Monthly ArchiveMarch 2007



Programming Languages &Software 02 Mar 2007 08:56 am

Ed Felten: Why Understanding Programs is Hard

Ed Felten: Why Understanding Programs is Hard:

In contrast to his earlier attempts, which I appreciated, this time Felten does not try to prove his point by explaining the fundamental facts of computer science. Understading[sic] programs is hard, he demonstrates here, because the results of some mathematical functions are hard to predict (in his example, a secure hash function).

While this enables Felten to give a short and easy to understand example, I think he misses the chance to explain why understanding (and predicting) program behaviour is hard in general. This would bring him back to the fundamental principles he discussed before, stemming from the halting problem. By going this route it would be possible to relate the issue under discussion to topics that are more directly related to LtU: how programming languages can help make analyzing program behaviour easier, how languages can restrict possible behaviours etc.

Be that as it may, more people outside the profession should be come to appreciate that understanding program behaviour is hard. This is something that takes time to appreciate fully, even when you are a programmer. It is one thing to know that finding bugs is hard in practice and quite another to appreciate the reasons why it is inherently so.

(Via Lambda the Ultimate.)

Humor &Science 02 Mar 2007 08:46 am

Hamiltonian

The problem with perspective is that it's bidirectional.

Muzak 02 Mar 2007 01:32 am

Desert Island Discs

I saw a friend tonight and he mentioned the notion of the Desert Island Disc Collection. It’s simple, scan through iTunes and make a playlist of the 10 albums you would take if you were stranded on a desert island (and you could only have 10 albums, of course.)

What a hard thing to do. Music addresses so many of the moods I have. Do I pick my 10 favorite moods? Moreover, he made the observation that you have a tension between genres and between best in genre. Quite a challenge, but I have started.

At this point, there are some albums I know need to be on the list. Though they are certain to change as I think through it more, but the following just gotta be on the list.

Love those albums. Good times…

OK, so I dunno yet and I don’t want to commit given the gravity of the topic. But I am thinking, what 10 albums to take?