Tag: science

Six-legged spiders

Here’s a quiz for you: what’s wrong with these pictures?

Black widow spider
Black widow spider
Advent calendar
Pyramids at Giza

Did you find anything wrong? Surely you noticed the black widow spider has only 6 legs, not 8.  Here’s the original – I amputated one leg with photoshop for the pic above. If you rolled-over the pyramids picture and saw the reference to National Geographic, you might suspect the pyramids are in the wrong locations. Not in this picture, though: there’s nothing wrong it. (source)

What about the picture from the advent calendar? If you’re at all familiar with this blog and my passion for teaching astronomy, you might have guessed I’m going to tell you about the Moon and its incorrect phase.

And you’d be right.

The November 25, 2011 edition of the Guardian carried the story, “Your moons are rubbish, astronomer tells Christmas card artists.” The offending advent calendar shows the Moon in the waning crescent phase:

As astronomer Peter Barthel correctly points out, this phase rises around 3:00 am and sets around 3:00 pm. No matter if this Moon is rising, setting or somewhere in between, you’re not going to find people caroling in the town square. The artist got the wrong phase. In fact, Barthel has done much more than point out this one flawed calendar. In an article submitted to the journal Communicating Astronomy with the Public, he finds errors in artists’ depictions of the Moon in everything from Dora the Explorer to Christmas wrapping paper, from the Netherlands to North America.

The responses to the Guardian story, and its offspring like this Globe and Mail piece, seem to fall into three camps:

  1. “Oh, puh-lease! It’s just a picture on a calendar! Gimme break, you grinch!”
  2. “Oh, c’mon! Everybody know the Moon cannot be in the waning crescent phase in the evening!” (I suspect the Guardian reporter might fall into this camp because he writes, “[t]he phases of the moon are easy to grasp.” As someone who teaches astronomy and studies astronomer education, let me tell you, for the vast majority of people, they’re not.)
  3. “Oh, dear.  Another case of scientific illiteracy.”

Me? I’m in Camp 3. Why can’t an artist do some fact-checking before drawing the Moon? Does the artist think to himself, “I wonder if that’s the right phase? Ah, screw it, whatever.” I doubt it. It’s more likely a lack of recognition that the phases of the Moon follow a predictable, understandable pattern. That is, most people don’t even realize you can ask a question like, “when does the waning crescent Moon rise?”

Or worse yet, there’s a distinct possibility that people (yes, now I’m talking about more than this one, particular artist — the problem is widespread) are completely unaware of the Moon, other than the fact that we have one. Why, just recently a colleague said to me, “I have no idea about phases. I never look at the Moon.”

Which brings me back to the six-legged spider. If you bought a book for your kid with a six-legged spider, you’d see the error. Would you draw in a two more legs? I would.  Even your kid would see the error and tell you the book is rubbish. Why the difference between spiders and the Moon, then?

“Because spiders are something everyone sees every day.” Uh-huh, like the Moon.

“Because spiders are icky and gross and awesome. And the Moon is, like, science-y. Boooorrrring…”  Damn.

What do I think we should do about it? I’d like people to learn some astronomy, sure. More than that, though. I want people to think scientifically. I want to live in a world where people have the awareness (and freedom) to stop and ask, “Really? Are you sure about that?”

That’s a tall order so let’s get on it. We can start by modeling scientific awareness for our kids,  students, friends. Show them it’s okay to be passionate about math. Show them it’s okay to step off the sidewalk onto the grass to look at a bug or an interesting stone. Read them stories that engage their brains. Don’t buy books, wrapping paper or calendars with incorrect science. And if you accidentally do, don’t laugh it off with a “whatever…” It only takes one or two of those for kids to learn the science is dumb and only grinches point out mistakes. Instead, take the opportunity to talk with them about how we should always be curious about how things work.

A society of scientifically-literate people? That’s a world I’d like retire in.

Thanks, Mr. Barsby

Today, October 5, is World Teachers’ Day 2011. My twitter stream is full of people sharing stories about their most memorable teachers. I can’t even finish reading the first sentence of any of these stories without thinking of my teacher, John Barsby. I don’t know if I ever properly thanked him for what he did for me. One blog post is far from enough but it’s a start.

Mr. Barsby, or JTB as we called him amongst ourselves, was my high school math teacher. I went to St. John’s Ravenscourt, a private school in Winnipeg, MB. (Thanks, Dad, by the way, for sending me there instead of River Heights and Kelvin.) There were about 80 kids in my Grade 8, enough for 3 classes. For math, they divided the kids into 2 “regular” classes with excellent teachers, I’m sure, and 1 “advanced” class for the kids who held promise in math. Or something. That was Mr. Barsby’s class. And I was in it.

This happened each year so I was lucky enough to have JTB every year, from Grade 8 until Grade 12. When I think back to high school, this class was my cohort, the group of close friends and familiar friends with whom I got through high school.

I don’t have time to describe all the things that happened in that classroom. One, I’ve got a meeting in 45 minutes and 2) high school was a long time ago and I’m turning into an old fogey, according to my daughter. But two things not just float to the surface of my memory, but jump from my memory whenever I think about JTB.

Ants by ceoln on flickr

He taught us about positive and negative numbers using red ants for positive, say, and black ants for negative. Whenever they meet, they eat each other. Red ants plus red ants means lots of red ants. Black and black: lots of black. But put red and black together and the total number of ants goes down. And what is good for red ants? Taking away some black ants: that double-negative is a good thing.

To this day, when I see one of my kid’s addition and subtraction exercises, in my mind I see what it looks like when you kick over an ant hill. Ants, red ones and black ones, scurrying about, adding and subtracting, until all the reds or blacks are gone and we’re left with just the sum.

That was how he taught us math, from positive and negative numbers right through to the 1st year University of Manitoba calculus course he somehow managed to teach us at our school. He used analogies and everyday experiences so we didn’t get bogged down in the mechanics of math. He taught us concepts.

[At this moment, I have to take a break cuz I’m gettin’ all teary-eyed. Happy tears, but still… Damn.]

Here’s what else I remember and it’s what I’m most thankful for. Even then, way back in Grade 8, I asked a lot of questions. Not stupid questions (“Mr. Baaaaarby, did you forget to square the 3 in the top line…?”) Well, maybe as many of those as the next kid, but the ones I remember were different. From what I know now, I was asking questions that made me more expert-like. Sense-making questions, which in math are often “push it to the limits and see if it still makes sense.” Like, when N gets really large, does the perimeter of an N-gon turn into the circumference of a circle? It does? Oh, cool.

I clearly remember some not-so-great moments when I’d toss out another of these. My classmates would groan, “Oh great, another question from Peter…” I could have stopped asking. I almost did. But I distinctly remember talking to my dad about not knowing what to do, and how he told me to tell my classmates, “to go suck eggs!” and keep asking questions. And I never, NEVER remember Mr. Barsbsy groaning or giving me the slightest hint of annoyance. In my head, I don’t remember any of his answers to questions but I still feel the comfort, the warmth (help me out here, I’m a science nerd with very little practice writing about feelings…) with which he welcomed and addressed my curiosity.  It’s the same feeling I’ve always had with my Dad (thanks again, Pop!).

I still ask questions. A lot of them. One of my role models is Simplicio from Galileo’s Two New Sciences. Simplicio asks a lot of questions of the wise and learned Salviati. Good questions. I like to think it’s almost like he knows what’s coming and asks just the right question at just the right time to help Salviati explain his discoveries. There’s a great line where Salviati says something akin to, “Ah, yes, excellent.  Let me just draw a diagram here in the dirt…” (I’ll update when I find it. Help me out?)

You see, I’m no longer afraid to ask those questions, the ones I suspect (or know) that other people have but are embarrassed to ask, or the ones I know (or suspect) will help the expert spit out a concept in a way the audience will get it. I’m quite happy to play the naive fool and put up with the occasional, “Oh no, here he goes again…” But I pick my questions carefully and thoughtfully. Just the right question at just the right time.

For the ability to ask think up those questions and the guts to ask them, thanks, JTB. You, too, Pop.

Sending bottle rockets to new heights (of learning)

My Twitter streams crossed this morning and before I even got to work, a blog post about kids, STEM, learning science, teaching science and rockets was practically spilling out of my head.

It started with a tweet from @physorg_com (h/t to @andrewteacher and @fnoschese) about this column “Don’t show, don’t tell? Trade-off between direct instruction and independent exploration” The researchers gave pre-schoolers a new toy with varying amounts of instruction and then watched what they did with the toy. The kids who were shown how one part of the toy worked could replicate that action, usually, but didn’t find all the other cool stuff the toy did. Kids who didn’t receive explicit instruction figured out much more about the toy. It’s a nice article – have a look if you have minute or two.

The article reminded me of my own experiences with the PhET physics simulations and some research the PhET developers have done (damn, can’t find the ref but I’m sure Wendy would be happy to point you in the right direction). The least effective way to use the sims is to give students a recipe (“Do this. Now click here. Measure this. Now do this. Now this….”) Better but still not terrific is just letting the students play with the sim (“Here’s a cool sim. Play for a while and see what happens.”) The most effective way to use the sims, in their studies anyway, is to give the students a goal or challenge (“Make the light bulb shine the brightest!“)

The other crossing Twitter stream started with @mrsebiology

The ensuing conversation with her and @irasocol reminded me of how I throttled up our UBC Summer Camp bottle rocket activity so it was much more than just something to fill the kids’ time.

Image by richpt on flicker (CC)

Bottle rockets are a popular activity with kids and families. My friends at the H.R. MacMillan Space Centre run Saturn 5 Saturdays where families bring a 2-litre pop bottle and build and launch their rockets. [Update 30 June: the next Saturn 5 Saturday is July 16, 11am – 2 pm. Thx @AskAnAstronomer] The rockets blast into the air, the kids (or leaders!) get soaked. They chase the rockets as they plummet back to the ground. It’s great fun.

But suppose you have the time, manpower and goal to make the activity educational, not just entertaining.  The recipe method (“Build the rocket like this: fins, nose cone, give it a name, now stand back as I launch it. Wheee!”) is fun, yes, quick, yes. Educational, not so much.  There are two ways we turned our rocket activity into a learning experience:

1. A rocket science experiment: What makes the rocket go highest?

How much water do you put in the rocket? More fuel = higher launch, you’d think. And how much pressure is best? Again, bigger is better, right? We made one set of tokens that read “low pressure”, “medium pressure” and “high pressure”. A second set has “empty”, “1/3 full”, “2/3 full”, “full”. One by one, the rocketeers pick one of each, setting the parameters for their launch.

After the launch, the group will decide if it was  a good one. Once, we tried using inclinometers to measure the maximum height of the rocket but that was waaaay too messy and confusing.  Instead, before they start launching, I ask them for 3 adjectives to describe bad, okay and great rocket launches. The group decides on words like “lame!”, “ok”, and “awesome!” Their rockets, their results, their words.

Then it’s onto to sending the rockets skyward on a ribbon of water.  After each one, we record the result in the matching cell in our results table:

low pressure medium pressure high pressure
1/3 full awesome!
2/3 full
full lame!

As the Table gets filled in, we start making predictions and then testing them.  It’s pretty funny to watch the full, low pressure rocket. The rocketeer and the rest of the group know what’s going to happen — when you pull the release on the launcher, you hear a tiny “pop” and the rocket falls over. It’s no surprise that the higher the pressure, the higher the rocket goes. But it is surprising that the 1/3 full rockets go the highest. There’s an interesting compromise being having lots of fuel and getting that fuel off the launch pad. The thrill of discovery is pretty cool.

And none of that occurs in the recipe method where the leader takes the rocket from the rocketeer, fills it 1/3 full (we already know that’s the best volume, you see), and then launches it. Don’t tell them the answer. Perhaps, don’t even shepherd them to the solution. Instead, provide them with tools and feedback so they find their own way. (Oh geez, that was the thread on physlrner this morning in response to this interesting “Socrates = Border collie” post.)

2. Add a parachu–, er, safe return system

After watching that many rocket launches, some kids start to get bored. You’re outside so let them go off and play tag or hide-n-seek for a while. But some rocketeers are aching to launch again. And again. And again. So turn up the challenge.

I usually bring out a box of “stuff”: cardboard, file folders, string, tape, plastic bags, elastics, etc. and tell the kids they can launch again but only after they’ve added a parachute to get their rocket safely back to Earth. They usually form small groups by themselves – two head are better than one. @mrsebiology tweeted back “the parachute option is part of the ‘final exam’ challenge.”

This morning, though, I had a great conversation with @irasocol about this added challenge. Perhaps saying “parachute” gives too much away and directs them too much. Who knows what they might think up — the space shuttle is a glider, right? Ira tweeted

Yes, I--, er, my son, has this amazing Lego space shuttle set.

Which got me thinking, in the real world, we don’t care about the rocket, just the astronauts. The next time I run one of these rocket activities, here’s what I’m going to do: Give each kid a Lego mini-figure and challenge them to get the astronaut safely back to the ground. Capsule with parachute? Sure. Glider strapped to the side of the rocket? You betcha. Another idea I can’t even imagine? Absolutely!

There you have it, some ideas on how to throttle up your bottle rocket activity into an opportunity to engage in science, problem solving, engineering. Oh, it’s still fun. But now, so much more.

Do you have your own ways to send this activity to new heights? Please add a comment and share them with us!