Yoshiki,
I was helping my son with Chemistry and the question on his test was "Which has more molecules, a liter of frozen vegetable oil or a liter of liquid vegetable oil. So I reminded him the experiment we did with the balloon and how it contracted when we put it in ice water and expanded when we warmed it up.
Then I thought your Particles Dye in Waterhttp://squeakland.org/showcase/project.jsp?id=7429project and tried resizing the Kedama World (which didn't work) I was able to change the worlds scale. I eventually created two separate Kedama worlds in another project each with 500 turtles and scaled them to convey the idea.
I wanted to make a copy of the Kedama World (two avoid creating the same scripts twice), to show the "Dye in Water" model with different tick rates at the same time to facilitate comparison (which is easier when you can see both at the same time). This idea came from my youngest son who suggested we try the Dye in Water with Ice Water and Hot Water.
So, couple of things:
1. Can you change the size of a Kedama world (w/o changing the size of the turtles?) 2. Just curious why does each edge have its own mode (bouncing, wrap, stick) as opposed to one for all? 3. How can I model the color changes for a Particles in Dye project. I was thinking of something along the lines of having the colors "mix" when the dye and water were in the same spot (or in the other's patch) but wasn't sure how to do that. I assume it has to do with setting the red/green/blue component from/into patch, but couldn't quite figure it out. 4. How can I add an extra turtle to a world? (ex: dye and water)?
Lastly I really love your question: "Is there really such a thing as a molecule? How can we avoid asking you just to believe it?" I have been posing this question to a bunch of folks including some professors at Princeton. Two of the three said something like "that's a really good question, I don't know I've just always believed it" One just got this big smile and said, "its a model and we use experiments to see how well the model works."
Thanks, Stephen