bits

dream

2012-01-23T01:59:00.000+02:00

Last night I had an awesome, disturbing dream. It began with me waking up and realizing I was dead. I was somekind of ghost that people couldn't see, but those close to me could hear and maybe touch. I on the other hand experienced the world as usual -- no walking through walls, no flying, no mind-reading -- it felt the same. Once I realized I could talk to people, I asked them what was going on, and everybody seemed to agree that I'm an invisible ghost now. I assured them I saw neither hell nor heaven, and asked them what they had done with my body.
"Oh, we just called the disposal team and had it incinerated, we thought that's what you would've liked us to do".
"Oh, yes, certainly, good job".
(That's got to be the greatest piece of dialogue I've ever experienced.)
Thoughts of unfinished business and unfulfilled promises raced through my mind, but they were quickly quenched by the realization that I could ask people to do said buisness for me. Still the fear remained that I would soon be unable to communicate with those I've left behind.
After a while I fell asleep and then woke up again and glitches started happening, like objects disappearing. I thought - maybe I was decaying. It was very short-lived. Things started looking and feeling normally again. Actually it felt so normal that with no dead body available I was starting to doubt that I was a ghost. So I challenged the people to shine a laser towards a wall. I put my hand in the laser beam and sure enough the spot on the wall disappeared. But the people told me that no, the spot is right there on the wall, unobstructed. I then told them to point a digital camera at the wall. Surely a system so complicated would separate my possible illusion from theirs, and most likely record the spot on the wall. But it didn't happen. It was just too complicated to dream. I woke up.
I've been trying to decipher this dream to no avail. Maybe I've been reborn or something. Maybe I've just been feeling weird. The Universe has been screwing with me lately, and it's been wonderful.
So remember, don't drink and sleep, and when in doubt, fucking lasers yeah.

heating

2011-11-05T16:17:00.000+02:00

I hear this annoying argument all the time: I live in a cold climate so my {home server, tube amp, idle set-top box, microwave oven display} doesn't waste electricity, it just helps keep my house warm.
I understand that resistive space heaters are popular in the U.S., but in the rest of the world some people like heat pumps better. The heat output from both resistive space heaters and microprocessors or all other electronics is equal to the electrical energy drawn from the grid. The heat output from a heat pump-based device is higher than the electrical energy input, the difference resulting from cooling the outside air. Just like air conditioning in the summer, but in reverse. So there, your inefficient technology is not only helping keep your home warm, it's also wasting electricity that could otherwise be used to heat it more efficiently.

oops

2011-10-01T21:59:00.000+03:00

I found this nice, classic "beware of macros" bug:

#define MAX(a, b)    ((a) > (b) ? (a) : (b))

[ ... ]

int x = MAX(foo, bar++); // incremented either once or twice

Oops.

supercrapinal

2011-09-24T00:47:00.000+03:00

Scientists studying neutrino oscillations have recently managed to screw up their measurements and come up with a speed for the particles that's higher than the speed of light. For those of you not familiar with particle physics, think of neutrinos as very light electrons but without the electrical charge. Having no electrical charge they seldom interact with matter and can pass through thousands of miles of rock undisturbed. So they generate the neutrinos at CERN and measure the time it takes for them to arrive in Italy. Of course, according to all we know so far and according to countless experiments, no particle travels faster than light. This paper, the authors of which could easily fill up a large bus or maybe a small train, details their method. The paper is properly written and simply presents their method and results; it makes no extraordinary claims, but rather states that the authors have yet to identify any more sources of error and are searching for those. Of course the media have picked up the story. The respectable outlets maintain the cautious tone, but several are trying to make this into a sensationalist news story: "Einstein's Relativity could be wrong". No. The chances of Relativity being wrong are extremely slim. The chances that an undetected error screwed up the measurements is overwhelming. The time measurement and calculation error from known sources is about 10 nanoseconds and the particles have supposedly arrived 60 ns too early. Given the complicated system used to do the measurements, whose systematic (fixed) errors that had to be calibrated are much higher than that, it's very likely that this result is due to an equipment problem or a mistake. For example, does the circuitry always have the same delay? Does that 8km-long optical fiber always have the same delay? Are those delays during the experiment equal to the ones that have been measured while not doing the experiment? 60 ns is a pretty long time, given that one light-nanosecond is about 30 cm. But it could easily arrive from faulty equipment or bad measurement techniques. I'm sure that in the following weeks or months these errors will be identified. Until then, supernova measurements indicate that neutrinos arrive at the same time as light, not earlier. If they were really going faster, then the signal measured from a supernova that's thousands of light-years away would precede the optical telescope detection by days or weeks, which we're not seeing. So neutrinos don't travel faster than light. One might think that there's a small region, near the area where the high-energy reaction that creates the neutrinos takes place, where some extraordinary phenomenon might be happening, and that is causing the effect - once they leave that area they behave normally. This is also highly unlikely. It's true that Relativity has to be adjusted at small scales and high energies, but those scales are very far off and a space-time distortion large enough to cause 60 ns or 18 meters of error is surely going to be noticed and cause some very weird shit so to speak.
So there. Calm down and wait for that defective satellite to fall on your heads tomorrow.

web

2011-08-16T02:02:00.003+03:00

The discussion on this article on Slashdot caught my attention. The article is complaining about the direction that Firefox development is taking, and many comments go along those lines. I won't discuss those comments and I won't discuss said development policies further than saying that one has every right to argue against those decisions in a civilized manner.
What pisses me off is people arguing in large numbers for web developers to drop Firefox support because of the new rapid-release cycle. I've noticed a pattern of people complaining that dealing with bug reports and generally supporting their web applications running on a large number of Firefox versions is painful and will cause them to drop Firefox support altogether.
Let me first say that this is a precise illustration of some of the many reasons for which I hate web developers, web programmers, Web 2.0 proponents and all the other web-*. With a few exceptions of course.
Furthermore, let me say that if your so-called application wasn't a monstrous, attack-prone, inefficient, poorly-documented, hastily-written-on-the-back-of-a-napkin-over-dunch, non-standards-compliant, unclear-specification-bending, latest-buzzstuff-incorporating, user-agent-string-dependent piece of spaghetti-code seasoned to taste with data, metadata and metacode, then maybe it would display OK and function OK in all reasonably recent versions of all mainstream web-browsers. I've worked (not a pleasure believe me!) with what I'm told are crappy CMS platforms and even those function reasonably well even in IE6, let alone Firefox, Chrome, Opera and that thing that Macs are using.
Now, even if your application isn't a monstrous, inefficient, undocumented, poorly-designed, badly written piece of html-css-js-xml-php-sql-jpeg-mashed-potatoes, that's still no excuse for being plain lazy with customer support.
But why so much venom? Why do I care? Because I'm forced to work with products that exhibit the above-mentioned characteristics on a regular basis, and that's costing me time and energy. I don't generally hate people who write bad applications, and I can always write applications that run on my PC if I don't like the ones that are around - at least theoretically I have that freedom, but I can't do that with someone else's web applications. It's when I'm forced to use some kid's late-night, inebriated brain-vomit that he calls a web platform, that I get pissed off, and I want to use this opportunity to say: I sincerely hate you. At the same time, I fully understand that somebody has to collect my garbage and somebody has to unclog my sewer, so you've got all my respect and thank God you're not programming critical infrastructure, I hope.
Getting back to the matter, I remember when I was a kid I came across a code sample from Microsoft on how to "sign"-or-something your ActiveX control that you wrote in Visual Basic so that Internet Explorer wouldn't warn the user that an ActiveX control is going to execute from the web page they're visiting, with the default IE settings at least. Yeah. ActiveX controls were IE's non-standards-compliant way of providing a 'rich web experience' or whatever it was called back then, and many businesses developed 'web applications' around said technology. Sadly ActiveX controls are not web applications, they're normal applications that contain normal machine code that's directly executable by the processor of the client computer and has access to all normal operating system functions, i.e. it is not sandboxed within the browser. Needless to say, that code can in principle do anything its writer wants with your machine. So yeah, go ahead and not support Firefox, and while you're at it complain that it's fat and slow, but remember that it's Mozilla who played an important part in promoting compliance to open web standards and distancing the web from the state described above. At least give them some credit for that, or just go ahead and implement your web application in platform-independent, not-quite-ActiveX Flash or Java or something and shut up.
Oh, and a late Happy 20th Birthday, Web, and a Happy 30th Birthday, PC. May you survive all this crap for decades to come and continue to bring us entertainment and prosperity.

solitaire

2011-07-09T23:19:00.000+03:00

The wonderfully idiotic game of Klondike solitaire is ubiquitous; there are countless embarassing pictures of people playing it instead of doing their job. It seems however that some people's job is actually that of playing Solitaire. Take this article for instance, which I found while terribly bored and wondering about whether they came up with a mathematical description for Solitaire and what are the odds of winning. It seems that no, there isn't a complete analysis yet - one of the embarassements of modern mathematics :)
Before discussing the article any further it must be stated that, while to some it might look funny, a waste of time, or downright idiotic to do a study on Solitaire, it's actually quite serious. While the game itself might be considered silly by some, if studying it can bring advancement in "artificial intelligence" then so be it. Because I'm anti-mainstream I like to actually call it "automated problem-solving", because there's nothing intelligent about it or many other game "AIs", but I digress. Studying Solitaire is as valid a scientific endeavour as studying chess or how to slice a pizza so it spilts into equal parts, though this last problem is considerably easier and has been recently solved (searching for the article is left as an exercise to the reader).
Getting back to the Solitaire article, they supposedly worked with a famous mathematician who "carefully played and recorded 2000 games, achieving a win rate of 36.6%". Their software supposedly obtained win rates of up to 70.2%.
So there. There is actually someone whose job is (among many other more productive things I'm sure) to play Solitaire. 2000 games at an average of 20 minutes per game as stated in the article equals exactly 666,6... hours oddly enough. Considering an 8-hour work day, that would equal rougly 80 days of playing Solitaire, or about 4 months. Cool thing indeed.

internet

2011-06-20T21:30:00.003+03:00

I'm on a long scientific visit at a scientific institute, I'm accomodated at a student guesthouse that's on the institute's scientific network and am not allowed to use the Internet for anything other than scientific purposes. I'm also not allowed to transfer more than 420MB/day or thereabout. Their leaflet says they'd let me but they can't because their traffic is metered and they're paying by amount of data transferred. I'm not a furious downloader, especially when I know I'm on a limited network. I just want to relax, read Slashdot and stream a news channel at some few 100 kb/s. But I can't because the institute's traffic is metered.

P.S. Oh shit this post is not scientific enough I'll be punished! [hides]

unfortunate

2011-06-15T22:42:00.004+03:00

There's a growing trend around here for newspapers to offer various book collections, probably to try to counteract their plummeting sales or something. Under slogans having to do with investing in one's culture and stuff, they're offering a new book each week for a relatively small price, and you're encouraged to buy them all to own the complete collection. While not bad in itself, this affair gets funny when the competition gets tough and the companies start getting really creative with their advertising. For instance, one collection is currently advertised along these lines: [display frog] For those who read, this is a future prince. For the others, it's just a frog. Yeah, pretty original, until they get to this week's book: The Marquis de Sade. WTF.
On a totally different thread, I've been wanting for a very long time to comment on dr. Michio Kaku's pet show Sci-Fi Science, which I also find very unfortunate. His take on the possible real-world implementation of various sci-fi memes is sometimes plausible, at few times interesting, at many times outrageous, and the show itself is worth watching if you're otherwise terribly bored. I personally liked him much more when he was making brief appearences in various science shows than as the star in his own project. On to the point:
1. About one in three 'problems' has negative matter as a solution. Enough with the negative matter that falls upwards, it's purely theoretical, there are some clues as to its possible existance, but for now it's pure speculation.
2. Let's make a sci-fi-style force field/shield, only it's not a force field it's a matter+laser shield. Reasonable, until the enemy spaceship attacks you with lasers, which your carbon-nanotube-or-whatever-future-material shield can't supposedly withstand. His idea - coat it with "photocromatic materials", which change color in response to light exposure, just like those adaptive sunglasses. Those are supposed to absorb the laser. Why on Earth would he use photocromatic materials instead of a mirror or nothing is beyond me. The energy absorbed by the shield with or without said materials is basically the same. It either melts or it doesn't. Maybe it absorbs more so that the laser doesn't pass through the shield and on to the ship? Who knows. That doesn't solve the shield melting problem though. It just looks like a half-baked hack with a lot of buzztech.
3. He suggests that teleportation might work by digitising a human, memories included, sending the data along a series of laser beams (x-ray laser beams IIRC, for the added coolness and information density) and reconstructing the human at the destination. He openly admits to this resulting in two identical humans, memories and personality included, but states that we've got enough time to work the kinks out of this problem. I find this "brute force" approach questionable and I've got a big problem with it. Would you like to be killed at point A after being copied to point B? There's got to be a more elegant solution. Even if it were possible to clone me with little error and come up with an identical self-aware being, the two of us would be disconnected. The new mind would be a different mind. Sure, to my friends I might look the same and they might never notice, but I sincerely doubt that what I call "me" would be the same. Kill the first body and the second would surely function OK as a new person with my exact same traits, but I strongly doubt that I'll awake inside it as if nothing happened.
And the list goes on.
There are of course the cool solutions such as the self-reconfigurable robot, but many of them are, as I said, unfortunate.
Some might label me pathetic for picking on a low-budget pop-sci entertainment show, but there's a deeper thought here. Some time ago being a geek was something to be proud of, as geeks could display high levels of skill and competence, and in a larger sense, a greater understanding of the world. Now there's a new breed of geek, the sci-fi/fantasy game geek, who also takes great pride in their passion but often times lacks the high levels of practical skills and only displays a great understanding of some fantasy world. It can of course be argued that this projects positively into the real world, but generally the fiction geek combines all the disadvantages of being a geek with none of the advanges of being a geek. Everyone who watched Sci-Fi Science would agree with me.
After all, some people watch a movie or read a book and enjoy it as such, some find parallels with human society, some dream of being princesses and frog-princes, and some dream of being Jedi wielding extendable porous ceramic lightsabres with nuclear batteries, adamantium cooling fans and superconducting plasma confinement magnets. Or something like that. There's nothing wrong with either case, and of course there's always money to be made.

aliens

2011-04-17T15:31:00.002+03:00

Just about every popsci show I've seen in the last few years favors the idea of aliens being everywhere. I'm sick and tired of hearing "reputable scientists" utter the stereotypical sentencte: "The Universe is probably teeming with life". Just because a lot of extrasolar planets have been found lately and just because alcohol's been found in deep space (along with other organic chemicals such as aminoacids) and just because bacteria can live everywhere on Earth doesn't mean that life just appears everywhere there's water and heat. And then becomes intelligent. A few decades ago you didn't see this almost-consensus that aliens must exist with high probability. Now everyone's being disgustingly optimistic about "not being alone in the Universe".
There are a lot of problems with the whole extraterrestrial life issue.
First, you can't do statistics on a sample of one. Therefore, you can't scientifically predict anything about life elsewhere. If we were to find life on Mars or Jupiter's moons or wherever, we'd have a sample of 2, which would still be insufficient, but a lot better than 1. To be pedantic, we don't even have a clear, universal definition of life, or a clear method to identify it; we can only speculate that if it existed, it'd be similar to what we see on Earth because the physics and chemistry are the same everywhere.
Second, we are very limited in our capabilities to detect extraterrestrial life. Radio searches have so far yielded nothing and I personally doubt they ever will, because radio "leakeage" from aliens would be too weak to be detectable. The whole "our TV shows have already reached dozens of stars" is bullshit, the signals are too weak to be detectable. A 100 kilowatt radio source on Earth would shine just about 10^-24 watts of power on a generous alien antenna (one square kilometer) placed not very far away (10 light years), for the same reason that distant stars appear so dim to us. If that antenna were connected to an incredibly sensitive receiver, say cooled to a tenth of a degree above absolute zero, the electronic noise due to thermal motion would still be 1000 times stronger. They could probably barely receive Morse code, which takes a lot less bandwith than human speech. Ramp up the distance to 100 light years and the signal gets 100 more times weaker. So in order for the aliens to hear us, either they'd have to have incredibly advanced receiver technology, or our beam would have to be focused and directed towards them. We're faced with the same problem when trying to detect alien radio signals. We could probably detect a signal if it was being intentionally broadcast, but we haven't yet. This raises another problem: how many times, and for how long, did we transmit such signals into space? Not that many, not that long. Maybe the aliens are doing likewise.
What other means of detection could we use? Take artificial lighting for instance. City lights on Earth can be seen from space, and they have a very distinct spectral signature. Aliens would possibly also use artificial lighting at night, but light has the same problem as radio signals. Maybe if we had a telescope powerful enough to see planets around other stars, we'd be able to detect these hypothetical lights. At least we'd know what to look for, given that aliens would probably see in the same frequency range as we do, because their eyes or whatever they have would adapt to the spectrum of their star, which would be similar to ours. If we watched the planet from the right angle, we could possibly even see these lights turning on in the evening and off in the morning. The total power coming out of our lights is much bigger than the power from our radio transmitters, so things might be the same on their planet. Light is also easier to detect than decoding radio signals.
Another thing that comes to mind are nuclear explosions. Any sufficiently developed aliens would do them, even if just for testing. They would be strong enough to be detectable, but did we ever see any sudden flash of light near a star? Did we ever look for one? I have no idea.
Finally, contrary to what some may think, there's not a shred of physical evidence that aliens have ever visited us. That might be due to the difficulty of interstellar travel, but nonetheless it hasn't happened.
So yeah, even if aliens exist, they can't get to us and we can't get to them. Relativity, which is pretty much proven to model this world correctly, while not forbidding faster-than-light travel, predicts that such travel would result in grandfather paradoxes and such. We also can't talk to them, because information, however we send it, radio, lasers, X-rays, whatever, only travels so fast. Maybe in a "parallel reality" we could, but not in this one. So there. We are alone.

power

2011-03-30T10:18:00.002+03:00

Are you deeply concerned with pollution, global warming, nuke accidents and all the shit that comes with modern, power-hungry technology? Are you thinking green, feeling green, living green? Caring about the environment? Celebrating Earth Hour by switching off the lights and burning stuff? Or are you just concerned with your electricity bill, netbook battery, or living in Japan where the power grid's flaky after the quake?
Well, then use a goddamn low-power web browser while you surf for pr0n!

chrome

2010-09-27T08:06:00.006+03:00

Had to set up a little website and wanted to test it on my server which doesn't use port 80. Works great under Firefox, wanted to also test it in Chrome.

A few months ago a similar setup worked just fine, but it seems some c0der/suit/whatever got smart and now I get

The webpage at http://example.com:1234/ might be temporarily down or it may have moved permanently to a new web address. (Gee, really? It was there 30 seconds ago!)
More information on this error.
Below is the original error message
Error 312 (net::ERR_UNSAFE_PORT): Unknown error.

Hey, it's mah puter and I read whatever port I want, bitch!
Furthermore, it seems there's no easy way to disable this stupid behaviour.

Can I say "Fuck Chrome" on a Google-owned blogging platform? Ok, I won't say it.

LE: There actually is an easy way to enable a list of ports; my bad for stopping on "recompile from source" in the bug discussion. Thanks Lucian. Still stupid behaviour.

research 2

2010-08-17T01:59:00.005+03:00

Look on the fourth page in this pdf, which is published in a scientific journal by someone who's a scientific doctor. Look at Figure 3. Yo dawg, I heard you like screenshots so I put a screenshot in your screenshot so you can copy while you paste!

crisis

2010-08-16T23:11:00.002+03:00

There's no economic crisis. If there were, you wouldn't be walking in a bar and having to wait 30 minutes for the waiter to take your order. This can be extrapolated to all levels of society.

research

2010-08-13T07:32:00.003+03:00

Hey look, this researcher working with both CERN and Fermilab writes that the protons in my ass might contain higher generation quarks. (do search the article for "ass"). I always thought life was made up of ups and downs... but I'm now feeling strangely charmed.

logic

2010-06-19T09:40:00.006+03:00

Do you know those 'logic' puzzles where you have to choose which item 'logically follows' in some sequence, or which item 'doesn't belong' in some group? You can do them for fun ('brain training') or they can be administered to you in certain situations such as a job interview. People would normally be employed based on their relevant skills, but it seems some 'progressive' management types think that they should be 'logical' too. That's an idiotic practice and should stop, because:

A. My logic can be different from the author's logic, and that doesn't make it any less correct:

In hindsight, it should have been obvious to me that 25*25 is 625 and that 30*30 is 900, but at the time it was obvious to me that answer A is the only number not divisible by 3. Fuck you, gbrainy!

B. The question text can be ambiguous:

'Frontiers between different sheets' means that where there's a line a sheet ends and another one begins (like with countries, you know, they don't overlap). In that case it's impossible to build that shit because there are non-square 'countries' in it. So it's clear that (a) the question is wrong and (b) the sheets must overlap.
Now there's a question of what the author meant: whether that's how the figure is seen from above or the lines are just paper edges (like sea borders or something where there's no other country there) and maybe the paper is semi-transparent or something. Of course, if that's what's seen from above and the paper is perfectly opaque, you need 5 sheets, but if those are just (possibly hidden) paper edges somewhere you only need 4, which is less than 5. You might say that I'm stoopid and of course paper is not even conceptually transparent. But then why can you see the brain in the background through the sheets? Fuck you, gbrainy!

C. The questions can simply be annoyingly stupid:

Yeah thanks for lecturing me on how P is 5 letters away from K which is 5 letters away from F which is 5 letters away from A! I knew there must have been something like that, but I didn't even bother counting*, because the answer was obvious from comparing the three squares: A-B-C, F-G-H, K-L-M, P-?-R, gee, what letter could that be? There was a similar question with some clocks where they put forward a similarly contorted explanation, while the minute hands on each column were all pointing to the same number. Fuck you, gbrainy.

---
* some of my friends know all the letter indices and ASCII codes so they only need to subtract. They can also read binary T-shirts.

fail

2010-04-30T20:15:00.004+03:00

Recently the ubuntu guys decided to move the buttons to the left of the window and eliminate the icon, like so:Worst idea ever. When I browse in a maximized browser or when I keep my Pidgin on the right edge of the screen it seems like the window is falling off into the void, because the space on the top-right corner is so empty.
Fortunately, this being an open system, you can change this, but not from some user-friendly application like the theme selector (where by the way, the sample window decorations are still drawn the classic way -- double fail), no, you have to use the gconf-editor, a kind of registry editor for Linux (ugh) and modify the button_layout under apps/metacity/general:

hour

2010-03-28T14:43:00.004+03:00

Last night they changed the time again, they stole one hour. 6 months later they're going to add it back again. But unlike the bank, where they pay me interest for the money I give them, the authority that implements daylight savings / time change doesn't. And I want my time back. I know I'll get it back in winter, but I want interest on that. I want 5 minutes officially subtracted from one work day by law. But I'd rather have daylight savings abolished altogether, and here's a few reasons why.
I don't know how it's like in other countries, but here, when they add an hour in autumn the trains actually stop for an hour at 3 am to align to the new time. Imagine that! In spring they supposedly run faster to catch up with the new time. Supposedly.
It's true that my computer's clock adjusts to the time change automatically, but many stand-alone clocks don't, and my mobile phone's clock doesn't. Well guess what, it's exactly those clocks that wake you up in the morning. A few years ago I actually arrived at work one hour late because of fucking daylight savings. As if in the 20-fucking-1st century when we have electricity and efficient lighting there were any relevance of "saving daylight" at 6 in the morning. But back to adjusting the clock. I will now adjust my mobile phone's time. I did it. It took 20 key presses and about half a minute. But even if I could live with this, if for example the state offered me 5 to 10 minutes interest on my borrowed hour, there's still the problem of when to adjust the clocks. Here they officially change it at something like 2 or 3 am, and that's when the computer does it, but most people are asleep at 2 am and need to wake up at something like 6 or 7, so there's the option of setting the alarm one hour earlier or adjusting the time in the evening before going to sleep. But what happens if the phone that implements the alarm clock actually does adjust itself at 3 am without the user knowing? You lose one hour of sleep or arrive at work one hour late. See, daylight savings creates a lot of unnecessary headaches and basically loses people money indirectly. Time is money you know. Its disadvantages outweigh it's advantages which are mostly historic. For goodness's sake Fuck Daylight Savings.
P.S. What if the state interprets my request for interest on time as me having to "pay" for the hour they give me in autumn and take back in spring? That would suck so much.
The other hour that happened recently was of course Earth Hour ("urth our! urth our!") which I explained previously is utter bullshit. People shut off the electric lighting for one hour and light candles and glowsticks instead. Candles emit pollutants into the atmosphere such as carbon dioxide (which causes, OH MY GOD, global warming!!1), carbon monoxide, ash, et cetera. Candles are energetically inefficient (horribly inefficient), much less efficient than a lightbulb plus coal-fired power plant. It is much more environmentally responsible to use electric lighting than to use candles. It doesn't bring you closer to nature or all that shit when you use candles. Candles are bad for the environment. Use electric lighting, which if supplied by renewable sources, has nearly zero impact. Idiots. Also, a small diesel or compressed-air engine on a lightweight, aerodynamic chassis is more efficient and pollutes less than you riding a bike. You breathe out global-warming-causing carbon dioxide too you know, hippie.

february

2010-02-28T02:21:00.006+02:00

Whoever decided that February should have 28 days was an idiot (less so than the idiot who came up with daylight savings but an idiot nevertheless). Why should all the months have 30 or 31 days with the exception of February which has 28? That's inconsistent and thus stupid. Why not have more months with 30 days instead of 31 and make February have 30/31 days as well? Because someone was stupid, that's why.
Here:

scheme	j	f	m	a	m	j	j	a	s	o	n	d	total days
stupid	31	28	31	30	31	30	31	31	30	31	30	31	365
stupid leap	31	29	31	30	31	30	31	31	30	31	30	31	366
fine	30	31	30	31	30	31	30	31	30	31	30	30	365
fine leap	30	31	30	31	30	31	30	31	30	31	30	31	366

There. Isn't my scheme much neater? Look how fine the months alternate. And on leap years you add one day at the end of the year, not at some arbitrary position. Much like they do with leap seconds on New Year now.

http

2010-02-22T14:18:00.005+02:00

One morning I was webbrowsing:

ret@ret-laptop:~$ telnet some-server.com 80
Trying some.ip.address...
Connected to some-server.com
Escape character is '^]'.
GET /32452tr534tfgr4 HTTP/1.1
Host: some-host.com

HTTP/1.1 404 Not Found
Date: Mon, 22 Feb 2010 12:07:12 GMT
Server: NOYB
Connection: close
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1

...404 and so on.
WTF? No shame:

# Server masking is optional
#fake server banner - NOYB used - no one needs to know what we are using
SecServerSignature "NOYB"

Hey, NOYB yourself, fucker! You know I'm OK with you bragging about how secure you are and everything, but what makes you think you can abuse protocol like that? It doesn't hurt to be polite, you know! Is it so hard to come up with something decent like "hidden"? So much for user interface. Kids these days...
Anyway, here's the rest of the reply:
(some-html-tags-that-blogger-chokes-on)

Apache/1.3.34 Server at www.some-host.com Port 80

(some-other-html-tags)

LOL.

Later edit: oddly enough there actually is a www.some-server.com which obviously has nothing to do with this post, please substitute www.example.com in the text above :P

mutex

2009-12-29T22:37:00.007+02:00

I got an email offer to attend a web seminar ("webinar" :-& ) by some company selling Real-Time Operating Systems. A RTOS is an operating system that, unlike usual PC operating systems, can guarantee that some task will be performed before some future moment, if properly used. The guys were charging $39 for the exquisite privilege of attending their online seminar about mutexes and semaphores. Not any seminar about mutexes and semaphores, but an introductory seminar on mutexes and semaphores. Mutexes and semaphores are used so that two programs don't work on the same data at the same time, in order to avoid corrupting said data. Here's an introduction to mutexes and semaphores. Enjoy.
P.S. Some time ago a colleague was asked by a professor what "methods" does a semaphore have ("P" and "V"). "And which one of them increments the semaphore?" Dude, how the fuck should I know, I don't speak Dutch and I don't care for Verhogen! Can't you just call them increment and decrement or up and down like normal people?

2009-10-27T00:17:00.002+02:00

I was browsing the Web for Information. There it was, the front page. An annoyingly blinking red-on-green banner was announcing that I am the 999999th visitor and it was congratulating me. I would've smiled if it weren't blinking red-green/green-red. Of course I couldn't have been the 1e6-1th visitor because (a) that's too improbable and (b) that site claims to have one million visitors, yeah right! So I scroll down, trying to ignore the ad, and I see this other banner, a vertical one this time. This one is blinking red/blue. It's saying that I'm the 10000th visitor, but this time, "this is no joke!". This time I laugh. At least this number was plausible, visitor-count-wise. Of course it would've been much cooler to be the 999999th visitor because (a) the number is almost 100 times bigger and (b) it's not one million, it's one million minus one (that's being creative!). But sadly, the lesser number was more probable, and besides, that wasn't a joke. Deciding that I had to settle for ten thousand, I scroll down and laugh again when another red-green/green-red banner (this time neither horizontal nor vertical, but squareish) informs me that I'm the 999999th visitor after all! OK, now I'm confused.
I fire up a new browser but this time under the guest user so that my files would stand a lesser chance of being trashed by malware. Wow, now I'm suddenly the 12796869939th visitor! That site must have a lot of traffic, given that I was at most the 999999th about 10 minutes ago. The "this is no joke" banner disagrees by a much smaller percentage this time, indicating 12769870797. The square one says 12796871217, but there's a twist: I'm the 12796bla-blath visitor to see "this lucky banner", so maybe there are other sites showing the same banner and there goes my "not enough visitors visiting this crap" argument down the toilet. The small difference could even be explained by the different times my browser queried the ad server for the three banners while loading the crap. [must be a very big server.] I hit Refresh and lo and behold, I'm either the 999999th or the 10000th visitor again. This clearly can't be, because I already visited the site before as both the 999999th and the 10000th, under a different identity.

So I hold my breath and click the first banner.

It asks for my name, address, and e-mail address. There you go. Move along, nothing to see here, and quit clicking stupid adverts and quit encouraging spammers by opening their e-mails and clicking on their links and buying their cockpills, because if you encourage spammers and spammers send me spam, then you're indirectly to blame. The fuck!

taxi

2009-09-18T07:09:00.005+03:00

I was in a cab one night and I glanced over the driver's dashboard, where the display was showing the total distance the car had traveled. It was about 170 Mm. I suddenly realized that such a distance is similar (of the same order of magnitude) to the distance to the Moon, or to one light-second (approx. 300 Mm). To realize that, during the course of a few years, a car can travel one light-something, where that something fits on the usual human timescale, is wonderfully mind-warping.

math

2009-05-26T00:45:00.003+03:00

(fourth grade) Math Problem:

A mother is 25 years older than her son.
In 7 years, the mother will be 5 times older than her son.

Where is the son's father?

Answer:

Let the child's age be c years and the mother's age be m years.
Now, m = c + 25.
In 7 years, m + 7 = 5 * (c + 7).
Substituting the first equation into the second one, we get
c + 32 = 5c + 35, from which 4c = -3, or c = -0.75.

So the child is minus nine months old, therefore the father is most probably in the mother.

sex

2009-05-23T19:39:00.002+03:00

After vast experimentation, we found the optimal parameters for sex:
* frequency: low, around 0.8 Hz
* amplitude: as large as possible (e.g. 15 cm)
* waveshape: approximately square wave
* duty cycle: cca. 80%
Something like this:

brideparade

2009-05-18T02:24:00.004+03:00

I came home this morning looking forward to a good sleep, only to see the news: there's been a "Brides' Parade" in Bucharest! Now I can't really understand how I missed that, given that I crossed about half the city... maybe it was because we were busy spending meaningful time together instead of dressing up and parading... maybe it was because I was too drunk... I don't know. The Brides' Parade featured "past, present and future brides" (basically any woman would qualify) in wedding dresses parading on some street, possibly in a 1900s car. I hate it when "historical cars" run on the road, they're ugly, obsolete and environmentally unfriendly (mwahahaha). But I digress. The fun part was watching a relatively young girl in a wedding dress being interviewed by some reporter: "So, are you married?" "No, no :)" "Are you getting married today?" "No, no! :) No guy will take me! :) Heeeey! Guuuys! Take me! Take me!!!! I'm [fucking] yours!!!!! Take me!!" Yeah. Yeah. Ok. Great for you.
Parade. Feel fine. Waste time. Feel good. Exhibit yourselves. Feel nice. Display your young, succulent flesh on the counter. Feel great. Spend. Feel wonderful. Burn, age, wither away,... death of the soul, indoctrinated in false grace. Be happy.

One six six! The number of the bitch!
One four four! The number of the whore!

bits

2009-04-24T02:47:00.006+03:00

I've had to learn the hard way that whenever you're taking a business trip (or a leisure trip for that matter) there are certain essentials that you have to bring with you, such as your towel. While having a laptop with your familiar environment and your favorite tools and music can make your life easier, it's not absolutely essential, given that you probably have an Internet-accessible box at home or at work. What is essential is a quick, straightforward way to get the job done. You need to be able to link your bits with their bits and measures. A simple way to patch your technological know-how into their system. Thanks to Microsoft et al deprecating "legacy" serial and parallel ports, now there isn't any simple, immediate way to interface stuff directly to a PC-class computer. You usually interface stuff directly to a microcontroller-class computer, but even that needs to be PC-linked to be programmed. So even if you're certain that you can find all the needed parts on-site, you still must always bring your own USB AVR programmer.

please

2009-04-07T20:45:00.004+03:00

I see more and more people embedding phrases such as "Please consider the environment before printing this email." near the end of their e-mails. I can only agree: please consider the environment before printing anything. For instance: energy/cut trees/oil/whatever needed for printing the document versus energy spent by you turning on your laptop to read the document while traveling (by train, of course). Stuff spent for printing and reading by daylight (or by incandescent light (inefficient) or econo-bulb (mercury-containing)) versus reading on LCD (or CRT) monitor, in darkness or in lit room. Think before you (don't) print. If I could be bothered to dig up the data, I'm sure I could find at least 8 cases in which it would be more "environmentally responsible" to actually print the fucking paper. I saw a documentary about loggers recently. Their company administers a huge area of forests, cutting down old trees and planting new ones instead, continuously. They claimed that younger trees absorb more CO_2 than old trees, therefore they're actually helping the environment. So there, when you're feeling lonely and depressed and nobody likes you because you're an environazi drone, go print a nice flower or something.

foolcoffee doubleclock

2009-04-01T17:51:00.008+03:00

I had a Digital Computers course where we had these logic design and implementation lab classes. We had to implement various modules in Verilog and run them in a low-end FPGA. But during the first lab we weren't yet familiar with Verilog, so we were supposed to enter a digital schematic graphically. The schematic was designed the hardcore, old-school way, by building a state machine on paper, assigning bits to states, writing equations, translating them to flip-flops and gates et cetera. The state machine was for a (famous with past and current students at our faculty) "coke vending machine". It never worked as supposed and I suspect (being too lazy to prove though) that the equations suggested in the lab documentation were wrong. Years have gone by and, while having a break in the faculty hallway, I found that maybe one of our graduates, now employed at a vending machine company, has finally got it working:

vi

2009-03-29T16:32:00.004+03:00

vi in an ancient text editor present on Unix-like operating systems, known for its two modes: a normal mode where letters and numbers mean commands such as move one word to the left, delete 3 lines et cetera, and an insert mode where chars are inserted into the text. Normal chars can also be deleted with backspace, but somehow \n (newline) can't. If you accidentally press q in the middle of the line, you can press Backspace and undo that. If you accidentally press Enter in the middle of the line, or for some reason you want to join two lines, you hit Esc to exit insert mode, then Shift-j to Join the lines, then i to enter insert mode again. That's wonderful ain't it? Now, on large computers people can use whatever editor they want if they hate vi. But on small embedded systems such as home routers and set-top boxes, vi seems to be preferred (due to its inclusion in the BusyBox userland, which is probably due to it being part of the UNIX standard), and even though there are ways to install other software, it takes time which I may not want to waste. Therefore - fuck vi, vi sucks.

copyright

2009-03-29T04:58:00.002+03:00

Came up with this while drinking with other computer engineers. Steps to become a rich lardass:
1. Write computer malware (virus, internet worm, whatever, can be mostly harmless)
2. Let it spread
3. Go public
4. Spend zero to 6 months in jail or do community service or pay a small fine or something
5. Sue antivirus companies for copyright infringement because of your virus signature that they include in their product which they distribute without your written permission
6. Collect $5 per antivirus copy/update distributed

Then, foreach virus_writer joe in earth.people {the above}
And suddenly you can't have antiviruses anymore. Dude, sick, what the fuck.

urth our

2009-03-29T04:03:00.004+03:00

This evening was Earth Hour again. Earth Hour is a rotating, evening-following event lasting approx. one local hour and 24 global hours. People are supposed to turn off their lights as a message towards wasting less energy. Instead, they gather and light candles, which as some including myself point out, is actually very energy-inefficient. Early news reports show people gathering under slogans such as "screw current events" (ro: nu fi la curent), obviously referring to electrical current, and lighting tons of candles. This is incredibly stupid. Electricity is one of the cleanest means to transport energy, and is readily obtained from solar radiation, wind et cetera. Candles release toxic gases into the atmosphere and some are actually made from fossil fuels (paraffin wax). Their luminous efficiency is shit, compared to even the most inefficient incandescent light bulbs and electrical power plants. Way to go dudes, way to go. Now it's actually cool and eco to burn oil derivatives, at least as long as it's diesel which doesn't need electric sparks, because, you know, electricity is satanic and stuff mwahahah \m/.
As a response to critics, the World Wildlife Fund (who came up with Earth Hour) said it's purpose is not to save energy or money, but symbolic. LOL!
Therefore I say: the purpose of hunting is not to kill animals and endanger more species, but symbolic. It's also fun. Not that I endorse it, but I can certainly see how some people find hunting challenging, rewarding, fun. Coincidentally, about 1 hour ago I saw a documentary claiming that the guy whose killing started World War One was a prolific hunter who used to travel the Austrohungarian Empire by train shooting every animal in sight. He supposedly killed about 300 k before being shot to death himself.
Sometimes I just get tired of ranting. Sometimes I just accept the fact that I live in a defective world full of defective people, including myself. For instance, if astronauts can phrase their speeches in such defective ways as to suggest that space smells, what the fuck can I expect from normal people? Please spare me the "it's metaphoric, dude!" explanation -- many people actually don't know that void can't carry sound or smell and many people couldn't care less, sadly. Wordings like "space smells of ozone" and "a whiff of vacuum" do nothing to help that.
After all, why the hell do I expect stuff from astronauts. Astronauts are more like soldiers than like scientists. They get too much hype anyway: Dood, let's off the lights and light them candles and watch the space shuttel land and celebrate urth our!!
Whatever makes you happy, people.

work

2009-03-24T17:00:00.005+02:00

Today I extended my "to do" note window 64 pixels downwards in order to prevent scrolling the "to do" list. It can grow 448 more pixels before reaching screen height. Depending on whether the speed at which the tasks are executed is influenced by the length of the "to do" list, or by the entries' age, the screen is predicted to fill up somewhere around September or October. I guess there is little or no influence, so I better plan on buying a higher resolution display. Put that on the "to do" list.

lemons

2009-02-04T01:02:00.005+02:00

Embedded Systems exam at the Bucharest Polytechnic.
"A lemon battery can supply an average of 0.1mA at 1V for about an hour.
1. How many lemon batteries are needed to run a 100W light bulb?
2. How many instructions can an ATmega128L execute while running from a lemon battery? Assume that an ATmega128L uses an average of 4nJ to execute an instruction."
At the students' request, further (obvious) assumptions were specified:
a) To simplify, assume that the lemon has an ideal U-I characteristic (it can deliver anything up to 0.1mA at 1V).
b) It also has an ideal U-t characteristic (at 0.1mA, it holds 1V for one hour then suddenly drops to zero).
c) Assume there is an ideal DC-DC converter between the lemon and the ATmega128L, providing it with the required voltage.
After thinking about it, and after remembering the jokes about ideal spherical lemons in vacuum, I decided that additionally, the ATmega128L's clock frequency should be set such that it draws exactly 0.1mA from the 1V lemon supply, or that it should enter very low power sleep modes as needed.
Answers:
1. 100W/(1V*0.1mA) == one fucking million (whoa)
2. 1V*0.1mA*3600s/4nJ == 90 fucking million (yeah).
Required frequency for ATmega128L to complete 90Minstr in 3600s:
f = 90M/3600s = 25kHz.
Current drawn by ATmega128L at 2.7V (minimum operating voltage) in order to assure 0.1mA from lemon, given ideal converter: 0.1mA*1V/2.7V = 37uA.
Typical current drawn by real ATmega128L at 2.7V at 25kHz, extrapolated from datasheet graph: 50uA (pretty close actually).
So there you go: light a bulb long enough to take a shit, or execute 10 trillion 8-bit computer instructions. Meanwhile, a high-end "PC" processor would do maybe 4 trillion 64-bit instructions, making it better than the microcontrollers, but not that much better. Moral of story: do something useful -- turn off lights, run computers (*).

energy, of the black kind

2008-12-29T22:59:00.006+02:00

As noted before on this non-blog, many self-titled environmentalists have no idea what they're talking about. For instance, this blog came up with the idea that a "black Google" would save 750 MWh/year (that's about 86 kW) because black pixels supposedly take less power to display than white pixels. The guy apparently failed to note that only obsolete CRT monitors do that, initially stating a 3000 MWh/year figure (see it in the URL, he also admits it). Apparently, when he found out that LCDs actually use more energy to display black than white (this comment on his blog agrees) he changed the figure to 750, a commendable action. Even so, his calculation is highly approximative at best. So it's easy to campaign for stuff without having the slightest idea what's going on. As CRT displays are being slowly but surely replaced with LCDs, his black background idea is actually going to result in increased energy dissipation. It's true that OLED displays might eventually favor his idea, but the point is he did no serious studies before launching an idea that thousands of sheeple intercepted and praised, leading to sites such as this, which was brought to my attention today. Its about page (where I learned about the naive but honest guy's blog) is full of smug about how much it protects the environment, while its front page mentions how much energy it saved. I guess if we take the approx. 1MWh stated and multiply it by 0.6/15 (measured watts increase in LCD consumption versus stated CRT watts decrease) we get about 40 kWh of wasted energy. At least it's not very much.

13:37

2008-12-28T13:37:00.001+02:00

again.

xmas

2008-12-25T08:33:00.003+02:00

I want to wish everybody who celebrates Christmas these days a Merry one.
Meanwhile, I am certainly going to feel the Christmas spirit (be it ţuică, răchie, pălincă, vişinată, vodka-based eggnog et cetera).

energy

2008-12-25T07:33:00.006+02:00

I once heard that the standby/clock display on a microwave oven uses more energy than the oven uses to cook food. I find that unlikely, so let's do a quick calculation. The microcontroller used to drive the clock or whatever's on display shouldn't draw more than a few mA, 10 at most, or else it's a piece of shit. Most LEDs (I'll assume it was an LED display, because segment LCDs consume next to nothing) are rated for 20 mA average current, though in many cases they're used with less. High-efficiency LEDs can glow sufficiently brightly with as little as 2 mA. Let's assume 20mA per LED (worst case scenario), and a display made up of 4 standard 7-segment digits and 2 dots. Now, not all LEDs are simultaneously lit, because the clock doesn't show 88:88. To find out how many LEDs are lit on average, I built the following table:


Digit          Number of Segments
0              6
1              2
2              5
3              5
Partial Total  18
4              4
5              5
Partial Total  27
6              6
7              3
8              7
9              6
Total          49

Note, totally off-topic, that 4, 5 and 6 are the only digits whose 7-segment representation has the same number of segments as the digit value.
Given a 24-hour clock (the worst case scenario), the sum for all 24 hours is: 6*10 for the leading zero plus 49 for the following early hours, plus 2*10 for the leading one plus 49 for the following mid hours, plus 5*4 for the leading 2 plus 18 for the following late hours. That's 216, so diving by 24 we get 9 LEDs lit on average to display the hours.
The minutes are just as easy to calculate: There's an average of 27/6+49/10 (for the first, second digits), that is 9.4 LEDs on average. The two points average 1 if they blink, 2 if they don't (worst case, which is what we choose).
In total there are 20.4 LEDs lit, that's an average current of 410mA, holy shit that's fucking much. In reality the current is significantly lower, but this is a worst-case calculation. So the display uses at most 420mA, microcontroller included. Suppose it's supplied with 5V, that's 2.1 watts. Assuming a supply efficiency of around 50%, the standby-mode clock eats about 4W averaged over a whole day, neglecting the small intervals the oven is used for cooking.
Now for the cooking. My oven has settings for 800W, 640W and 320W or something like this. I don't know if that's the useful power or the total power drawn. For the worst-case we're discussing I'll assume it's the total power. I always use it on 800W for about 1-2 minutes. So let's say the oven is used for 10 minutes a day (an average family might use it for 20-30 minutes a day). The display eats up 4W*24(hours)*60min=5760 watt-minutes. The cooking eats up 800W*10min=8000 watt-minutes, which is more. There, the display does NOT consume more energy than the oven-proper. If I only used the oven for 5 minutes a day, and the display was a really lousy one like the one described above then yes, the display might have consumed about as much energy as the cooking. Note, my oven displays a singe 0 when not in use, so that uses more than 3 times less energy. It still eats up quite a lot of energy, which sucks, but still significantly less than the oven-proper, so there goes the propaganda down the drain.

honk

2008-12-18T10:43:00.003+02:00

I was relaxing in the bar, calmly enjoying my beer. Outside, the traffic was horrible. The intersection was almost blocked and the drivers were angry. A car blew its horn. I thought I saw the lights in the bar blink. It was obviously just a brain glitch. Surely the lights can't dim when a car is honking outside, can they? A great thought came to my mind. What if they actually could? I mean, when a lightning bolt hits a powerline or transformer station, the lights most certainly blink. They dim a little. The same thing happens when someone in the building is welding - the welder draws a lot of current so the line voltage decreases significantly. The question is, when a tram or trolleybus or even a train goes past the building, does it create enough of a disturbance for the lights to noticeably blink? In most cases, I guess it doesn't. But do the lights blink unnoticeably? Possibly. It's not necessarily an electrical disturbance that can cause the lights to blink. Air currents for instance do modify the light output of all devices, be them incandescent lamps, fluorescents, LEDs, whatever, simply because light output is dependent on temperature, no matter how slightly. Me shouting at the lightbulb can potentially alter its output. By how much, that's another discussion. It's certainly not noticeable, but is it measurable? If it's not directly measurable, is it at least statistically measurable? How many photons a second does a lightbulb's output vary with when a car honks outside? I don't know. Fewer than air currents cause? Electrical disturbances from people turning their TV on or off in the next building? I don't know. It's an interesting thought. My guess is about 5.

elevator

2008-12-17T14:20:00.006+02:00

It's said that people who live on the first and second floors die older, because they rarely take the elevator and thus have more healthy exercise. On two occasions today I shared the elevator with people who ascended just one floor. A few days ago the elevator was nonfunctional. It was stuck at the second floor. I can't be totally sure, but my guess is that someone walked into the building, took the elevator to the second floor, got out and instead of closing the door in a civilized fashion, they kicked the fuck out of it. The door bounced back just as someone else was calling the elevator and the interlock was closing. It didn't have enough time to close so the door got stuck open. Then again, the interlock might have just been defective, not allowing the external door to open, and the person getting out might have manually opened it, got out in a civilized fashion and left it locked (it can only be overriden from the inside). If the first scenario actually happened (I don't claim it did), I can only wonder how could someone be so lazy as to take the elevator to the second floor, and at the same time blast the shit out of the door. Maybe they were in a hurry.

whistle

2008-12-17T14:09:00.004+02:00

I've found this slightly evolved interface. It lets you whistle in commands. Plus, it uses %.2f and $_ and _#_, which makes it even cooler. And it's not 2.0.
Which reminds me: Can you whistle 2400 baud? 9600? 14400?

netbooks

2008-12-11T19:04:00.003+02:00

Laptops are now called notebooks, because they get too hot to hold in one's lap. From the article: "A study by State University of New York researchers found that heat generated from laptops can raise the temperature of the scrotum, potentially putting sperm count at risk." Small laptops are now called netbooks (Firefox 3 spellchecker underlines the word red) because well, I don't know why. Maybe it's because they have a network interface, as opposed to normal laptops which somehow don't. There is some truth to that: my laptop's internal wireless card failed a few months after purchase. Fuck warranty, I wouldn't have been able to use my computer for a month or so while they repaired it. I tapped the card firmly and it started working again, it worked for another week and then it finally kicked the bucket. Given the low price of PCMCIA or USB wireless cards, fuck it. Maybe I'll reflow the solder some time (fuck BGAs and fuck RoHS (I wonder what they use to replace the Pb in CRT glass - you know, the Pb that shields you from the X-rays generated in the CRT)).
Anyway, thank Microsoft for indirectly limiting netbook performance.

techmangle

2008-11-30T14:06:00.003+02:00

I'm watching this show on the DARPA Urban Challenge. Some team's truck, which is supposed to drive itself through a city environment, is hitting some wall. The team decide the sensors are functioning perfectly, therefore it's clearly a software problem. The software guy calmly informs his team that he can quickly reprogram the car and fix the shit. Then we see the guy inserting a line of code in some if () block. There's only one problem. The code is clearly using OpenGL to draw some lines. Whaaaaat? Nice.
This reminded me of another show I saw some years ago, where they were talking about realistically rendering moving water using computers. They took the Navier-Stokes equations that describe liquid motion and "simplified" them by either making them a puzzle and shooting out pieces, or by deleting the right hand side. This "simplification" supposedly allowed the simulation/rendering program to run at reasonable speed.

hmel

2008-11-26T17:27:00.003+02:00

Part of any self-respecting ev0lvεd interf☺ce is an XML-based back-end.
I overheard the word "XML" in a conversation. It triggered the following thought: if the famous software is pronounced "teh", then how do they usually pronounce "XML" in Germany, or, for that matter, in Greece? achh em ell? och më lë? hmel? Kindly share the information if you have it. I'm really curious. Yeah.

ev0lut1on

2008-10-31T19:05:00.006+02:00

We had a course in the last year of faculty called "Evolved Interfaces".
It talked about cute stuff like how a menu should ideally hold no more than 7 items, a notion which I later heard, during another course, in the form of "humans have a 3-bit memory", to which I quickly crafted a reply I (very wisely) never uttered.
Besides the cute stuff, the main stuff was about Web thingies. Sitez, Blags, F0rumz, Chats and the likes. We actually had to make a team project which consisted of a website using modern xml-y and javascripty and CMSy stuff and an accompanying blog. The site had hit counters and points (which made up a percentage of the course's final grade) were awarded for hits and Google PageRank. This is why each year around this time, people start putting up weird Messenger statuses linking to their Evolved Interfaces projects. People click the links because they sound intriguing and students get hits. This pollutes Messenger contact lists.
Evolved Interfaces is the only course I've had which mentions "Web 2.0" as a valid concept. I find that revolting.
Semi-off-topic: stupid TV commercial for Orange: "...I'm Reeves, the first too point ooh poet and I'm inspired..." bla bla. No, you're just an idiot who "uploads downtown and downloads uptown" and thinks that's so fucking creative and poetic.
Back on topic, I'm not saying that webby stuff isn't evolved interfaces, but until I can tell my light bulb "dim please" or "turn off please", and my air conditioner "computer, 20 degrees please", I'm not buying it. I mean we're in the 21st fucking century and I still can't buy an affordable, widely-available product that takes voice commands and performs useful stuff such as opening my windows (the real ones not the broken ones), flushing my toilet or heating up my dinner. Or at least changing the TV channel. And intelligently replying to queries such as "computer, tell me how that vote in the Parliament on the teachers' salary raise went". That's what I'd call an evolved interface.

gaming

2008-10-29T11:36:00.003+02:00

There are games (such as chess) where player skill matters, and there are games (such as roulette) where luck matters.
I hate games which pretend to require thinking but actually require luck:

Fuck Minesweeper.

ufo

2008-10-23T10:40:00.003+03:00

I saw a UFO a few days ago.
I first saw it at about 60 degrees above the western horizon.
It was a small sphere (about 1/6 to 1/4 of the moon's apparent diameter) that seemed to turn from black to shiny at regular intervals.
A friend noted it was flying "a few hundred meters up, a km at most".
It was moving slowly towards the west, apparently descending; in about 3 minutes it disappeared behind the building.
Probably some bi-color party balloon drifting in the wind.

dos

2008-10-04T19:46:00.005+03:00

In 2008, this guy is still including dos.h.
Vista's command prompt still uses DOS commands.
In Romania, certain high-school programming contests are still happening in Borland C (on DOS), and many high-school students are still learning programming in Borland Pascal (on DOS).
A few weeks ago a 1990s program didn't work in dosemu with a USB-to-RS-232 converter. Was it failing because of the high clock speed, like the Pascal library? Was it written like the guy's code? Was it failing because the serial converter wasn't emulated accurately enough? I don't know.
Anyway, I thank Microsoft for removing the serial ports from desktop PCs and notebooks (they're not called laptops anymore, because some dissipate too much heat to allow comfortable use in one's lap).
Apart from the once ubiquitous but now outdated dial-up modems and serial mice, serial ports are actually useful for a huge lot of devices and tasks, such as:

dial-up modems. Over mobile GPRS or satellite.
serial mice. Why occupy a hi-speed USB port with a low-speed mouse? (if you happen to want 2 or 3 mice on your system)
serial barcode scanners
small serial printers (frequently used for printing receipts)
uninterruptible power supplies
networking (wireless modules for interfacing low-power sensor networks, for instance. The networks run IPv6, btw.)
GPS receivers
mobile phones and PDAs (some mobile phone "USB data cables" are actually USB-serial converters)
a huge variety of industrial and laboratory instruments (meters, process controllers etcetera)
infrared communication (with mobile phones, PDAs, instruments etc)
serial console for configuring and debugging routers and other embedded systems and screenless devices. Frequently used by network administrators.
microcontroller programming, homebrew hardware, firmware upgrade for various devices
small auxiliary text-mode LCD screens to display what song you're playing or what mail you've got or whatever
infrared remote control receivers (for controlling your computer from the comfort of your bed/armchair/whatever)
low cost, easy to build laser links between buildings (with enough speed - 92kb/s - to stream medium-quality audio, transfer documents or work in a remote shell)
etcetera.

There. Fuck you, PC 97.

imaging

2008-09-29T01:52:00.004+03:00

I was watching some mediocre movie where the actors were playing detective on an open hard drive. Weird, negative chars filled the hexdump, with an occasional readable string.
"It's an image!" the guy exclaimed upon reaching a "²¡¤³§«©±°something.jpg⊧⊤⊧⊩⌬".
"Let's see it!" said the chick.
The image is slowly loading.
"It looks digital", the guy wisely concluded.
No shit Sherlock! Wow, they actually did not use a VHS recorder on those platters, those are actual BITS, wow.
Fortunately there's at least one professional photo* guy on the webs who maintains that digital sensors are not intrinsically different than film when it comes to capturing images.
-----
* about 3/4 down the page: "there's nothing at all digital about that look".

puţa

2008-09-24T19:02:00.003+03:00

It's now Google's turn to show me questionable advertising. True, this is not spam per-se, but it's close:
Translation:
Penis enlargement 6 cm - Total satisfaction or your money back. 100% Guaranteed, test it for free!

I find this situation truly alarming, as I usually receive useful advertisements in the WebClips, and I certainly believe Google to be a reputable company that adheres to higher standards.

пр0н

2008-09-24T10:42:00.004+03:00

I've started getting spam in Russian:

Translation:

pussy - Huge boobs video clip

I hate spammers.

waste

2008-08-26T03:45:00.008+03:00

Look at what people at some Indian atomic research center are producing.
Simply put, the guy comes up with a "clever" way to measure stuff using a lot of "general purpose" chips, instead of the obvious, straightforward solution that everyone uses: a programmable microcontroller. He gives a complicated schematic that underutilizes an expensive component and needlessly employs another expensive component. It's more of a novelty, an academic curiosity (though not a particularly interesting one), than a sane product.
Table 1 below lists approximate prices for the components in the guy's design:


Component     Price    Link
-------------------------------------------------------------------
DLP-USB245M*  $25      http://www.dlpdesign.com/usb/usb245.shtml
MAX187CCPA**  $14.81   https://shop.maxim-ic.com
74LS164***    $0.49    http://www.futurlec.com/IC74LS00Series.shtml
74LS90        $0.49
74LS74        $0.29
74LS132****   $0.30
R,C etc.      negligible
--------------------------
Total         $41.38

Table 1: Guy's Bill of Materials
*not an actual "general purpose" component, at least not as general purpose as a 74LS chip, and certainly less general purpose than a microcontroller; to save money, it could be replaced with just the FTDI IC, crystal and USB socket, because you don't actually need to include a prototyping module in a production device (unless you can't solder SMD).
**the weakest performance variant
***74LS parts could probably be found for cheaper, for instance $0.37 for the '164 at www.ti.com, but for 1000 units.
****implied, part number not listed on schematic

So that's 42 bucks just for the parts. Given that there are a lot of parts, the PCB is going to be big, so that's also going to cost a bit. Also, using just 8 of the 12 bits the 15-dollar ADC gives out, now that's pure waste. Nobody gives a crap about a data acquisition system that gives 8 bits (256 levels), unless it's very very fast, which this isn't. The author states that the system can be modified to make use of the full 12 bits, which is reasonable, but no schematic is given, and I have a hunch it would require at least one more 74LS chip.

Now here's the proper way to do it. A lot of manufacturers offer microcontrollers with integrated USB circuitry, as well as on-chip ADCs. So there go the two most expensive components. Plus, a microcontroller, being programmable, that is, having code, and memory, can do a lot more interesting functions such as calibration, unit translation, alarms, outputting control signals, whatever. Plus, a lot of microcontrollers have many analog inputs, so they can measure more than one thing, unlike the guy's design. And they're cheap, very cheap.
My idea would be to use an AVR microcontroller, such as the ATmega8. Using the software-only USB implementation kindly provided by obdev, and the internal ADC of the ATmega8, I can measure 8 voltages with 10 bit resolution (4 times finer than the guy). Moreover, I can increase the resolution in software by using oversampling. Well he can do that too actually, but I can do it in firmware which is nicer. And my PCB will be much smaller and cheaper, because I only use ONE integrated circuit instead of 6. Table 2 below lists my costs:


Component     Price    Link
-------------------------------------------------------------------
ATmega8-16AU  $2.23    http://nuhorizons.com
USB socket    $0 - low-speed device mandates captive cable
                   (like in USB mice)
R,C,D etc.    negligible
PCB           less than the other guy's
--------------------------
Total         $2.23

Table 2: Proper Bill of Materials

As you can see, it's much cheaper, and much simpler to manufacture (therefore even cheaper). It will be slower and it probably won't pass USB certification, but it works. Using a proper USB microcontroller would make those two problems vanish and still cost no more than about fifteen bucks.

Table 3 below summarizes the results of my analysis:


Designer      Price (excl. PCB, enclosure etc.)
-----------------------------------------------
Atomic Guy    $ 41.38
Me            $  2.23

Table 3: Comparative Wastage

There. More than 18 times cheaper, and much better specs. Waste.

idiocy

2008-07-26T03:29:00.005+03:00

1. I stumbled upon some show on some channel where they were showing some stuff and then blurring some other stuff "for security reasons" or something like that. Good thing I don't remember. If the stuff they were blurring out was in fact real and not some "reconstruction", they'd have made a terrible mistake. Blurring doesn't "delete" any information, it just "scrambles" it. Furthermore, it's a poor scramble. Blurring does what's called a convolution, which is basically adding pixels to their neighbors. They can be easily subtracted - the frame can be deconvolved, revealing the original image. It's being used to enhance pictures that come out defocused or otherwise distorted (by analog convolution versus the digital blurring you do in the GIMP). So I hope those sequences were bogus.
2. News are getting dumber by the day. Besides the presenter obsesivelly calling some kids who pretended to sell stuff on some websites, without actually sending the items, hackers, which is insulting to all hackers on many levels, some other dude was reporting on the way cool "thousands of decibels" at some concert the actual TV station was organizing. Yeah, i'd have liked having a few thousand dB SPL there... any increase in news quality is welcome; though anything above a mere 200 dB isn't physically sound anymore, it's a blast shockwave, a concept similar to the one discussed near the end of the previous (relevant) post.
2000 dB SPL (the smallest that could count as "thousands") equals about 2*10^{^}95 pascals (notably, almost one googol, or "ten duotrigintillion":), of them). Normal air pressure is about 10^5 Pa, or 2{90 zeros} times less.
Having failed to find what the pressure is inside a neutron star, the densest object known, let's calculate a very rough estimate. The average density of such an object is thought to be about 10^17 kg/m^3, although it varies from the surface to the center in a way I don't know, so this limits the accuracy of my calculation. Anyway, the pressure dp contributed by a layer of thickness dx at distance x from the center is dp(x) = rho(x)g(x)dx. The gravitational acceleration g(x) = Gm(x)/x^2, where m(x) is the mass contained in the sphere of radius x. Assuming a constant rho(x) for simplicity and lazyness to search for data, dp(x) = G*rho^2*(4/3)pi*x*dx. Integrating over x from 0 to R we get the pressure in the center of a homogenous sphere of density rho and radius R: p = 2/3 pi G rho^2 R^2. In terms of its mass, that would be p = 3/8pi G M^2/R^4 (the smaller, the more crushing). Doing the numbers, I get around 1.4*10^32 Pa, which is of course much, much, much less than 2*10^95; any other more accurate model would still give a result that's much, much, much less than 2*10^95. So on second thought, I wouldn't like having "thousands of decibels" anywhere, if that were possible.

13:37

2008-06-30T13:37:00.001+03:00

again.

noise

2008-06-21T06:03:00.004+03:00

Mkay... some ex-convict, who also happens to be famous, is denied entry in the UK. The UK rules, I love the UK. I fully agree with the British Border Agency: "we continue to oppose the entry to the UK of individuals where we believe their presence in the UK is not conducive to the public good". (In one way or another.)
Mkay... stupid mascot causes floods, or maybe it's just that Chinese symbolism is dumb and outdated. Also, those mascots are hideous. While we're at it, why don't we just shift all those eights a little bit? (pausing for a few moments) Aha! so that's how one transmutes prosperity to death and darkness to light etcetera. Interesting, I've learned something today.
Mkay... A lot of time has passed and people are still discussing Pluto. It's still amazing to see how much time and energy people invest in such irrelevant matters. Gravity Probe B canceled on the home stretch? Anyone? Bah! Pluto! You know what? Fuck Pluto and fuck the Hubble telescope for not being able to snap a photo of Pluto that's more than six pixels wide. We have pictures of Neptune, both from deep-space probes and from that orbiting piece of scrap that's been launched in space without being properly tested first, but we have great difficulty in obtaining pictures of Pluto. We also know there are bodies larger than Pluto beyond it and we don't call them planets, but we're still giving a shit about that piece of crap that can't even hold it's own orbit. We've failed as a race.
Mkay... crazy fanatic preacher admits to inscribing "an X, not a cross" on students' arms. A-ha! So not all terrorists are Muslim! We've learned something today, haven't we? The interesting thing is that he used "a science tool known as a high-frequency generator" to do what he did. This warrants further comments:
1. On the one hand, what he did is obviously wrong on many levels, but why the hell did he have to use an RF generator? I said this before in a previous post, concerning laser pointers: a knife can be used to prepare food, to heal people through surgery, or to kill people. Are you ready to ban knifes just because they can be used to kill people? I don't want to live in a world where I'm not allowed to use an RF generator because it can be used to burn people or cause interference. I know the article isn't about this, but I feel the problem needs to be raised. There also remains the question: why the hell use an RF generator, which is intrinsically evil and satanic as per the Bible, when there are matches and cigars and stuff available?
2. On the other hand, the guy might actually earn some bonus points for his technique. I mean, that's being inventive. It has hack value. For instance, if I had an RF generator and wanted to draw stuff on my skin, I'd certainly consider using it for that purpose, but maybe I wouldn't be thinking about this, had it not been for this guy's misdeeds.
Mkay... I was simulating some low-power wireless network and it wasn't working. No packets would get from one node to another. After countless hours of digging through the sources (I was lucky I had the sources), I found out that the simulated noise what at a constant level of plus 127 dBm. Sadly I can't give a fancy link to Google Calculator because it doesn't seem to know dBm, but I can tell you that's huge. I mean just look: Wikipedia has tables that speculate on how a hundred yottameters look like, but its dBm-to-watts table stops at 80. To get 127 dBm of noise power, or 5 gigawatts, you'd have to be inside a fusion reactor, or better yet, a hydrogen bomb. Well, the radio simulator would detect a collision at anything above -70dBm (like the physical chip does), which, as the Wikipedia table states, is quite a reasonable value. Anyway, fuck that, and fuck the fact that the interface for specifying noise in the radio simulation changed from TinyOS 2.0.0 to 2.0.1, breaking compatibility and silently failing (at least in the code I was working on, which I admit is... particular). You know what? Fuck bad programming, and fuck such a lousy sense of physics. This however raises the question: If I wrote a simulator from scratch, would I give debug warnings when parameters go haywire? Of course not, if only because there is no clear threshold after which a value can be safely identified as being totally insane. Maybe I should submit a patch that simulates the RF chip instantly vaporising into a greenish puff of smoke, so hot that even all the magic's gone away. I mean, if they simulate noise and attenuation and collisions and bit errors, why not?

analog

2008-06-16T01:20:00.005+03:00

A few days ago I was out with my girlfriend to have a beer and watch the soccer game between Romania and Italy, which ended with a 1-1 draw. There were two places side by side where you could drink beer and watch the game. One had a huge wide-screen TV and was full when we got there, and the other had a small black&white TV that's probably older than me, with a small antenna. Of course we settled for the small TV and watched the game with the few people that were around. Every time something interesting happened, we would lay down the beer glasses and turn our heads towards the TV, occasionally cheering and applauding. About 2 to 3 seconds later, the crowd in the other bar would do the same. Of course, being a digital TV it probably had some amount of processing lag. I don't know how much, so I'll cautiously add the delay from the cable provider who also does some processing and might suffer from additional satellite delay, as opposed to the analog TV which was about... 4 miles from the TV station. So there goes the live. Having sorted out the intriguing relative delay between the small crowd and the large one, I am only left to wonder what the absolute delay was between Zürich and that old real-time analog black&white TV.

misc.

2008-06-13T14:37:00.003+03:00

Sorry, but I just couldn't refrain:

1. Couple has sex in church confession box

"Oh my God! They killed Kenny!"
"He had sins that he didn't confess!"
"And he didn't take communion!"
"He's doooooomed."
"Better go and confess before WE die!"
"Come on, hurry up!"
"Oh no, it's locked!"
"Oh no! It can't be locked! Nooo!!!11 We have to confess before we die!"
"There's that window in the back that's usually open."
"Come on, hurry up!"
"Look, the confession box is over there!"
"I'm first, I'm first!"
"Oohhh!"
"What the?!"
"Oh, son of a bitch!"
"You're a sinner! You're doing unnatural things in the House of God!"
"Oh, forgive me Father, for I have sinned!" etcetera etcetera.

2. Manholes

"Like WTF, there were only ten people killed! Sheesh, quit making such a fuss!"
Hypocrites.

voting

2008-05-28T08:22:00.004+03:00

This weekend is, er, was voting day. We're supposedly electing mayors, local councils and the other things that come with them. Therefore, last night I dreamt I was voting :D It was an interesting experience, akin to a trip into a future world and its voting ways.
So without further ado, I give you

Voting: 2084.

It was a cold April morning and the dew on the grass was frozen like tiny beads of glass.
I turn off the artificial landscape and open the window to smell the warm, polluted air.
Aaah, nitric dioxide, so sweet. Sulphur trioxide, yummy. Etcetera. (We still didn't find a cheap, pervasive way to command our windows to open and our lights to turn on in 2084, although computers students are still studying "Evolved Interfaces", but based on Web 4.0) First there was the Web, then pr0n, then the Social Web 2.0, then the Semantic Web 3.0 which failed to deliver, then there was Web 4.0, the EmoWeb, where people would use galvanic skin response, blood pressure, rectal probes and other sensors to upload their feelings online. Then of course marketoids were talking about Web 5.0, where you could blog by thought alone, but that wouldn't happen until 2337.
Alas, I reluctantly get up, take a shower, put some clothes on (dumb clothes, mind you, no electronics or anything) and walk out the door. I reach the voting room, sign on a sheet of paper, the supervisor hands me two booklets (where I am to stamp the desired candidates) and some advertising leaflets. There was absolutely no other person in that room. It was big, empty and quiet. Therefore I take my time and slowly walk towards the voting booth, which is a small, improvised box with dark blue drapes obscuring my secret choice. As usual, I might say.
I start analyzing the advertising materials and going through the list of candidates. Oddly enough, most are well-known TV stars. I finally decide on a sexy female TV presenter. After all, no mayor has done anything of note for the city in the last half-century, at least we'll have a sexy, charismatic mayor. But I'm not yet ready to cast my vote. I take a peek outside the small voting booth, and there are still no people around. Even the supervising authority has gone out for a smoke, leaving only a low-resolution security camera to keep watch. I calmly walk out of the booth, go into the next room, take out my 2-kg laptop, connect to the nearest wireless access point, and start searching for data on the few candidates I like most. After half an hour of searching, I think: Oh shit, I left the voting booth occupied! Think of the queue! Heck, what queue. There was no queue.
The End.

outlawing

2008-05-14T09:45:00.003+03:00

Some British chef wants to outlaw out-of-season vegetables. Besides this being extremmely funny, it's of course stupid. Let's compare this to some hypothetical situations, in order to better understand just why is this so stupid.
First, let's assume some "celebrity" fashion designer decides they want to outlaw out-of-season or out-of-fashion clothes. I guess nobody is going to pass such a law (in a serious country in this timeframe), but just the idea of lobbying for something like this is preposterous. Imagine stores being unable to sell ... t-shirts in winter. Imagine yourself not being allowed to... I don't know, wear a blue hat because it's unfashionable and thus illegal.
Let's imagine then, that some "celebrity" "deejay" decides to lobby for a law banning songs and records that are more than 3 years old. So then I go to the usual rock bars and I'm not able to listen to 80's rock because some idiot passed a law that some other idiot lobbied for.
Then, let's imagine that some "celebrity" porn star bans you from having sex in other ways than the missionary position (a real law in some USA state).
Finally, let's imagine that some celebrity electonic circuit designer bans electrolytic capacitors, which they should actually do, as electrolytic capacitors currently suck balls and are a main cause of appliance failure. That would be extremmely stupid, because electrolytic capacitors, though unreliable, are very small and cannot be replaced with some other type without ending up with for example a mobile phone the size of a bucket.

kloks

2008-05-07T13:37:00.001+03:00

This is about the 5th time in the last two weeks when I look at the clock and it shows 13:37.

transformation

2008-05-02T01:14:00.005+03:00

1. Yesterday police have turned decorative Christmas lights back on in major cities around the country under the slogan "drinking alters reality" or something like that, in an effort to reduce drunk driving.

2. Hypermiling (what?) can supposedly save gas and cash. Tune your car to use up less fuel, and drive less aggressively. Yeah, right. One problem is, in the U.S. at least, that a certain percentage of people feel that driving an efficient car is {lame, gay, laughable, whatever}. Who the hell cares about fuel. $3.61 per gallon? What the fuck is a gallon anyway? I drink water out of 2L bottles and don't know how much that is in gallons. I have no fucking feel for how much a gallon is, even though I know roughly how much a mile or an inch or a pound is. Anyway, Google knows, almost 3.8L. So what, $3.61 for that much petrol is expensive? Bullshit, here it's over one €vro per litre.

3. Fish eat, they digest, they crap, and other fish eat their crap and do the same. ("Dirty Jobs" on Discovery). Then the second group of fish are fished out after having fattened up, and sold as human food.

3. Hyperprogramming. Processors read programs and execute them over data, chomping it up according to the programs. They crap out new data and heat. Scientists are looking for new computing models and paradigms to help decrease energy consumption.

4. Pain. As years pass, pain settles down on the bottom of a lake, where it decays into mud. From that mud, beautiful water lilies grow and shine under a crescent moon.

testicles

2008-04-26T23:09:00.004+03:00

A very funny piece of news caught my attention today. Don't you just like the part with the North and the South? :D Apparently some Florida senator thinks truck nuts are offensive and must be banned. WTF? Not only that, but the guy owns a gun shop! :)) So basically, the way I see it, is: killing people is not obscene, but displaying a pair of fake animal testicles is. Way to go dude, way to go. See my previous post about some people having zero respect for life. Of course, people are hypocrites, and morality is just a word. ("Stop the world... ... Peace is just a word...") I guess to some people it is moral and ethical to own and sell guns, but it is unethical to well, jack off to porn, kiss in public, or stick some plastic balls on your truck.
Here in Romania most people are Christian Orthodox, meaning we start celebrating Easter this night. One of the bigger TV establishments here is running an entertainment show intended as a fund raiser to help some sick kids who need a ton of cash to well... live. You dial a number and donate $$$ if you like the stars' performance. The $$$ go to some kids who need surgery. One of the kids needs a treatment based on stem cells if they are to well, live. Of course, one can't treat people with stem cells in the 'civilized' western world anymore, because it's illegal. They have to do it in China. Why? Because some people think they have the moral authority to decide who lives and who doesn't. Because they don't necessarily value life, but they have to appease the vocal fanatic hypocrites who don't know shit about anything but feel they have the answer to life, the universe and everything else in some book or text or judgment or something. Whatever. Go on preaching damnation, salvation, environment, cloning, genetic engineering, global warming and nuckular \/\/ar while I go eat a sandwich or something.

war

2008-04-23T10:42:00.004+03:00

Laser pointers have been banned in "some Australian state" after a number of idiots pointed them at aircraft cockpits. Now, the article isn't very clear on wether all laser pointers are banned, or just high-powered ones that can really blind pilots. For instance, the crappy ones that I can get here for around half a buck couldn't blind anything more than 10 meters away. So instead of just arresting and convicting the idiots who endanger passengers' lives, the state just bans laser pointers alltogether. What next, banning forks because one can stab people with them? Should we eat with Chinese sticks then instead of forks? What if someone finds a criminal use for chopsticks then? Eat with our bare hands of course. Then someone uses their hands to beats up somebody else to death and we all get to wear little remote-controlled collars that give you a paralysing shock whenever the state says so. Maybe that would be good. But until then, what if lasers get banned in my country as well? Maybe I want to build a long-range laser data transceiver. Will I be able to do so without a license in 5 years time? Will I be able to get a license then? Will a high-school hacker with reasonable technical knowledge but no engineering degree be able to get such a license? This sucks.
Then I learn that Hillary Clinton, who is ugly, said that the U.S. could wipe Iran off the face of the Earth. Well of course they could! The U.S. can wipe anything out, including the whole planet. So can Russia, and a couple other countries can do some serious damage. We all know that. Do they want to wipe everything out? No. There was no Cold War, there was no Cuban missile crisis, in my humble opinion. No one in their right mind would have launched their nuclear arsenal against another nuclear power. It was all just bluffing and political bullshit, regardless of what the press or Discovery says. But I'm probably wrong. I was walking through the Polytechnic's campus this morning and I was thinking... scientists don't understand life, and maybe it's good they don't. When humans understand something, they tend to devalue it. For instance, we (the civilized world) no longer attribute lightning to some gods being angry, and we no longer fear it and sacrifice animals to calm the gods down or something. Well. Kind of. So it's lost its value. Now it's just a meteorological phenomenon. Yeah, some may find it beautiful, sure, but it's not divine anymore. Its value has diminished. Solar and lunar eclipses, same shit. Sure, there are still a lot of uncivilized or semi-civilized people who hold a wide variety of beliefs regarding these, so these phenomena have a much greater emotional value to them than to us. Steam engines (think the ancient Greek spinning ball that was used for magic and stuff). Whatever. So when we understand life, when we begin engineering life in the lab for good, then we'd have lost all respect for it. Of course, big political leaders never had any respect for life. Think Hitler, Stalin, the Crusades, the World Wars, the Roman, Otoman, British, Spanish empires, whatever. We can wipe Iran off the face of the Earth, sure. Yeah I also hate oppresive regimes, I hate oppresive cultures, but you can't just kill everybody who's not as civilized as yourself from certain points of view. Maybe they're more civilized in ways you fail to see. And finally, maybe there are space aliens out there who are far more civilized than we are, and they don't go around killing us just because well, we suck. And until the U.S. and Russia and France and the others scrap all their nukes, they have no moral right whatsoever to accuse Iran of wanting to have their own. Fuck Iran, fuck the U.S., fuck Australia, fuck the human race, peace already.

earth hour

2008-03-30T00:09:00.003+02:00

This Saturday some idiots and newspeople asked me to turn off the lights for one hour, along with Sydney and some other big cities that were going to do the same thing. Images of people sitting at restaurant tables around a candle as the lights went off flashed around the TV screen all evening long. "Turn off the lights and use candles" seemed to be the message. Well, that's insultingly stupid. That's not an invitation to decrease pollution, but an invitation to return to the dark ages! Don't get me wrong, I hate pointless artificial lighting. I absolutely hate not being able to see the stars and other astronomical objects because of all the fucking lights. Who the hell needs lighting at 2 am in the night? That's a total waste of electricity and a fart in the face of all astronomers and stargazers everywhere. But candles? Let's take a look at the luminous efficiency of candles versus modern lighting. The humble incandescent light has a terrible efficiency of only 2.5%, because of all the thermal radiation it emits, only a small part is visible. The more advanced fluorescent gas-discharge lamp can reach 15%. LEDs are currently worse, contrary to popular belief. Low-pressure sodium vapor lamps can reach 27% efficiency, which is huge. They have an added advantage of being easily filtered out when doing astronomy, because their yellow color has a very narrow spectrum. Take a power station efficiency of let's say 10%, which is a very, very low estimate, stick an incandescent light bulb at its output and you get an overall efficiency of 0.25% from coal or whatever noxious fuel you're using to pure light. Now take a candle and burn it, releasing carbon dioxide, carbon monoxide, soot and useless heat into the atmosphere, get an efficiency of about 0.04% (so that's more than 5 times worse than the most inefficient coal-to-light technology in current use) and brag about how great an environmentalist you are. Then smell your farts and comment on their exquisite flavor. Then exchange farts with all your brain-dead environmentalist friends who don't know shit about physics, chemistry or biology and brag and lick each others' asses. And celebrate Earth Hour.

the drunken man problem

2008-03-19T12:03:00.004+02:00

The Original Drunken Man Problem

A drunk man is standing next to a pole at moment t_0=0.
At each moment t_s,k = k * tau the man takes a step in a random direction.
Find the most probable distance between the man and his initial starting position at time t.
For simplicity assume a constant tau = 1 second and all steps equal to 1 metre.

Elaborating on the Problem

An inebriated individual stumbles out a bar at moment t_0=0.
At each t_s,k = k * tau the guy takes a step in a direction given by angle alpha.
Every p steps alpha changes to a random direction then remains constant.
p follows a Poisson distribution with lambda = 4.
The distance travelled during one step follows a normal distribution with mu = 0.5 m and sigma^2 = 0.5 m^2.
To complicate matters further, upon colliding with the bar wall a new alpha is selected.
Find the most probable distance travelled at time t.
Then assume a normal distribution for tau too.

science fiction

2008-03-08T03:35:00.009+02:00

"Captain, we've lost optical output in the converters in room 100!"
"My god! The molecular reactors cannot function without sustained input from room 100! The life support systems are in danger! Not to mention the crew being unable to perform their duty without proper environmental conditions in the waste dispoal facility!
"I agree, the situation is looking pretty grim. What should I do, Captain?"
"Quickly, energize the emission coils!"
"Coil temperature is reaching 3000 Kelvins, Sir."
"Good. Now decrease the converter frequency to get closer to resonance."
"Decreasing operating frequency 35%... The positive-coefficent thermistors are heating up. No-go, sir. The power controller has detected an overvoltage in the resonant circuit and is shutting down."
"Yellow alert! Everyone prepare for emergency biostasis in case of environmental failure. Officer, reset the controller, move the frequency back up and wait for the thermistors to cool down."
"Done. The emission coils are operational. Increasing field strength to 900 volts per meter."
"Are the atoms responding?"
"Yes, we've got arc ignition. The resonance point is dropping... Hold on, the plasma is getting unstable! It's oscillating chaotically on a subsonic frequency! I can't keep it going! It's out, we've got another overload!"
"Reconfigure the overload threshold to 120% and retry the ignition sequence with a 30% increase in the ionizing field."
"Yes sir. Heating up the emission coils... field is increasing... we've got ignition... no, the plasma column is not holding."
"Try again with 50% field increase for 5 seconds."
"Trying... the protection network cannot hold much longer with all that power coming from the resonant circuit! We've got to get that plasma to increase in density or we're dead!"
[Officer 2 enters command deck] "Captain, the life support systems have shut down! The bioreactor has run out of input material! We need the crew to start shitting NOW!"
[Officer 3] Yes, besides, I can't hold it in much longer! We need to get that damned toilet fixed!
"Red alert! Everyone to the stasis cells now! Prepare for immediate hibernation on my signal. Officer, increase average power to 175% and switch to discontinuous mode."
"The pulse capacitors won't tolerate 175% sir. That's way over their nominal rating! We risk losing the entire converter assembly!"
"I'm willing to take that risk, officer. Quickly, short-circuit the output divider! Decrease the feedback ratio in the boost converter! Adjust the inductive reactance! Lock on that phase! Enhance those FETs!"
"Disabling overload threshold... Increasing main voltage... Setting target frequencies... Yes, we've got constant output! Decreasing power to nominal... Plasma is holding Sir! We've got optical output!"
"Good job, officer! Cancel alert. Everyone report to room 100 in decreasing order of intestinal discomfort. Go get yourself a beer officer!"
"Thank you Captain!"
"Captain's log supplemental. With the optical converters in room 100 fixed, crew morale is better than ever and everything is back to normal. These happenings have delayed our mission to Sirius 5, so unfortunately we missed our chance to meet Ambassador Kuux. Ironically this might have come as a blessing to us, as we learned from a Karbazian subspace transmission that Atheist
terrorists suicide-bombed the Agnostic conference room where the meeting was taking place. They detonated 300 micrograms of superfluid qvadrilithium crystals using a modified antiselenium primer. Both are undetectable to Karbazian bosonic spectrometry scanners. We sent our deepest most sincere regrets to the people of Sirius 5, but we sure are glad our asses weren't fried in the blast. Thus life goes on aboard the Sputnik V, leaving one to wonder just how has humankind evolved over millenia from flesh-eating, spear-wielding top-of-the-foodchainers to space-travelling woosies who won't even take a goddamned shit if there's no light in the toilet."

You will not

2008-03-05T04:08:00.003+02:00

(spam me)
an essay* to ruin your day :D
*based on a true story.

You will not advertise anything I might not be interested in when sending me e-mail. I hate spam.
You will not use big fonts and bright colors for it. I hate spam.
You will not send me mass instant messages. I hate spam. Each message incurs a 3-point penalty with a 2-day exponential decay constant. 10 points and you get banned. No questions asked.
You are allowed to do whatever you want in your personal space: the status text.
But only if it's not scrolling or otherwise updating every second, flooding me with useless packets. I hate bandwith-munching spam. You get banned. No questions asked.
You will not post pictures when your comment on my web pages. They (a) will probably ruin the color scheme and (b) will almost certainly ruin the layout, because Web 2.0 sucks and people writing Web 2.0 CMSes and layout templates don't care to think of stuff like: hey, what if some guy posts a 1000-pixel-wide image here? I hate web sissies. And spam.
You will not send me animated xmas e-cards lifted from the web, chainletters, pictures of dogs or bunnies or whatever, jokes (I hate bad jokes) or anything else. I hate everything, and spam. You get banned.
You will not send me docx files.
You will not talk to me.
You will not look at me.
You will not talk about me.
You will not think of me.
You will pretend I do not exist.
Or else.

factoring the time

2008-02-20T04:04:00.002+02:00

$ watch -n 60 factor \`date +%H%M\`

http://xkcd.com/247/

lambda * delta = crap

2008-02-13T04:57:00.006+02:00

I was wandering aimlessly through the murky waters of the interwebs having forgotten my surfboard at home. After hours and hours of swimming around in the dark I stumbled upon this dude. From what I understood by skimming through the website, the guy is doing artsy spirity things using electromagnetism instead of classical stuff. Kind of cool because very few people do art and electronics and programming. So his scrying boards are programmable in Scheme which is supposed to be (his words): novel, highly expressive, dynamic, introspective, elegant, extensible, a {lightweight, mobile, active} means of describing worlds and processes, thus perfect for such stuff as scry-programming. Wow. So if you followed the Wikipedia link you might have seen that ugly lambda starring at you. After a quick skim through the article, I most sincerely can't find the elegance, expressiveness, beauty, simplicity or whatever this language is supposed to have. Before going to Wikipedia I first looked here, where else but the famous MIT. There's that damned lambda again. Why do people have to hail lambda calculus and build virtual statues and monuments to lambda calculus and kiss it in the ass like it's somekind of hyper-meta-rational godly piece of abstract shit? So I go to the big famous MIT and what do I see? A crappy black and white logo that's the most noisy logo I've seen in the last 6 months. (shiver!) Why can't people antialias their pictures? Is it so hard? Or is 1-pixel wide monochrome the new fad? There are tons of image editing packages out there that can do a proper picture resize, and many of them are free. But people still put out bad graphics because a)they're lazy or b)they don't care for proper sampling and quantization. Well of course they don't, they care for lambdity (lambdaness? lambdacity?). I took a quick look over the Scheme doxumentation on the MIT site and damn, I really can't call it simple, expressive, elegant, let alone introspective. But of course I can't argue about it not being statically scoped and properly tail-recursive, as its homepage states. So let's take the first decent example of Scheme code (is it called "code"? maybe it has some esoteric, intellectually pretentious name? am I perpetrating a terrible insult by calling it code and not self-referencing internally-reflexive external character-stringy description or something?) - so let's take this piece of code that's found on both Wikipedia and the MIT doxumentation and just post it here:

;;; The FACT procedure computes the factorial
;;; of a non-negative integer.
(define fact
(lambda (n)
 (if (= n 0)
     1        ;Base case: return 1
     (* n (fact (- n 1))))))

Man, now that's introspective!
The same code written in a proven, widely used, respectable, expressive language like C would sound a little bit like this:


/* If you do not know what a factorial is
 you should search it on Wikipedia or Google. */
int fact (int n)
{
assert(n >= 0); //jackass!
return n > 1 ? n * fact(n-1) : 1;
}

Much cleaner eh? Compare that to 1-2-3-4-5-SIX parenthesis. And their code screws up bigtime for negative numbers assuming n is a signed integer (I don't know, I hate lambda-anything, I suck), while mine doesn't. (Who would want to be using unsigned numbers by default anyway??) Mine also warns the careless programmer who feeds negative numbers to the factorial function. So not only is their canonical "hello world plus a little bit more" example ugly, it's also an infinite loop if my perfectly reasonable assumption of n being allowed to be negative as well as positive holds. Well, it might not be infinite because the hardware might not let it, but that's fucking bad practice. And after 5 more minutes of searching it seems that my assumption indeed holds, because according to the MIT documentation (- 3 4) gives -1. After another 5 minutes I opened up a GIMP script console and entered the code, then called the function with -1. It froze.

This more complicated example does the same shit but without (rather idiotically) wasting stack space with recursive function calls:

(define (fact n)
  (define (fact2 n m)
    (if (= n 0)
        m
        (fact2 (- n 1) (* m n))))
  (fact2 n 1))

Of course it has a pretentious name called proper tail-recursivity and Scheme is such a great, wonderful, revolutionary, INTROSPECTIVE =)) language for supporting it.
Here's the same shit in C, which also does not choke on negatives, unlike the code above.

int fact (int n)
{
int f;
for (f = 1; n > 1; f *= n--);
return f;
}

Fuck lambda calculus and fuck computational linguistics.

darkness

2008-01-26T04:38:00.000+02:00

God damn it, they've made black paint. Finally. But it's still not black enough.

computational linguistics

2008-01-14T08:28:00.000+02:00

I have a course on something that I guess resembles computational linguistics, for which I have to take an exam in 2 hours.
So what is text mining and data mining useful for? Building "a more intelligent Google" of course.
And what about an example of a malformed sentence? "The green, colourless ideas are sleeping furiously."

My New Hobby:
Confusing text mining web bots with ambiguous sentences.

"Would fine times be forever flawlessly falling through the fallacies of faceless fires!"

"John, come here!" "What now?" "I think the text bot got high on semantic tree cycles again!"

happiness

2008-01-01T06:10:00.000+02:00

I just realized upon opening the blog dashboard that the previous post had been the 100th.
Well, I was under the impression that this includes updates to previous posts to fix typos and shit, but no. It does however include one or two drafts whose content I'm not very sure about yet. So whatever, let's celebrate the new year with post number 101. Or number 100 if you think the new millenium came in 2000, which it did not.* By the way, there's a bank called "Millenium" here whose offices look more like beauty salons or something (which is not necessarily a bad thing, it's actually rather original). They kind of built "Europe's tallest Christmas tree" here in Bucharest. Well, it's not actually a tree, it's more like a regular steel structure that vaguely looks like a tree, and I find it very ugly, distasteful and ... well... not too tall actually. Nevertheless, when they lit it up for the first time on December 1st (which is also the National Day), 'bout 100 kilopeople rushed to see the kitsch. 'bout 50 kids got lost, people stepped on each other, it was mayhem, hell, chaos, whatever you like to call it. The square and its incident streets were flooded with people, traffic ground to a standstill, busses carrying people couldn't move anywhere, and of course people started ranting about busses being severely overcrowded and arriving way too late. So basically the whole city was fucked. "The tallest Xmas tree in Europe" they say. Some even doubt that assertion, but I couldn't care less actually: it's ugly, it's pointless and it's small. So big wow.
So happy new year, happy 100 posts and whatever.
If happiness were a piece of shit, would it smell like fresh forest soil?
---
*) You'd also number this post 100 if you were a reasonable computerist who liked their addresses to start with 0, but in this case you'd be celebrating the "binary millenium" in 2048.

black magic

2007-12-22T01:35:00.000+02:00

If you measure an optocoupler's output while driving its input directly from a 9-volt battery, you get a 2-leg transistor.

laugh! ha ha ha!*

You can still use it as a temperature sensor or maybe even as a radiation sensor.

"Merry fucking Christmas!"**

---
*) I HATE those movies where they insert laughter in the background whenever some idiotic underpaid actor recites some funny line. It's an insult to my sense of humor. Is it like, am I too stupid to figure out for myself when to laugh and when to go take a shit? Good comedies never insert that stupid laughter. Only mediocre ones that target mediocre people need to.
**) a famous quote by Mr. Garrison.

environment2

2007-12-20T15:51:00.000+02:00

As I said before in posts such as this, fuck environmental fanatism. People are part of the environment, they're part of nature, they're not above it. They can't objectively protect it or destroy it, they evolve with it, they go with it, they live and die within it. All toxic materials created by human industry come from the Earth (where the hell can they come from, outer space?), so they're part of the environment. Everything on this planet is part of the environment: stones, critters, humans and all the tools and crap and toxins they produce. We're not hurting the environment with anything, but we might be putting ourselves in a position of being evolved out of it a as species, I mean killed and re-integrated into it as dead molecules. Species go extinct all the time and that's a natural thing. So quit worrying about stupid panda bears that don't like to reproduce and small furry mice whose 20-head population count doesn't really influence anything, and start worrying about yourselves. This guy says it perfectly and I totally agree with him, with absolutely every word and sentence. And he's funny too.

math

2007-12-18T18:31:00.000+02:00

This article claims that monkeys are just as good at math as college students. Well, 'mental math' at least. I saw a documentary once where chimps would remember a sequence of numbers at least two times better than an average human. Of course we like to claim we're the best and shit, but think about this: it's pretty normal for college students to be as dumb as monkeys, given the fact that certain 'big' and 'famous' colleges teach courses about... how iPods allow you to create a personal music library.

cbjts

2007-12-14T06:13:00.000+02:00

CMOS integrated circuits are almost exclusively used in modern computers and stuff because they're small and profitable. They also sometimes consume little power when doing nothing.
Digital circuits using bipolar junction transistors are usually TTL, and sometimes ECL, maybe even IIL.
But BJTs can also be arranged just like MOS devices. I mean, why not. So without further ado, here is a CBJTS inverter:
(Complementary Bipolar Junction Transistors with Schottky).
The Schottky diodes can of course be omitted, but they make the circuit faster.
I shoud really build some of these when I find some time, as simulations tell me it's interesting. Apparently it can switch in 20 nanoseconds, works with a 1 volt supply and draws between 1 and 2 milliamperes depending on temperature. I guess the supply voltage needs to raised a little bit above 1V if multiple-input logic functions such as NAND are to be implemented in the same way they're done in CMOS.
Anyway, it should be fun. Just try to pronounce "cbjts". It sounds and looks cool.

evolution

2007-12-12T12:48:00.000+02:00

British religious leaders urge people to cut the crap regarding Xmas. They're not OK with people trying do de-Christianize and neutralize Xmas for the sake of "religious equality" and "political corectness". That's right. It's not called Winterval (idiots) it's called Christmas and many people celebrate it just because it's a nice holiday, eventhough they're not Christian. Now that's a good example of sensibility and reason versus fanatical idiotic political-corectness.
On the other hand, "biologist" guy sues employer for firing him for being an evolution-bashing, close-minded, bible fanatic. Good. I hope he loses. So this is the difference between religion as a positive element in human life, that gives hope and meaning and motivation, and misunderstood religion that dumbs people down, and misused religion that's used as a pretext for war by people that have no connection with moral and ethics whatsoever.
My comments on the second article:
Dude, you can see evolution in the test tube. Why do you think bacteria are getting stronger and stronger each year, while researchers are battling to come up with stronger and stronger antibiotics? Because bacteria evolve through natural and artificial selection. Wait, sorry, I forgot. Bacteria don't exist because God didn't create them in 6/7 days in the Bible. Sorry. Didn't mean to say that. Idiots.
Furthermore, humans have created artificial evolution using Machines. For example, Computers can be used to evolve all sorts of stuff in Virtual Reality. Such as antennas/ae for communications. All Hail Machines, Computers and Virtual Spaces. People have evolved electronic circuits on reconfigurable fabric, that outperform even the best human-designed circuits. They look tangled and mysterious. They seem to have parts that don't do anything, that are apparently separated from the main circuit. But take them out and the main part ceases to function, because they're connected in subtle ways that human engineers intentionally neglect, as those couplings are uncontrollable and weak. So the artificially evolved circuits almost look alive. They evolve to fit their environment perfectly and profit from all its resources. Their only downside is their fragility - change the environment a little bit, such as a few degrees of temperature, and they die. We're working on that.
Anyway, just as I can evolve circuits inside a machine artificially, life evolves "naturally" on Earth. So evolution really doesn't exclude God or other deities, it's just that most scientists are not interested in God because God is sometimes very hard to see or contact. There is no problem with that, the problem is with all the idiots and fanatics that interpret in a literal fashion some old texts that have no traceable super-human origin.

ho

2007-12-07T01:38:00.001+02:00

A Santa was fired because he said "ho ho ho" and sang "Jingle Bells", two classic Western Xmas emblems. This happened because the word "ho" is supposedly insulting due to its "American slang" meaning of whore.
First of all, it's not strictly American slang, it's American ghetto contraction.
Second, it's American "slang", not Australian slang, and the stuff happens in Austrialia. So I don't get it.
Third, a lot of words can have very different meanings, and unintentional double entrende happens all the time without anyone in their right mind getting offended.
Fourth, a woman that would get offended by a Santa chanting the well-known festive "ho ho ho" may very well have a good chance of either being itself a whore, or terribly sexually frustrated.
Fifth, a man that would ban Santas from ho-ho-hoing is itself an idiot that has nothing better to do to and chooses to take such radical and unwarranted actions in order to justify its salary.
Sixth, Xmas is almost as bad as Valentine's Pay.
Seventh, it's not 'the word "ho," which is', it's 'the word "ho", which is'. The comma inside the quotes is illogical, and due to very old, outdated reasons having to do with the mechanics of typesetting.
Eighth, it's probably correct to write "ho' ", but who cares anyway.
Ninth, "They're trying to kill the spirit of Xmas", said the man who was fired. Notice the logically-correct use of punctuation in my case versus the original article, but what spirit of x-mas?
In some unrelated news, some Indian court decides women are allowed to serve drinks in Delhi. What an impressive sign of progress. Maybe in 10 years they'll be able to be kissed by men on their cheeks. Maybe in 100 years they could actually marry whoever the hell they feel like marrying. Make that 300 years. Maybe in 600 years they'll be able to tell between actually wanting something and being educated to want something. It's interesting to see how in a country plagued by poverty and overpopulation, people choose to worry about stuff like this instead of increasing the standard of living or something. They deserve their fate. Everybody does.

decoupling

2007-12-03T05:03:00.000+02:00

I've been feeling horrible lately and yesterday's night out didn't help much. So I decided I had to pop something off the project queue and just do it. A night of testing capacitors revealed some interesting results. Here is the story:

Introduction.

Whenever you need to power electronic stuff you need a constant voltage source. Circuits are specified to work for certain supply voltages, for example 5 volts plus or minus 10%. Circuits also like to draw different amounts of current depending on what they're doing, and that's bad for the power supply, who must struggle to keep a constant voltage output as the current demand from its load varies in time. So what happens if the power supply is suddenly required to provide more current for, let's say, a processor that's waking up from sleep and starting to do some work. Or a light or motor or something. It's bad. It can't keep the voltage constant. The voltage will drop for a very short time until the supply can sense that through its feedback loop and stabilize it. If it drops more than 10% or whatever the design margin is, the circuits might malfunction. When the circuit is done working and reduces its current demand, the opposite thing can happen and the supply voltage overshoots for a short amount of time. It it overshoots too high, the load circuit is fried.
So how can we fix this? Well, it's very simple in theory. Don't change the load current abruptly, so the supply has time to follow it and compensate for its change and mantain constant voltage output. The simplest way to do that is to throw a capacitor across the load. If the supply is slow to respond, the difference in current will come out of the capacitor instead of the supply, and the voltage variation will be much lower and everyone's happy.
Because the supply voltage is now constant, it means that various modules can't talk to each other through the supply wires (which would be bad), so they're being decoupled. That's why they're called (supply) decoupling capacitors.

My Problem.

People have always recommended using many small ceramic capacitor near integrated circuits and a few big electrolytic capacitors. The idea is that ceramics take care of the higher frequencies (rapid current variations), while the electrolytics deal with the lower ones. For a long time I've been wanting to actually test the effect of different kinds of capacitors on a power supply that's required to quickly switch between two values of current. Now I decided it was finally time to do that.
So I took a piece of copper-clad board and cut some trenches in the copper, isolating two big islands for the power and ground nodes where the action takes place, and some small islands for the other voltages. I soldered a good-old 7805 voltage regulator with capacitors on the input but not on the output, and a genric transistor that would suck a little bit less than 100mA when turned on by a signal generator. Some ports for the control signal, oscilloscope and raw power input, some very tight construction to avoid "parasitic inductance and capacitance", and it was ready. So here's the schematic:
Notice the Schottky diode connected from base to collector á la 74LSxx. It diverts control current from the base to the collector whenever the collector voltage drops too low, preventing the transistor from saturating. That ensures fast switching.
So here is how the regulated voltage (that's supposed to be constant) looks like when current is switched on and off.
First, with no capacitor at all:
Notice the almost 2V undershoot and 0.5V overshoot. That's... quite bad.
Here you can see a zoom-in on the negative spike:
The oscilloscope samples at 100MHz, so that's 10ns between samples. The spike is just 3 samples. So it takes a bit of luck for its peak to coincide with the moment the sample is taken. Most of the time the peak falls before or after the sample, and the drop in voltage appears smaller than it actually is. You can see that in the first picture, where the drop is only around 1.7V, while in the second one I waited for a lucky sample and you can see the full 2V. Even after the spike is quickly dealt with, it takes a lot of time to compensate for the remaining half a volt. The same can be said about the 0.5V overshoot. I mean, 2 microseconds is a lot of time.
So I soldered in a 4.7 uF (microfarad) electrolytic capacitor, rated for 63V, and here is what I got:
The red trace is the control signal. The current is drawn when the control signal is high. You can see an enormous improvement: the spike is gone, the drop is now only 100 mV (20 times less) and the overshoot is only 50 mV (10 times less). But it still takes about the same amount of time to stabilize. Anyway, while the first case would almost surely upset 74xx logic circuits, in this case they'd function allright. With no ceramic capacitors, mind you.
Then I did something horrible. I desoldered the capacitor, which was soldered close to the board, and put in a new one, holding it with my fingers. Its leads were about 1 inch long, which is supposed to be a big no-no: long leads means inductance, which slows down "reaction time" and prevents the capacitor from absorbing rapid current variations, leading to the voltage spike you saw in the first picture. But it was not the case:
The 1 inch of wire did nothing noticeable, and that's in agreement with what the theory says. The oscilloscope samples at 100MHz and it's supposed to record signals at least as fast as 60MHz. How can you record a 60MHz signal on a 100MHz oscilloscope whose Nyquist frequency is only 50MHz? Figure it out, you most certainly can. So if, per Google, light travels 30cm in one nanosecond, it travels 3 meters in 10ns (that's 100MHz), which is much more than the 3 cm of the capacitor's leads. So they shouldn't matter that much.
Next I connected a 10uF, 16V tantalum capacitor. That's supposed to have a better frequency response than the usual electrolytics, as well as lower ESR (effective series resistance) - the stuff that limits how well it can filter spikes (think voltage drop over the ESR caused by the current you draw from the capacitor). It looks a little better:
It's got a weird shape now. Oh well.
Here's a 22uF, 25V electrolytic with short leads (it's 20mV/div as before):
Worse than the tantalum.
On all the pictures you can see the command signal feedthrough: when it goes down, the current is shut down and the voltage goes up temporarilly. But before the current is shut down and the voltage goes up, you can see a small downwards spike that's caused by the current injected from the command signal through parasitic capacitors. Because it's very fast, it gets through (it's coupled even through very small parasitics).
Next I connected a serious 100uF/50V capacitor with 1cm leads. You wouldn't normally want to use less than 100uF for decoupling a usual circuit. The improvement is clear:
Now comes a 470uF/16V one, which is a little better, but not by much:
Here is a 2200uF/10V:
And a bigger 2200uF/35V:
same, with 1 inch leads:
You can begin to see that indeed, very fast spikes are filtered by the electrolytics worse than slower variations. That's what ceramics are for. Long lead lengths do add inductance (especially on the bigger capacitors where the leads are spaced farther apart -- it's area, not length that gives inductance) and spikes do get noticeably larger. You also couldn't see the effect of leads on the first capacitor (4.7u) because, well, look: 500mV per division sensitivity there versus 20mV per division here.
So if you want to get rid of those fast spikes, electrolytics are by no means totally useless as some might say, but a ceramic does a better job, especially if it's a low-inductance SMD (surface-mounted device) that has no leads.
Here is a 100nF ceramic disc capacitor, rated for 2kV (it's quite big for a ceramic, 1 cm in diameter), with ~1cm leads:
Oops! :D It looks like the 7805 is oscillating when 100mA are pulled from it and a 100nF capacitor sits on its output. It's something that's mentioned in some datasheets, but not in all. Many voltage regulators are stable with low or high capacitive loads, but not with medium ones, and it also depends on load current. You can see some nice stability graphs in the TL431 datasheet from TI if I remember well.
The nasty thing is that it's a high-frequency oscillation, about 5MHz. It can go totally unnoticed if one doesn't have an oscilloscope, and low-frequency circuits would start acting in all sorts of weird ways. Plus, you don't want radio-frequency oscillations if you don't need them, because they could radiate and interfere with stuff. If they don't radiate directly from the circuit board, then signal and power wires on outside connectors are incredibly good antennas.
RF oscillation aside, a very important thing must be noted: no more fast (10-20 ns) spikes. You can see the fast voltage drop is slightly longer than with the electrolytic capacitors. That means better high-frequency filtering. But don't expect any low-frequency filtering from such a small capacitor - There's still a 1.2V drop.
At this point I soldered a 10nF SMD capacitor very close to the switching transistor. The oscillation is now much weaker, and you can see it's dying out - that's just my luck, the supply could have oscillated with 10nF just as well, and I would have had to find another value.
Notice the slightly deeper 1.5V drop (smaller capacitor), but still no fast spikes. It actually works better that the 4.7 uF electrolytic, which is almost 500 times bigger :)
Here you can see the steep drop that's not nearly as steep as with no capacitor:
The samples have been highlighted. It's at least 20 times longer.
Here is the 100nF ceramic added in parallel:
Interestingly enough, there's no more oscillation. Well.
Here's the tantalum added:
There's that strange shape again, and hey, there are spikes. They were always there, but just as with the 4.7u, we were looking on a 500mV/div scale, and now the filtering is so good we had to zoom in to 20mV/div and the spikes are now revealed. I have a suspicion that the spikes might be coupled inside the oscilloscope, which is also a signal generator and outputs the switching control signal. So I have to generate the signal somewhere else, but I already took all the screenshots for this article and packed all the stuff up before realising this now, so hell. I also really don't get why adding the tantalum speeds up the initial drop, it probably has something to do with the regulator, not the capacitor.
Anyway, here's a zoom-out with just the ceramic 10nF SMD capacitor:
Now here's the same, with a pulse frequency 10 times lower:
Damn it, it WAS oscillating :))
You can see two modes of oscillating, one high-frequency on turn-on and one low-frequency on turn-off. They both die out, but it's still not good for supplying a circuit.
Here are both ceramic capacitors:
Just as with the faster pulse repetition rate, the high-frequency oscillation is gone; but the low-frequency one persists, and it's interesting to note it's slower when both caps are added.
The tantalum capacitor kills it for good, but gives that weird shape on turn-on:
Here's a zoom-in of that:
Here's the turn-on for the "normal" 100uF electrolytic:
And the turn-off overshoot, complete with command feed-through spike:
Until now I've been switching between 100mA of current and almost nothing. This is quite hard for the supply to deal with, hence the 2V drop when the current was turned on with no cap.
So I added another 50 ohm resistor directly on the output, so I would switch between 100 and 200mA.
Here it is, with the 10nF SMD capacitor:
High-frequency oscillation with 100mA (strange, it didn't use to do that!), which ceases with 200mA (I was talking about stability graphs earlier). The effect might be caused by the fact that, as you let more current through a transistor, it becomes faster, and this happens inside the regulator chip.
The 100nF ceramic stops the oscillation:Here is the 10uF tantalum:
And here is just the 10nF SMD (first graph in this sequence), with the repetition rate increased 10x. It does look similar:
But it wasn't oscillating at 100mA before I connected the 50 ohm resistor! wtf? To answer, here's a graph after shutting down for 3 minutes to take a wee:
Yes, it's the regulator chip temperature. You can actually watch the oscilloscope as the chip warms up (it does get pretty hot with 150mA average current, significantly hotter than with just 50) and suddenly the mild, damped oscillation turns into the ferm one I was puzzeled by. Then put your finger on the chip and it ceases. Or just blow hard. Fun.
I took out the SMD cap and here is what I got:
and a zoom-in:
The spike dropped from 2V to a little over 100mV, as a consequence of switching 100mA next to the existing 100 as opposed to "suddenly waking up" the regulator in the first case. Also compare the graphs taken with the tantalum cap. The peaks are smaller in this case also.This is normal, and almost no datasheet specifies transient performance ("load regulation") with the current step starting from zero, just because their numbers would be awful :)
Next I had to debunk a myth related to electrolytic capacitors. It seems that electrolytic caps get worse as they get older: their capacitance decreases, their ESR increases, their ability to filter decreases. So I took some capacitors I had lying around that I had taken out of some old monitors for the specific purpose of testing them. Now the time has come! :)
I should point out that said capacitors come from a scrapyard and have been rained on repeatedly. The other components on the PCB had their leads severely coroded. Compare with fresh off-the-shelf 10uF tantalum and 100uF electrolytic seen a few graphs above.
1000uF/35V:
220uF/100V (higher voltage ratings supposedly have lower ESR -- good) :
100uF/100V:
330uF/250V (very big, 1 inch diameter, 1.5 inches long)
This last one was quite big, very light, and different construction from others. Obviously filters less well, but that's acceptable, I guess it was designed to sit in the mains input circuit.
Well, there you go. Dirty old rained-on electrolytics filtering very well, quite better than new ones I might say. Of course, if they've leaked or grown internal pressure, scrap therm.
Now to try some film capacitors. These are big, but designed for high voltage, high current use, and I guess they also have less leakage than electrolytics.
Here is a huge 1.5 inch, 3.3uF/400V from the same scrapyard:
I guess the capacitor itself is resonating and I'm getting those damped sinusoids. I can't be sure until I pulse it in a passive circuit.
Here is a smaller 330nF/250V with its leads spaced about 1 inch apart:
This also seems to shoot up when the current is increased, like the previous two caps, and unlike all others. I'll investigate this further some other time.

In conclusion: when in doubt, use a bigger capacitor.

tape

2007-11-30T21:19:00.000+02:00

My Hobby:
Diminishing double-glue-sided scotch tape by forming it into a Moebius strip.

olives

2007-11-30T21:07:00.000+02:00

I like olives very much. Do you know those olives that come in squareish plastic boxes with a thermally-sealed plastic film cover? I think I've gone through three or four brands and all of them have the same flaw. The plastic film is thermally sealed around the box edges, but on one or two corners the seal is moved inwards to allow you to pull the film upwards and open the box. I couldn't open a single box using this suggested method. All of them had their cover cut with a sharp knife. This is stupid. Why the hell do they provide opening tabs on the corners if the film is so tightly sealed it simply won't come off? One time I used a set of lineman's pliers to pull on the tab and it still didn't break the seal, it did however tear the tab. Piss-poor design.

so?

2007-11-24T20:01:00.000+02:00

Italian expert is skeptical of cave supposedely linked to Romulus and Remus, the guys who founded Rome in some famous legend. Well. After a boring read of the article, I can only say: So? So fucking what! Rome sucks anyway and I hate the Roman Empire being so praised and overrated.
Porno-prof teacher suspended, also in Italy. What does porn have to do with being a good teacher, if one maintains a proper attitude in the school, which seems to be the case here? I mean it's not like the woman was an exhibitionist or a pedophile, like that guy in dot-berlin who was let to teach in kiddiegarden. So why did they suspend her? Don't ask me. I don't know. I'd rather die than go to Italy.

the list

2007-11-22T23:31:00.000+02:00

I have a theory regarding the latest South Park episode. I'm terribly said because it's also the last in the season and I won't be seeing any more South Park till spring :| But still, I have a theory regarding "The List" and it goes like this:
Haven't you noticed that Abraham Lincoln's ghost has a striking resemblance, in its looks, voice and behaviour, to the Ghost of Human Kindness that abducts children? :D Well, I guess thousands of people saw that too, but I din't care to google so as not to skew my description.
So I was laying down comfortably watching Kyle plot to burn down the school, and the ghost of Abraham Lincon shows up and I'm like: Ohhh shit! :D He's going to abduct him now! :D Come on! Come on! Abduct him! :D But he did not abduct him, and I think I found the reason why: you see, unlike Butters, who ageed with the Ghost of Human Kindness after his instructive lecture, Kyle did not. He just went on to be a "fucking asshole".

misc

2007-11-22T23:00:00.000+02:00

miscellaneous shit.
1) i didn't have time until now to rant about how much halloween sucks. first of all, that's not even a name, it sounds too stupid and awkward to be a name. it sounds more like a kid's joke. a deranged, physically abused kid. second, treat-or-tricking is stupid. it encourages begging and property damage. it presents them in such a light as to make them seem acceptable. they're not. third, what's with all the ghost-vampire-werewolf-whatever costumes? if i were to wear black and white paint on my face, that would freak the fuck out of people. but on halloween it's somehow acceptable. there was some kid in some disco on tv: "i'm the cute blood-sucking vampire, excuse me, i have to hit on some more girls and suck their blood". i have only one thing to say about that: "do you like to eat red carpet?! do you like to eat red carpet?!" oh yeah :) fourth, fuck halloween, just another opportunity to spend money on shit. well, at least you're not being emotionally blackmailed to do so like on valentine's pay.
2) some misguided kids broke a world record in bucharest some weeks ago. care to take a wild guess? yes, they built the world's longest condom chain, allegedly to raise awarness towards aids. well, you could raise awarness towards aids by DISTRIBUTING condoms for free, rather than ruining them by tying them up and laying them down on the fucking asphalt! you should distribute condoms and informative flyers, not ruin perfectly good products worth at least as much as a truckload of beer. damn, condoms are too expensive! no wonder people prefer to drink one more beer and then go home and have unprotected sex, rather than use a condom and drink a beer less. and these kids ruined a shopful of condoms just to get some media attention. shame.
3) lack of toilets is fatal to approx. 2 million people each year. i knew that. i respect the modern toilet. it's humanity's greatest invention ever by far.
4) oppressed indian in malaysia sues britain for... 4 trillion u.s. bucks. good luck.
5) chestnut from anne frank's tree auctioned. at first i thought: who the fuck is anne frank, what an ugly name. then i googled and man, is this whole thing ugly. sad. ugly. sad. ugly. horrible. what if fascists in italy and nazis in dot-berlin were to rise to power again? heck.
6) as low as 4% of "charity xmas cards" earnings actually goes to charity. well, what did you expect. why the hell would i buy "charity cards" anyway? go see "filantropica". and while you're there, go see "the company" too. and yeah, just as the article says, read the goddamned fine print. "4% of earnings goes to charity". "drink our juice, it has natural ingredients, bla-bla. contains 0.2% fruit juice". true, legal, fair.
7) whatever, i forgot.

offensive

2007-11-16T05:01:00.000+02:00

This early morning I'm feeling very dark, cynical, uncaring, self-centered, rightfully judgemental and rightfully offensive. Again :)
To start, fuck Italy again. Don't buy Italian products and don't go to Italy. If you're Italian, consider doing whatever it takes to clean up your people's attitude towards the immigrants who support a good part of your goddamned economy. Or at least obey the damn fucking law.
Further, fuck dot-berlin again. Watch this: pedophile allowed to work in kiddiegarden. Way cool, keep it up. At least he didn't fuck the kids, but what if he had.
Fuck Japanese culture. Why the hell would you ban pictures of genitals? Is it like they're not part of the human body or something? Is it like they don't have as right a function as other body parts? Is it like I can drink through my mouth, but it's somehow dirty to urinate through my dick? Is it like I can play idiotic Japanese video games with my hands and feel some idiotic pleasure in my brain, but I can't somehow masturbate or have sex without feeling guilty? Furthermore, fuck their work culture. Remember the guy who derailed the train he was driving, killing a lot of people, because he was like 1 minute late? Oooh, the dishonor! Oooh, the shame! One full fucking minute, dude! Well, a former co-worker of his actually commited harakiri when his train was late some 40 seconds, so it figures. Also, fuck their writing. They have 2 different alphabets for writing words as syllables, and they sometimes do that on signs, next to the main text. However, they still choose to use ideographs, which is a plain stupid idea because of objective reasons: they're fairly complex to display, they're hard to alphabetize and sort, there's too many of the goddamned symbols, and it's a primitive, retarded system. In my exceedingly unhumble opinion. This also applies to Chinese. I was reading an article a long time ago, also on Oddly Enough, about some Chinese politicians having names that are spelled with some ancient arcane characters that nobody knwos how to draw or pronounce. Well. 26 letters is an idea too simple or elegant for you idiots to adopt.
Next on the list, Singapore bans video game for sexy scene. Well. Singapore rules in many ways, for example they employ corporal punishment on criminals. Bamboo sticks to the ass. That fucking rocks. Law and order, by reason and by fear. Unfortunately this philosophy has the side effect of reducing some personal freedoms, especially when it comes to sex, but so be it. Nobody's forcing you to live in Singapore. And being such a small country that has it so well, no wonder their politicians spend time banning video games for just one questionable scene, albeit a very sexy and exciting one - I mean, having not seen the actual game, just the mental picture I get from reading the neutral description in the article is very hot. And here I am, shamelessly praising a Microsoft product.
Finally, some tropical fishes can live out of water for months. Well. Nature sure is cool. Evolution wins again, Ha-Ha!
But wait. Now I'm also finding out that yesterday some Japanese welcomed the year's first shipment of Beaujolais nouveau by... bathing in it. Apparently the wine needed to be poured in the pool by a sommelier. Well. Sometimes French does have a certain liquid quality to its sound.

discrimination

2007-11-11T02:47:00.001+02:00

Once I read some label/advertisment/whatever that had an intersting notice: "Foobzbar is an affirmative action / equal opportunity employer." At the time, I viewed that as a very positive thing and discussed it with people: look, this is civilized. Foobzbar is (at least in writing) a modern company. They specifically state they don't discriminate. Bla-bla. Then I learned what affirmative action really means :) When I first read the notice, I thought it had something to do with you getting promoted based on your merits. Man, was I fucking wrong. As can be read in the Wikipedia article, it's nothing but positive discrimination, and in many countries it's unlawful. Yes. Illegal. Like all kinds of discrimination should be. I don't even find any merit in commenting any further.
I will however comment on the current events in Romania and Italy. It seems some Romanian guy went to Italy (a lot go there to work an pay taxes, and a few go there to steal or beg). The guy allegedly robbed a woman, beat her up and raped her. She later died. Of course the press, being the shitpresser that it is, erupted in anger towards all Romanians, as if some guy committing a crime makes me a criminal too. Then it seems the woman wasn't actually raped, just violently robbed. So all the posters put up by extremists with emotional crap like "how can you look a raped woman in the eyes" and bloody crying faces were left without merit. Whatever. Discussions, talk shows, prime ministers meeting, shit for the press to feed on. I don't even care. I went to Italy once, and well, big deal. I'm never stepping there again. I mean, I heard some guys speaking Italian in the subway. Should I have started yelling "Booo, mafiozzi! Pizza spaghetti! Francesco Pazzi!" ? No. But Romanians are now genuinely afraid to speak Romanian in Italy for fear of being assaulted.
This being said, here is my short essay on why I don't like France but France is OK, but Italy sucks.
There's a flash film that shows why. I've last seen it some good years ago, so I had to google for the link. I wanted to search for "italy eu flash". Oddly enough, after typing f I got a suggestion for just that, and the first hit had the film I was looking for :D
But I have to add some stuff.
1) I visited some famous museums there, and most of the statues had their penises chopped off. Ouch. How very Latin, I should say.
2) The Pope lives there. The Pope is anti-progress, anti-freedom, anti-sex-ed, anti-everything and they should put a rabbit in his holy place. Italy gave the Pope his seat back (a whole state!) in the early 20th century (fuck Roman numerals), plus some money, when they could have chosen not to do that. They should have told him to respect their authority and shut up. What? You want a state? Ha-ha. No. What do you mean you had it before? So? The Dacians had their state untill we conquered them in the 1st century when we were called Romans. And now that the Roman Empire has fallen apart they're called Romanians, otherwise they'd still be under out authority. No. You don't get your state, beat it.
3) The Roman Inquisition
4) The Roman Empire
5) Electricity plugs :)
Look. Look at this map. Do you see? Do you SEE? :)
Roughly above the equator is the civiliz-pardon me, relevant world. Well, count Australia in too. So, what do you see? You see America in purple and Europe + Russia in green. Those are the two main standards for electricity plugs. Let's analyse. I belong to the green majority, so I can safely say I have "normal" plugs :) Like the one currently on top-left of the Wikipedia article. America is America, they have their own standard, it's OK. Who's gonna argue :) Japan uses the same type apparently, so that makes it even more OK. Of course, one can always use two stripped wires, two matches and a 100-250V AC/DC-to-DC universal supply and plug into every plug in the world, but that's dangerous and maybe illegal. There are all sorts of adapters, but I'll intentionally ignore that due to the fact that man, I forgot it at home! So this discussion is perfectly warranted :) So there's the American plug, and the "normal" Russian plug. Then there's the British plug which is well, British. That's also OK. I mean, they have the pound instead of the euro, they have a queen, they're British :) They have every right to be particular about their heritage, language, lifestyle, weather, and electrical plugs. It's perfectly acceptable, because they're British and London, unlike Rome, is a really cool city. And then there's Italy, where plugs have three pins and don't fit in the rest of European sockets. However, some European plugs do fit into Italian sockets ha-ha :) So when you, the fascist Italian, travel abroad, your plugs won't fit. They won't fit anywhere else in the world. That's because they're Italian. Ha-haa! That's what you get for being Italian, loser. Think twice before discriminating against my people, asshole.
Peace brothers.

news

2007-11-11T01:37:00.000+02:00

I usually read Oddly Enough just for the sake of irrelevant stuff that happens around the world.
The first article I will point you towards is, of course, about death. It seems that some Canadians have the correct attitude towards death, their tombstones engraved with witty last words. This caused me a lot of trouble. Usually when I think of some stuff that's "so cool, man!" I can't wait to have it done. So now I can't wait to die and have "Goodbye, and thanks for all the fish." written to my tombstone. That's so fucking twisted. No! And usually when I can't wait for something, time starts going faster. No. I want to live! I've got stuff to do here, God damn it!

The second one is really nice. Pure urban poetry.

And finally, it's official: you don't have to live in France! :D
___
*) I don't like France. I don't like words having genders (especially when those genders are different from my own language -- like, is this a gay fork or what?). I don't like using the plural of "you" as a mark of respect, even though yes, I'm forced to do that here also. (What's with some people here addressing their parents with the polite plural form of "you"? Is that your idea of teaching kids about family ties, parents?) I travelled on both Boeings and Airbuses and only the latter gave me an allergy from whatever they were freshening the air with. I don't like the French calling computers "ordinateurs" when "computer" is a word of Latin origin. I don't like the French Wikipedia page saying that ordinators interface the environment through peripherals such as keyboards, screens and modems. That sounds straight out of an eighties textbook. I agree it's true, but sincerely, a network card or mouse would be more widespread than a modem as of 2007. I don't like the same page describing a computer's insides in a style reminiscent of a seventies textbook. For instance, a modern bus isn't made up of address, data and control lines anymore. Hasn't been this way for at least 15 years. Oops. Let me check the real page to see if that's also written there. Nope :) And it's also more fun and informative. People don't read Wikipedia to learn that computers have a CPU and a modem. They read Wikipedia to learn about interesting aspects in the history of computing, about various contemporary achievements, to see a picture of a computer inside a watch, to see a punched card or an ISA slot and understand that's history, stuff like that. I don't like the French Wikipedia, just as I dislike all its other local variants. I don't like the French being so fanatical about their language, though the dot-berliners get first place for this. For example, the article mentioned above is about ordinateurs, but they contain cache memory, not cachée as would be appropriate French. Screw this. I also think the French Revolution is a bit overrated. I like France for using nuclear power and for having nukes and the balls needed to keep them, I don't like France for anything else. And all the new Peugeots or however they're spelled seem to be laughing at you with a dumb grin. In fact, some other new cars seem to be doing that as well. So to be fair, I should point out that bad taste is in the eye of the beer holder, and irrespective of nationality.

podding

2007-11-11T00:49:00.000+02:00

How seriously can you take a university that teaches classes on iPods? Really! :D I mean, ... listen to this: "... for the first time allows you to create your own auditory world bla bla" What? I mean doh. This is what you're teaching university students? I mean, I would feel intelectually insulted if someone attempted to lecture something like that to me. Well, actually I did a couple of times, but that's another story. Dude! What kind of university students are those who can't figure out for themselves that a music player coupled with a digital music library/store allows you to create your own auditory world? It's silly to have a course about that, and it's discrediting to the university, at least in my view. But then again, I guess they have a lot of courses on even more trivial subjects. So it's no wonder that a lot of people who claim to be experts in some field actually have little idea of what they're doing. Take the music "industry" for instance. When Steve Jobs launched the iPod and iTunes, he had to work hard to convince them to allow music to be bought off the Internet. Then he had to work even harder to convince them to allow the purchase of individual songs rather than full albums. The man knew what he was doing, and the enormous commercial success of his idea is proof of that. But people who counted and who should have really known better didn't initially approve of his idea, and that was plain stupid. I mean, here is this huge economy ruled by people who we're supposed to credit for its functioning, right? We should trust that they know what they're doing, that they do everything to ensure that everything goes well. Hell, this is so stupid. One day a man comes and states the plain obvious -- you're doing it all wrong! This is how it should be done! And it works, and the numbers speak for themselves. But it took someone like Jobs to actually implement such an idea, not because it hadn't been thought of before, but because he had the necessary charisma and influence. And one might think that "artists" (I somehow hate that word in its modern meaning) should be, well, you know, smart people. They should feel the world around them, they should be aware of their fans' opinions and feelings. But no, you had big names saying that no, albums are "thematic" and shit, and they should be sold as a whole, not broken up into songs. Why? Probably because the record house said so, and that's degrading to an artist's status. Everybody knows that people like to select the songs they listen to and build playlists and shit. It's been done that way for a long, long time, ages before the iPod, with MP3s. But some are unwilling to acknowledge that. I mean, people buy CDs, the companies get their money, then they vocally bash illegal downloads (which probably got the buyer to buy the CD in the first place), and it kind of works, so why actually encourage legal downloads? Why offer a service that actually fits like a glove over what the users actually want? I mean, if the billions are pouring in, then fuck the consumers, as long as they consume. Right.

computing

2007-11-04T23:10:00.000+02:00

Homebrew computers. Some people like to build their own computers as a hobby. I don't mean buying subassemblies from computer stores and sticking them together in a case, I'm talking about building the actual boards, and designing and building CPUs from discrete chips. You can see dozens of CPUs and computers built out of TTL chips on the 'net. They have varying degrees of performance, but none can match a modern computer, of course. That's not the point. The point is building your own computer for fun and for learning stuff. One of these discrete TTL chip computers (designed and built by a guy who also did 'real' integrated CPUs as a job) runs Minix and is comparable in performance to an early 8086 PC. Others are notably less powerful, but as I said, that's not the point. The point is, it's a computer built from cheap, very low tech, off-the-shelf parts that have been widely available since the 1970s. I mean, in case of apocalypse, maybe ultra-high-tech semiconductor fabrication facilities may not be available anymore, but simple TTL chips can literally be fabricated in someone's basement with some little investment. Sure, they're slow, but who cares. We don't need luxury in order to survive. We need food, a roof and maybe a toilet. A flushing toilet would be a rare and highly prized item in such a scenario. Similarly, computers need not output high-definition DRM'ed video streams on wide screen monitors. Postapocalypse, we'd be OK with a command line on a mechanical teletype. Low-resolution graphics on some old rugged TV would again be considered luxury. And that would allow us to quickly redesign the old technology, if resources and politics allowed.
But even if this postapocalypse scenario is kind of stretched, there's still the cool factor, the DIY factor and the learning-all-by-yourself factor. So any criticism of this kind of endeavors is pointless. However, I mighs have some suggestions.
1. Why use 74LS chips? They're slow as hell. I mean sure, it works with 74LS but it also works with 74S which are much faster. Sure, they burn more gas, but who cares, it's a hobby not a mass-produced consumer item. Sure, they have to be laid out a little bit more carefully, but it can be done. Well, there are many reasons. First, as stated before, raw speed is not the ultimate goal, because you don't use these for actual 'work'. So yeah, one could say "I built it with 74LS because those are cheaper and more widely available, it works, it can theoretically be done with 74S but hell." and that's correct.
2. Why not PLDs? CPLDs? FPGAs? Because, that eliminates the physical work of making/wiring a lot of boards and soldering in the chips/sockets. Sure, it's faster to design, it runs much faster because it's all integrated in one chip, and that's why it's done this way in the industry. But this is hobby! :) Then, it's also harder to debug because you can't just put an oscilloscope or voltmeter anywhere in the circuit, it's integrated! There are ways to work around that, but it's less 'hands-on'. This being said, there are lots FPGA-based computers built by both amateurs and professionals. There are free soft-processors and peripherals that you can compile and download into FPGAs or even make into hard chips, on opencores.org.
3. Why not transistors? I mean, if you really want to DIY, and do it hands-on, so not inside an FPGA, why use TTL chips and not discrete transistors? That's cheating! :) Transistors are much easier to fabricate even than TTL chips, and there isn't any hardware that's lower-level. Sure, you can build a computer with relays, and for that you only need iron and wood, but that's to big to DIY in your house. Transistor boards would of course be much bigger and take much longer to build than equivalent TTL chip boards. So there's a point. But there's still no better way to wipe off the aura of 'black magic' that surrounds computer internals other than building one out of simple transistors. They have just two main terminals and a control terminal - no chips, no mysterious black boxes. And you could attach LEDs and see the bits flow.

So I'm officially launching a contest. Whoever can design a Brainfuck processor with the least number of transistors wins the respect of hardware hackers worldwide. Nobody cares about speed, area, or cost, it just needs to be Turing-complete. This is hobby. Also, nobody cares on how many bits you encode the instructions. They don't need to be ASCII, just have a 1-1 mapping to Brainfuck. Oh, and no scientific papers can be officially published on it, because it contains the word fuck. Thankfully.

laughable

2007-11-01T03:57:00.001+02:00

Stuff that's laughable.
1. dot-berlin. So not only do Germans hate speaking English (well, many of them at least), not only do they oppose reforms by the EU, but now they want a new TLD for their capital city =))
So, what if, London wanted .london, and Paris wanted .paris, and New York wanted .new-york, and then some other special-interest-group from New York wanted .newyork because it's shorter, and what if then someone from Bucharest where I live wanted .bucharest? Then what if we would require .baneasa, .berceni, .militari, .muncii - areas of Bucharest. Do that with every major city in the world, and we would have tens of thousands of top-level domains, just because .berlin.de isn't enough. And we would have to do that, because we can't discriminate against other major capitals or cities just because Berlin speaks Deutsch and has some Communist wall. On a related note, now that .cat has been approved and some other significant linguistic groups are requesting their own TLDs, maybe they can also assign one to each of those decrepit languages that are spoken by 20 to 50 people and were once heavily advertised on the Discoveries during breaks. So maybe they'll get contempt with having like, between 0 and 3 sites and advertise their decaying culture there, and stop trying to take over my mind 3 minutes at a time. Like I should somehow get impressed and maybe donate half a penny so they could further raise their children to spear-hunt animals and sing 3-note songs when there's microelectronics, quantum mechanics, molecular biology, macroeconomics and western music to study, among lots of others. That's fucking annoying, and pointless. So fuck .berlin, fuck .mobi, .museum and other dots, fuck trying to save endangered species consisting of 0 to 5 individuals, and fuck daylight savings.
2. Fuck PPPoE.
3. Fuck wisdom teeth
4. Fuck neckties (the most useless object ever invented)
5. Fuck daylight savings
6. Fuck outdated medicine
7. Fuck leaded gasoline
8. Fuck fuckedee fuck fuck fuck
9. Fuck daylight savings
10. for sale: Cat-5 Ethernet cable, 20m, IPv6-compatible
11. that's all.

lameness

2007-10-30T06:55:00.000+02:00

I saw some lame TV show (guess where) about how they "caught" some Internet cracker who stole some "sensitive information" or something. Of course, he can't be extradited from Argentina or wherever he lives to the US, even though they have a warrant for his "misuse of a computer" (LOL), because well, "ha-ha". The funniest part is how they "caught" him, I mean, found his identity: he boasted in some chat room, and then the investigators used "powerful Internet tools, called Internet search engines" to look up his alias or something, and then found his posts on some forum. Hell yeah. I remember when I was in high school in the computer lab and bored to death and the admins or however they were called left some passwd file on public ftp, which I of course opened, because it was public, unrestricted, unprotected and even without a notice stating that I am not allowed to "go there". I later learned that I had misused the computer, as the admin came steaming into the computer lab, IP logged and matched and all - "Did you look into the passwd from this computer?" "Yes." "You're not allowed to do that." "Really?" Of course, being public, open internet-accessible ftp and all, I took the liberty of downloading it all from outside the building without the guy lecturing me about what bits I am allowed and prohibited from sending into his network port. This happened some days later, and the files still had not been removed from public view. I vaguely remember also finding some winDOS .pwl files (oh, the old times) which, unless fake, were indeed crackable, unlike the passwd which contained no actual password hashes. And now I'm wondering, was that some kind of honeypot or plain stupidity?

colo(u)r

2007-10-28T06:31:00.000+02:00

Having cooled down after the spontaneous daylight savings ranting, I am now ready to rant about my original intention.
Just like that idiot William Willet, who was a philologist / builder, and should have had nothing to do with time, some people think they can somehow transcend science and push bold ideas such as black and white not being colors. Some of my art teachers in school did this. Fuck art. Art is spontaneous and creative, it's not something you teach. If I want to paint red next to green next to blue next to dark gray because I feel so, you don't have to come and tell me it's wrong and the colors don't match and it has a weird, heavy feeling. Maybe that's what I want it to be. Oh, and I also don't care about anything. I remember when I was in childrengarden (sic), and the teacher made us paint some stuff on a sheet of A4 paper. Each one's sh[i|ee]t was then posted on a huge panel for public display, and they were all sorted according to 'value'. Mine was of course last, because it consisted of an entirely black sheet. To this day, I take great pride in the fact that my sheet was displayed last. That was true, innocent, creative, art. I had never heard of postmodernism, heavy metal or anything, I was just a 3-year old kid who painted a black picture. But that's not all. The philosophy behind my black, flimsy piece of paper is much deeper than this. I initially started to paint what everybody was painting: some stick people, grass, flowers, sun etc. Then I admired my complex work and thought: this is wrong. I took the tube of black paint and blackened it all. It looked much better. It was remarkable. And it couldn't have had a better place on the display board. I am still PROUD. :)
Some years passed and school started. And of course, we had art class. We had to paint stuff that strictly followed some given form. Of course, it had a point, it taught you basic elements of painting, but it was far from stimulating creativity. At one time we had a teacher that gave us the option of using a computer to generate some drawings instead of messing with paint. That was way cool and progressive, and I didn't fully realize it at that time.
But anyway, some people insist that black and white are not colors. Well. They might have a point, but not a strong one. There are only two disciplines that can rightfully tell whether or not something is a color, and those are physics and biology. As you can see, whatever-art-whatever is not among them. Unless of course, one takes the liberty of defining color however they please. Certainly, one can be high on LSD and taste orange and smell blue, but that's an exception, as are the cases of people who naturally do that.
So, to explain why black and white ARE colors, regardless of what some might assert, let's start with a definition. Color is visual perception that can be classified in red, orange, yellow, green, blue, violet and a lot of other names depending on how precise one wants to be. The other visual parameter would probably be brightness, which is a little easier to define: the intensity of perception, which is of course directly related to the intensity of the stimulus, light. A comparison beetwen light and sound, and between sight and hearing is useful in showing why all colors are colors. Both light and sound are waves and their natural properties are frequency, or how fast they vibrate, and amplitude, or how strong they are. We'll use intensity instead of amplitude. Any sound or light wave can be thought of as a sum of elementary waves of various frequencies and intensities. This mathematical decomposition is called the spectrum. It can be drawn as a graph that shows how strong each frequency is within a complex wave. So slowly vibrating air gives a low-pitched sound, while rapidly vibrating air gives a high-pitched one. If air is vibrating both slowly and rapidly, you hear both pitches. Yeah, it can do that, vibrate both slowly and rapidly, no big deal. It's called linear superposition. Think shaking your wrist very fast while also moving your whole arm up and down, slowly. Then, if the electromagnetic field (light) vibrates slowly, you see red, and if they vibrate rapidly, you see blue. Of course, slow and fast are relative to the phenomenon in question and to human perception. We only see a very small part of the electromagnetic spectrum and only hear a limited part of the mechanical spectrum. And light vibrates much, much faster than sound. Just as most sounds are complex, so are most colors. For example, you can't speak using just one sound frequency, and many colors can't be generated using only one light frequency, magenta being a good example. So if the equivalent of red is low pitch, that of blue is high pitch, and mixing red and blue light gives magenta, and mixing low and high pitches gives...ummm... low and high pitches, then: pure black is silence, pure white is hiss (also called white noise), pink is also some kind of hiss called of course pink noise, and so on. So if hiss is a kind of sound, then pure white is certainly a color. Either that, or pink and most other colors aren't actually colors. Anyway, there's no pure white, so how do you call a white that's a little bluish or yellowish or whatever, but not so much as not to call it white? you either call it a color, or you slowly increase the blue/yellow/whatever content until you can't call it white anymore, and don't call the resulting stuff a color either. So it is natural to call white a color. Some insist on calling it a sum of colors or whatever. True, it's a sum of all other colors. So? White hiss is a sum of all other sounds and it's still a sound. Every color is a sum of more elementary colors. There's no pure red, green, or blue, not even in the most precise lasers, let alone in a painting. If we skipped this and defined "mostly pure" colors, which indeed exist, then yellow can be a pure/primary/whatever you might call it color, meaning a single frequency of light, or can actually be two such frequencies, that of red and that of green. So there is a pure yellow and a yellow that's actually red+green, and they look exactly the same, and that's because of how our eyes are built. So all these attempts to refine the categories into which colors are placed and the idea that white is somehow different are absolutely pointless. The question of black is a little more difficult, because it is the absence of light. Is silence a sound? I don't know. It might be. Many artists talk about the sound of silence. The simple fact that we hear lets us categorize sounds into loud, soft, and absent. We wouldn't know what silence is if we didn't know what sound was, so silence is part of our audio perception. I guess it's still not a sound, but I don't even care. I'm making a comparison, not an equality. There is no pure black, at least not in paintings and shit. There is always light reflecting off even the blackest paint. So it's not equivalent to pure silence so it's a color. And if you were to be locked inside a totally dark room, you wouldn't see color anymore. You would see exactly nothing. So it's not black you're seeing, it's nothing, the equivalent of hearing nothing, or silence. There. Cut the crap once and for all. If I wanted to say that 1,2,3 and 4 are numbers but 5 isn't, I could, but it would be a very stupid thing to say. If I said that 1,2,3,4 and 5 are numbers, but zero isn't, that would be less stupid but still stupid, and it's been said throughout history. So feel free to classify numbers into positive, zero and negative, feel free to classify colors into warm, neutral and cold or whatever, but just please, cut the fucking crap.
PS. I also skim-read the Wikipedia article and found no indication of this stupidity. Is it a local tradition or something? Good enough reason to kill it ASAP.

purity

2007-10-28T05:39:00.000+02:00

I found a sketch in my Google Docs about purity. I thought I posted about this earlier, but a search reveals that I have apparently not. M'kay then. It was inspired by something someone said / wrote, I'm just sorry I can't remember who they were so I could give proper credit. The original text only had one of the items in the list, and I took the liberty of expanding it. So here it goes:

Purity
is for

drinking water
fresh snow
colors
vodka
24k gold
deionized water
semiconductors
sampling clocks
extraterrestrial signals (you know that song the seti guy sings? :D)

et cetera.

Purity is for water, not for people.

Superb.

Oh, I have sinned tonight. Let me remember... how many times. Let me think how many sins I have commited during this life. It's comparable to the xkcd number I guess. (The xkcd number is/was at some time the largest number concisely defined.) I am certainly going to fucking heck (having just mixed curse levels) where it's comfortably warm and otherwise interesting - i.e., not just clouds and singing angels. I mean, if the angel songs are played for ever and ever and ever, are they creative enough for me not to get bored? I guess they might be, actually. I shouldn't care anyway, because I'm going down there where there's solid matter for me to engineer. Let us again quote the wise words of William Murderface - "I'd rather DIE than go to heaven!"

So. Oh. Sorry. I just saw on TV that time has changed. (Times have also changed, but that's another story). This calls for a heavy dose of ranting. I mean, I think I should invest several femtograms of energy in ranting about how FUCKING STUPID DAYLIGHT SAVING TIME IS! Dude! It's TIME! You DON'T fucking change it!!! It's STUPID, POINTLESS, and ECONOMICALLY IDIOTIC! FUCK DAYLIGHT SAVINGS< FUCK DAYLIGHT SAVINGS< FUCK DAYLIGHT SAVINGS! I never use Caps Lock.
Although forms of DST were apparently used in ancient times, modern DST was invented by an idiot called William Willett, who printed pamphlets and lobbied politicians to implement his demented idea into law. Most people (including the idiots in the press who said it on TV this morning) think that Benjamin Franklin invented DST, but they're WRONG. I mean, that's insulting to the great Franklin. I was quite disturbed when I heard it on TV, so I checked. Of course, my intuition was right. Franklin couldn't have invented such a monstrosity. Instead, he did a much, much, MUCH more reasonable thing: he just told people to wake up earlier in the summer. Which is just, because you don't change time to force people to adapt to the planet's natural cycle. DOH!! Fuck daylight savings, they aren't saving anything. They're causing chaos, they're messing up people's rythm, FUCK DAYLIGHT SAVINGS A(g64,g64) times over! Then drill 10 more holes in it and fuck it again till it fucking dies! "William Willett did not live to see daylight saving become law, as he died of influenza in 1915 at the age of 58". GOOD! Fair! There is a God! Oh. And I don't like Coldplay.

cheers.

2007-10-28T05:30:00.000+02:00

February 23 - October 28 - 8 months of bits - 500 chars max.
(I wanted it to be lowercase but the template capitalized it, and I was too lazy to change it.)
Why exactly October 28th and not, for instance, October 23rd so there would be exactly 8 months? For that matter, why 8 months and not 6, half an year? Because.
Cheers et cetera.
Now that this note has been posted and the toast has been made, hm. Wish bits 8 more months of success.

environment

2007-10-22T04:32:00.000+03:00

I was talking some time ago about how much I hate pollution. Simply because it smells and it's toxic. I also said I didn't care about carbon dioxide emissions. We have a great deal of stuff to worry about that's more pressing and more important than CO_2. CO_2 can be absorbed by trees, if we stopped cutting them down and started planting new ones. Toxic gases and particles ("industrial ash") have a more direct impact on human life than global warming. Even more pressing is the oil crisis. Even if it's not a real crisis right now and it's driven by politics (may be, may be not, I don't care), it's still going to run out eventually. So that's the real problem, because then, the world economy is screwed. And then what? Riots? War? I don't know, I don't want to think about it. I hope a solution is found. What I care about today is bashing environmental fanatics. For instance, I use my bike and public transport most of the time, but I'm not fanatical about this. I don't have a problem with using a car, especially if there are more people in it. Think about this: according to Wikipedia, muscle efficiency is between 14% and 27%. A modern gasoline enginge on the other hand can have an efficiency of 25% to 30%. With Diesel engines that gets even higher. So I could get a better efficiency by riding say, a high-tech motorized skateboard / miniscooter, than by riding a bike. Guess what, you exhale 'dirty' carbon dioxide when you cycle, when you walk, when you sleep, all the time. You burn hydrocarbons just like a car does, and you eliminate CO_2 in the atmosphere. So by using a high-tech engine on a lightweight chassis you could actually 'hurt the environment' less by using motorized transportation than by cycling. Of course, cycling may be healthier, but that's another issue. Now think hybrid cars, where much less energy is spent on braking so the overall fuel consumption drops even more. Someday they're going to be markedly better than cycling. I should also mention a keen observation by my friend Wacky. All animals burn hydrocarbons and breathe out carbon dioxide, like we do. All plants on the other hand absorb the CO_2 and feed on it. So if you're somewhat of a vegetarian like I am, you're not protecting the environment by not eating animals, you're hurting it. You shouldn't kill and eat plants, who absorb CO_2, you should kill and eat animals, because they put CO_2 in your beloved atmosphere. And then campaign for cheaper condoms. We're complaining that the world population is increasing, that AIDS and other diseases are spreading sexually, and that's fucking normal! Because condoms are damn expensive. Especially in poor (pardon me, "developing") countries where a lot of people care more about finding half an old bread and a rotten apple to eat. Also, people are hypocrites. They're moral, they value family and bla-bla, when in public. But in private they spread AIDS and other diseases sexually. Actually, even if condoms were handed out freely, I guess many wouldn't take them because they're "highly moral and abstinent". Yeah. But still, condoms are fucking expensive. Hm. Seems I unintentionally found a problem worth campaining for: humanity's obsession with sex. The traditionalists' obsession with limiting and controlling it, the emancipated western(ized) peoples' obsession with having it, and the hypocrites' saying the first and doing the latter. And all the unnecessary taboo that surrounds it. There. Campaign for people to have less unprotected sex and make fewer children so there'd be less CO_2 emissions from breathing and from using technology. And then kill and eat all the animals that also breathe out CO_2. I think the environment would be perfectly sustainable with just humans, cockroaches, bacteria and all the plants. For instance, what role do panda bears play in the ecosystem? I mean, they're symbolic to the whole extinction craze. But besides being subjectively and questionably cute, they're dumb and poorly adapted. They only eat bamboo and reproduce with difficulty. So from an evolutionary standpoint, they deserve to die and go extinct. Big deal. So ideally, there'd be just many, many plants, us humans and little to no other animals. I mean, I guess there are plants that don't rely on insects for pollenation. Or just let the bees live, honey's good. And kill them if they multiply too fast. There. Clean air and sustainability. Then genetically modify humans to make their skin act like a plant leaf. There. No more fucking CO_2, and we get to feed on light. No more eating animals OR plants. Hippy nirvana peaceful utopia: us, the flowers and the trees. So we all happily feed on light and CO_2 instead of each other, until the CO_2 starts to run out and we can't synthesize organic matter any more. And so we burn half the forests to release more. And they all lived naturally ever after. The end.

exceptions

2007-10-16T01:24:00.000+03:00

Exceptions again. I thought about them again after posting earlier about how pointless they are. I found some cases where they might be useful, but then I changed my mind.
For instance, I know it's truly elegant to write a = b + c * d - x++ with overloaded operators and just catch the exception instead of checking the result of each operation, but what if(a.has_error()) do_stuff_to(a.get_error()), something like aggresively_spit_message(a.get_error()->
get_human_readable_text_including_error_ \
type_and_operand_misvalue_and_any_releva \
nt_environment_problems())?
And do whatever you like within the operators regarding operating on data with errors, just pass on the error.
I also know that even if you don't (can't) overload operators some methods must return useable objects, especially if you have immutable objects. Then either have mutable objects and pass them by reference, or make the error part of the object just as above. Duh.

fry

2007-10-15T23:43:00.000+03:00

Today I am going to talk about frying electronics. According to arcane lore, all electronics function by means of a mysterious substance called the Magic Smoke. It is inserted into the components when they are manufactured, through a highly secret alchemic process. Whenever the magic smoke is released - for instance through subjecting the component to an electrical current many times the one specified for normal functioning - it ceases to function. This is sometimes accompanied by strong luminous or acoustic events (flash-bang). Other times, depending on the energy involved, it also results in flying sparks and shrapnel: "Timmy, put down that transistor! You might poke somebody's eye out!"
Although sometimes embarassing, especially when frying something worth a lot of money, accidentally killing electronic components is seen by engineers and amateur enthusiasts alike as sort of an initiation rite.
Frying electronics can be the result of numerous mistakes, such as:

applying a voltage of incorrect polarity or magnitude - this results in internal breakdown or excessive conduction, which allows large currents to flow. Large currents times some voltage equals large Joule dissipation equals melting, and sometimes pressure increase = bang!
allowing too great a current by wrong selection of component values - see above
using a small resistor instead of a larger one (ohmically or mechanically) - ouch, it burned my fingers! Also see above.

in particular, short-circuiting something that can deliver a large current does indeed that, sometimes with unpleasant results.

As you can see, it's always about overstress. Some particular cases include:

electrolytic capacitor overvoltage - fizz, bang
screwdriver across electrolytic capacitor - bang, sparks, screwdriver welded to terminals, capacitor internally overheated and mechanically stressed - bad
diode across mains - boom, blown fuse (trust me and don't try)
integrated circuit inserted backwards in socket - what students do in the electronics lab in the Bucharest Polytechnic to confuse their teacher - "Teacher, the circuit is not functioning, come take a look, I guess we wired up the thing wrong! [.......] So it's defective? Well, then, could you just let us off?" - the sockets are hidden on the back of the board and the traces and resistors are on the top side, for some arguable reasons like clarity and "don't touch those ICs, we don't have many more replacements! You don't need to see how those sockets work! Google it or something." -- doesn't work :)
electrostatic discharge - ellusive, nasty and sneaky.

Many components such as integrated circuits are designed to shut down when overheated to try and prevent further heating. This sometimes works, but not always. Most are designed to shut down or limit their output current when short-circuited, but not all. Some are even designed to survive reversing their supply voltage, but again, some aren't :) In any case, most will not survive severe overvoltage. Resistors, capacitors and diodes are not designed to survive overstress and will heat up. Some will fail open-circuit, so the heating stops quite rapidly, but others will continue to heat up until they blow violently. Bad, m'kay? In any case, open-circuit is a relative term. Under sufficient voltage, any material or gap becomes conductive.

There are also more interesting ways of frying electronics. We had some "Digital Computers" labs where we would design some simple stuff involving digital logic and stuff it into an FPGA and test it. Worth mentioning is the famous "Automatic coke dispenser" that was simulated using switches for dropping coins and LEDs* for releasing bottles as well as for internal diagnostics. *) Under the right conditions, any diode can emit light in the form of thermal radiation. Most can only do it once.
The coke dispenser never worked, partly because it was very easy to do the equations wrong, partly because the state machine was hand-designed and hand optimized instead of being written in some behavioural language, and partly because there was no switch debouncing. But, it taught us about whistling bits into an FPGA and reminded us how to hand-design stuff.
Another interesting one was the "robot ant" that navigated through a maze. It had VGA output but that module was already written so it was very cool (dude! video output dude! on the fucking monitor dude!) but not that challenging. The ant always looked like it had a blind desire to mate with the walls, but hey, it was all done in hardwarde. Sort of.
Years passed and one of my friends had to go through this lab. He asked me: is there some way you can fry an FPGA by misconfiguring it? I immediately said no, thinking of the usual mistakes one might do when generating the configuration bitstream, the same mistakes one would do when doing classic C programming for instance. After all, an FPGA is a very, very expensive thing to fry and you wouldn't want to be able to do that in software. Not easily at least. And the guy was sincerely concerned and I had to calm him down. And then I thought, well, if you wanted to fry it, I guess you could very well do that. (Don't!) You could for example take the clock and use an internal PLL to multiply it 6, 7 or even 10 times, maybe even way beyond what the chip is specified to properly function at. Then you would clock all the possible flip-flops with that, and tie all the combinatorial logic to it for good measure. That would surely overheat the chip in no time. If you're lucky, you might even blow up the power supply. If you're really lucky, the power supply might think you're short-circuiting it and shut down, preventing you from frying anything. Anyway, don't do such stuff.
Then (read hack a day!) I learned of a design that can really fry itself by software. It's a brilliant design actually, if proper protection is added. But it's just for proof of concept. Say you want to control a switching power supply by software. Need I say more? :) There's no greater opportunity for self-frying than this. This said, I would never trust software to keep me alive. I don't really know why we allow so many bugs to exist. I mean, when you design something physical, errors can creep up, but usually you do all the calculations and show that the stuff is going to function as planned. Not with software. Nobody does state diagrams and flowcharts anymore. In high school, we used to laugh when the teacher was trying to push flowcharts onto us. "What? Flowcharts?! That fucking looks like it's from an old sixties manual, I want to write some code!". Well. I admit it, I myself hate both flowcharts, Petri nets and proving algorithm corectness. Hell.

fuck i18n

2007-10-14T02:55:00.000+03:00

sau de ce suge wikipedia în româneşte.
Pentru că, evident, sunt mult mai puţini oameni care scriu în porcăria de wichipedie românească decât în aia englezească (cu adevărat internaţională).
De exemplu, vreau să caut cum se zice în iengleză la a restitui ceva în natură, pentru că-s prost şi nu ştiu. Sau cum se traduce răspundere juridică, că poate-i un termen special, ceva. Mă, n-ar fi fost injust să fie nişte pagini dacă nu cu titlul ăsta (caz în care clicăiam linkul spre varianta internaţională), măcar să fie dracului menţionate pă undeva. Nu găseşti.

Romanian Wikipedia is a waste of resources and sucks by lacking lots of articles and it will never be able to get them (just as many of its other 'international' variants suck), fuck 'internationalization', the only international language is English.

titan

2007-10-13T19:14:00.000+03:00

This should be part of the 'press' series. I saw an article about some astronomers discovering there's rain on Titan. Of course, it's not raining water but liquid methane, which is named an 'explosive gas'. This reminded of some show they used to air on Discovery about the moons of the Solar System. They were saying that, if oxygen were present on Titan, and one were to light a match, the whole moon would go up in flames. They were showing an expanding ring of fire that eventually circles the whole orange sphere leaving it black behind. Well, I find that very wrong on many levels. But first of all, methane is not explosive alone, it is explosive when mixed with oxygen, so don't call it that. On Earth it's an explosive gas under normal conditions, true, but not everywhere. Both sources recognize that, but the first still calls it explosive. Second, the whole idea of the moon going up in flames is pointless, because (a) there is no oxygen there and (b) if there was, it would have ignited with the methane from stuff like meteorites. Why ask oneself 'What if there was O_2 on Titan?' if that's not the case? Just for the trivially exciting fire ring. What if suddenly there was a lot of cianide in the air on Earth? We would all be dead, instantly, you could see all the people fall. Cool. Equally pointless.

sound

2007-10-10T13:53:00.000+03:00

There are more or less frequent discussions of bad science in movies, games etc. Damn, this computer is slower than my typing, much slower. It's much slower even than the eBox I have at home, from which I've once blogged. It's so slow I can't be bothered to look up the link to that certain post.
Anyway, bullets have low momentum and can't launch a dude in the air, lasers travel at light speed which is for all practical purposes infinite*, and sound can't travel through empty space. Neither can laser light scatter off empty space, so the beams should be invisible except where they hit something. It's light, not projectiles.
*). compared to practical lengths for spaceships and human eye response time.
So people like me praise old, well thought-out movies like 2001: A Space Odyssey, where there was no sound in space, no gravity on space ships et cetera. New movies on the other hand feature low-budget crappy CGI, all sorts of glowing beams, explosion sounds synced with space stuff blowing up, and Earth-like artificial gravity everywhere. Then I thought. Dude, you can hear the sound from a blast in space, because debree would be hitting your vehicle. But I'm pretty sure it would sound very different from fire crackers.

anti-patterns

2007-10-10T02:27:00.000+03:00

Time to relax (slow down brain clock while browsing Wikipedia articles on simple ubiquitous stuff just to see if something trivially interesting pops up).
Of course, this also leads to reading articles of a more specialized nature.
One of these would be the article on anti-patterns. I find the 'Reinventing the square wheel' list entry the funniest :D
Note the smileycon used as sentence-terminating punctuation mark.

Anti-patterns are called so because in many (most?) cases they're bad, m'kay?
Not always.

1. Come From and Go To
(listed as 'Spagetti Code')

goto is useful, and is indispensable if programming in assembly language. Few processors support 'if' and 'for' and 'while' natively, most use jumps (gotos) to emulate them.

2. Busy Waiting
(spinning in a loop waiting for something to happen/finish instead of doing something else and waiting for a signal)

They taught this with great passion and emphasis in Operating Systems class. No busy waiting, use wait functions that yield control to another thread, halt the processor to sleep if it has nothing to do. Which is obviously reasonable. You don't want a task to spin doing nothing, you want it to sleep and let another one run. If none has anything useful to do, halt the processor to save power. That can't be anything but good, right?

Wrong. Turning on the processor to do useful stuff and then off while waiting for more stuff to do trashes the supply voltage by drawing large current spikes. In an improperly designed (or cheap) system, this can induce audible noises in the speakers, audible noises from power supply coils (hear them when scrolling text?) and electrical noise leading to poor measurement precision in embedded data acquisition systems. That's why all my microntrollers spin and never sleep. Many don't use interrupts at all and poll all peripherals except timing-critical ones. Waste of power? At some tens of milliwatts, from the mains and not from batteries, I couldn't be made to care. I own and control all tasks, I know how long they (should) take, I schedule them, I own all time and silicon Mwahaha, I spend 4 hours debugging. I rule :)

Also, spinlocks and atomic operations are good, m'kay. And well-documented.

3. Raising, catching and ignoring exceptions
(and all sorts of other problems)

Blah! What's wrong with just checking return values?
Why do we need exceptions? Certainly not because of abstraction and object-orientation.
If I ask you to please go take a shit, you can do it and reply with "Done." (return 0, or the more oxymoronic ERR_OK), or you can not do it and reply with "All portable toilets in range have their doors locked." (return ERR_NO_TOILET), or "No." (return ERR_GENERIC). I can then choose to check or ignore your return value, or just check to see if it's null. You can even return a pointer to an error object (supposing that the method halts on the first error encountered, use a list otherwise), though you would need some sort of RTTI to implement various types of errors just as you traditionally do with typed exceptions. But that can be messy, so you could just use one single object type for all errors and fit all necessary info there or make it polymorphic or something. Anyway, what's so wrong and unobjectful about switching through some possible error types on an error_type field in your returned error object versus writing the same amount of catches for each possible exception object type you might catch? Don't want to check function (excuse me, method) return error type after each call? goto somewhere after a group of calls you would otherwise try and check there. That's what the compiler assembles anyway. But no. Passing objects by return is not enough. We also need to throw and catch them through some abstract, exceptional aether. There. Fuck exceptions**.

4. Magic numbers

Examples:
0xdeadbeef, 0xbaadf00d, and combinations thereof. Rotten.
0xcafebabe. Sexy.
0xfee15bad. It does. Fuck 1337*.
MZ. Sounds tough.

*). I remember when I was young and dreaming of optimal ways to represent text on 7-segment displays.

Bad examples:
for i from 13 to 69 do stuff with i involving 833 and 647.

My examples:
clock_divisor = 47; // because I say so, dammit! MY code, my clock! See (2).

And, the winner is:
123. Loop-switch sequence

for i from 1 to 3
if i is 1 do this
if i is 2 do that
if i is 3 do some other stuff
fuck autounindentation end for

Funny :D
Seen that in programming books. Bad, m'kay ?

**). Regarding abstracted and formalized exception handling, another reason why I tend to look down on object-orientation fanaticism is that everything is defined backwards. If I have a computer and it contains a 3D-accelerated graphics card, that's a subassembly. The GPU per-se is a subassembly of that card. But no, in OOP if I derive a class from another and add functionality, that's a subclass, and its parent is of course a superclass.*** And if I choose to draw that hierarchy in UML all the arrows have funny heads and generally point backwards. Of course, the inheritors are under (sub-) their parent, which is above (super-). So 'subclass' is not about its ability to substitute its superclass. It's about counterintuitive back-arrows. As you might have guessed, you actually can not generally substitute objects of a derived class in place of objects of the base class (inheritance is supposed to model the "sub is a super" relationship) and that's called the circle-ellipse or square-rectangle problem. (with square pronounced skwaah****, like Cartman: "So I kicked 'm skwaah- in the nuts!") Final solution suggested in linked article: change the paradigm.

***). Too bad you don't have #defines in Java. Then you could #define ultra super*****
****). skwåh?
*****). Credits: Wacky.