Don’t forbid phones in class, embrace them

Posted on April 4, 2011 by Peter Newbury

It’s not uncommon to hear, as I wander the halls at UBC, faculty complaining about students preoccupied with their computers and phones in class. The most common solution is to just ignore it (“if they don’t want to pay attention to the class, it’s their loss…”) Can’t disagree with that, as long as students aren’t distracting others who are trying to pay attention. Another solution is to ban computers and phones. Well, some students legitimately need their computers (students with disabilities, for example) so I know of a few instructors who ask these students to sit over there, off to the side.

But here’s another solution: don’t forbid phones in class, embrace them.

Naive? Perhaps. Impossible to faciliate? Ye— Ah! Not so fast!

The April 2011 issue of The Physics Teacher contains an article by Angela M. Kelly that describes a collection of iPod Touch apps (which should also on iPhone and iPad) and how to use them to teach Newton’s Laws of Motion.  Cool idea: use the games the students are already playing to teach them physics.

I want to add to her list my own favourite physics app. This one’s not a game so it might not – no, who am I kidding, will not –  have the same appeal. But xSensor (which, at the time I write this, is free!) is a great physics app because it gives a real-time readout of the accelerometer, in the x-, y- and z-directions. The pix below are screenshots from my iPhone (captured with that magical “click on/off and home buttons at the same time” feature.) Here are a couple of screenshots that show some cool physics. The app will also record the data in a log you can email yourself.

xSensor screenshot showing circular motion. The sinusoidal curves encode the constant centripetal force.

I made this one by putting my iPhone flat on my desk and swirling it around and around. The curves sweeps across the screen recording about 5 seconds of readings. The numbers on the screen, 0.02, -0.14 and -1.18 are the instantaneous accelerations measured in g’s.  The z-acceleration is pretty constant at -1 g. Can’t get rid of gravity… The accelerations in the x-direction and y-direction show beautiful sinusoidal motion, 90 degrees out-of-phase, encoding the centripetal force of the phone’s circular motion. It’s shaky because I can’t swirl my phone smoothly.

Okay, the “can’t get rid of gravity…” line was a strawman. Because you can. If you drop your phone. Which I did. Very carefully.

xSensor screenshot during free fall when, for a brief moment, the phone recorded zero acceleration.

These graphs show me holding my phone still. About halfway through the plot, I dropped it. For a short period of time, the acceleration in z-direction snaps up to zero g’s: free fall! Then there’s a big blip as I clumsily catch my phone and take the screenshot. But there, just for that moment in free fall, my phone appeared to be force free. That’s Einstein’s Principle of Equivalence: floating free in deep space is just like freely falling in a gravitational field. (That NASA link include the famous Apollo 15 hammer/feather drop video.) It’s not a Gedankenexperiment, though. It’s the real thing, right there in your hand! Well, you know what I mean.

So, don’t ban phones from your physics, astronomy or science classrooms: embrace them! Better yet, chuck ’em across the room!

Do you have a favourite physics app? Have you discovered another cool experiment you can do with xSensor? Hope you’ll share it with us.

Posted in interpreting graphs, physics, teaching | Tagged , , , | Leave a comment

Learning Multiplication

Posted on March 27, 2011 by Peter Newbury

I know a little bit about the differences between teaching with “blocking” or with “interleaving.” If you were teaching multiplication with blocking, you’d teach the “4 times table”, then the 5x, then the 6x and so on. With interleaving, you’d mix them up so students had to first identify what kind of question this is (“Oh, this is a 4x problem”) and then answer it. There is some nice work in cognitive psychology that shows interleaving leads to better retention.

I use the example of multiplication because that’s just what my 8-year-old was doing yesterday. He had a set of 5x flashcards that he asked me do with him. He didn’t have too much trouble, except for 5×9. As I was running through the cards, I thought of the multiplication table board I’d made a few years earlier when my other kid was learning multiplication. I remember being fascinated by a board like this when I was in Grade 3.

My home-made multiplication board. The green 1-10 along the top and left side are glued down. You put the 24-tile, for example, where the 4 and 6 intersect. Hmm, or the 6 and 4. Or 8 and 3 or 3 and 8!

The tiles are from a square hemlock spindle I got at the local hardware store, sliced on my mitre saw, sanded smooth, and then numbered. Green 1-10 tiles are glued across the top and down the left side. You put the blue 24-tile, for example, in the space where the 4 and 6 intersect.

My son and I got out this board, dumped the bag of tiles on the carpet, and he started to fill it in. The first row is easy: 1, 2, 3,…,10. Then he started on the second row. “2 times 1 is 2. 2 times 2 is 4. 2 time 3 is 6…” And about here, he stopped doing the multiplication and started counting by 2’s. I asked him how much 2 x 7 is, and he had to stop and think, despite the fact that he’d just placed the 10, 12, 14, and 16 tiles.

Uh-oh. My goal is to help him learn his times tables, I don’t want to reinforce repeated addition. What’ll he do with 104 x 56 next month?

So I turned the table on him. I started handing him tiles. “Here, where does this one go? How about this one?” That was pretty hard. For me, that is, because I had to quickly find the next tile I wanted in the big pile on the floor and hand it to him by the time he’d placed the current one.

I realize I was asking a different question: “What numbers multiply to give you 24?” is a lot different than, “What is 4 x 6?”. But this new version of the “game” worked nicely. He did some repeated addition in his head, searching for sequence that hit, say, 24. And he occasionally put a tile in the wrong place but I didn’t correct it. He discovered his mistakes as he lay down neighbouring tiles and the patterns were messed up.  It also forced him to estimate where in the empty board to place tiles any without neighbours.

He soon discovered repeated addition works vertically, too, so he could hop down the 4-column to find the 4x tables.

After a few minutes of this, I turned it up another notch (which was possible because there were fewer tiles left in the pile and I could find them faster.) I started handing him stacks of the same tile, for example, 4 40-tiles. “Here, put these down.” I only prompted him once or twice (“Well, if 4 x 10 is 40, what about 10 x 4?”) I was astonished how quickly he picked up the symmetry. “32 goes here at 4 times 8…Oh! And over here at 8 times 4!”

Older sister dropped by to help him with the high tiles – I don’t think my son’s had much practice with the 7x, 8x, 9x tables yet. The two of them finished off the board, fighting (in that friendly brother-sister way, of course) for who gets to put in the last tile.

There are so many patterns to explore on the completed board. We discovered where on the board to find the same tile (symmetric across the diagonal) :

Me: Here’s 7 x 3 and here’s 3 x 7. Here’s 4 x 6 and here’s 6 x 4. Hey, what’s up with 5 x 5? Where’s its match?
Him: It doesn’t have one, Dad, cause 5 x 5 is the same as 5 x 5. D’uh!

A friend dropped by with a 3-year-old and she asked the toddler to his age. My son helped, helping him find all the 3-tiles. And his 8-tiles. Then my daughter (who’s 11) dropped a little nugget that confirmed this “game” was worthwhile:

Well, I don’t have a tile because my age is a prime number.
[W00t! FTW, Dad!]

I’m sure the math ed people and elementary school teachers can tell me the history of multiplication boards and best practices for using them. But it was so much fun watching my son discover the patterns for himself. And to reinforce that math is something you can play with and — Zoinks! — even have fun with!

If you’ve got the tools and some patience (100 tiles is a LOT of tiles!) I highly recommend you make a set for your kid(s). Do you have any ingenious suggestions for what to use instead of cutting wooden tiles?

Creative Commons License Multiplication table  photo Peter Newbury is licensed under a Creative Commons Attribution 3.0 Unported License.
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Persian New Year

Posted on March 24, 2011 by Peter Newbury

Ali Narimani

Ali Narimani is a astronomy graduate student at UBC. Ali facilitates the labs we run in our introductory “Astro 101” course. While developing an activity about the motion of the Sun across the sky, we were trying to figure out why students should care about predicting the equinox. Ali excitedly said, “…because of Persian New Year!” He’s a great TA who cares about helping students learn and about his Persian culture. He emailed this story of Persian New Year to all the astronomers in our Department on Sunday, March 20, 2010, the day of the Vernal Equinox. With his permission, I’m posting it here.

[Update March 19, 2012: This post was originally published March 20, 2010. In 2012, equinox occurs on March 20 at 05:14 UT]

Persian New Year is celebrated at spring equinox of the northern hemisphere. Today at 4:20pm, we will start our new year which is also the first year of a new decade. Our new year does not start at a certain time of the day each year, but we should tune ourselves for the moment of equinox. (which is on March 20th at around 4:20pm, this year)

Tradition:

Traditionally, member of the family sit around a table called “Haft-Sin”, meaning “Seven S”, some minutes before the start of the new year and pray for a healthy, wealthy, and happy year. The table is called Seven-S because there should be 7 different objects on the table starting with the consonant S:

  1. Sprouts (Sabzeh) : is a symbol of *rebirth*
  2. Apple (Sib) : is a symbol of *beauty*
  3. Garlic (Sir) : is a symbol of *health*
  4. Coin (Sekke) : is a symbol of *wealth*
  5. Silverberry (Senjed) , is a symbol of* love*
  6. Vinegar (Serke) : is a symbol of age and *patience *
  7. A very Sophisticated Persian Cuisine (Samanou)

I have attached a picture of this table:

The table called "Haft-Sin", meaning "Seven S"

Right after the new year time, the usual part of celebration is hug and kiss, and the most fun part for the kids is to receive their new year gifts. New year holiday lasts for 13 days and during this period members of the big family (including all Aunts & Uncles) go to each other’s place for a visit. Younger members should visit elders first. The fun part of these short visits is that everyone wears nice new clothes, and again the kids receive some gift from their aunts and uncles. (the definition of Kid is a little vague in here since my grandmother still likes to give some “new year money”, kept in Quran for a couple of days for holiness, to my 65 year old father as new year gift).

Dance:

I have attached two traditional Persian dances:

YouTube Preview Image YouTube Preview Image

Bests

Ali Narimani
Department of Astronomy and Physics
University of British Columbia

Posted in astro 101, outreach | Tagged , | 5 Comments

Another day of agile teaching

Posted on March 21, 2011 by Peter Newbury

The prof I’m working with in our introductory #astro101 class at UBC surprised me today. I thought he was sabotaging a teachable moment when in fact, he pulled one of the most “agile” moves he’s made yet. Here’s the story:

Today is March 21, 2011, the first full day of Spring. The vernal equinox occurred yesterday, March 20 at 4:21 PDT. The instructor, let’s call him H, started today’s class with a clicker question:

The correct answer is A) but I fully expected a bunch of students to vote B), confusing the “going North” and “going South” for the Sun’s motion along the ecliptic.

The students thought, then voted. H looked at the results and said (I’m paraphrasing from memory),

The correct answer is A. 70% of you said that…

Oh, no, I thought to myself. He just gave away the answer and the success rate – only 70%, not terrific – and totally short-circuited the teachable moment that comes via peer instruction.

That thought took about 1 second, of course, so it was all over by the time H continued with

…Very few of you said B, C, or D and 30% said E. Let me show you one slide and then I’ll come back to the super moon.

The "super Moon" as seen from Vancouver. (Credit @gmarkham, used with permission.)

You see, there was another event this past weekend. The full Moon occurred near perigee, the point in the Moon’s orbit around the Earth when it is closest. This means we had a full Moon, closer than usual, so it appeared bigger. Super, even. Oh, and it was.

So, here I was, getting alarmed that H was missing the opportunity for the students who voted A) to convince the students who voted B) to change their answers. But that’s not what happened at all. Hardly anyone voted B. They either knew the right answer A) or were more interested in the astronomy-in-real-life super Moon event. And H agilely, er, with great agility, confirmed the correct answer and followed up with an something 30% of the students cared about. He talked about the full Moon, how it was 14% bigger and 29% brighter. Not twice as big – don’t believe everything you hear on TV. That’s slightly bigger and closer than usual but not much. And no, the super Moon did not cause the earthquake in Japan.

Wow. I was impressed. He had the whole thing planned out but tailored his response based on theirs. Cool.

What about you? What teaching have you done, witnessed or experienced that shows agility?

Posted in astro 101, clickers, teaching | Tagged , | Leave a comment

#eqjp, a teachable moment

Posted on March 11, 2011 by Peter Newbury

In my current assignment through the Carl Wieman Science Education Initiative in Physics and Astronomy at UBC, I’m working closely with a senior astronomy professor to help him better teach his general-education “Astro 101” course. It’s a mixture of providing resources, mentoring, helping him clarify what he wants the students to learn, and coaxing (sometimes dragging – he’s a great sport!) his teaching to a learner-centered approach.

Today was supposed to be the first class in the last, big section of the course, comparative planetology. That is, the characteristics of the planets and other bodies in our Solar System and, more importantly, what their similarities and differences tell us about the formation of Solar System some 4.5 billion years ago. Traditionally, one follows the textbook’s lead. Chapter 10: Mercury. Chapter 11: Venus,… Chapter 15: Saturn,… Chapter 20: Other Crap, Chapter 21: [finally!] Formation. And by this time, nobody remembers Mercury, Venus, or gives a damn. I’m glad to say we long ago scrapped that approach and instead, focus on the gathering and analyzing the evidence that points to a single formation event. Our learning goal states that a student will be able to

deduce from patterns and properties of the planets, moons, asteroids and other bodies that the Solar System had a single formation event.

Where was I? Oh, right, teachable moment.

Last night (March 10), there was a massive earthquake in Japan. Magnitude 8.9, one of the biggest earthquakes recorded. The ensuing tsunami(s) devastated parts of Japan. I pay attention to these things, perhaps more than others, because my home, Vancouver, is on the list of places expecting The Big One. And we can be hit by tsunamis caused by earthquakes around the ring of fire. Thankfully, the west coast of Canada and the U.S. were spared this time.

It occurred to me, on the bus ride to work this morning, we could use last night’s earthquake in class today. Seismic activity tells us about the structure and evolution of the Earth. Similar signs of earthquakes and volcanoes on other planets, or lack thereof, tell us about their structure and evolution. Not seeing volcanoes on a planet is just as telling as seeing them. Using the earthquake to introduce this last arc in the course would set the tone for the next month of classes: we don’t care about the exact surface temperature on Mercury or the exact density of Neptune. We care about patterns in the physical properties of the planets. And we care about how we find, collate and reconcile those patterns.

Shortly after this “A-ha!” moment, my brain countered with, “Is this a teachable moment. Or are you exploiting the earthquake because you can’t think of an interesting way to teach comparative planetology?”

So I tweeted…

…and, as usual, was overwhelmed by the quick and intelligent response of the great tweeps who follow me. Thanks @TanyaCNoel, @penmachine, @snowandscience, @cpm5280, @derekbruff, @erinleeryan, @cosmos4u. The overwhelming advice was take advantage of the teachable moment:

Good idea. Understanding is always helpful.
teachable moment. everyone’s talking about it anyway…
Definitely a teachable moment

I’m also thankful to @ptruchon for putting words to something that bothered me:

Tough one…Do some of them have family in Japan? If so, are they ok?

So, I went for it. And by went for it, I mean I decided to convince the prof to use the earthquake in today’s class. I proposed he could run the “Earth’s Changing Surface” lecture-tutorial but he decided against it. Instead, he used the earthquake to segue from “here are the 3 or 4 key patterns that support a single formation event” to “how do we know all that, anyway?” Through open questions  like, “What does the earthquake tell us about the structure of the Earth?” and “What does this picture [of Mars’ Olympus Mons] tell you about this planet?” he lead a nice discussion with the 170-or-so students in class today. Many students, men and women, from the front and the back of the lecture hall, participated.

A very successful class, in my opinion, one that demonstrated to me and himself and the students, how “agile” this prof is getting. I was proud that we were able to adapt our presentation so quickly and help the students learn about something they care about.

P.S. A special hat-tip to @cpm5280 who reminded me about that this earthquake was predicted, yes predicted, by the Super Moon wingnuts. I gave the prof a quick summary, just in case. And sure enough, at the end of class, a gaggle of students came down and asked him if he knew anything about the Moon being super-close on March 19. He hit them with a few, key scientific facts (in particular, that because gravity follows an inverse-square law, the tiny decrease in distance won’t do very much) and told them that the whole earthquake-prediction thing was, “a load of crap.” He used their language and they, like, totally got it.

Posted in astro 101, communicating science | Tagged , , , | 2 Comments