Arnt Richard Johansen's home page

The sun is that far away?

The slogan for this tanning studio says Our only competitor is 930 million kilometers away.

Yes indeed. The Norwegian mil is equal to ten kilometers. Presumably, the competitor to which they refer is probably the Sun — which is roughly 150 million kilometers away, or about 93 million imperial miles.

The UltraSun chain doesn't appear to be active in any English-speaking country, which makes the use of imperial units in Norwegian all the more odd, since it can't be attributed simply to a careless translation of some English slogan.

[Tuesday, Jul 04, 2006 @ 10:02] | [miscellaneous] | # | G

Kakebaking som straff

Da jeg lette gjennom bokhylla for å finne noe å lese på før jeg gikk og la meg i går kveld, fant jeg noen sammenstiftede A4-ark klemt inn mellom to tidsskriftkassetter. Den tynne blekka viste seg å være utkast til samarbeidsavtale for EiT-gruppa vår fra 2004.

Den såkalte samarbeidsavtalen brukes visst fremdeles i Eksperter i Team. EiT er jo et temmelig spesielt fag i universitetssammenheng, siden alle på hver gruppe får samme karakter. Det er derfor viktig å sørge for at arbeidet blir rettferdig fordelt, og at eventuelle konflikter blir løst før de fører til at grunnlaget for karaktersetting faller bort. Hensikten med samarbeidsavtalen er å regulere dette, men forslaget til standard avtale beskrev et rigid kontrollregime av en annen verden (dette ser ut til å være den nåværende versjonen, men slik jeg husker det fra 2004 var det enda verre). Gruppa vår bestod av veldig flinke og fornuftige mennesker, så vi radbrakk standardavtalen til den ble akseptabel for oss – og altså helt forskjellig fra den opprinnelige. Jeg skal ikke gå særskilt inn på detaljene, men ville bare dele med dere en paragraf jeg likte spesielt, fordi den var skrevet så bra:

5.1. Tiltak ved mislighold
Kommer man 20 minutter eller mer for sent, skal man servere kake på neste ordinære møte. Kaken skal ikke inneholde marsipan eller nøtter, skal inneholde høyst moderate mengder fløtekrem, og det skal være nok til alle. Kaken skal være hjemmebakt. Subsidiært kan en kake kjøpt på bakeri eller konditori godtas, såfremt den er av tilsvarende eller høyere kvalitet enn en hjemmebakt kake.

Det var ingen som kom for sent i løpet av hele semesteret, så den kom aldri til anvendelse. Dessverre.

[Thursday, May 25, 2006 @ 19:25] | [miscellaneous] | # | G

Ego satisfaction

Yesterday evening I was listening to the podcast of the Norwegian radio programme Språkteigen, which is about the Norwegian language, and language in general. The last topic in the programme from April 6th (mp3, this direct link will probably disappear soon) was creaky voice. After a barrage of examples of creaky voices, a normal voice started reading the following passage:

Knirkestemme eller laryngalisering er en form for fonasjon der arytenoidbruskene i strupehodet dras tettere sammen enn normalt og stemmeleppene strammes ekstra opp. Det gjør at luftgjennomstrømmingen blir lavere og vibrasjonsfrekvensen går ned til omkring 20–50 pulser per sekund.

After the first ten words or so, this started to sound eerily familiar. Hadn't I read that before somewhere? Maybe it was from one of my old phonetics textbooks, but I had doubts that any textbook in Norwegian had this much physiological detail. Then it hit me. The reason it sounded familiar was that I had written it! It was a quote from the article on creaky voice on the Bokmål Wikipedia.

Of course my name wasn't mentioned (Wikipedia articles are written collaboratively, after all), but it sure was fun to hear my own text on national radio!

[Monday, Apr 10, 2006 @ 15:54] | [miscellaneous] | # | G

You can't code Python with pencil and paper

The fact that Python uses indentation to indicate block levels is mostly a good idea, but how does one sketch code longhand in a reliable way? You'd have to use squared paper for that.

[Friday, Mar 31, 2006 @ 15:55] | [tech] | # | G

New game invented

So. You've visited every geocache in the area that is available in winter. There are no interesting waymarks nearby, and you lack the determination to go to a degree confluence. What other ways are there to have fun with a GPS receiver?

The answer lies in a pair of dice. Or, as we shall soon discover, about 3 to 5 of them. The idea is to pick out a random set of coordinates, and see where they will take you. You could just do it the old-fashioned way by throwing a dart at a map, but who has a map that size, and a dart-proof wall on which to hang it? Besides, part of the fun lies in not knowing where you end up until you get there. Or at least, as close to the spot as possible. The second time I did this, the exact point turned out to be in the middle of a heavily trafficked road. Obviously going all the way to the spot could have some, ahem, adverse health effects.

There are a couple of challenges involved in rolling geographical coordinates with dice. First, obviously you can't roll the DGS coordinate set in its entirety, unless you are prepared to go on a circumnavigation. (Well, maybe you do want to find out where in the world you are going to spend the next holiday. But for me, who just wants to go for a walk for a few kilometers, it's absurd to include the whole world in the probability space.) So you have to limit the set of possible locations somehow.

My first approach involved keeping degrees and minutes the same, and rolling seconds and tenths of seconds, 3 x 2 digits in all. Use a d6 for the first digit (interpreting 6 as 0), and a d10 for the two last one. It is also possible to use a d10 for all digits, but then you have to re-roll if you get a value above 6 for the first digit. That gets tedious after a while.

The problem with the above is that if you don't find yourself smack in the middle of the degree-minute square, you're more likely to walk in one direction than in another. The walking distance will also be skewed. The solution to this is to not roll actual coordinates, but the distance and direction from your current position — sort of a polar coordinate system with you in the origo. The distance part of this is the easiest part. It depends on how long you are willing to put up with walking. I used a d10 to roll the number of tenths of kilometers (the lowest resolution my GPS receiver accepts for making one waypoint the offset of another), and the value of a d4 modulo 2 for deciding whether or not to add an extra kilometer, making the maximal distance 1.9 km. You can also add several dice with the same number of sides to get a binomial distribution centered on half the maximal value.

Now here comes the tricky part: direction. (The denizens of #tut will now understand why I have been pestering them about how to ensure linear distibution while rolling the values from 1 to 360.) You can't roll it digit by digit, because if you roll 0 to 3 with, say, a d4 (subtracting one from the value), each of the digits will be equally likely, when in fact 3 has only a 61 in 360 chance of occurring, while 0 has 99 in 360, and 1 and 2 both have 100 in 360.

What I did was to use two d6 and one d10. First, take the value of the first d6, counting 6 as 0, and multiply it by 60. Then, take the value of the second d6, again counting 6 as 0, and multiply it by ten. Finally, take the value of the d10, counting 0 as 10, and sum the final values of all the dice. This gives a result from 1 to 360 that is linearly distributed.

[Saturday, Mar 25, 2006 @ 18:14] | [miscellaneous] | # | G

Programming languages created by women

The relationship between programming languages and facial hair is well-known. When the author has a full beard, the programming language tends to be successful in the industry for decades. When the author is clean-shaven, the programming language tends to be lean, beautiful — and very rarely used for practical purposes. The truly bizarre and perverse languages (such as Perl) tend to be created by guys with moustaches.

So one day I was thinking — COBOL has certain stereotypes associated with it: it is very verbose and full of declarations, it is almost bureacratic in nature. And it is associated with a woman, Grace Murray Hopper (although, as I later found out, she didn't actually create it herself). Do other programming languages created by women have yet other amusing commonalities, similar to those Tamir Khason pointed out with respect to facial hair?

There aren't a lot of those languages, for sure. The lack of woman-made programming languages reflect a skewed gender distribution in computer science, and in science in general. However, with the help of John Cowan (who is quite knowledgeable about almost everything), and others, I have found the following:

FLOW-MATIC was written by Grace Murray Hopper. (Thanks to Jay Kominek for pointing this out.)
FORMAC was written by Jean E. Sammet.
COBOL wasn't actually written by Grace Murray Hopper — although it was very much influenced by her FLOW-MATIC. However, Jean E. Sammet sat in the committee that specified COBOL.
Icon was created by husband-and-wife team Ralph E. Griswold and Madge T. Griswold.

So there it is, programming languages created by women. All four of them. That's altogether too few to say anything interesting about it, but at least now it's collected in one place, on the web and searchable for ever. If anyone knows of any additional ones, please let me know, and I'll update the list.

[Thursday, Feb 09, 2006 @ 22:39] | [tech] | # | G

You forgot Pluto! (Or maybe not.)

I'm immensely happy to report that finally, after numerous postponements and cancellations, NASA's mission to Pluto, New Horizons, was launched yesterday.

I've been waiting more than sixteen years for this to happen. Ever since Voyager 2 passed Neptune in 1989. I could hardly believe it — that spacecraft had been moving steadily since before I was born, sending pictures of planet after planet, and never skipping a single one. And now it was leaving the solar system without visiting Pluto, the last one! In the media reports, they even said that Voyager 2 had gone past Neptune, the outermost planet in the solar system. This left me puzzled: didn't everyone know that it was Pluto that was the 9th and last planet? I didn't realise then that the orbit of Pluto crosses that of Neptune, so that for a short period from 1979 to 1999, Neptune actually was the farthest planet in the solar system. So for a while I believed that they had forgotten about Pluto entirely — or, at least, considered it less than a planet, and not worth visiting. (There is actually now talk about demoting Pluto fram planethood, but that of course doesn't make it any less interesting as an object for study.)

Of course, Voyager 2 wasn't meant to visit all of the planets: the mission only covered Jupiter, Saturn, Uranus, and Neptune. You can't just send a space probe blasting off in an arbitrary direction, you have to plan the trajectory carefully, so you get the exact amount of gravitational assistance. The position of the planets at that time was favourable enough to make that journey, though not favourable enough that Pluto could be reached.

So, to the JPL: I'm sorry I doubted you, and I wish you the best of luck with your new mission.

[Friday, Jan 20, 2006 @ 15:18] | [science] | # | G