Optical Illusion
I saw this today. I thought it was interesting.

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WTF?
I'm used to guitarists mocking the bass and bassists. It doesn't bother me too much. But this... This irritated me. A lot.
Today at work there was a group of people talking about Rock Band and Guitar Hero 3. None of them actually know how to play intstruments but they claim to be great at these games. They seem to believe this entitles them mock bassists.

• "Oh man, bass is so easy. It's the guitar that's the hard part. Yeah, I'm on expert on the guitar."
• "Yeah, bass is so stupid."
• "So It's me, my brother, and my sister. I play guitar, he's on drums, and my sister sings."
  "what about bass?"
  "My friend just got Guitar Hero 3. I'll make him play bass."
  [Both laugh]
• After making statements indicating this person believes he actually is better than Tom Morello, "After you make Tom Morello or Slash your bitch, they play bass for you."

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chdir(2)
So today at work another developer many years my senior, with many more years experience than I, came to me with a Unixy problem.
"When I have a program, how can I have it so the current working directory for all processes it starts isn't the one that it started in?"
"chdir."
"No, I want so that if this process starts something like ls, when ls stats 'dot' I want 'dot' to be the directory that process wants it to be, not the directory that process was started from."
After about 15 minutes of me suggesting chdir while he said that's not what he wanted but then describing chdir, I finally wrote something along the lines of the following

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int
main (int argc, char *argv[])
{
  system("/bin/pwd");
  system("/bin/ls");
  chdir("/tmp");
  system("/bin/pwd");
  system("/bin/ls");
  chdir("/etc");
  system("/bin/pwd");
  system("/bin/ls");
  chdir("/");
  system("/bin/pwd");
  system("/bin/ls");
  return 0;
}

I compiled that, ran it, showed him the output. He said, "Yeah, that's what I want to do."
I showed him the code.
"chdir does that?"

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Alpha
Due to the power failure, there was the loss of several hours of work. Last night I installed FreeBSD 6.2-RELEASE on an old DEC AlphaStation 200 I have. I had started building a new, smaller kernel for it around 23:30 last night. It had not completed by the time of the power outage. I have restarted that build.
Any one reading this would reasonably ask, "Why are you not as confused/angry/annoyed with a compile that was not finished in 7 hours as you were about one that took 3 hours?"
The answer is simple. This AlphaStation is powered by a 100MHz DEC Alpha EV4 CPU and has 64MB of RAM. To the best of my knowledge, DEC made this machine around 1994 or 1995. I expected the build to take a long time; the machine is around a dozen years old.

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How long does it take to build a linux kernel?
It has been a number of years since I built a linux kernel. Slackware 9.1 was the last GNU/Linux distro I used before switching back to BSD. Tonight I put together a machine from some old parts (1.2GHz celeron with 256KB cache, 256MB RAM, 20GB hard drive) and installed Slackware 12. I customized a kernel configuration and attempted to build it. I don't remember the 2.4 kernel taking as long to build as this 2.6 kernel. It took nearly two hours. Granted, this machine is fairly old, but 2 hours? After I complete the tasks for which I needed this setup, I'm going to install an older Slackware with the 2.4 kernel and build that. I may also install FreeBSD and NetBSD and build their kernels. I'd like to get an idea how long it takes to compile other kernels on this rig.

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Thoughts on National Computer Science Education Week
This week is apparently National Computer Science Education Week. Code.org is organizing the "hour of code" to promote teaching of Computer Science and Programming in schools. They're also organizing petitions to make CS courses count as credits in Mathematics or Science for High School graduation requirements.

In High School, my CS courses were by far my favorites, Programming in Pascal, AP Comp Sci in Pascal, Programming in C++, and AP Comp Sci in C++ ( the language for the exam switched my junior year). I learned a lot about structured code, elegant, efficient code. I learned enough about Data Structures and Algorithms that I didn't have to study for my college CS classes until Computational Structures (Discrete Math II with Scheme, essentially) in my third semester. I had an amazing Computer Science teacher who also taught me Calculus and the proper order of precedence in life: God, Family, Math. I wouldn't be where I am today without that educational opportunity I had in High School. I want others to have that opportunity too.

However, this is where I differ with the opinion of the Code.org folks. I do not believe that CS classes should count toward the Math or Science requirements. In this state, CS counts toward the "practical or performing art" requirements, I'm assuming under the "practical" label. I think this is a better place for it at the High School level.

Computer Science is not a hard Science. It's not Physics. It's not Biology. It's not Chemistry. There's a saying that if the subject has science in its name, it's not really a science. That is true with Computer Science. It's not studying the how and why of atoms, of molecules, of living systems, of anything really. It's not science.

Computer Science is really applied mathematics. I am very fortunate that the college program I went through was very strong in mathematics: Calc I and II, Linear (Matrix) Algebra, Discrete Math, Discrete Math II in the guise of Computational Structures, Probability and Statistics, Theory of Computation, Algorithmic Analysis... the list goes on. All of these mathematical foundations were then applied to a machine, to make the machine carry out a task in an efficient manner. It's those mathematical foundations that are the true core of Computer Science.

While mathematics is the core of Computer Science and Computer Science is essentially applied mathematics, I do not believe it should count toward the Math requirements. The CS classes would likely detract from other mathematics courses such as Geometry, Trigonometry, and Calculus. These courses are far too important to an education to be replaced by a Computer Science course. Many, maybe even most, High School Computer Science courses focus more on "programming" than the fundamental mathematical theories. They will pick the language du jour and teach you the syntax and semantics. They'll teach about basic data structures like arrays, and linked lists. The AP exam currently focuses not on implementing lists, trees, stacks, queues, and sorting and searching algorithms, but on arrays and lists using Java library calls. This is not math. This is learning Java syntax.

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