On 24.11.2005, at 09:01, Hübner, Uwe wrote:

How can I start, for example, an 'infection' process with bouncing atoms?

If you get the halos, in the red halo there are three entries at the bottom:

startInfection set atom count show infection history

Is it possible to influence anything else in 'bouncing atoms' object?

Not too much... it's not possible to control the atoms or the atomMorph with eToys. The only things possible thus is 1) using the menu entries shown above, 2) change the smalltalk code (that's for the real hackers) or 3) do some simple things with direct manipulation.

I use 3) sometimes in demos to show the power of Smalltalk: You can e.g. copy a atom, change it's velocity (using smalltalk development tools), then put it back in.

That's a quite nice demo for showing the difference to people used to more static programming languages like C++.

For teaching things that go into the direction of what the bouncing atoms are (particle systems), you should look at Kedama.

english: http://www.is.titech.ac.jp/~ohshima/squeak/kedama/ german: http://www.mttcs.org/Skripte/Ang/material/kedama

I think this is part of the latest squeakland.org squeak version.

Marcus