So John Wiltshire-Gordon and I realized we don’t actually have any idea how matrices work. Rather, why they work.

We figured out how Gaussian elimination works generally. It looks like if you have an augmented matrix [A | B] and you Gaussian-eliminate it into [C | D], that AD = BC, always. That’s why it works to find the multiplicative inverse as well as the solution to a linear system. We also traced the determinant throughout, and saw that each time you multiply the pivot, you change the determinant. (Well, we knew that already.)

The real question is, what really is a determinant?

I’m sure this will make some great Monday Mathematics columns later.

OK, so I was getting plane tickets from O’Hare to Indianapolis, a one hour flight. I checked the websites of both American and United. American Airlines’ website offered me, along with a host of non-stop flights, a one-stop flight to Indianapolis (!) which stopped off at Dallas-Ft. Worth (!!) for one and a half hours (!!!) in between flights, making it a grand total of five hours and forty-five minutes (!!!!) before I would get to my destination.

Maybe that option was for people who just love airports. They’re so exhilarating.

After purchasing from United, I looked at United’s FAQ section. One question was titled, “I have a non-refundable ticket and will not be traveling. Can I obtain a refund?” (emphasis mine). To my disappointment, the answer didn’t really address the question — it simply mentioned that you can exchange tickets for another date. I guess I shouldn’t get a job writing the answers to frequently asked questions.

Aegis has to complete two tournaments in the next two weeks?

Yeek. I’ll pay you five dollars for a time machine.

Yeah, I’ve been really busy lately. Give me ideas for more Monday Mathematics columns, and I’ll write more.

Nick and I are moderating at the scobol Kickoff tournament tomorrow. It’ll be the first time we get to see Aegis Questions in action.

I just opened my Inbox and found ten new messages there. I last checked it twenty hours ago.

Between quiz bowl, math team, and the class of 2005, I am getting a ton of emails every day.

I’m the Scobol Solo 2006 Champion! Woohoo!

Yeah, so everyone at New Trier has pertussis. It’s gotten to the point where the Health Services office (Newtrierese for “school nurse”) sent a letter to all the teachers insisting that everyone who coughs more than three times be taken out of class to get evaluated by the nurse. If this seems totally ridiculous, it isn’t really…yesterday (the day before this edict was announced), almost 100 people were sent home, and a few are already confirmed positive.

Everything at New Trier that involves other people coming to our school has been postponed or cancelled. This is on the say-so of some governmental health office. In the case of Scobol Solo, this means that Solo is taking place at Stevenson this year. Boo hoo.

Oh wow! Saddam Hussein was sentenced to death! This was unexpected!

It’s pretty meaningless too. (The EU says “Don’t kill him!”) This sounds like a sham. Not necessarily in that the trial was done unfairly, but just in that…the trial didn’t mean much to begin with. It was supposed to be the new Iraq finishing the business of the old Iraq, but like the occupation, it seems like it’s really about the U.S.

Just my 29.55 Iraqi dinars. (.02 USD, for the rest of you.)

MV is going to be taught by a student once a week. Today, John W-G presented partial derivatives to the class. (With logistical assists from myself, as usual, heh.) He did a good job, and I think that this presentation thing could be a very good idea. Everyone says it, but it’s true: to teach something, you really have to understand it yourself. He explained it well to us too, so hopefully the class learned a lot.

Also, I think the tablets really are a good idea for the math and science teachers. They’re like the smart whiteboards, except a hundred times better. It’s especially useful when they post the PDFs on Blackboard. I don’t think non-math/science teachers need them at all, but it’s their business. Maybe I’m just biased.

I’m curious to see what direction this presentation stuff will go, though. I’m going to be next, and I can predict a few people that would be interested in presenting after that. Once the obvious candidates are done, the rest of the class is timid or otherwise less able as presenters. I don’t know how that will turn out.