Tag: kids

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.

Making memories stick. With Play-Doh.

My boss, Carl Wieman, likes to describe what we do as “looking for the pattern of how people learn science” (as he does in this video.) And the places to look are classroom studies, brain research and cognitive psychology. I certainly agree with the first place – that’s teachers and teaching. And research like this, that and this other thing about how the brain physically changes while you learn in very cool – that’s science. But cognitive psychology? I’ve been a science geek since, well, since before I can remember anything else, so I really haven’t been exposed to psychology and those other disciplines they teach on the “Arts” side of campus.

Carl says it’s important, though, and I trust him, so my colleagues and I read a cognitive psychology paper for our CWSEI Reading Group “What College Teachers Should Know About Memory: A Perspective From Cognitive Psychology” by Michelle D. Miller (College Teaching, 59, 3, 117, (2011)). Here’s a link, if you have access from where you’re clicking.

The paper is a nice summary of the models of memory. Short term, long term, working memory, ecological (or adaptive) memory. Here’s my interpretation. Every bit of information that’s stored in memory is accompanied by “cues”. Think “tags”, like the ones that accompany this blog post. When you see the cues, you recall the memory, just like finding blog posts by clicking on a tag. Without the tags, finding posts means paging through the archive. With a tag, you can zero in on the post. And the more tags on the post, the easier it is to find. Same with memories: the more cues linked the memory, the easier it will be to recall later.

Not all cues are created equal, though. As Miller puts it,

[u]nderstanding the role and importance of cues enables a richer and more accurate understanding of why people remember — and forget — what they do. (p.119)

Miller carefully crafted descriptions of the kinds of cues that trigger recall, so while I’m cutting them into a list and adding some bold, these are Miller’s words (p. 120):

Here are what I believe to be the cues that trigger us to “tag” information as being survival-relevant:

sensory impact, termed vividness: Concrete information that comes accompanied by sound, visual qualities, even tactile sensation tends to be more memorable than abstract information. Visual information is particularly salient to human beings, so that anything that can be visualized tends to be particularly memorable.

emotional impact is another cue that incoming information warrants long-term storage. Consider situations that relate to survival in a “natural” setting—a sudden danger, a new food source, encountering an enemy—and all would come accompanied with an emotional “charge.”

relevance to one’s own personal history is another indication that information will be useful in the future

structure and meaning—the ability to interpret information and put it into context—helps us distinguish useless background clutter from information that we need to keep

personal participation, as contrasted with passive exposure. This will come as no surprise to those familiar with the “active learning” trend. If we watch someone else do something, that activity may or may not be relevant to us, and it we will likely opt not to form a detailed memory of it. However, if we ourselves carry out the action, there is a greater likelihood that we will need to learn from and recall that experience later. We may also encode a richer set of cues when we are actively involved, which increases the likelihood of retrieving the information later.

Don’t you love it when you read an article that concisely and explicitly describes all those things you feel, in your gut, are important? It’s times like this that make me re-evaluate my naive and, frankly, prejudiced view of psychology, “C’mon, how can you possibly know how humans work?” “Oh, like that, ” he says, sheepishly. “Um, thanks. That’s cool!”

The week my colleagues and I read this paper, I was preparing the next activity for an introductory, general-education astronomy course I work on. This activity, like the others I’ve written and am sharing through the Astro Labs page on this blog, is a chance for “Astro 101” students to get some hands-on interaction with astronomy. Up next was the activity on black holes, especially spaghettification.


Talk about a made-up word, huh. Not by me, mind you. Chat with any astronomy instructor and you’ll find we all know exactly what it means because it’s the perfect word to describe what happens if you fall into a black hole.

<astronomy lesson>

A black hole with the mass of the Earth would only be about the size of a grape. Imagine it this way: if you could pack together and compress the entire Earth down to the size of a grape, the force of gravity would be so strong curvature of spacetime would be so high that not even light, traveling outwards as the speed of light, could escape.

That describes trying to get out a black hole. What about falling in? Let’s imagine you’re 2 metres tall and your lying on your back with your feet 2 metres from the black hole and your head 4 metres from the black hole. You can see it down there, between your feet, a little shiny grape a couple of metres away. It’s okay to think classically here, for a moment. Gravity is very strong but, being an inverse square law, it drops off quickly: your head is 2 times farther from the black hole than your feet so the force of gravity is only 1/4  as strong. What do you suppose happens when the black hole pulls 4 times harder on your feet? They get ripped off, that’s what. Your body gets stretched out as your feet accelerate towards the black hole, leaving your knees, hands, chest and head behind. This difference-in-forces is called a tidal force because these same kinds of forces occur in the Earth-Moon system where the Moon yanks on the water on Earth’s near-side and leaves the far-side water behind, giving us the tides. Newton worked that one out for us, more than 300 years ago.

The force of gravity between the Moon and the water on the near-side of the Earth is stronger than the force between the Moon and the more distance, far-side water. Earth's watery skin is deformed, giving us the tides. (Graphic: Peter Newbury CC)

Meanwhile, back at the black hole, the hapless astronaut is being pulled down a little funnel that ends up on the grape-sized black hole. Happy astronaut one second, long and skinny piece of spaghetti the next. Spaghettification, baby!

</astronomy lesson>

Ouch, that’s gotta hurt! LOL. Yeah. But how do we get Astro 101 students to remember it a month from now on their exam? Play-Doh, that’s how. Our activity progresses from setting up the phenomenon of tidal forces, to sample calculations demonstrating tidal forces are real, to recreating the spaghettification of a Play-Doh astronaut.

An astronaut falling into a black hole, before spaghettification...
...and after!

Here’s where the part about memory comes in. Students are potentially reluctant to play with Play-Doh. This is University. We’re not Children anymore. Teaching assistants and instructors are equally reluctant to ask students to play with Play-Doh. “Why,” they wonder, “should I?”

Because, I tell the teaching assistants who, if necessary, relay it to the students, it will help you remember. Playing with Play-Doh, stretching the poor astronaut’s legs, often pulling them right off his body, and squishing the Play-Doh into to a narrow strip, is tactile. And emotional – you just ripped his head off, dude! It gives relevance and a physical structure to those calculations. And it takes personal participation – oops, I just pulled his leg off!

Good in theory but how about in practice? The activity ran. The teaching assistants sold it. The students did it. All of them! Now we just have to see if they (1) learned anything and (2) can remember it. For (1), one of the questions they answer at the end of the activity is, “In your own words, describe what happens to the astronaut. Why do you think it’s called ‘spaghettification’?” Here’s one student’s answer, typical of many I thumbed through:

as the astronaut falls toward the black hole, feet first, its body stretches as it nears the black hole. the closer body parts (feet, then hands) stretch faster and fall faster than the head and body. It’s called spaghettification because the legs and hands stretch elongate like spaghetti.

Yep, I’ll take that. Would have been nice to see the word “tidal” in there but he did make the connection between closer and faster. For (2), we’ll be sure to put something on the final exam that tests this material. I’ll let you know in 4 weeks.

As my pop likes to say, “learn by doing.” Let’s update that to, “remember by doing.”

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!