Daily Sheet Snippets (again)

I got really excited when our group…, and we came out with what we feel are valid claims that…

It makes sense to me that… what I’m still confused about is…

I feel like we have made sense of…based on the assumption that…

I feel like …., but still want to hear the last groups’ argument on…

What does not make sense to me now is… Is it … or …? It makes sense that it would be…

I really liked the example of… Seeing it this way helps to show…

I was wrong in my original prediction where I thought…, because…

Our claim from Monday about… really confuses me now.

I feel like … is beginning to make more sense. I think that after observing this weekend, it may come together more.

It makes sense to me that… I changed my mind after…, because I now know…

After thinking about…, it makes very little sense.

I’m really blown away with… I never would have guessed that.

I like tinkering with… it helped me to visualize

I do not understand the theory for how… The group has not explained it clearly enough yet.

When we did…it made more sense. Now I realize that…

I believe that it cannot be… or else we would … We do not see…, so it must…

I don’t understand the way that… If it’s…, wouldn’t we see…?

What made sense to me is that… we were able to see that there is no way for… but there is at some point, but when? And how? What’s the difference between … and …?

Initial Moon Ideas in Inquiry (Brain Dump, Processing)

In Inquiry, we have two not-yet satisfying theories to explain the moon phases:

Shadow-Theory: The first is that the earth can act as an obstacle for the paths of light from the earth, thereby being capable of casting a shadow on the moon. As the moon passes behind the earth, it can move into the shadow either fully or partially, creating moon’s phases. This idea clearly places the new moon as occurring when the moon is on the far side of the earth.

Cupping-Theory: The second is that the rays from the sun can only “cup” half the moon–the side facing the sun. When the moon is between the moon and the earth, you are staring at the uncupped side which is dark. You don’t see the moon because the lit side is facing the wrong way for you to see it.

  • One problem this group is facing is that they *want* the full moon to be when the moon is opposite the sun, but they can’t figure out how the light rays get to the moon. That is, we know we’ve seen a full moon at night, but we can’t figure out how the light gets there, when the moon is tucked behind the earth. Here are possibilities we came up with:
    • Maybe light scatters off the atmosphere of the earth, like the way we’ve seen light scatter off tissue paper.
    • Maybe light “turns” and bends around the earth–the way we’ve seen happen with glass.
    • Maybe light is getting to the moon from other objects besides the sun–star, planets, redirected sunlight off of asteroids.
    • Maybe the sun is so big that there can still be straight paths that get to the moon, even when it’s behind the earth. Maybe the problem is we aren’t drawing things to scale.
    • Maybe the moon orbits around the earth north-south, not east-west, so it’s never behind the earth.

Love those ideas.

Anyway, there was lots of movement in class towards the cupping theory (which by the way it’s called cupping because the student was trying to show which side of tennis ball was lit by cupping their hands around one half of the ball). I acknowledge what made sense about the idea, while really selling the problems we had identified. Another problem also came up, in which, a student said that the new moon explanation doesn’t really make sense, because it seems like that would be more of an eclipse, when the moon passes directly over the sun.

Moon Orbiting

The idea about the how exactly the moon orbits around the earth has lead to some other ideas as well.

One group claims that the moon orbits the earth in the opposite directions that the earth spins. This group has some ideas for why this makes sense to them, and I’m not sure yet, but I think it has to do with thinking about what an app on their phone is showing them.

One group claims that the moon orbits the earth in same direction that the earth spins. This group claims that this can explain why the moon appears to rise later and later each day.

Other have floated the idea that the moon might changes its orbit, or that it’s orbit might not be perfectly with equator, or perfectly north-south, maybe it’s at an angle.

What about Moon Spin?

Another group worked during the day to develop the claim that the moon doesn’t spin. I pressed them to collect evidence for it, and they are working diligently to exam all the photos we’ve collected over the semester to prove that the same side of the moon is always facing toward the earth. Curious to see where they have gotten.


Thoughts about Directions for Tomorrow:

Push groups to seeing if by using props, if we can model all the moon phases by either casting shadows or by creating different moon cuppings. Then, bringing the challenge to representing those 3D models in 2D diagrams. Basically, right now our theories only discuss new and full moon, and I want to push the span of those theories to see how and if they can explain other phases.

Getting our orbit ideas well-developed enough so that they can be linked to observations. One group has done this–linking their model to moon rise times. But we need to do same thing with north-south orbits–what would we see differently in the earth was passing more northward or southward.

Scale! I’m stuck on whether we should try stick to things we can figure out from direct observations. OR, letting them first think about and look up the distance information… and then beginning modeling those scales. Going out to the football field with props, figuring out to diagram things to scale, and what implications that can have on whether light can get to the moon when it’s behind the earth.

I need an opportunity to problematize what N,E,S,W means, and how to relate that to maps, globes, our earthly perspective. That’s always a trouble.

Groups, of course, are interested in other questions

  • How is moon seen differently in different parts of the world?
  • Why does moon sometimes appear BIG, sometimes appear different colors?
  • Where did the moon come from? How would life on earth be different without the moon?
  • What’s the relationship between moon and the tides?
  • Is their a relationship between moon and the seasons?
  • Why does the moon appear to “turn” throughout the day?

Moon Clock!

Oh! Last idea that is really cool. The group that is focused on the claim that the earth rotates the same way the moon orbits the earth is using a cool clock analogy. They are claiming the moon only orbits a little bit each day. They are saying how when you look at a clock, you can see the second hand moving, and that’s like the earth moving–you can tell the earth is moving by watching the moon/sun. It’s harder to tell the minute hand is moving because it doesn’t move very far, you sort of have to wait a minute, and you can tell it’s moved. They think the moon is like this, it’s moving so slowly, that you can’t tell in a given day that it’s moved, but if you wait a day, you can tell it’s moved. They have this diagram labelled, “moon clock” that I haven’t yet had a chance to learn about, but I’m intrigued.


Observational Markers that Force(s) are Happening

In teaching physics, our plunge into forces has been:

#1 Qualitative observations with hover pucks, consolidating observations into generalizations about what effect doing nothing, tapping, and pushing has, to some degree following the activities and discussion outlined by Kelly O’Shea.

#2 Introduction and practice with system schema diagrams, followed by readings and discussion about the ontology of force, interactions, and force pairs, and what this has to do with understanding / learning the force concept.

#3 Yesterday, we formalized our ideas into specific observational markers that force(s) are happening. We then worked our way through reasoning, discussing, and collecting observational evidence that a table exerts in upward force on a book, largely following the instructional sequence outlined by Clement.

Here are our observational markers for force(s) happening

Squishing or scrunching–visible deformations like when you stand on a carpet, or lie down on pillow top mattress.

Stretching or elongating–like when you are stretching a rubberband, or using pulling back a slingshot.

Sound + contact: Two surface in contact with accompanying sound–a baseball bat hitting a ball and making a knocking sound, or scratchy sound of sandpaper over wood,

Tightness or taughtness–like when a string is pulling you can feel the string is tight and see the string is more straight than it would otherwise be.

Bending–standing at the edge of a diving board, you can see the board bending.

An object is speeding up, slowing down, turning around, or changing direction.


Tomorrow, we try to quantify operational quantify amount of force, largely following the thinking and experimenting outline by Arons, which is really trying to bootstrap back and forth off observational marker #2 (about stretching) and observational marker #6 (about speeding up). Here is the gist:

  • Use an uncalibrated spring to tug on an low-friction cart of certain mass. First, try to keep the amount of “stretching” constant and pull. See what effect that has on mass using motion detector. Verify that this is repeatable–same stretching of string attached to cart always results in the same acceleration. And verify that it doesn’t just speed up but it’s speed up with a relative constant acceleration when you have a relatively constant spring stretch.
  • Stretch the spring to different amounts, and see how the effect changes, using same cart. We don’t assume linearity or spring force–i.e., don’t assume twice as much stretch = twice as much force. Instead, see what acceleration happens with different stretchings. This allows us associate the spring stretch with a specific acceleration for known mass, without making assumptions about the spring.
  • Motivate and invent a unit of force– for example “1 Robert” could be an amount of force that will accelerate the known mass at a rate of 1 m/s/s. Label various spring stretches in terms of their Roberts.
  • Now, vary the mass to see what effect that has–what effect does a “1 Robert” force have on different masses. Construct various plots of Acceleration vs. Roberts for various masses.

Curious to see how this goes.

I’d probably be OK if this was all they really took away from my class

“It’s amazing how much the children already know, and it makes me wonder how much of our own knowledge was “oppressed” buy vocabulary and worksheets.”

“I am learning in this class that you build off what the children know.”

“I have always thought I had to teach a lot of background knowledge before actually teaching the topic. It is amazing how much children already know or can come up with–ideas that are closely related to the topic and will guide them to the “right” answer.”

“What I have started to realize is that student’s have more of that information then I am giving them credit for,… taking information from experiences that they already have to apply to the new topic.”

“I am definitely guilty of assuming students this young are not capable of in depth discussion and critical thinking.”

Redirected Sun: Same Light or New Light?

In inquiry, many groups today wanted to say that every point on an object (like a tree) acts like its own source of light. And they wanted to call each point on the tree a secondary source of light, because objects like trees only act like sources of light when there is a primary source of light (like the sun) shining on it. One group talked about this being like a food chain. Plankton is a primary food source, but things that eat the plankton become food for other things. We don’t say that only plankton is food, because everything in the food chain is food for something else. And so with light, everything that sunlight hits becomes a source of light itself. The secondary sources of light need primary sources, just like links up the food chain need primary sources.

Others in class didn’t really like the idea of calling objects like trees sources of light, even if we acknowledge their secondary nature. One argument is that objects like trees are not sources of light; because they merely act as obstructions that can redirect the light. They don’t produce and source out any light. Many in this camp would, however, be OK with saying that objects like glow in the dark stickers can be sources of light, because they can glow on their own, even once the primary source is taken away.

A wedge point became whether or not the light coming off objects was the same light or not, and if it is the same or different, what exactly is the same or different.

Some of the ideas that emerged were the following:

When sunlight comes upon an object like a point on a tree, the light that comes off the tree is

  • Essentially the same light that came from the sun, simply redirected along new paths. The light that comes to the tree and off the tree is just light. Light is light is light. 
  • New light altogether, because the “sun light” was first absorbed and then different “tree light” came off. The “tree light”is the color of the tree, not the sun. 
  • The same light that came with the sun, but now with something more it picked up from the tree. The sunlight is now green, because it now carries the tree color with it.
  • The same light but filtered–in the process of hitting the tree, some of light from sun was absorbed and some of the light was redirected. The green light is redirected, but other light is used for photosynthesis.

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