good to know

One of my memory sticks made it through the washing machine alive. It didn't even have a lid on it. Phew. I'm glad it was in the pocket of pants that don't go in the dryer.

The sensible versus the ordinary

I was explaining to Dion yesterday how unthinking students can be in applying rules for significant figures. They try to memorise and apply rules of thumb instead of reason. Many will tell you that "Zeroes after the decimal point are significant; therefore, 0.00182 m has five significant digits." I suppose it would have eight if written in km. 0.00000182 km. No consideration of certainty or precision is to be found here. Dion's response was that they should just be using scientific notation, i.e., 1.82 X 10^-3 m. Indeed, scientific notation is superior to standard notation in this respect. Unfortunately, in everyday life and definitely in most Physics textbooks, most values are stated in standard notation.

This reminded us of an incident I meant to blog. At Chinese New Year with Dion's extended family, we played the name game. One clue provoked later discussion on the relative merits of improper versus mixed fractions. Most of us prefer improper fractions. Mixed fractions are computationally inelegant. We're snobs with engineering, science, accounting, ... degrees. However, as a math teacher, I felt obliged to point out that in everyday life, no one uses improper fractions. Would I say that I'm 15/2 months pregnant? Of course not. The paper is 17/2 by 11 inches? equally stupid.

Dion's cousin, who is in Grade 9, was in the game for the first time rather than just time keeping and recording scores. He had put in one clue then later picked it up himself. He was able to get his teammates to say, "improper fraction," but despite clear appeals to the equivalence of another form, they could not come up with "mixed fraction." After some time and several tries, he exasperatedly retorted, "Don't you guys know math?". Pwned.

Good Workout

For the first half of my pregnancy, I was heeding the old-fashioned advice of limitting my heart rate at 140 and doubling the during of my workout. But since that was about as boring as can be and I had done a little more research, I upped it to 160, which is the most conservative limit being suggested these days.

I had taken a couple of weeks off the treadmill since I'd been feeling a cold coming on. I never got sick but the feeling has been lingering. So when I went for a workout today, I decided to go easy, keeping my heart rate around 140. I control my heart rate with the pace and incline settings on the treadmill.

Well, today, I had to increase and increase the settings - way past the settings that normally get me to 160. I took me 30 minutes of increases to get to 140 and I was sweating buckets, so I just stuck with 140 for the rest of my workout.

Just a good day? or am I in the best cardiovascular condition I've been in all year - maybe since playing varsity? I felt like a machine.

I'd heard that pregnant women oxygenate better than other women and that elite endurance athletes who are mothers outperform non-mothers (I don't know if that is controlled for age/experience). I guess pregnancy is like altitude training.

Technology in the Classroom

WARNING: Physics- and Pedagogy-Intensive

I’ve often liked certain specific technological activities for improving understanding. For example, I really like motion sensors with real-time distance-vs-time displays for various motion activities. A particularly cool one is the distance-vs-time graph for an object moving at constant speed in circles.


It’s a very graphic, so to speak, connection between the unit circle and sinusoidal waves and transformations thereof. Most systems will do v-t and a-t graphs also.


About a week ago, I was looking online for a simple demo for electric fields and/or the motion of charges in electric fields. We don’t have much equipment for this topic at the school, so I have struggled to make electric fields even somewhat concrete for the students. Lots of chalk-and-talk. But online, I found a great little simulation applet (http://www.colorado.edu/physics/2000/waves_particles/wavpart2.html) that shows the motion of an electron in the electric field of a proton. So, the next day in class, I connected my laptop wirelessly to the internet and to a data projector. I illustrated a 1-D calculation I was doing on the board and then later showed some of the 2-D possibilities and we talked about the shapes and energy transformations involved. I loved it but I had no idea it was going to be such a big hit with the students.

There are more such simulations (not all fields) indexed at http://www.colorado.edu/physics/2000/applets/ and many other websites.

But I experienced an enrichment of understanding through simulation for myself today.

I had asked my students to submit proposals for the fields unit test they were writing today. I like this exercise in that it often yields perfectly valid test and exam questions (not just bonus questions) and it gives every student the opportunity to think as deeply about the material as they are ready to. The winner this time was: “Sketch the electric field diagram for two positive point charges and one negative point charge fixed to the vertices of an equilateral triangle. All three have the same magnitude of charge.” A tough problem for grade 12s, to be sure. During the test, I spent a good 15, maybe 20, minutes making a pretty detailed sketch. And although I was reasonably confident that I had a good answer, I went online to try and find a textbook answer. I didn’t find one, but I did find an applet (http://ww2.slcc.edu/schools/hum_sci/physics/tutor/2220/e_fields/java/) that would let me simulate it. Here is the applet answer and mine.


Pretty much I got it but I didn’t have the “ears” or “heart-shape” exaggerated enough.
Aside: After the test, I overheard one student asking another, “Did your answer to the bonus look like a jellyfish?” Woah. I have no idea what a sketch of a jellyfish would look like.


Then I went home and started telling Dion the story above. He had no visuals to go on but when I said I had all the key features, and listed them including, “heart-shape,” he replied, “well, of course, that’s what I’d expect – a circle subtracted from an ellipse.” Uh, what the hell was he talking about? Turns out he was thinking of the equipotential contours, which are at all points perpendicular to the electric field we were supposed to be sketching. Ah, vector calculus. Something about the derivative of a changing vector being perpendicular to it. I truly do not remember sketching equipotential contours. I probably did, but I’m sure I forgot it all 10 minutes after the exam. Anyone remember when we did that – Dimi’s E+M? ODE’s with Smith? I never took PDE’s.

So, after showing Dion the applet and how it does both field lines and equipotential contours, I started playing around with various configurations. Some pretty patterns came out. And some mundane ones. But this one really caught my attention.


The red dots are positive point charges. The grey lines are the electric field lines. The fuchsia lines are equipotential contours and at all points perpendicular to the field, of course – that much I have solidly known for some time.

But I know that fuchsia pattern from something else. If those red dots were charges moving out of the page, then the fuchsia lines would be the net magnetic field they create (per Oersted’s Principle and superposition). I use this diagram in Gr 11 Physics to explain the shape and strength of the magnetic field created by a solenoid/electromagnet.

Hang on there. The (1) electric equipotential contours perpendicular to the (2) electric field lines created by (3) static charges have the same shape as the (4) magnetic field lines created by (5) motion of charges.
(1), (2), and (5) or (1), (4), and (5) are all mutually perpendicular.

MAXWELL!

If I could just remember all that div, grad, curl stuff, I could write this down much more concisely. Actually, the Cartoon Guide to Physics (Gonick and Huffman, Harper-Collins) has Maxwell’s equations. I’ll scan ‘em for y’all later. BTW I cannot recommend the Cartoon Guide to Physics highly enough.

Anyway, who knows when I might have reencountered these ideas so intimately without the simulation software, some unconstrained time to explore, and some “expert” input from Dion. I might be able to transfer some of this experience into my lesson/unit planning.

Problem is, I am me and they are not. If I give 17 year olds unconstrained time to play with simulations, how effectively will they use that time? Will they be inclined to think about what they’re playing with? How much time is needed before the probability of gaining a new insight becomes reasonably high?

And now if I can ask a favour? Can anyone figure out how to get a working local copy of these applets? I’ve downloaded all the related source files (and the objects they call) I can find and maintained the file structure, but they just won’t run. Do they have to phone home? I’d like my own copy as the internet connection at school is flaky and who know how long these websites will be maintained. Thanks.

start to second semester

After getting to 10% in almost 3000 games, I reset the stats. I'm playing a lot less but doing a lot better. In 500 games, I'm one game over 250. Does anyone say that? Or can one only say one game over/under 500.




Wrapping up first semester was really hectic but second semester is off to a good start. My classes are strong academically and I have some personalities, too. I have started out really on the ball. I'm trying to have everything in order for the sake of my replacement if I need to start my leave suddenly. This is probably the first weekend since September that I didn't have anything to mark. I'm also trying to be on the ball for the sake of Kaitlin, who is teaching 12U Physics for the first time. We're doing the units in an unusual order (starting with the hardest three of six) for a few reasons.

1. I will be starting my leave right around midterm, so I'll be at school to help Kaitlin through the weirder stuff.
2. This will leave the easiest half of the course for my replacement.
   
3. The grade 12's usually go on virtual vacation as soon as midterm marks are in, as these are the basis for most university acceptances. (They'd really have to tank to have any offers rescinded.) This way, I have their attention and motivation for the tough stuff and more of them will learn something.
4. These are the units I enjoy most anyway. Why leave them for someone else?
   
5. I'm sending a message to all those students with 80 and 90 percents at midterm in first semester who drop the course and retake it second semester, thinking that they may as well get tested on stuff that they've been taught twice and never get tested on the tough stuff (at least before marks go in to the universities).

I think that #3 is enough on its own and I may continue to do this in the future just for that reason. Some of my students seemed a little disappointed but none has given me any grief about it. In fact, several students seemed to nod their approval as I explained that starting with the harder stuff is for their own good.

The only downside is that the actual instructional planning can be a little complicated. Until the students have covered circular motion and momentum, a number of applications need to be postponed, e.g., the Compton effect, cyclotrons, and calculations for Rutherford electron orbits.

Two weeks of vacation

let me forget how tiring my job is. Good grief, I'm knackered.

I had photos,

so I thought, "what the hell, I'll post." and then it ended up super-long. grr.

SINCE LAST POST

junior girls' volleyball has been hit and miss. A nice group of girls (and nice to each other, which is rare) but a little immature. good athletes but underperforming. I think we're 1-5.

bought Gina's old car - a 2003 Echo 4-door manual. done all the paper work, plating, insuring etc.... Johnson's quoted us over 4000 per year, including condo. Got a State Farm Policy for about 2000 per year, including condo. (It's so high because I've never been insured before.) Here's a photo I found online. Same colour even.

Holidays have been very nice.
-Greyhound to Ottawa on the 22nd.
-all Christmas shopping accomplished in around 4 hours on Saturday.
-visited Doug and Mel (Mackenzie and Keira also) in the afternoon, Uncle Mike in the evening
-went to the Christmas Eve service at McLeod-Stewarton. Dion mostly enjoys ripping apart the organist. She improvises the harmony for the last verse of every song, making it impossible to sing any of the harmony voice parts as written. pretty self-indulgent, no? plus the unevenness of the right hand. appalling.
-snacks at Joan's after church.
-nice brunch on Christmas then on the road back to T.O with Dad and Ian for Christmas dinner on Goldhawk. built gingerbread houses after dinner - very fun. Let's do that again. Also very fun are Dance, Dance Revolution and the wii. I sucked at DDR but kicked butt bowling on the wii. Dion is a DDR natural, of course.
-saw the "new" Bond movie on Boxing Day with Ian.
-showed Dad and Ian the condo, went to Indigo with them. I restrained myself to 4 books. Ian bought closer to a dozen.
-went for lunch with Dion and 5 of his WOW DJ friends. no surprises really. a clean-cut, late 20s group.
-don't remember much more but did do some marking last week. I have SO much marking to do.
-New Year's Eve at Ann and Steve's. good fun. Sophia loves Dion. Opposites attract? I brought crudite and a cheese plate. Apples to Apples, the boardgame Becky gave to me for Christmas last year, was a pretty big hit. I really was just throwing "Gallbladder" away. Who was to know that Evan would think that a gallbladder was unscrupulous?
-Dion demoralised that Ann, Steve, Evan, and Daniella won at curling without us on the 22nd.

-lots of research into pantry/cabinetry/storage options for the hallway opposite the kitchen. Finally ordered wardrobes from Ikea.

TODAY
-did some marking
-bought some maternity pants. Don't need them quite yet. but soon, very soon.
-exchanged some bathroom accessories because they didn't quite match. kinda bold for me and Dion but I like it. Here's a photo of what I got in exchange. (the shower curtain plus stacks of coordinating towels. Our ensuite bathroom is painted the same colour.) colour doesn't always come out. walls - pistacio. towels - plum.






11 weeks I think. I can't find the 19 week one right now. This one's cuter anyway. I'm 24 weeks now. baby should appear around the end of April. front-runners for names are Adam and Jill.







MOVIES
Casino Royale (Bond). I like the new guy very much. I also liked the reduction in cheesy lines.

BOOKS
bought
The Giant Little Book of Science Facts
The Giant Little Book of Science Experiments
The Trouble with Physics by Lee Smolin
Vinyl Cafe Unplugged by Stuart McLean.
I've been reading the last one and I even read a couple of stories to Dion last night. best line so far: "Murder was in his house and it sounded just like someone trying to flush a cat down the toilet." italics by the author.

delight and outrage

delight - senior boys vball wins north region championship 25-22, 25-23 on thursday. game not really as close as it looks. we were in control of the match except from 0-0 to 4-9 in the second set.

outrage - grade 11 physics class. got the sense that they haven't done homework in ages. took one entire 75 min period to take up two nights homework.

• each table assigned one question to copy solution onto chart paper.
• of course, most not copying solution but doing problem on chart paper.
• solutions posted around classroom.
• announce: open book quiz next day, 3 of these problems, one number changed.
• remainder of period: walk around classroom with notebook, read questions study solutions.
• solutions left posted over lunch time.

results: mediocre. 6 failed. but a bunch (13 of 31 students) got 14 or higher (no more than one part mark per question lost). i can't think of a bigger gift though. tomorrow: copy three of these from your notebook onto the quiz paper.

outraged

Yesterday, I had only 6 of 9 players at the Jr Boys Volleyball practice. And one of them showed up 40 minutes or so late. That was not what outraged me.

Today, the player who was late informed me that he could not play today. That was not what outraged me.

I asked the referee and was informed that I was not allowed to field only 5 players. I was forced to play players who had skipped/missed practice or default. I felt the latter option was unfair to the opposition who had travelled for a game and to the five players who had practiced.

The game started, I looked down the bench and saw my remaining two players. One was on the phone! The other was doing homework!

Not clear on the concept of team. Not even pretending to be interested in what their teammates were doing, cheering for them, supporting them, or even being prepared to substitute into the game.

I'm still seething.

Spider Solitaire

I have clearly spent WAY too much time playing this game. It has taken me a LONG time to hit 10%. Especially since the stats always round down. I've been over 9.5% for quite a while. I believe it took me 60 or 70 tries to solve one.

stirring the melting pot

One of my volleyball players told me yesterday that he'll date any type of girl but he's going to marry someone from Afganistan, as he is. Besides his mom would kill him if he didn't.

Where does that sit ethically?

Is it racist for his parents to insist that he marry a girl from Afganistan? I think it depends on the details of their motivation for it. But on the face of it, I don't think it's necessarily racist.

Would it have been racist for my parents to insist that I marry a white man? I think blatantly so.

Double-standard? absolutely. The world is subtle. Equality is not treating everybody the same.

Also, there must be a tipping point in the middle, right? How many generations?

Another example. Racist for whites to use the n-word? absolutely. Racist for blacks? I'd say no. Is it "good" for black people to use the n-word? not good but not racist either, IMHO.

double Hugo and Nebula winner

I read Flowers for Algernon today. I remember talking about the premise in my Gr. 5 class with Mr. Seidenspinner. It's really good and a quick read. I confess that I cried through the last few pages.

We bought a condo.

exterior

living room

breakfast bar

master bedroom

2nd bedroom

dining room (the + of 2+)



904-25 Maitland. 1200 sf. 2+ bedrooms. Everything's in good shape. Clean. Just move in in November. Close Oct.31.

Canadian Idol

I thought that the final two was going to be a coronation for Eva, who is consistently excellent. And though I've always kinda liked Craig, too, I didn't think he was up to it. He's been underperforming and nervous. But he really brought his A game. surprisingly good, especially on his first two songs. played to his strengths - super powerful. Eva, of course, did really well and deserves to win. I'm just glad Craig made a game of it.

Results are in: Eva won. 3% difference, I think I heard.

interesting...

The Guardian has a noteworthy article titled: Websites that changed the world

I agree that these are all influential; however, some are better described as "websites that changed the world wide web."

1. eBay.com
2. wikipedia.com
3. napster.com
4. youtube.com
5. blogger.com
6. friendsreunited.com
7. drudgereport.com
8. myspace.com
9. amazon.com
10. slashdot.org
11. salon.com
12. craigslist.org
13. google.com
14. yahoo.com
15. easyjet.com

a good book

bought it Friday, read it Saturday, done by bedtime.

What Should I Do with My Life: The True Story of People Who Answered the Ultimate Question by Po Bronson. ISBN 0-345-48592-0. $10.99 in Canada.

It's definitely a good read. It's a collection of human interest stories on how some people have made work work for them in different ways at least temporarily. The author admits that he doesn't have a representative sample of Americans - very few minorities, mothers, immigrants etc... mostly white boomers and GenXers.

• There's a guy who gives up law to open a store that sells homestyle cakes (Becky).
• There are several people who find work in and out of their field overseas (Kern and Kristin).
• Several writers (Jaclyn).
• Many people who find or devote themselves to their cause. Why don't I know people who work fulltime for their cause?
• There's only one case of a guy who had spent his life preparing for one profession (marine biology), hated it, made an immediate switch to another profession (dentistry), and lived happily ever after.
• Otherwise there aren't really any fairy tales.

I would not hesitate to recommend it to anyone, regardless of whether s/he is satisfied with his/her work.

This was in The Guardian. The Guardian!

"According to Levine, parents should take care not to pressurise their children to try to be outstanding at everything...."

pressurise. pressurise!

I believe in language growth and change. I really do. But I cannot accept this.

Woe is I!

Photos from China

I actually have very few useable photos because of my camera's death and the number of times my film canisters were X-rayed. Which made the following compilation come together very quickly. To the right is my favourite shot and probably the biggest highlight of the trip - hiking the Great Wall at Simatai.


Our guides were invariable surprised that we went to the Great wall twice in Beijing. But they were very different experiences. Compared Badaling, Simatai is a little more remote (about three hours from Beijing versus 1.5 hours) and allows for more climbing. Simatai was restored during the Ming Dynasty and is more rustic than Badaling that has been more recently and heavily restored. There's no climbing the Han Dynasty wall near Dunhuang at the Western-most section of the Great Wall. It's made of straw and clay. This section is about the height of tall person.

The Great Wall
The Great Wall near Dunhuang Han Dynasty	Simatai. The Great Wall near Beijing Ming Dynasty	Badaling. The Great Wall near Beijing Ming Dynasty

The Forbidden City

The Other Four shots that actually developed properly
The Seventeen-Arch Bridge on Kunming Lake at the Summer Palace in Beijing	Jiaohe ruins. There were at one time Buddhas in each of the cubby holes. Jiaohe was a stop on the Silk Road until it was abandonned during Mongol invasions.
One of our stops on the Silk Road. This is the view from our hotel in Dunhuang	Yang, our favourite guide

The prime directive.

Dion insists that Yolande and I violated the prime directive in Dunhuang.

Our guide, Vicky, was a sweet but mousy young woman. Late on our last night while we were waiting for the driver I decided to make some fun. I asked Vicky if on a night like that, when she gets home late, whether her husband has dinner waiting for her. Well, by the look on her face, you'd think I was from another planet. Of course not. He gets fed at his mother's house.

I explained that in general, Dion and I split the cooking. If I cook, he cleans up. If he cooks, I clean up. cook together, clean together. Vicky was astonished. Not only was I recounting this freely in front of my mother-in-law but even more shockingly, my mother-in-law seemed pretty happy about it. She's proud that Dion pulls his own weight. She pointed out that it's fair that way when both people work and that Vicky could tell her husband that. Vicky's response? "I will. Thank you?"

I also told her that she should teach her son (now 3 years old) to cook. He'll get any girlfriend he wants. Vicky's response? "I will try." I don't think she meant it.

making friends in China

On my last night in China, I discovered the easiest way to make friends in China. Sit in an internet cafe with English prominently displayed on your monitor. Eventually, someone will sit beside you and start reading and making conversation. Exactly as 19-y.o. Xiaolaoshu did in my case. It was particularly fun since Xiaolaoshu speaks about 10 words of English so we had to make do with my Mandarin. In fact, we've already exchanged a couple of emails.

Having internet access also facilitates conversation. Babelfish from Altavista is helpful. Google Earth is a big hit but, unfortunately, it doesn't cover any part of China I've looked up.

I was also able to find a way to display the images that I have previously posted on my blog. Several were a source of great amusement for Xiaolaoshu, including that little paragraph in pinyin and characters that I wrote about a weekend. I was pleased that the pinyin seemed funnier than the characters. Xiaolaoshu also had a good laugh at a picture of me and Dion, although, I think he was just laughing at Dion because that is when I pointed out that Dion does not speak Chinese.