Jan Krüger's blog

Creative Engineering and randomness

The most challenging part of making your own cola is getting a proper and stable emulsion of the flavour oils in the concentrate (and beyond, when actually making cola from that). If the emulsion isn’t all there, any of the following could happen:

Making Cola

I don’t even remember why I started, but I mix my own cola from first principles. It’s a fun hobby and I get to experiment with the flavour components – therefore, in theory, ending up with a cola that’s particularly close to what I like. It’s been taking a fair number of iterations, though. I’m currently on my third batch (two of 45 litres, this one is 22.5 litres). Here’s my journey, including the fine details that some other sources don’t mention. I’ll close with the recipe I used and what I’ll change in the next batch.

For about eight years this blog was powered by WordPress. When I tried to upgrade to HTTPS (thanks, Let’s Encrypt), I ran into slightly insurmountable issues with resource URLs generated by it. I never really liked WordPress all that much, anyway, beyond the sheer convenience, so I decided it was time to move on. I’ve always been fond of static website generators, because they remove most of the work the server has to do when someone tries to view a page, and so I started looking for one that can do both blogging and other stuff, and is reasonably customizable.

Well then. There’s been a tiny little bit of interest. Good enough. Let’s talk about the fundamental requirement for getting better at singing – according to me, anyway. It’s in how you approach the whole process.

As I’ve said throughout the intro to this series, becoming an awesome singer consists of three kinds of tasks: doing the less of the wrong things, doing more of the good things, and doing both of that more consistently. All of these need to be approached in slightly different ways, but there’s one thing common to all of them:

You have no idea.

Okay, this is hardly a new topic on the internet… but it’s yet another new topic on my blog (the strategy is to have as little focus as possible and thus make it completely impossible to “monetize” the blog). The topic, formulated as a question, is: how do you improve your singing? And your speaking, I guess. The problem with that topic is that there’s a lot of information about it on the internet, much of it either wrong, misleading or irrelevant. So I thought I’d add some more noise, and I’ll try to give you a few explanations of why I think certain parts might be more or less useful.

So, here’s an introduction to all the stuff you’ll find on the internet, and which parts of it really matter (if you ask me). (Note: I made substantial changes to this article shortly after first publishing it.)

Well, this is embarrassing. I thought I had done everything to avoid portability problems. But in trying to avoid them, I stepped right into them, doing something that by now I know very well not to do. Oh well, here’s an updated version of dmsetup-tc (which you can use to mount TrueCrypt®-encrypted Windows system drives/partitions on Linux). It’s no longer really necessary since the Linux version of TrueCrypt® added support for this back in version 6.

There are a lot of open source licenses. Even if you look at only the OSI approved ones, that’s still a list of 67. And, of course, they are all different in subtle (and not-so-subtle) ways. Can you keep all the small details straight in your head? I know I can’t. That’s why I just made a quick reference page: HTML version: http://j.mp/opensource-licenses PDF version: download (A4 paper, 46 KB) It focuses on just a few commonly used licenses (at least from what I can see), but covers more criteria than the other comparisons I’ve seen so far.

Update: This patch is pretty outdated. There have been major rewrites in mod_gnutls since then. I’m not sure whether the current version properly supports subjectAltNames; I don’t use mod_gnutls myself anymore.

Yesterday, I wrote a small patch against mod_gnutls (that’s the GNU alternative to mod_ssl, and it’s leaner; and it supports SNI (server name indication), whereas even the version of mod_ssl in the upcoming Debian squeeze release doesn’t). It took me quite a while to figure out the problem in the first place, and I guess it’s a bit of a corner case, but I can’t imagine I’m the only person who might run into this problem, so here is an explanation.

I just had some time to procrastinate away, so I built a little open source graph pastebin web application called Instagraph. It’s based on GraphViz, PHP, MySQL and Apache. At least the first three need to be installed on your web server, and the fourth one is necessary unless you tweak your way around using the included .htaccess file (which makes use of mod_rewrite).

I’ve been wanting to write something like this for ages. Often enough I want to explain concepts in IRC and find myself struggling to present all the relationships between different things in an understandable way. Now I can just use a private Instagraph instance to make a nice picture that will speak a thousand words for me. Awesome.

Instagraph is woefully underdocumented but shouldn’t be too hard to set up. It’s also extremely simple and has no user interface to speak of.

Intuition is an interesting concept, and I believe that it’s a bit hard to really make sense of for people who don’t consider themselves intuitive. At least it didn’t make a lot of sense for me a year or two ago.

I suppose many think that intuition is something you are born with… some people just “know” certain things without being able to reason them out, and other people have to conduct an elaborate analysis of the facts in their minds to end up with the same conclusion. If that’s the way you think about it, you might believe that intuition is something of an unfair advantage.

Another widespread position seems to be that intuition is very risky… after all, intuition doesn’t give you the certainty that logical reasoning can give you, right? So perhaps if you go by that idea, you might say that it’s better to not use intuition at all.

I think that the answer is somewhere in between, as it often happens to be… and I’m going to tell you how intuition became a natural thing for me, even though I wasn’t exactly born with it, nor did I think it made sense to trust in it. But now I do have it, and I do trust it, because I use it in a way that I’m confident in. And don’t worry, I’m not going to cite the usual hogwash about left brain versus right brain… I’ll just explain a useful way of looking at intuition, and I’ll also waste a few words on how important I think it is for knowledge engineering.

Pseudoscience is significantly worse than what science claims to be, and that’s the problem: science isn’t actually what it claims to be. Many people who boast about their extremely scientifically oriented thinking don’t actually know what science is, and they’re actually thinking religiously or even dogmatically.

Whew. That’s a rather provocative first paragraph, isn’t it? I’ll have to be extremely scientific to avoid getting shouted at by would-be scientists. Don’t worry, dear scientists, I’m not against science! I’m a huge fan of it. Until some “scientist” starts making overly general statements. That’s where it stops making sense. Why? Well, let’s have a brief look at how science works.

Here is a (not necessarily complete) list of philosophical “isms” that I believe in. I don’t believe in “isms” lightly at all, because I feel that adopting an “istic” view is a rather drastic thing to do.

The following list will give you deep insight into the way I understand life, reality and science… if you want to find out, that is.

Oh well, better late than never. I present to you the next version of Stereo Pan (announcement for previous version), introducing a second mode of operation: the subtle mode. It’s called that because its effect is more subtle. Duh. A great property of it is that it doesn’t distort the sound if the output is downmixed to mono. If you downmix to mono while using Stereo Pan in its normal mode, you get a flanger-style effect on the sound.

(A newer version is available!)

So perhaps you noticed that I’m a musician and also a coder. What better than to combine both of those and write software I can use when making music?

My first project for this was writing a VST plugin (VST is a trademark of Steinberg Media Technologies GmbH and it’s basically an effect interface supported by a large number of DAW applications) that does stereo expanding. What’s that, then?

A trick that’s well known among musicians and mixing engineers for making something sound fuller is to record the exact same thing twice and then superimpose these two takes. A special case of that is putting one take in the left stereo channel and the other in the right. If you do that, it will sound a lot “wider” in the song, and it will also dominate the overall sound of the song a lot more.

Sometimes, though, you’re short on time or don’t have two takes of something handy (or it’s actually impossible to get two takes). Enter stereo expanders! They basically pretend that you recorded two takes, and pan them left/right for you. I’ve got one right here for you, and it’s free to download.

I haven’t posted anything for months, but I feel very strongly about an experience I had yesterday and I want to tell you about it. This is a story involving a person who had been feeling extremely strong pain for months and months, and myself.

At first glance this post will look like it’s rather unrelated to what I have posted about before. In fact, it’s about the human mind and about how it works, and about how it changes.

Please understand that I have to suppress a lot of details and slightly warp the story to protect the identity of that person. I just flipped a coin to determine that I’ll be presenting that person as male, and I’ll call him Chris. I don’t know any person called Chris, so I guess that’s okay.

So Chris had been trying everything he could find. Pain medication, stronger pain medication, elaborate diagnostics, alternative approaches to healing, everything. All doctors pretty much agreed that there was no physiological basis for the pain. Chris found that hard to accept, because that had to mean that it’s a psychosomatic thing; a signal from the body that things aren’t going right… a signal that change needs to happen. Still, he started looking into psychotherapy. A few attempts had no real effect; at some point he found a therapist who could indeed help him reduce the pain for a while (in exchange for a lot of money, of course). A permanent solution wasn’t in sight, though. The last thing he tried was an inpatient therapy, during which on some days he actually felt really good… but there wasn’t any method to it. The pain would keep on coming back.

Then we met, and we talked about it.

Dear users of browsers other than Firefox, I’m not talking to you now. Sorry. Dear remaining readers, have you ever disliked having to a) remember all of your different passwords for all websites or b) store them on your local computer so you can’t get at them from other places or c) use the same password everywhere even if that makes the impact of security issues a lot worse? I used to go with option b) but I didn’t really like it. Now I’ve found something else; allow me to share.

The submission timeframe for the current Song Fight, “Paper Thin”, ended four days ago and the submissions were just published. Unfortunately I didn’t manage to submit my song in time (I recorded most of it in the last few hours) but you can listen to it anyway.

Good news! A couple of weeks ago I found the Song Fight website. Song Fight works like this: a song title is posted. You write a song for that title within a week and submit it to the fightmaster. When the week is up, the fightmaster will publish the list of all entries on the website. Visitors can now vote for songs until the songs of the next fight are published. The winner of a fight gets to brag… and not really anything else. Apart from a serious boost in creativity and musical skills when you make it a habit to participate, that is.

Yesterday (going by the local timezone) I submitted my first Song Fight entry for the title “Interesting Times”. It will be up on the Song Fight website shortly, and it’s now available here.

Take note if you had problems using dmsetup-tc, the program I published last month that allows you to use TrueCrypt®'s encrypted system drives/partitions (also called the “pre-boot authentication” feature) from Linux environments (and possibly other Unices). I have found a few rather embarassing bugs in it that made it rather unusable in pretty much all cases (it’s actually really astonishing that it even worked for myself…). So if previously you got a cryptic message like “fatal error: Success”, now would be a great time to try again.

Update: I made this program in 2008. In the meantime, some other guy appears to have written his own, apparently much more complete re-implementation. Feel free to check it out here: https://github.com/bwalex/tc-play – chances are that if that one works for you, I won’t be updating dmsetup-tc anymore.


TrueCrypt® is a multi-platform on-the-fly drive encryption tool. It allows you to encrypt all your data in a filesystem and still use everything normally. On Windows, it supports encrypting the system (boot) partition (or the entire boot drive); you can even make TrueCrypt® encrypt your existing partitions live and continue working (though the I/O performance sucks until it’s finished encrypting everything), pause and resume the encryption process (even across reboots). In short: it’s rather useful.

Even though TrueCrypt® introduced Windows system encryption in version 5.0 in February 2008 (that’s five months ago), its Linux version still doesn’t support accessing these encrypted partitions at all (it does mount “normal” TrueCrypt® volumes though). Since I recently encrypted my entire Windows drive but couldn’t live without the music files stored on it, I now humbly present the result of two wasted nights: a solution.