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Tuesday, May 24, 2005

[General] Morning Ramble

Good morning, it’s thiry four minutes past eleven and I’m onto the second coffee. This means I have only just woken up.

Last night was the world premiere of Blind Man’s Bluff: The Musical, which was the film we entered into the 48hours film competition. It went as well as we could have hoped. People laughed at the right bits and the story was easily understood (unlike some of the other films). We hope that our strong story will make up for the missing music etc. There were a few good films that were ineligible for any prizes as they were handed in late.

There are seven heats, 57 valid entries and only twelve finalists for Wellington. So we might have a chance. Of course none of this was done for the glory of winning but rather the satisfaction of a job well done.

Our lighting man and documentarian Paul Campion (here and here) has put together a making of that I am dying to see. Apparently there is a scene of Mike and me writing which involves us staring into space for 15 seconds, not moving at all. It's a fair and accurate depiction.

Speaking of Mike, go and check out his website because he has updated his blog to include a cast and crew list with weblinks to everyone’s sites.

I’m a little worried about the search terms people are entering which find this site. Here is a quick list of some of them:

Finally for this post (it feels like a multiple post day today), scientists in Israel believe they have discovered the part of the brain that deals with sarcasm. How great is that!? Wow, that is the best discovery ever!

In other weird news items (yeah, I know I said the last one was “finally”, sue me): examiners in the States have run into a problem with one of their maths questions. In an effort to make maths “real” for kids the examiners used a sports example for a question.

The question used an American football team and asked how what their average yardage was over the first six plays if: on the first play they lost six yards; on the second play the made three yards; on the third play they lost two yards; on the fourth play they made seven yards; on the fifth and sixth they made twelve and four yards respectively.

The answer they were looking for was: three yards. However, as all the football fans would have picked up instantly, after the first three plays the team faced 4th down and 15yards and only made seven yards which results in a turnover. So the fifth and sixth plays wouldn’t have happened. The examiners stated that the question was thoroughly checked for mathematical accuracy but not once for sports reality, and fair enough.

"It has nothing to do with football," Mildred Bazemore, chief of the state Department of Public Instruction's test development section [sic] said. "It has to do with the mathematical concepts that you're studying."

Too bloody right Mildred!

This is an annoying issue with the current system of the world. Long gone are the days when maths was fun because it offered a challenge to the brain, in the last 100 years we have had to make maths (and science in general) relevant to the world around us. There was an article on Campbell: Live about it last week, if you saw it you know what I mean (I actually missed it myself).

I remember when I was doing Sixth Form physics and our teacher had to come up a question about motion and inertia etc. He had to write it as a real world question but he couldn’t think of a real world situation where this type of thing would happen (i.e. no friction etc). So he said: “Mary is having a dream, in the dream…”

We all had a good laugh and then answered the question.

I understand the need to teach kids how to use “applied mathematics”, but it gets annoying when you always have to come up with a real world example for every topic. Imaginary numbers (see also: complex numbers) are always a favourite. To start with they are imaginary, they are purely theoretical, you can’t have 1+7i apples, a car does not cost $(500+82i). Try explaining to secondary students that you use imaginary numbers for electrical engineering or that e^(i*Pi)+1=0 and they’ll just give you a blank stare.

That’s as close to a rant as I’m gonna get today. There will probably be another post today, check back for it. In the meantime ponder this (sorry JC): what is a good real world example to show how a negative number multiplied by a negative number gives a positive number?

3 comments:

ben.run said...

The best kind of math has no practical application at all. Oh I loved the pure algebra's. None of this calculus crap for me :-)

Ben.

mike said...

Sorry to bust in on you pure mathematicians, but I have to have my 2c as an engineer! I was going to come out swinging and lay into you pureheads, but I have to agree with all you're saying. Often you just have to accept things for what they are - e.g. it's better to bend your mind to accept imaginary numbers than try to bend imaginary numbers to your mind.

Having said that, as an engineer, we need real-world examples, as that's what engineers do. I guess, then, the use of the mathematics defines how it should be presented. If the use is for a real-world application, then a real-world example should be used. If it's not for a real-world application, or is a fundamental concept, then real-world applications or analogies should probably be left out, as they may confuse the issue later. As for imaginary numbers, unfortunately, engineers have to use them quite a lot (and we use j instead of i, because, as we all know, i is the symbol for instantaneous current). It's definitely more a tool than a reflection of reality though - I mean, what the hell is imaginary power??

Hmmmm...an application of two negatives making a positive is tough. Well, I guess there is the old AC current x AC voltage = Power. If current and voltage are in phase, even though they change in time from positive to negative the power is always positive (except for when the current and voltage are 0, when the power is also 0). When current and voltage are out of phase it gets a bit more complicated (and is one situation where i, er j, is necessary)! This is a pretty weak analogy, because the voltage/current isn't really going negative, it's just changing direction.

Anonymous said...

You guys suck you really do (I'm pretending I'm on talk back radio, and flaming when a well reasoned argument would do).
Firstly: i is not a pure as the driven snow kind of concept. We only use it cause it's applicable. Do students love learning about i? No, cause i sucks. The graph for square roots has NO solutions in the negative area, ergo no i plural.
As for real world examples of things Surely we only talk about voltage cause we've never seen these electrons (or fundamental particles). So the maths tells us what voltage is. And we are going to use this maths (which is not represented by a thing we can ever have a meaningful relationship with) to represent the negative times negative problem? Sounds fishy. Step back (I do this for a living):
If your friend takes 4 strawberries (something you can have a meaningful relationship with), then you can say you have lost 4 strawberries. Hence, negative 4 strawberries. Well, if you then find out the person was going to steal 4 strawberries off you twice, but never did, you'll be eight strawberries better off. Eight positive strawberries. Actually, bank accounts are better for illustrating this kind of thing.