while talking with a friend about learning programming, i searched for course material for the best programming course i ever had so far, namely dibo’s “programmierkurs java” (which i praised so often when it comes to this topic). while looking, i found a new website by dibo, called programmierkurs java, which features the lectures (both slides and video recordings!) and exercises. in case you want to learn programming and understand german well enough, take a look there!
ok, so much for advertising. when taking to the friend, another topic was “what is the right programming language to begin with?” in this case, the canidates java and c++ were named. i would definitely go for java, even though i prefer to use c++ myself for most things i program, as java is more allergic to programming errors: if you try to access an array out of the boundaries, it will throw an exception and will not result in unexpected behaviour. moreover, it is widely available (for free!) and easy to set up, there is a huge amount of (good and bad) literature about it, it is not too far off from the real world programming languages which one might use later (in case one wants to learn more than one language, it might also be a good idea to start with something more esoteric, like functional programming). moreover, it can be used both imperatively (which is in particular useful in the beginning) and object oriented (which one shouldn’t touch too early, in my opinion).

as you may have noticed, i use wikipedia a lot – both for linking to descriptions of terms i use in this blog, and for looking up stuff myself which i encounter somewhere, may it be offline or online. usually, chances are good that wikipedia offers at least some kind of description which answers my questions, or at least helps me getting an idea. but from time to time, it happens that you try to look something up on wikipedia, only to find out that such an article existed but was deleted – for example, because it was “not relevant”. i can understand that people do not want to see wikipedia flooded by biographies of john doe and jane roe – only a handful people are interested in these, probably most notably john doe and jane roe themselves.
but there are cases where i simply can’t understand the decision. for example, there is the chilenian doom metal band mar de grises, which i discovered by chance in zurich’s now deceased knochenhaus. according to the wikipedia deletion log, it is “not noteable” and failes some guidelines. so, who decides what is noteable and what is not? and, after all, the simplified ruleset explicitly mentiones

ignore all rules – rules on wikipedia are not fixed in stone. the spirit of the rule trumps the letter of the rule. the common purpose of building an encyclopedia trumps both.

i can pretty well understand that not every small band hobby band project should be mentioned – in particular the ones which sound bad and dissolve quickly with none or almost no productions. but that’s not the case for mar de grises. besides that, the deletion log also mentiones other problems with the article (namely, being badly written and failling to provide references for some claims), but why not throw these parts out or reduce the article to a stub?
two other examples, this time from the german wikipedia, are sinnlos im weltraum and lord of the weed, two fandubs. according to the english wikipedia, sinnlos im weltraum (a redub of a star trek series), dating back to 1994, is one of the first such projects, essentially starting the whole genre of fandubs. i don’t know how many people know it, probably a huge number. lord of the weed (a redub of the beginning of 2001’s lord of the rings) is also rather well-known; i don’t remember how often i saw it – at least ten times. well, it is obviously true that these movies haven’t been shown in movie theaters or on television – as they contain copyrighted material (i.e. the original movie), used without permission. for the same reason, they haven’t been shown on film festivals, you can’t buy them on dvd. they are also not listed on the imdb. but – so what? does that make them not noteable? irrelevant?
on the other hand, a lot of totally trashy movies – which, compared to sinnlos im weltraum and lord of the weed, are really crappy and lame – are featured on media, two good examples are a music video by grup tekkan and the infamous star wars kid, making a fool out of himself. these are pushed by media as “youtube movies you have to see” or are even shown on tv. and they can be found on wikipedia. even though they are real crap. in the case of star wars kid, the really embarrassing movie was uploaded by “friends” of its actor and will probably haunt him for a very long time. to make this even better, a lot of online versions of famous newspapers or magazines feature this video as well, showing it to an even wider audience. and i thought the use of a pillories are outlawed in modern countries.
anyway. i’m still using wikipedia, even though of these reasons. and i even created an account at the english wikipedia and started writing an article about infrastructures (number theory). as so far, nobody else dared to write something on this subject, and a google search only gives documents featuring other kinds of infrastructures, or scientific articles about this subject, i thought it would be time to add something to the web. i’ve started a series of posts on my math blog on infrastructures, but as google usually ranks wikipedia articles higher, i decided to also add something to wikipedia. so far, it is more a stub and far from being a complete article, but at least provides some information and several references to literature.

while updating some old posts with photos (just designwise, no content changed), i once again experienced a complete lockdown: the server became incredible slow and was floaded with apache processes, and i had to shut down and kill -9 all apache processes several times to be able to continue to do anything except waiting. this isn’t the first time this happend, but this time i had apache’s logging enabled (waiting for something like this) to see what was causing all the accesses. well, out of the 13.000 logfile entries (ranging over a week, i think), around 3.300 were by wordpress – and 99.9% of these happend in the last few hours, while i was updating the old posts. it seems that every time i updated a post, wordpress accesses all links and images in the post, also the local ones, and downloads them. yes, downloads them – also the big versions of panoramas. and if i’m updating posts with often 10–30 photos, some of them large, this clearly explains why the web server was dying. to put it that way, wordpress dosed itself. (the funny thing is that it did not first use a head first, to see what kind of link this is, but starts with a get to first download the whole thing. after downloading all links and images, it uses head on them.)
anyway. i don’t know at the moment what to do against that.
but another annoying thing is that the blog is loading rather slow. i also decided to see what is causing this. well, it turns out that the old main page was doing 298 sql queries. after disabling role scoper, this jumped down to 34, with loading times more or less the same. but then, i disabled the tag cloud. this just saved one query, but reduced the page generation time from around 10 to 2 seconds. wow. enabling role scoper again (i really need that one), i now have a bit less than 50 queries with maybe 4-5 seconds of page creation time.
well, still far from optimal, but already faster.

just found on xkcd, and its so right:

(copyright © 2008 xkcd.)

while i was searching for a plug-in which allows access control to posts based on users and/or user groups, i stumbled about many different plug-ins, some of them very promising, but either dead, not updated for a long time, or simply not exactly usable by producing a long list of php error messages already in the admin screen after activating them. grrreat. well, of course, i could also try to do it myself, as usual. but hey, that sucks: i’d be better of writing my own blog software.
well, i talked about the problem a bit with kornel, and we concluded that an optimal blog system would be a very slim piece of software, just providing the very basic features, i.e. managing posts, comments and pages, users and user groups/roles/whatever, and access privileges, while everything else—such as galleries, embedding videos, gadgets, comfortable post editors, …—is implemented as plugins.
anyone want’s to do this, and produce a well-documented, slim, bug-free blog system with a good plugin interface, together with a few standard plugins? :)

today i stumbled about a song called gloomy sunday, originally composed by the hungarian pianist rezső seress. there are probably as many urban myths about this song, which is also known as the hungarian suicide song, as there are cover versions… i like the original lyrics the most; you can read them here (both the original hungarian version and a literal translation). reads like a typical doom song, just written around 50 years too early…
for me, it seems like a really strange idea to kill yourself because of listening to a song, and in particular, it seems really strange to blame a song for making people commit suicide. for me, it sounds like an excuse for not having to search for other reaons… maybe it was the last straw to tip people off, or suicideers decided to listen to it on or shortly before their suicide because it expresses their feelings.
but anyway. i’m somehow wondering whether a doom metal band has covered this one, too; the only metal band i found who did this is a german black metal act called negator; a video of a life performance can be seen at their homepage (don’t watch it if you don’t like black metal); they are performing sam m. lewis‘ english version of the song. i didn’t like it too much, first of all because i don’t think black metal fits here and, secondly, i’d prefer something more close to the original lyrics.

it is autumn and the leaves are falling
all love has died on earth
the wind is weeping with sorrowful tears
my heart will never hope for a new spring again
my tears and my sorrows are all in vain
people are heartless, greedy and wicked…

literal translation of the first stanza taken from phespirit.info.

after watching a horror movie which i didn’t like too much (it felt too constructed, the horror was too obvious), i watched another movie, den tredje vågen (imdb), a swedish one, called the third wave in english, and this one was really, really good. despite being an action movie. reason is, it has a story. a good one. the only bad point was that i could only watch the german dubbed version, as the original was in swedish and i don’t happen to understand that language…
the setting is europe, being threatened by organized crime. the hero, an ex cop, is dragged together with his family into a chase through europe (london to the netherlands to munich) after a backer’s wife who wants to give information to europol. the story is solid, seems to be well investigated and plausible, is mostly not predictable, tension increasing until the end, which is a partially happy end with a deep dark shade left, leaving my mind rattling, chunking on different thoughts. making me fear the environment is too real, too realistic. this is way more creepy than creep.
it’s really a shame this movie wasn’t shown in german cinemas, as it’s way better than most of the movies which were.

every time i plan to start a new project, let it be a web project, a programming job, a latex document (or a combination of those), i’m thinking hard on whether to use something already existing as a base or whether to do everything myself, from the scratch. for latex documents, i usually reuse macros i’ve written myself. for programs, i use libraries like opengl and zlib (two random names coming to my mind, there are of course a lot more), i reuse my own code, and write the rest from scratch. for this blog, i used wordpress, for usage statistics i use phpopentracker. and, of course, i use php and mysql as backends. even though i could implement the whole stuff myself. if i just would have enough time… but i don’t, and so i have to cope with all the restrictions, specialities, whatever these programs and libraries are throwing at me.
the reason why i’m thinking about this at the moment is a new project of mine i’m thinking about, which i’m planning to code more or less from the scratch (using, of course, some backend stuff like php, mysql, phpopentracker, you name it). i just started drawing some sketches, like its logical structure with hints on the physical implementation. sometimes i wonder whether i should spend more time on such things. despite there probably already exists a system which does exactly what i want, making one yourself is way more fun. although its also way more work.
let’s see if i manage to pull this one through… wish me luck.

it’s amazing how fast it is getting dark outside; it’s pretty obvious that summer is gone. even though, today the weather was pretty nice, at least during the afternoon: the sun was shining, and in the sun it was pretty warm. well. after spening two more hours in the darkness (why are there seminar rooms with no window to the outside?), i decided to grab the chance to enjoy the scenery at the zürisee, and then, on the way there, i decided to take a boat trip. and so i did. it was really beautiful, watching the waves, the sun, though it tried blinding me, letting the thoughts wander around, listening to good music (communic, unholy, swallow the sun). it was fantastic. even though the sun began hiding, swallowed by the mountains, the air getting chilly, even cold. the waves are fascinating, changing from a plastic like look to very complex patterns in a minute, somehow reminding me of fractals.
then, coming home, while darkness is crawling upon the sky, changing into blackness, as it is now, only artifical light left. me sitting here, typing, drinking hot chocolate, thinking. the sun is gone for today.

consider the field of all numbers. meaning, of course, the complex numbers. we say that a number is representable if we can describe it by a text (for example, by a binary coded string of 0’s and 1’s of finite length). the set of all representable numbers is countable, as there’s a surjection of the set of binary strings (which is countable) onto it. moreover, it is a field, as if a and b are representable numbers, we have that a + b, a − b, a ⋅ b and a / b are represented by strings as “sum of (description of a) and (description of b)”. obviously, every algebraic number is representable, so our field of representable numbers contains the algebrically closed field of the algebraic numbers. but then, our field also contains euler’s number e and archimedes’ constant π, so it’s strictly larger. this opens the question: how does it’s algebraic closure looks like? not too surprisingly, it turns out to be already algebraically closed: every element in its closure can be represented by “root of polynomial with coefficients (description of coefficients)”, as all coefficients are representable. hence, our field, being countable, is strictly larger than the smallest algebraically closed subfield of the complex numbers, but still countable. and it contains lots of transcendental numbers. isn’t that cool?