Working Mathematician's Blog

The biometric passport ballot just became a little bit more interesting

2009-05-10T21:35:00.001+02:00

Why? See here or here (sorry, german only).

Sync Google Calendar with iPhone

2009-04-14T08:43:00.001+02:00

This may have been around for some time but I found out about it just now and it's what I've been looking for quite some time.

Good News, Everybody!

2009-03-15T22:23:00.001+01:00

He does it again!

Remember the Keytar?

2008-12-23T18:02:00.000+01:00

"This lightweight strap-on keyboard was introduced in the 1980s, just in time to make countless new wave, hair metal and R&B acts look even more ridiculous."

As it will be Christmas soon...

2008-12-20T21:31:00.005+01:00

...here's some music to get you in the mood: Twisted Sister singing "Oh come all ye faithful" and Billy Mack singing "Christmas is all around" ("...except, we changed the word love to Christmas").

Secret Geek A-Team Hacks Back, Defends Worldwide Web

2008-12-13T11:49:00.001+01:00

This makes you think (and my apologies to Wired magazine for simply copying their title).

Tres faciunt collegium

2008-12-06T22:20:00.003+01:00

As I'm über-enthusiastic about Dylan's upcoming European tour, this is my third Dylan-related post today. The following claims from You Know You're A Dylan Fan If... apply to me:

you don't get tired of "Tangled Up In Blue" - even though you've heard it over 10,000 times

you think polka-dots are cool and fashionable

you take it personally when friends comment that Dylan can't sing

practically anything someone says to you reminds you of the line of a song

you divide music into four categories: 1) Dylan; 2) music that influenced Dylan; 3) music influenced by Dylan; and 4) crap

you refer to him by nicknames (e.g., His Bobness, Bawb, Mr. Zimmy, The Dylanator, The Bobinator, Bob-o-rama, Uncle Bobby, Uncle Zimmy, Maestro, The Big "D", Mr. Zim, Brother Bob, The Bobster, Bob-a-roni, St. Dylan, God, Ludwig Von Bob, Leonardo de Dylan, Mr. Bobourine Man, Lucky, The Jester, The Boxer, Dr. Bob, My Man Bob, Elmer Johnson, Sir Bob, Alias, The Master of Song and Lyric, The Master, Master Dylan, Grand Master Dylan, Renaldo, The Zim-meister, Jim Nasium etc. ---- but you'd NEVER call him "Bill Dylan")

you use at least one Dylan quote in every paper you write

you can't understand why your friends don't like Dylan's music

you can't figure out exactly what the line "My love is like some raven, at my window with a broken wing" means, but you know it sounds brilliant

you have a copy of every Dylan concert you've been to

Ten improbable covers

2008-12-06T21:05:00.003+01:00

The Rough Guide to Bob Dylan quite rightly says "what on earth were they thinking" about the following Dylan covers

The Chipmunks: Mr Tambourine Man

Burl Ives: The Times They Are A-Changin'

Jonathan King: Million Dollar Bash

James Last: Like A Rolling Stone

Cliff Richard: Blowin' In The Wind

William Shatner: Mr Tambourine Man

Nancy Sinatra: It Ain't Me Babe

The US Navy Steel Band: Blowin' In The Wind

Lawrence Welk: Don't Think Twice, It's All Right

Mae West: If You Gotta Go, go Now

Why did Wittgenstein attack Popper with a poker?

2008-12-06T19:33:00.001+01:00

I don't know it, but I will soon, as I ordered the book Wittgenstein's Poker by John Eidinow and David Edmonds.

Bob in Basel

2008-12-06T19:27:00.002+01:00

Bob Dylan honours Switzerland by visiting Basel on April 14th 2009 and Geneva on April 20th 2009, for details see the tour homepage. Here are some impressions form the last visit of his Bobness

EVAMAR II: The empire strikes back

2008-11-29T15:05:00.005+01:00

Just have a look yourself (sorry, german only):

How do you introduce a legend?

2008-10-20T21:58:00.002+02:00

“The poet laureate of rock 'n' roll. The voice of the promise of the '60s counterculture. The guy who forced folk into bed with rock, who donned makeup in the '70s and disappeared into a haze of substance abuse, who emerged to "find Jesus," who was written off as a has-been by the end of the '80s, and who suddenly shifted gears and released some of the strongest music of his career beginning in the late '90s.”
(from a Buffalo News article 9 August 2002).

(see here)

Masterpieces in words of one syllables

2008-10-17T23:19:00.002+02:00

When you're asked to explain the famous second incompleteness theorem of Kurt Gödel, what is maximum length of words (measured in syllables) you think you will have to use? George Boolos managed to do it in words of one syllable. You can find the text here.

Tour de Suisse, part 7: Geneva

2008-10-12T17:41:00.003+02:00

Today we went to the Expat Expo to buy some cheese from cheeseclub. Afterwards we also enjoyed a nice (although a little foggy) autumn day in Geneva. By the way: the cheeses were delicious, there was Stinking Bishop, Cheddar, Red Leicester and Stilton and many more (just to name a few of the familiar ones).

Have we been teaching programming the wrong way around?

2008-09-21T20:02:00.004+02:00

I'm just preparing the exercises for a lecture on human-computer interaction (HCI) and therefore read Donald Norman's book The Design of Everyday Things. I then noticed, that usability is rarely a topic in high school computer science classes (actually, it even isn't in colleges, but this shall not be our concern here) in Switzerland. Although programming is the main part of computer science education on this level, usability is hardly ever mentioned, interface design (and so on) is just seen as a by-product of the programming process (actually it's worse, teachers will think, students are just able to design an interface and usually don't point out bad or good design). There are some known disadvantages to today's computer science education. First of all, it doesn't appeal to women (I won't discuss possible reasons here, this is just an empirical observation). Secondly, people who are learning to program are expected to build mental models of the software they're programming (this is understanding algorithmics, design patterns as well as "the big picture", i.e. what the software is to do eventually) at the same time they're usually struggling with syntax and standard libraries.

I think some of the troubles mentioned above stem from the fact, that we still consider programming as something "mechanical", we don't see it as an art that produces stuff that should make people's life easier. So what is my suggestion? Instead of teaching programming try to teach human-computer interaction and include programming as a necessary aspect of this (and don't begin with programming, begin with the behavioral parts!). What could this look like? Well, just take a good HCI book and teach as much as possible of it: how does the human mind work, how do humans behave, lots of examples of good and bad design and also explanations why something is good or bad and so on. Let them draw pictures of user interfaces, let them build mental models of software, etc. And only then teach them a programming language and make them able to realize their designs.

What do I expect from this? As my knowledge of didactics is actually rather humble, I must advise you, that this is all on your own risk (so don't blame me, if it doesn't work), but I think, we might achieve the following things: First of all we might make computer science more appealing to women, as we can show, that it has many aspects of behavioral sciences and its final aim is to produce useful things and make people happy. Secondly, we might also reduce the difficulties mentioned above, when learning to program as the two aspects are separated (architects also don't design houses by putting bricks on top of each other!). But wait, there are even more advantages: Teaching HCI is fun, you can do lots of interesting experiments about human behavior and almost every object (even doors and faucets) turn into subjects of investigation. I also think this approach might lead to very good results in metacognition which is one of the central facets of teaching. So, what do you think about this? (Perhaps it has already been tried or done, in the end it isn't such a revolutionary idea).

The reading of Norman's book also taught me an important lesson for teaching software uses: When something doesn't work or something goes wrong, blame the software (actually, blame the software's poor design). I think it is essential to tell people (even if it is only course on writing letters in Word or something) that most of the time something goes wrong, they're not to blame, but poor design of software. We might even try to teach people to reconsider their mental models of the software (or why a software might have led to a wrong mental model in case of problems). By doing so we help people to solve problems themselves and we can take away the fear of using certain software products.

Bern as you may not have seen it before

2008-09-14T23:19:00.004+02:00

This saturday, Bern was celebrating it 25th anniversary as world heritage site and therefore quite a lot of buildings were opened for public. Here are some impressions

Tour de Suisse, part 6: Basel

2008-09-03T17:57:00.004+02:00

Some time ago I attended a lecture in algebraic geometry in Basel. So this seemed a good place (actually as good a place as any) to resume my journey through Switzerland after the worst symptoms of my cold had passed. Below you can find some pictures of the Münster and the Rathaus in Basel.

Tour de Suisse, part 5: Bern

2008-08-29T16:28:00.004+02:00

As usual when I'm on holidays, I catch a cold, a flu or whatever. So I had to spend this day at home, where I did some further HDR experiments. I'd gladly present you more, but my computer here is far too slow, so there's only one picture so far.

For all those who like some pictures of my travels, I append some pictures of Bern I've taken some time ago.

HDR:

Bern:

Tour de Suisse, part 4: Lyssach

2008-08-28T17:50:00.002+02:00

As the electrician had to fix some power sockets in my flat, I didn't take a long trip, I just went to IKEA and got a Pello, a Fixa and Dokument. I hope nobody is disappointed about my report now, sometimes this stuff also needs to be done.

Even More Wack-o Rock Star Movie Cameos

2008-08-27T19:00:00.002+02:00

Gibson's lifestyle page is writing about rock star movie cameos, so far there are part 1 and part 2, if there is ever going to be a third part, then they surely should include Brian Setzer and the Country Bears in this clip.

Tour de Suisse, part 3: Murten and Avenches

2008-08-27T18:40:00.002+02:00

I spent this beautiful day in Murten and Avenches. The latter is known for the Roman city Aventicum.

Murten:

Avenches:

Tour de Suisse, part 2: Brig and Sion

2008-08-26T19:08:00.003+02:00

Today I enjoyed the beautiful weather in Brig and Sion in the canton Valais. Of course I visited the Stockalperpalast in Brig and in Sion I climbed up the hill to the Basilique de Valère where you can find world's oldest playable organs and you have also a beautiful view over the whole valley and especially to the nearby Château de Tourbillon.

Brig:

Sion:

Tour de Suisse, part 1: St. Gallen

2008-08-26T08:36:00.004+02:00

Yesterday I've been to St. Gallen. I was in St. Gallen before, but I've never had the time to take a look at it. It's quite a nice city, but it was also a little bit disappointing as I especially looked forward to see the abbey library which was smaller than I imagined and taking pictures wasn't allowed. Nevertheless, it was a nice journey.

The master of far fetched fiction

2008-08-05T21:36:00.003+02:00

People, knowing my fondness for and broad knowledge about books, often ask, which are the most remarkable books I've ever read. And after a lot of sophisticated remarks about classic novels, some good sips of brandy and furious critique of the post-modern literature, I always recommend to have a look at a certain Mister Rankin from London.

Actually, neither of the above is true, but I've read some odd books and among the most extraordinary books I've read are those of Robert Rankin and at the moment I'm reading his The Da Da De Da Da Code, so this is where I got the idea to tell you about this. It's pretty hard or actually impossible to describe Rankins books, so I suppose you just read them yourselves. The Brentford Trilogy, the Cornelius Murphy Trilogy (consisting of The Book of Ultimate Truths, Raiders of the Lost Car Park and The Most Amazing man Who Ever Lived), The Witches of Chiswick or The Brightonomicon might all be a good starting point.

But beware, you might consider it good advice to read one of Rankin's many biographies or have a look at the man himself first.

Natural language is not context-free

2008-08-03T18:56:00.003+02:00

Richard McKinley recently pointed out to me that the evidence against the context-freeness of natural languages was first found in Swiss German. Now I'm looking forward to read the original paper Evidence against the context-freeness of natural language by Stuart M. Shieber.

A question about modal logic

2008-07-31T09:19:00.003+02:00

Do modal logics enjoy a deduction detachment theorem?

My advice: Think really carefully about it and don't ask logicians about this. You're likely to get quite different answers.

"The sun's not yellow it's chicken"

2008-07-31T09:10:00.002+02:00

Is there a better version of Bob Dylan's Tombstone Blues (see also here) than the one by Richie Havens in the movie I'm Not There?

(I actually prefer the soundtrack version where you only hear Richie Havens sing).

By the way, according to www.bobdylan.com, Bootleg Series No. 8 Rare and Unreleased 1989 - 2006: Tell Tale Signs will appear on October 7th 2008.

The best introduction to set theory

2008-07-28T20:28:00.007+02:00

In my opinion, Yiannis N. Moschovakis's Notes on Set Theory is the best introduction to this topic for several reasons. First of all, it's written in a very clear and understandable style (which is far from usual even in undergraduate math books). Secondly, Moschovakis doesn't begin with a list of all ZFC axioms (as it is very often done), but begins developing his theory with as few axioms as possible and thereby is able to show which axioms are really needed for what and how. Last but not least, he manages to include lots of interesting topics such as recursion theory, order theory or descriptive set theory, which usually are omitted in introductions to set theory. There is even a really nice construction of the real numbers. By the way: for those of you who want to know even more about set theory, there's still the bible.

If you're looking for a general and very well readable overview over mathematical logic, I recommend a look at A Tour Through Mathematical Logic by Robert S. Wolf.

Book vs. Movie

2008-07-27T20:27:00.002+02:00

I know that movies based upond books are always a little bit disappointing, but The Golden Compass has been my biggest disappointment in this respect so far. It seems like writers have scarcely read Philip Pullman's His Dark Materials, the trilogy upon which's first book Northern Lights the movie is based. I'd like to explain here, why that is, but this movie is just so weirdly gone wrong, that I can't. It's probably best, if you find out yourselves (or actually, it isn't, just read the book and leave it to that).

I wonder how the two excellent novels Jonathan Strange & Mr Norrel by Susanna Clarke and Special Topics in Calamity Physics by Marisha Pessl will turn out as movies?

By the way: I really liked both the movie and the book Atonement by Ian McEwan.

Recent nudity trends in music

2008-07-25T20:07:00.006+02:00

Nudity seems to be popular in music right now. The Icelandic band Sigur Rós has quite a naturalistic approach, see the music video for the song "Gobbledigook".

Quite a different and a very playful approach to censorship can be found in the BPA's in the music video for the song "Toe Jam" (if you have a YouTube account, you may access it directly here). This one is quite ingenious, but the again, has Norman Cook ever done something bad?

I can't get enough of Tom Lehrer

2008-07-22T15:50:00.001+02:00

Poisoning pigeons in the park

2008-07-19T21:52:00.001+02:00

According to Wikipedia, Tom Lehrer said: "Some of you may have met mathematicians and wondered how they got that way."

Der Screamer

2008-07-19T19:03:00.004+02:00

This afternoon I built myself a Tube Screamer Clone called Der Screamer available as a kit at Musikding. Below you find the very first, well, screams, recorded using a Fender Mexican Standard Stratocaster (upgraded with Lace Sensor Pickups) and a Roland Micro Cube (with the "Black Panel" model). (Sorry for my bad playing skills and the recording quality, I just finished the project and I took whatever lay around to record it). Now I'm thinking about doing an amp kit from Tube Amp Doctor.

Game theory and empirical observations (this might be interesting for you, Parcival)

2008-07-18T17:17:00.004+02:00

Encouraged by Parcival's comment on my post about modal logic, I'll pass on some wisdom of Joe Halpern's recent course in Lausanne (see also this post).

The short version is this: In game theory, the concept of Nash equilibrium (now famous by the movie A Beautiful Mind) is considered as the "best" solution (in some sense), but empirical observations showed that players may use completely different solutions to a particular game than the Nash equilibrium supposes.

Consider for example the following game: Two people are asked a (natural) number between 2 and 100. If both answer the same number, both will get as many dollars, as the number they said. If they answer different numbers, whoever said the lower number will get as many dollars as the number he said and additionally 2$ bonus, while the other one also gets the lower number, but minus 2$ penalty. Say for example, the two players both say 100, then they will get 100$. If the first player says 98 and the second says 99, then the first one will get 100$ and the second one will get 96$. Are we still together? (to quote Joe Halpern.) By the way, this is known as Traveler's dilemma.

Now game theory tells us, both players should say 2, as this is the only Nash equilibrium (for details, see below). But even without empirical studies, you clearly see that almost no player will say 2. Even members of the Game Theory Society didn't stick to this strategy, as a survey shows, the most popular strategies were to play 90 or higher. What's the problem about playing 2? It's quite simple: you will regret it, because you could have made a lot more money (even though you might make less than you opponent). So, people will usually choose strategies, that minimize their regret: If you play 2 and your opponent plays 95, you best response would have been 94. So you could have won 96$, but as you played 2, you will win 4$. So the amount of money you regret is 92$. People seem to be very sensitive to regret, it's not only important, what they won, but also what they could have won. So, you're trying to minimize your regret. And some simple calculations later you will see, that the optimal strategy to minimize your regret is to play 97. And this also agrees with the empirical studies.

More details can be found in this paper by Halpern and Pass.

Machines rule the world

2008-07-18T08:49:00.003+02:00

I'm just reading Yde Venema's Lectures on the modal μ-calculus and it's quite interesting but all those automata, like the Büchi automaton, the Muller automaton or the Parity automaton and their variants (think streams, trees, flows, biflows, nondeterministic, alternating, logical, etc.) make me feel dizzy sometimes. I really like the coalgebraic approach, universal coalgebra seems to be a nice thing, but I don't know that many things about it yet, so I will read Rutten's paper Universal coalgebra: a theory of systems when I find some time for it.

By the way (for those who are interested), there's also a thing called universal algebra and this is really nice theory (which I can tell you because I know some things about it). There's an excellent free book on this topic, namely A Course in Universal Algebra by Burris and Sankappanavar.

Modal logic & all that

2008-07-14T20:17:00.004+02:00

As some of you know I recently began working on my PhD thesis. I have a lot of fun (really!) reading about new (to me) stuff such as modal logic, epistemic logic, common knowledge and μ-calculus. I already did some work in the field of logic, but this was mainly classical mathematical logic and proof theory and had only some basic knowledge in fields mentioned above. As I see now, I should have looked at them earlier, they are lots of fun for several reasons. First of all: epistemic logic has various (natural!) connections to lots of different fields: philosophy, game theory, mathematics and computer science. Second: This is the first time in my mathematical career that I'm able to explain at least some basic ideas to my non-mathematical friends (if they'd only ask...). Third: there are all this funny riddles, like the wise men puzzle (although I prefer this solution), the muddy children puzzle (which is the less violent version of what is called Josephine's puzzle in the first source to the wise men puzzle) or the mind tingling surprise test paradox.

Interested? I'll try to keep you up to date on this topic, but in the meantime I recommend the excellent book Reasoning about Knowledge by Fagin, Halpern, Moses and Vardi. For a start you might also spend some thoughts on Plato's famous tripartite definition of knowledge as justified true belief.

HDRing around

2008-07-05T20:13:00.004+02:00

Today I just felt like taking my trustworthy old Sony Alpha 100 and making some HDR images of my Framus Renegade Pro.

By the way: I'm quite busy at the moment as I'm currently attending the Logic Colloquim 08 in Bern.

Happy new guitar day!

2008-06-22T21:36:00.003+02:00

For some it's just a bit of wood, for others the Fender Telecaster is the ultimate noise-generation tool. Yesterday, my Lite Ash Telecaster (shown on the left in the picture below) got company from an American Vintage '52 Telecaster (shown on the right).

Some nice days in Lausanne

2008-06-22T21:28:00.003+02:00

Joseph Halpern is holding an interesting mini-course in Lausanne. During lunch break we took a walk down to the Lake Geneva.

Oh yes, we are nerds!

2008-05-31T09:29:00.001+02:00

By the way: When will the second and the third season of Veronica Mars be available on DVD in Europe?

Bob was right

2008-05-22T12:52:00.003+02:00

Bob was right, when he sang "Some are mathematicians,
Some are carpenter's wives." (at least concerning the singleton set containing me since yesterday 11 am). If you've got no idea, what I'm talking about, you might wonder, whether I'm tangled up in blue.

What were they thinking?

2008-05-22T12:18:00.003+02:00

economiesuisse proposes: "Die Koordination zwischen den Hochschulen muss auf ein notwendiges
Minimum beschränkt werden." (Translation: The coordination between universities has to be restricted to a necessary mininmum), the full text can be found here.

I don't know what they mean by this and why someone should propose this in the time of Bologna. Were they thinking of some kind of Apple business model for universities? As I've already mentioned, I don't know...

I won't say, I knew it, but...

2008-05-22T12:15:00.002+02:00

According to an article in Science:

"Undergraduate students may benefit more from learning mathematics through a single abstract, symbolic representation than from learning multiple concrete examples."

How much does a college droupout cost?

2008-05-15T12:40:00.007+02:00

According to a survey of the "Stifterverband für die Deutsche Wissenschaft" Germany loses about 2.2 billion euros a year because of college dropouts. They also claim that if you include private investments and evaded incomes, the loss is as high as 7.6 billions.

How did they calculate this figures? For a scientific society there's quite a lack of sources (in words: zero). They give us a hint that they "correlated" the following datas: rate of college dropouts, average costs of a college place per year and average study time of college dropouts. I don't know how exactly they "correlated" those numbers, but I suspect, that they used a fairly (say: way too) simple calculation model. Using their reasoning it would also be quite a sound claim to say that it's best to shut down all the universities as soon as possible because students are a huge economical loss.

Let's think about it: If the average cost of a certain study place are about 10,000 euro a year and, say, we have ten dropouts. Does somebody (the state or the university) get 100,000 euro paid onto his bank account? I don't think so, because in a lot of courses, it doesn't actually matter whether you're teaching 100 or 150 students because most of the costs are fixed (the only thing that varies are the average costs of the college place depending on the number of students). On the other hand, is it really fair to consider the money spent on a college dropout lost? There are a lot of succesful college dropouts (and if you're using the reasoning from the "Stifterverband" they're actually earlier generating money in the economy than they're still studying counterparts at the university).

But we haven't faced the most important (and what actually should have been the first) question yet: What is a college dropout? Someone who quits college completely or someone who just switches his college courses? (Or some variation of this...). Think of someone who begins studying computer science as major and math as minor and finds out that she's just more a math type and therefore swaps her major and minor. Would you call her a dropout (she might turn up in some statistic as such)? Did she do any economical damage to the state (perhaps there were some slight administrative costs)?

What I want to say is, that some people have (in my opinion) far too simple views on this topic. I myself have actually no idea how you can calculate the cost of a college dropout and I even don't know how to find a good definition of a college dropout, but I think we should sort out this kind of questions first, before we are going to throw are trusty old Humboldtian university ideas over board and begin to restrict access to the universities and lose the academic liberties.

Things are getting interesting over at Flickr

2008-05-12T22:18:00.003+02:00

Second picture that got noticed by somebody, this time even by two persons! Thanks, Qtpfsgui.

Do you know where the first book in Switzerland was printed?

2008-05-12T13:08:00.005+02:00

I do, or at least I do know, where the first dated print was made in Switzerland. It was 1470 in the small village Beromünster when the seventy years old canon Helias Helye decided, it would be a nice idea to have a printed issue of the Mammotrectus (some kind of bible-related dictionary written by Marchesino da Reggio). By the way, Beromünster is always worth a visit as it is a really beautiful small village with over 1000 years of history (the site of the printing, a medieval tower called Schlössli - engl. little castle - is still around and is nowadays a museum with a reconstruction of the original printing press) and some interesting stories and personalities, such as Ignaz Paul Vital Troxler, Josef Vital Kopp or Pirmin Meier. By the way: If you're looking for good book to read this summer, I can recommend Kopp's Der sechste Tag (engl. The sixth day), an account of Kopp's youth in Beromünster around the time of the first world war. It's also an interesting portrait of a central swiss catholic milieu at the beginning of the 20th century.

Pay attention where your teaching material comes from

2008-05-12T12:43:00.005+02:00

I just saw a promotion for teaching materials called Ideen sind etwas wert (Ideas have a value) on the official swiss education server. Their object is to promote awareness for copyright and intellectual property in music business. So, this is basically an interesting topic, especially for computer science teachers.

Now guess, who has paid for these materials? (Hint: It's not some official swiss education office, you can find the answer in this link). Of course, this made me slightly suspicious and so I took a closer look. Want a sample? There's a claim that copy protection on audio CDs was absolutely necessary because of internet piracy (although they somehow forget, that this measure mostly is a punishment for people who actually buy CDs and - along with the CDs themselves - does not work. Oh, and there's also this story of violating a very succesful standard...). They also remind you of the fact that downloading MP3s is a huge security risk (in comparision with, say, buying Sony CDs?).

Although there are some interesting and correct facts, the makers of these teaching materials seem to have missed quite a lot of the recent development in music business. But then againg, you didn't expect a well-balanced account on copyright from something sponsored from the IFPI, did you?

The Terminal 5 Song Revisited

2008-04-21T16:49:00.002+02:00

Parcival is worried about Heathrow's Terminal 5, let's hear what Monty Python said some years ago about Heathrow

Brainfuck on SwissEduc

2008-04-21T13:27:00.002+02:00

My Brainfuck lesson is now available on SwissEduc.

Epiphone Les Paul with new GFS Pickups

2008-04-17T15:31:00.005+02:00

Epiphone Les Paul Standard Plus with GFS Crunchy Pat High Output Humbuckers recorded with Audacity
and a Line 6 Pocket Pod. For the rhythm part I used both pickups, for the melody the bridge pickup only. Sorry for the bad Quality, I somehow had to operate the computer and play guitar at the same time while balancing no a chair...

Mission accomplished

2008-04-13T16:10:00.003+02:00

Gone insane writing Brainfuck programs, gone back to normality, compiled a lot of LaTeX to PDF: LOFS Project finished.

This is for Nicole and Parcival

2008-04-04T08:27:00.001+02:00

Have a nice wedding!

My first Flickr Photography, that was noticed by somebody else!

2008-03-25T22:24:00.001+01:00

I knew, I just had to wait long enoug.

The Complexity of Songs

2008-03-25T21:57:00.001+01:00

I know, this is a classic one, but there might still be some people out there, who haven't seen this: http://www.cs.utexas.edu/users/arvindn/misc/knuth_song_complexity.pdf

State of the Art

2008-03-25T21:38:00.003+01:00

Having solved the main technical issues (see previous entry), the main text was almost writing itself. I even gut some further ideas for other LOFS lessons (most of them were about TeX, LaTeX and Metafont, as I recently read Donald Knuth's excellent book "Digital Typography". If you've got some time go read the extraordinary articles about "Breaking Paragraphs into Lines" or "The Letter S"!). The main work was finding some nice (not too easy, not too hard) exercises for most students and some really interesting (and also hard) exercises for all the nerds out there.
This leads me to another issue: The lesson about Brainfuck is most probably not suitable for most computer science classes, as it is quite technical and mathematical and needs a lot of patience and riddle-solving skills. So I made that quite clear in the introduction to the LOFS, hoping no teacher will be as foolish as to try that one with a class that doesn't like a nice mathematical puzzle.
The other main problem was, that Brainfuck is in some areas rather poorly defined. What happens if you're on memory position 0 and make a step backwards with < ? Some interpreters will just overflow to the maximum memory positions others will accuse you of ill programming. There's a lot of other uncertainty of this kind, I think I will have to address this in the main text, as I'm not willing to settle on one single Brainfuck IDE.
By the way, I quite like this one: http://koti.mbnet.fi/villes/php/bf.php. Internet-based solutions are always best in school, as you're not having trouble with some IT guys who don't want to install the software you'd like or all the other compatibility issues

When you're lost in the rain in Juarez and it's Eastertime too

2008-03-24T11:41:00.003+01:00

Well, it's been a long time since my last post. (of course I've been busy working on my LOFS-Project. Remember? That's why I started this blog). The most important result up to now is generating a table of ASCII characters using LaTeX only (because I was to lazy to copy it). So here's the result:


\documentclass[a4paper, 12pt]{article}

\usepackage{forloop}

\begin{document}
 {\tt
 \newcounter{symbol}
 \begin{tabular}{|rr|rr|rr|rr|rr|}
 \hline
 Nr. & Symbol & Nr. & Symbol & Nr. & Symbol & Nr. & Symbol & Nr. & Symbol\\
 \hline
 \forloop{symbol}{33}{\value{symbol} < 126}{%
 \arabic{symbol} & \char\thesymbol&%
 \ifthenelse{\value{symbol}<125}{\addtocounter{symbol}{1} \arabic{symbol} & \char\thesymbol&}{& &}%
 \ifthenelse{\value{symbol}<125}{\addtocounter{symbol}{1} \arabic{symbol} & \char\thesymbol&}{& &}%
 \ifthenelse{\value{symbol}<125}{\addtocounter{symbol}{1} \arabic{symbol} & \char\thesymbol&}{& &}%
 \ifthenelse{\value{symbol}<125}{\addtocounter{symbol}{1} \arabic{symbol} & \char\thesymbol\\ \hline}{&}%
 }
 \\ \hline
 \end{tabular}}
\end{document}

Things not to do

2007-12-30T17:27:00.002+01:00

1. Walk into a guitar shop with plenty of Christmas money in your pocket.

Home Sweet Home

2007-12-05T11:16:00.000+01:00

The Future of Copyright Law

2007-12-05T10:32:00.000+01:00

One of the most interesting article I've read for a long time was Japan, Ink: Inside the Manga Industries. Looking at the title you might think it's an article about mangas, but actually it might be glimpse into the future of copyright law. In Japan fan-produced mangas (called Dojinshi) are extremely popular. Usually characters from a "regular industry manga" are taken and a new story involving them is written and then sold.
You might now expect that the copyright holder of this characters will sue the hell out of them, but they don't. Basically there consists a kind of mutual agreement calld anmoku no ryokai. The dojinshi creators publish only a limited number of editions, so the industry isn't at risk of losing to much and hence lets them publish. There's also a large number of benefits the manga industry gets: a free customer care program, a pool of new talents and cheap market research program (just look what characters are popular in the dojinshis and you'll now what goes on in the manga scene).
Another point is, that the current copyright law is designed for a read-only culture, but as it seems now, we are shifting to a read-and-write culture (think Web 2.0) and there are some issues concerning copyright which have to be solved. So the final question is, whether the Japanese model might be the future of copyright law?

LOFS 2: The empire strikes back

2007-12-05T10:15:00.000+01:00

As some of you may have seen in my last (and also first) post, I got feedback from our professors. They're a bit sceptic about the first topic "To Mock a Mockingbird" and most probably they are right. It will be difficult (if not impossible) to relate the topic of combinatorial logic to the other topics in computer science which are usually treated on secondary school level. Furthermore there's a general problem with those logical riddles: some like them, some hate them. And for the latter it will be rather hard to be motivated to solve them.

As for "Brainfuck": Although this is a case of rather unfortunate naming, the didactic possibilities that lurk within overwhelm this point. "Brainfuck" gives deep insight into the function of computers, programming languages and Turing machines (and this all at once, if you want to!). The leading question(s) will be "What can / can't be done with Brainfuck?" (and I think for some of you there may be a surprising answer).

As you may have guessed meanwhile, I'll settle for "Brainfuck". Now let's go and ask Lukas whether he wants to join me in this project or if I should do it all by myself.

A New Blog is Born

2007-10-25T20:57:00.000+02:00

First of all I'd like to say a nice 'Hi' to everybody out there. This being my first blog ever, I'm not quite sure what to write about. So perhaps I'll just explain, why I am starting this blog. As some of you out there may know, I've been working on my diploma thesis for some time now and this term I also started my studies at the PHBern, the local college of education. There I attend a course about the didactics of computer science.
During this course we will have to do something called LOFS, which is basically just preparing some lessons about a special topic in computer science (by the way, my two ideas are: introducing combinatory logic by means of Smullyans book "To Mock a Mockingbird" or an introduction into Turing machines via the esoteric programming language Brainfuck).
Meanwhile you might have guessed it: to document our work we were encouraged (Note to myself: this is the first time I'm using this didactic euphemism) to use a blog. So, here we go...