> physics programs are supposed to offer interactivity. Else whats the point?

To solve differential equations for which analytical solutions do not exist?

Edit: Differential inclusions, if inequality constraints are included in the system (as they would here).

Of course it depends on what the goal of the program is, but something like this should offer user interactivity. By solving whatever is necessary (or faking it).

a) I know, that is still WIP :) b) There is no friction, and as Newton's First Law states "an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force" :)

Hey, again no offense meant. I just think the whole point of something like this is to mimic the real world. And after a couple of seconds my illusion is broken. Ps. It is cool, just needs to be cooler :)

ahah, no worries it will get there! In the meanwhile you have to give me also some "suspension of disbelief" for the sake of enjoyment :D

hehe. Best of luck dude! :D

The link is for interactive demos.