Archive for May, 2007

Build a Dumber Mouse

May 26, 2007

Frankly, Douglas Adams had it all wrong. I’ve had my fair share of experiences with mice, and I’ve never been particularly impressed by their intelligence.

My first example comes from my high school days, when I was working during the summer at a Cub Scout camp. I returned to my tent one night to find that a mouse had given birth in my sleeping bag. And you can guess how I found that out. Well, those babies didn’t last long.

But more recently, we’ve been having a bit of trouble with mice in our house. For the first month or so, it was as you’d expect. Every now and then we’d hear a mouse scurrying near the cabinets. We got a mousetrap, and it worked very well, besides taking more batteries than can possibly be necessary. After killing a few, the problem seemed to disappear.

A few weeks ago, however, the mice came back. The zapper has long been out of batteries, and nobody has bothered to get more. Nevertheless, Darwin has stepped in to fill the void.

This new generation of mice has found a plentiful source of food — in our garbage can. Of course, the drawback to this is that the inside of our garbage can is two feet tall and smooth, so every week we find a few mice trapped inside. The first time this happened, I was amused enough to free them (a significant distance from the house). However, when it happened again, I decided it was better for the mice to take a trip downtown in a garbage truck. They’ve been going out with the garbage ever since.

Last night, though, one mouse, whom I shall refer to as Bob, decided he’d had enough of this. Adding injury to insult, Bob got stuck in the washing machine. He probably thought it was a spa. Anyway, before we even got a chance to know him, Bob died a swirling, sudsy death, luckily not in my clothes.

So, it’s time again to go and get some batteries. You might wonder why, since the problem seems to be taking care of itself. But with the way this trend is going, it’s really the humane thing to do.


May 23, 2007

Some of you probably noticed my website was down over the weekend. My server decided it was too sexy to reboot, so it will be down until I can talk some sense into it. In the meanwhile, my website is being hosted on the same server as The Math Message Board, thanks to David Manura. Everything should still work there, except for the gigabytes of unadvertised content, so most people won’t notice any difference.

An Engineering Challenge

May 14, 2007

The trouble with one hour breaks during the school day is that you can’t accomplish anything significant. By the time you’ve finished walking back from class, checking your e-mail, eating lunch, and so on, you have twenty minutes to do something before you have to leave again. And the past two quarters, I’ve had 13 and 11 one hour breaks per week.

Rubber Band on DVD

Naturally, I started finding things to do. My latest diversion is a DVD I found in one of my classrooms. In an effort to improve its rolling ability, I decided to wrap a rubber band around its edge. In theory, this would increase traction and angular momentum, as well as just add weight in general.

However, this turns out to be harder than it sounds. After several days, I finally accomplished my task, but the result, unfortunately, was not particularly stable. Even that was with a fairly wide rubber band. Nevertheless, it was a nontrivial exercise in engineering, and I encourage anybody who leans that way to give it a try.

So, here’s the challenge. Without the aid of another person, adhesives, fasteners, etc., wrap a rubber band around the edge of a CD or DVD, so that it stays without being held in place. There is a reliable way to do it, and it’s certainly not brute force. Just keep in mind that, although the problem is difficult, it’s not impossible, and I have pictures to prove it.

P.S. If you’re wondering why the DVD looks that way, it’s because I put it in the microwave.

On Math Awards

May 12, 2007

On May 4th, I received an e-mail from Kent Morrison, the department chair, advertising the annual math department awards banquet. Here’s the relevant portion:

-$10.00 – Cal Poly Students
-$20.00 – All Others
-Free – Awardees

I wasn’t receiving an award, so if you know anything about me, you can guess my reaction: No Thanks! I don’t spend $10 on food in a week.

Four days later, I received an e-mail from Francesca Fairbrother, one of the math department staff, informing me that I’d received an award. Naturally, I assumed they’d figured out my situation. I wasn’t going to go unless it was free, so they made up an award for me. I haven’t done much here besides harassing people, so the other possibility seems unlikely.

I do have a bit of a history of receiving awards with no notice whatsoever. Upon graduating from Junior High, I received the “Most Studious” award. Back then, I watched TV somewhere around 8 hours per day. I did my homework during lunch or at the beginning of the class when it was due, if at all. And when you consider the fact that everybody who voted for me had to try to spell my name, you see that I had a lot of adversity to overcome.

I also received $100 from the Northwestern math department for adding a math major. Of course that’s not what actually happened, but that’s the way I tell it. The real award was “Outstanding Achievement in Mathematics by a Junior”, which presumably had something to do with my Putnam score.

Tinh, my officemate, also received an award. His position was rather different from mine, though. Evidently he had been contacted a few days earlier regarding personal information needed for a scholarship, so he thinks he got one. I caught him looking through the list of scholarships to see what he got, but I’m pretty sure you need to apply to get those. Either way, the scholarships pale in comparison to the real prize: free dinner.

How To Circumvent Spam Filters

May 5, 2007

An interesting piece of spam appeared in my inbox recently. That happens daily, of course, but they’re generally interesting for completely different reasons, such as: 1) managing, despite obvious deficiencies, to avoid gmail’s spam filter; 2) there are people who are so dim-witted that they fall for these scams. But this e-mail was wholly different. It wasn’t offering drugs, to increase my pagerank and sexual appeal, or to handle my bank account for me. In fact, there is no clear evidence that this spam was promoting anything at all, and that’s what makes it so special. See for yourself — the e-mail appears in full at the end of this post.

Let’s examine the possibilities. First of all, the subject “This is done by invoking the method runFinalizersOnExit of the class System with the argument true.” is a line from Sun’s Java documentation. I doubt this was their doing.

On to the content. The line “In our plan we already have our agents at work, weakening their will to fight, ready as well to kill their leaders of war when the time is right.” comes from the book Wing Commander: Fleet Action. This appears to be a very popular book, and you can get it, besides from that website, from Amazon for 46 cents. It seems unlikely that this is a marketing ploy for that.

I investigated the IP addresses of the connecting mail server, but I didn’t notice anything unusual, at least for spam. There are no hits on google for the “sender”, marc Pegu. The domain name of his address was, which is sort of the swedish equivalent of comcast. It seems unlikely that one of their users is actually spamming people (especially considering it came from Turkey), which is why I believe the e-mail address is forged.

What does that leave? Well, it could be an attempt to discover whether or not my e-mail address is valid. That hardly seems worth it. They could do the same thing with a real spam. It’s not like they possibly could have guessed the address, anyway.

So, there doesn’t seem to be any reasonable explanation for this e-mail. It does serve as a lesson for all spammers, though. One great way to get past spam filters is by not including any spam content whatsoever.

As promised, here’s the spam in full, except the e-mail addresses, which I’ve censored (including the sender’s, since it might have been forged):

Delivered-To: ***
Received: by with SMTP id f12cs824208huf;
Mon, 30 Apr 2007 12:30:13 -0700 (PDT)
Received: by with SMTP id v8mr12461369qbd.1177961413053;
Mon, 30 Apr 2007 12:30:13 -0700 (PDT)
Return-Path: ***
Received: from ? ([])
by with ESMTP id 20si15872955nzp.2007.;
Mon, 30 Apr 2007 12:30:13 -0700 (PDT)
Received-SPF: fail
Received: by with SMTP id djulLRgYxGWZr;
Mon, 30 Apr 2007 22:30:07 +0300 (GMT)
Received: by with SMTP id lzllfEQHJlJjay.6796365840029;
Mon, 30 Apr 2007 22:30:05 +0300 (GMT)
From: “marc Pegu” ***
To: ***
Subject: This is done by invoking the method runFinalizersOnExit of the class System with the argument true.
Date: Mon, 30 Apr 2007 22:30:02 +0300
MIME-Version: 1.0
Content-Type: multipart/alternative;
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.3028
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028

Content-Type: text/plain;
Content-Transfer-Encoding: quoted-printable

In our plan we already have our agents at work, weakening their will to fight, ready as well to kill their leaders of war when the time is right.
Content-Type: text/html;
Content-Transfer-Encoding: quoted-printable

In our plan we already have our agents at =
weakening their will to fight, ready as well to kill their leaders of =
war when=20
the time is right.


Oh, and the book is pretty good. I just finished it.

A New Home

May 3, 2007

Following Geet’s example, I’ve decided to move my weblog off of my main site. While I’m perfectly capable of writing my own blogging software, I don’t want that to be consuming any of my time. The features I need are fairly minimal, and the lack of complete control over my content is made up for easily by the community-focused features of blogging sites.

The Societal Benefits of Rape

May 1, 2007

My morning commute was recently interrupted by a crowd of people crossing the street, waving signs admonishing rape. Ever since, I’ve been left with the nagging question of what they hoped to achieve by doing this. I wonder how many people saw them and thought, “hmmm, maybe I should stop raping people.”

Rapists are a lot like murderers: they’re too sociopathic to be swayed by popular opinion. When’s the last time you heard somebody argue that rape was actually beneficial to society? With war protests, there is at least a minute possibility that the nutjobs who believe murdering another country’s poor people is an acceptable way to effect social change will notice that their opinion is unpopular, provided the people waving signs aren’t all wearing tie-dyed shirts. But rape? Honestly, they might as well have waved signs saying cats are fuzzy.

Of course, their goal could have been to raise awareness. I’m aware of rape, thank you. What am I supposed to do about it? Not even the activists have better ideas than walking around town with signs, and they certainly spend more time thinking about it than I do.

Now, don’t get me wrong. I’m not trying to belittle rape or any of its victims. Quite the opposite, in fact. My point is that rape is close enough to murder that the thought of protesting it is absurd. Think about it: what would your reaction be if you saw a crowd of people protesting murder? You’d probably think it was about abortion or war — you know, something that people have been known to argue about.