[IAEP] [Its.an.education.project] An example on statistical dynamics on XO

[Yoshiki Ohshima]

  Hi, Greg,

> - I'm not familiar with the formula  PV = nRT. I can't say that the
> sample app taught me it either :-( Is it Pressure * Volume = a material
> constant (n) * R (?) * Temperature?

  Yes, basically.  n represents "amount of substance", and the form is
what learned as the "Boyle-Charles's law", but probably the variation
of the same idea is taught slightly different form around the world.
R is the constant also that depends on the unit system you use.  (And,
it looks like "k" is commonly used.)

http://en.wikipedia.org/wiki/Combined_gas_law

> I can look it up, but tried to learn
> from the description and 10 minutes with the app. If the formula is the
> central point, put the variables names and values on the screen.

  Yes, that is a good idea.  Can you make a good one^^;?

> Understanding ratios is not trivial. Two variables in a linear
> relationship is about all I can hold in my head. Seeing the numbers
> change on screen may help.

  The numbers are all available, except volume.  Pull out ceilingpos
variable's watcher from the KedamaWorld's tab to see the volume on
screen.
  
> - In general, I suggest you start with the phenomenon and not the
> equation. Show something happening and then let the user discover the
> relevant variables and how they interact.

  Yes.  In physics and science, that should be done off computer.

  My example is after people see/learn about the real phenomenon.

> Historically speaking, how was
> the formula originally derived?  Start from there and see if you can
> update it to some modern day activity.  Mentos in a coke bottle is the
> latest buzz on home experimentation in my house:
> http://www.youtube.com/watch?v=hKoB0MHVBvM

  Well, I guess that wasn't the latest buzz^^;

> If you could simulate that by changing the pressure rapidly it would
> tie it to the real world.

  That kind of non-linear change might be hard to do in simulation,
especially in Etoys.  (The explosion part in my simulation is not real
simulation.)

> - More options to tweak would be good. Let the kids "pour" a
> substance in and examine the results. What if the "molecules" are
> made of milk or oxygen or water or neon?  Have a small library of
> items and then allow the kids to create new ones. Maybe they can try
> it in the physical lab then try it on the computer. Can they adjust
> the temperature? Dials, buttons and switches make it more fun to
> use.

  Well, this is an important point, I think.  It really just depends
on what you would like to simulate and teach.  Remember that computer
itself is rather like mathematics than physics.  For a simulation of
physics phenomenon, it is perfectly ok to do simplifications *as long
as it is honest*.  And, again, what we should avoid is to try to make
students believe something without proof from real world.

  If you provide the "library of substance" such as "milk" on
computer, how do students know that milk's behavior reflects the real
world's milk?  You can do whatever you like on computer, but imitating
the nature in false way on computer is more harmful than simple but
honest simulation.

  Yes, I think they should do it in the physics lab.

> I didn't look at the eToys implementation so maybe adjusting the
> variables is more clear there.

  What?  (I was writing above under the assumption that you at least
looked at it.)  What do you mean by not looking at the Etoys
implementation?  All implementation is shown on that screen!  Clicking
on the shooting star icon to start Etoys, then click on the Gallery
cloud, and click on the thumbnail and all implementation is visible to
you.  It was three clicks but was I asking too much?  Or, you felt
that you need to look at how the entire particle system is
implemented?

> However, I don't want to spend time looking for and tweaking the
> code. I just want to play with the options.

  You can certainly play with the options in Etoys version.

> If I wanted to learn
> how to program squeak that's different but here I want to learn
> physics or chemistry and the programming is extra work.

  You don't have to learn how to program Squeak.  It is Etoys.

> - Just brainstorming suggestions. Let me know if any don't make sense. I
> suggest you get a science teacher to comment. Also, find a kid to play
> with it.

  Do you think we have never done that?

> - The bubbling cauldron of experimentation paradigm looks like a real
> winner to me! Let the kids throw stuff in and see what happens. E.g. add
> water, then lower the temperature (may not fit as water expands when
> temperature goes down!).
> 
> "Double, double toil and trouble;
> Fire burn and cauldron bubble. "
> >From Macbeth
> 
> HTHs. Nothing like a real application in development to get the creative
> brain thinking :-)

-- Yoshiki