "50 mDkW-1H-1" in LaTex reformatted to HTML.
But wait! The hour isn't SI-legal at all. Have to use seconds. So we divide the 50 by 3600, to get the nice legal form:
0.013888888 mDkW-1s-1
Completely unreadable! And as an extra bonus, it's much less exact than the primitive old-fashioned 5 cents / kilowatt-hour. Just the way we like it in SI!
Now this article in New Superstitionist shows a new example of SI-lliness.
We have dog years, financial years and calendar years, but a quest to get geologists and chemists to agree on a scientific year has led to a surprisingly bitter dispute.The official bodies representing the two groups have now settled on the annus as their definition of the year, allowing both groups' data on the half-lives of radioactive elements to be pooled.
Some are still enraged by the decision, however, and a universal scientific definition remains elusive, as the annus differs from the year favoured by astronomers. This changes slightly every year because of the Earth's slowing orbital rate, so the team chose as their reference point the year 2000, when the tropical year lasted 31,556,925.445 seconds. They are using the Latin name for year, annus, which will be denoted by the symbol a, and expressed in terms of kilo-annus (ka), mega-annus (Ma) and so forth.
So far so good. But when a draft proposing the idea came out in early 2009, some members of the Geological Society of America cried foul.
They didn't object to the idea of a precisely defined year, or to the chosen length. Their gripe was with the fact that geologists already use the symbol a (as well as ka and Ma) to denote time in years ago, or "absolute age". Historically, the abbreviations y, ky, and My (or yr, kyr and Myr) have denoted the time interval between two events.
Well, at least that corresponds to the real world. Most people who find the annus interesting would rather use KY than kilo-annus.
Oh, the author of the article is Celeste Biever. Now I'm convinced it's April 1.
Labels: Aptronym Alert
¶ 8:38 AM
