http://serc.carleton.edu/spaceboston/2010activities/46911.html#discussion http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12751 Laura Schofield 1277604360 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12751 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12754 - J]]> James Tanton 1277644800 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12754 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12755
Some random thoughts from me as a non-scientist as I read through things.

1. SUMMARY: Convection is a component of plate movement, but if I understand Lindy's lectures correctly, it is really ridge push and slab pull that is the primary cause of movement. Perhaps replace the word "major" in your final sentence with "a component of"?

2. DAY 1: I am wondering what the connection is with the popcorn activity and the discussion on matter/energy? Am I, as a student, meant to be linking the concepts "solid, liquid, gas" with what I saw and observed in popcorn making? Also, "heat only moves in one direction" - I am guessing you are going to be talking about atoms jossling about back and forth, but by "uni-directionality of heat" you mean that heat moves from hot to cold, even those the atoms themselves are jossling in all directions. Good to be clear about this with kids?


3. DAY 2: Lindy pointed out to me that melting butter won't really do it, alas. If you think about how butter melts in a pot, only the layer touching the pan melts and the top of the stick stays solid and, presumably, basically the same temperature.

I like the other two experiments. For the "passing the clap" experiment do you want to say that instead of being planted in place (solid) there is an intermediate stage of being allowed to run 5 paces down the line to another person (liquid: molecules "run" an average distance before bumping into another molecule) rather than have one person run all the way down? And then ask kids to model themselves as a gas and try out what this might mean for energy transfer. (e.g. they space themselves all about the room, and have to run a random direction, and they might or might not bump into anyone after a very long while.)

All this looks grand. I like it (by "it" I mean your activity unit!) Good stuff!

- J


]]> James Tanton 1277646120 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12755 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12785
I love this activity and all the thought you have put into it. I agree you'll have to fool around with the possible experiments but they all look promising to me, really good.

My main concern is with the popcorn activity. It seems to me that the action of microwaves on water molecules inside the popcorn, heat from convecting air that conducts into the solid popcorn, and heat from (possibly slightly convecting oil) that conducts into the popcorn might add up to too much complexity to be well-understood in your convection/conduction world. Perhaps just more discussion under teaching notes to explain how to make that activity most relevant.

I'm really eager to hear how this proceeds!

Lindy]]> Lindy Elkins-Tanton 1277734380 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12785 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12789
Thanks for you comments.

James,
My hopes with the conversation after the popcorn activity is to have students start thinking about how heat transfer is affected by phase, solid, liquid, gas.

As far as the clapping activity, I need to think this model out a little more. I, personally, need to get a better understanding myself of what is happening with the heat transfer at the molecular level.

Thanks

Lindy,
I agree with your thoughts on the popcorn activity, because in each of these "methods of making popcorn" you have more then one method of heat transfer, it is quite complex. I think this is why I wanted so badly to think of an experiment that teases, the methods of heat transfer, apart. I need to do some more reading myself - I've pulled out my college physics textbook to help.

Thanks,
Laura]]> Laura Schofield 1277740860 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12789 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12812
May I add to James's comments about modeling gases with the pass-the-clap model? That might be best done outside as gases under atmospheric pressures have a distance between particles on the order of ten times the radius of the particles. It might be hard to have enough space inside for average distance between student-particles to be on the order of 10 to 20 feet (or more, depending on how you measure the radius of a person--arms outstretched or at the side).

Just a chemist's point of view,

Aaron]]> Aaron Keller 1277751240 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12812 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12870
How great that you're working out a series of activities with materials that will give students information to make sense of as they develop their ideas about heat transfer. I'm sorry not to have good suggestions about materials for your heating solids. Will something like coconut oil or Shay butter pose the same problems as dairy butter?

The popcorn demo seems to me most useful as a way to focus students on recording procedures and observations, and might have a role that way. It doesn't seem like the most direct route to comparing convection and conduction.

Experiment 2 - is it worth trying this with discs of different materials?

Experiment 3 - I'm curious about this experiment and what it might yield. I'm imagining how it might work if the layers are of the same basic stuff (say, salt water, in more and less salty layers), and what might happen with different liquids...I'll be interested to hear more about what you try and how that fits into your big scheme!


Ellen]]> Ellen Doris 1277926800 http://serc.carleton.edu/spaceboston/2010activities/46911.html#post12870