Tag Archives: science

A Good Dam Lesson

Wanted to throw up some thoughts and photos on the end of a pretty good dam lesson (hah) that I led this past week.  Briefly: it was built on the back of a unit about the interaction between water and landforms, which used stream tables (pictured) to do experiments about how water flow, slope, etc. change patterns of erosion and deposition.  Much of the unit was focused on the process of scientific investigation: asking questions, making predictions, running experiments, collecting and analyzing data, using that data to write a conclusion in which we also change our ideas about the mechanisms behind phenomena, and speculate about further experiments.

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This particular lesson took the unit in a new direction: kids got to create and imagine, and also got to learn about the design process.  They had a prescribed amount of certain materials (Popsicle sticks, straws, toothpicks) with which to build a dam in order to protect a tiny fictional town from flooding.  The lesson progressed from a class discussion about dams (including analysis of a picture of a dam on the Skagit river and discussion of the design features of that dam) to group-work on designing dams, to actually testing them in class last Friday.

The kids were SUPER into testing the dams, and as we tested them one-by-one, I made sure to ask 2 students who hadn’t been part of the dam in question’s design team what they noticed about the design (which resulted in lots of good vocabulary use) before the test, and ask 2 students who had been part of the team what they’d change, after the test.  All in all it was a very engaging lesson which clearly resulted in solid learning on the part of the students involved.

Coming out of this week, one of the main challenges I’ve set for myself is to be much more conscious about differentiation of instruction and assessment – to be much more intentional and explicit about these issues in my lesson planning.  In this particular lesson, this mainly manifested in me making sure to check in with as many students as possible about how the lesson was going for them – specifically, giving as many students as possible to answer my questions about the dam designs.  I feel pretty confident that I managed it with this lesson – I’m sure that the format of the lesson, with everyone gathered around and commenting excitedly about how the water was moving through the stream table, really helped some of my “focus students” stay engaged, and checking in with them throughout resulted in a strong impression on my part that they were getting the learning targets for the lesson (namely, parts of the design process and important design elements of dams, specifically).

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The Next Step

The first week of a new quarter of college classes is always a little surreal – doubly so when you’re also coming back into a learning-by-doing situation, i.e., teaching-methods classes where you have to jump right into figuring out how to help kids learn.

I’ve spent the last week being terrified that, over about 3 weeks of winter break (ah! the luxury), I forgot everything I learned last quarter.  This after I spent about 2 days compiling a digital portfolio of, essentially, everything relevant to teaching that I’ve learned or produced in the past year.  But I’m sure anyone who’s recently attended (or taught) any school knows what I mean: rooms full of students who stare blankly at the mention of even a simple concept which was delivered towards the end of the previous quarter.

Thankfully, my professors are doing a good job of including “briefly review such-and-such chapter” in their reading assignments, and I’m beginning to get my bearings back.  I’m very excited for this quarter, and for new secrets to teaching science and intermediate math and literacy to be unlocked – all three areas are going to be immensely helpful for me in my 5th-grade internship placement.  Science methods, in particular, is going to be a very fun class for me – I especially can’t wait for the chance to have some really meaty discussions regarding the purpose of teaching science, as well as how popular perceptions of it might help or hinder our attempts to do so.  I’m sure my readers will hear plenty more on this sort of thing from me in the coming quarter.

Anyway: here’s to a new quarter, and another step toward teacherdom.

Dyad Moon Science Reflections

This week, the middle-schoolers I work with had a science test.  The test covered a space-science unit which touched mainly on the Solar System, the Sun, the Moon, and the concept of scaling – i.e., representing sizes and distances at a different scale.  The kids were also challenged to make ample use of scientific notation in their answers: i.e., representing “1,000,000,000” as 1×10^9.

I started observing this class only a few weeks ago, and have only been in the class effectively once a week during that time.  I’ve observed my master-teacher’s science instruction, which included a lab on the orbital mechanics and phases of the moon which I thought was engaging and clear – students got their hands on flashlights, model moons, and small globes, and got to experiment of different “Earth-Moon-Sun” configurations to see how the position of the moon in its orbit affected how it would be seen by observers on Earth.  There was also a really cool performance task in which students were given a geometric shape on paper and tasked with measuring it, scaling it up by a factor of 2, and then building a wooden replica in the school’s well-equipped shop, painting the replica and then adding it to a tessellating puzzle of all the other student’s pieces.

Tessellation – not my class’s.

Here’s the problem: after all the above engaging, hands-on learning activities, the test showed that a pretty large portion of the students weren’t getting core concepts.  The question “Why do we on Earth only ever see one side of the Moon?” yielded results like the following: “Because the Moon doesn’t rotate,” or “Because only one half of the Moon is lighted by the Sun” (which is technically correct, but happens to be the answer to a different question).  The clearest indicator to me was the first answer, and those like it – “Because the Moon doesn’t rotate”.  (To clarify, only one side of the Moon is ever pointed toward Earth because it completes 1 rotation per month and one orbit per month – thus, its near side is constantly turning toward us as it moves around us.)  Clearly this concept wasn’t explained well.  Also, I didn’t get a chance to observe my master-teacher’s instruction on scientific notation – but it’s clear from the almost universal arbitrariness of students’ renderings of numbers in this way that this, too, is a concept which will need to be revisited.

My master-teacher was clearly frustrated, and the kids were clearly stressed.  Which is all perfectly natural, of course.  It left me with a very clear picture of experiences I’m likely to have in the not-too-distant future: seeing what hasn’t sunk in during the course of a unit, and then trying to figure out how to revisit it in a different way.  We re-start the unit with a different group of kids in 2 weeks – I’m going to get the opportunity to help teach parts of it, which I’m very excited for – and I’m very curious to see the changes my master-teacher might make to the curriculum, in order to better communicate these concepts and skills to this group of kids.

Just for fun, I’ll throw out one or two ideas of what I might do, had I infinite time and money:

1. Actual astronomical observation of the Moon.  Getting to see, as a class, the Moon’s progression through its phases over the course of weeks might make more impact than a lab in a classroom.  Too many people simply don’t look up at night, or make an ordered study of astronomy – that’s why it’s easy for average people to get such notions as “the Moon doesn’t rotate”.  The difficulty of this, of course, is the fact that we can’t exactly ask kids to come to school after sundown.  Or can we – maybe as a once-a-week activity for the course of the unit?

2.  Incorporation of truly huge numbers into scientific-notation instruction – for instance, the average distance from Earth to Alpha Centauri (our closest interstellar neighbor at 4.13×10^13 kilometers), or the breadth of the Milky Way galaxy (about 1.04×10^18 kilometers) – and then comparing them to each other.  Teach them how to add, subtract, multiply and divide in scientific notation to show kids how useful this notation can be – and to feed into the notions of scale which are the core of this unit, being able to know one quantity in terms of another.  I’m not sure the best way to package these ideas, but going through them in a more in-depth and, at the same time, playful fashion might help some students.

Which Bubble Will Fulfill My Dreams?

Standardized testing has been coming up a lot in recent readings and discussions in my education classes.  I find this fantastically well-timed, as I’m about to take my WEST-E exams in middle-level math and science.  Very briefly: the WEST tests are the state of Washington’s exams, the passage of which is required as part of one’s acquisition of a teaching certification.  In Washington.  I’ve already passed a handful of these exams; these next ones are specifically in pursuit of my middle-school-level science and math endorsements – i.e., they’re meant to prove that I have enough math-and-science knowledge to teach these subjects to 6th-thru-8th-graders.

Standardized testing is a monstrous issue in close orbit around the current maelstrom of American education reform, and I don’t intend to get deeply into all the pros and cons here.  I’ll simply state my position: that standardized testing has been given too much power to force American education in the wrong direction, and I am unsatisfied with the unthinking assumption that it is the best or most efficient method of “fixing” American education.  I am also unsatisfied with the unchallenged assumption that American education is “in crisis” in a way which can be positively affected by standardized testing.  Bill Ayers weighs in eloquently:

“Teachers, parents, and youngsters need to know exactly how the tests are made, who makes them and for what purposes, and who wins and who loses among test-takers.  Without this knowledge, our awe of the power of test scores is a bit like the folks admiring the emperor’s new clothes – everybody else sees it, so it must be there.  Armed with detailed knowledge of the process and the product, we may become like the little boy who can’t see the clothes . . .”

That’s from Ayers’ “To Teach: The Journey Of A Teacher”; Seth Godin’s “Stop Stealing Dreams” is of course also a good resource.  For a more comprehensive (and perhaps less biased) list of the pros and cons of standardized testing, here’s Procon.org‘s page on it, though I warn that many of the “con” arguments are very suspect – for instance, the statement “93% of studies have found student testing, including the use of large-scale and high-stakes standardized tests, to have a ‘positive effect’ on student achievement”.  What does that even mean?

Anyway, I’m looking down the barrel of not one but two standardized tests within the next three weeks.  I decided to get them out of the way early.  I wasn’t too worried about the math exam, as just last quarter I got a 4.0 in a college pre-calculus course – I think (and hope) that makes me safe in this case.  I wanted to make sure I had my science down, though – it’s been a long time since I covered biology or chemistry, for instance, in what I’d call an “academic” setting.

So I did the logical thing: I bought an expensive test-prep book.  My poison of choice was “WEST-E SECRETS: Middle Level Science (013)”, prepared by Mometrix Media LLC, which I now assume is a subsidiary of the Galactic Empire from Star Wars, or some similar organization.  Actually, no – I’m sure a product endorsed by Emperor Palpatine would probably be more devious in its method for crushing wills, rather than doing so merely by an accident of stupidity.

Let me explain what I mean with two selections from the practice test near the back of the book.

“18. Which of the following is NOT an example of one of Newton’s laws of motion at work? a) Once in orbit, a satellite will continue moving around the earth. b) It takes three times as much force to move a block that has twice the mass of another. c) A ball rolling across the floor will continue moving across the floor. d) When a shotgun is fired, the gun moves sharply in the opposite direction of the bullet.”

Now, according to the answer-key, the correct answer is B, and a quick calculation shows that if Force = Mass * Acceleration (Newton’s 2nd Law), and I have a block weighing 1kg, I would need a force of 1 Newton to move that block at an acceleration of 1m/s/s.  If I then had a block weighing 2kg, I would need 2 Newtons of force to move the block at the same acceleration.  Here’s the problem: the only information the answer gives is that I have to move the heavier block.  It doesn’t specify a desired acceleration.  The 2kg block will still move when 1 Newton is applied – at 0.5m/s/s acceleration.  Basically, the statement in B could be true, if a desired acceleration were given – but as it’s written, it could certainly be false.

Compare that with answer A, which the book says is in fact an example of Newton’s laws – the answer key explains that we’re looking at Newton’s 1st Law here – “An object that is at rest will stay at rest unless an external (unbalanced) force acts upon it.  An object that is in motion will not change its velocity unless an external (unbalanced) force acts upon it.”  Notice that I emboldened velocity.  I did this because a satellite in orbit around the Earth is constantly changing its velocity – that, in a way, is what distinguishes an “orbit”, when you’re talking about the trajectories of objects in space.  One object is circling around another, constantly being attracted by the orbited object’s gravitational pull – i.e., constantly being acted upon by an outside force, which stops it from hurtling off into deep space.  The satellite’s speed may not change – well, not significantly, and not if it’s in a near-perfect circular orbit as opposed to an ellipse, and not if it’s in a high enough orbit to avoid friction with the Earth’s upper atmosphere – are you beginning to see why I began to feel, as I stared dumbfounded at this question, that answer A seemed the least perfect picture of one of Newton’s laws, and therefore must be the correct answer to this question?

Here’s one more example, and then I’ll get out of your hair.

“17. Which of the following properties of a meteorite moving through the planet’s atmosphere would change as it approached the surface of the Earth? a) mass b) volume c) density d) weight”

The book’s answer: D, weight.  The correct answer?  All of them!  As an object descends through Earth’s (or any planet’s) atmosphere, it encounters tremendous friction as it has to force its way through dense clouds of molecules which weren’t there when it was happily traipsing through the vacuum of space.  This friction heats the object rapidly and to extreme temperatures; heat causes it to expand (lowering density) but also to burn away (lowering volume and mass).  I’m fairly certain that the book-answer took into account only the phenomenon of the mass of the meteorite getting closer to the mass of the planet, thereby increasing the gravitational attraction between them, which is measured by weight; though by the time the rock hit the planet’s surface (if indeed it got that far), its weight would be much less than if the unaltered rock were somehow teleported straight from the vacuum of space to the surface of the planet.

If this question had been written: “As an asteroid approaches the Moon, which of its following properties will change?”, then, in my mind, D – weight – would be an acceptable answer – the Moon has no atmosphere.  (Another technical point to bring up is the choice of the word “meteorite” in the original question – it’s only going to be called that by geologists who dig it out of the ground, after it hits.  In space it would be an asteroid; within the atmosphere, it would be a meteor.)

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Now, I must stress – the above questions are not actual questions from the WEST-E exams, they are questions from a test-prep book which I’m now convinced was prepared by some underground cult of reptilian humanoids bent on world domination.  But nevertheless, they’ve got me worried; I’ve been bingeing on Khan Academy lectures ever since I took the practice-test and got an atrociously low score.  The above questions were only the most confusing and poorly-written selections from the prep book – there were many others which I got wrong simply because it’s been perhaps 10 years since I’ve been required to remember the obscure biology and chemistry terms demanded by the test – which is the other problem with these exams, really: they’re testing one’s ability to cram, and nothing more.  (This also proves to me, at least, the uselessness of the traditional treatment of topics in science: as a boot-camp of term memorization, the unconnected data easily forgotten within a year of the final exam.)  So cram I must, and cram I will.  Will there ever be a point in my life when I can consider myself free forevermore from cramming?  Only time will tell.

Image-ining Education Exercise

This hearkens back a few weeks – one of the first exercises I engaged in as part of my teaching certification cohort involved finding 5 images which convey my reasons for deciding to teach.  Everyone had fun with this one, but the original assignment called for images only – i.e., no further explanation of why the images were chosen, which led to some interesting assumptions when we all got to go around the room and examine each other’s slide-shows.

I decided to post my slide-show here – with some additional explanation, thank you very much.  Enjoy.

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This is Jupiter.  It symbolizes my passion for science.  This is a huge factor in my decision to teach – this subject matters so much to me, I have enjoyed engaging with it for almost longer than I can remember, and I am excited to show my students how amazing an experience it can be.

Incidentally, I’m hoping to build my summer-house on Callisto, Jupiter’s outermost large moon and one of the outer Solar System’s best candidates for human colonization.

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This one, as you might imagine, drew the most comment.  Why on Earth would you use an image of global destruction to convey a reason for teaching?  My answer is that I have tremendous concern for the future of humankind.  Not only do we currently have the technology to make Earth practically uninhabitable within a matter of hours (see above), but within the next century, if we do nothing – if we simply allow ourselves to keep on as we have been – we will make this planet a hell for ourselves.  Temperatures will rise, crops will die, and billions will starve.  It’s as simple as that.

The only way to avoid that future is to be smarter.  To be honest with ourselves about our flaws, and figure out a way to work together to correct them.  The key to that is education, and I want to be at the forefront of that struggle; it’s too important for me to take a back seat.

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No, I don’t remember what species of bird this is.  The picture symbolizes my sympathy with my students.  I’ll be teaching middle-school, a time in students’ lives when they are struggling with immense change, and being confronted with questions like “who am I” and “how do I face the world”.  In a sense, they are learning to fly.  I want to be there during that process – to guide, or to nudge, or simply to watch – whatever they need of me.  I want to see every single one of them take wing and be a silhouette against the sky.

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Yes, we’re seeing a theme here.  This photo symbolizes inspiration – something I feel personally whenever I read about human triumphs in science and exploration, and something I want to infuse into every other human being.  That stuff I was talking about before, about avoiding worldwide destruction?  That will take a monumental amount of inspiration, and I seek to inject it into my students.  With a giant syringe.

This picture symbolizes the idea that, given sacrifice, will, and hope, human beings can achieve the incredible – for instance, touching the surface of the Moon, something our species has dreamed about for tens of thousands of years (at least).

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Finally, here I’m trying to symbolize my hope for humankind’s future.  If we manage not to blow ourselves up, or bury ourselves in sludge, or do any number of awful things to ourselves, then maybe we can survive longer than an eye-blink of galactic time.  Space colonization, interstellar travel, a human empire among the stars; all these things are physically possible.  But they are expensive, and difficult, and require that we survive first.  I want to do whatever I can to get us there; I have decided that the best way I can contribute is in the classroom.

The ship pictured in the image above is a form of Bussard ramjet, one of the cleverer concepts for interstellar travel so far proposed by the minds which muse upon these topics.

Image credits:

Slide 1: https://lh3.googleusercontent.com/-Zmk5-5vkE6w/SfZb_Nr45ZI/AAAAAAAAAKg/2j5YFOqUjKQ/s471/jupiter.gif.jpg

Slide 2: http://b.vimeocdn.com/ts/452/223/45222386_640.jpg

Slide 3: https://lh6.googleusercontent.com/-iUVQCryaW4s/UAF5x1oFPmI/AAAAAAAAALQ/Sf4PLOQa2Us/s640/29%2529%25207-14%2520all%25204%2520back%2520in%2520nest%2520IMG_1783.JPG

Slide 4: http://i113.photobucket.com/albums/n233/glasscottage/Politics/Apollo11.jpg

Slide 5: http://th01.deviantart.net/fs47/PRE/i/2009/233/2/2/Daedalus_Starship_by_GuilleBot.jpg