Quote: "@andrew, if you would stack perfectly round bowlingballs exactly on top of eachother, this would happen. But mine are sort of elastic balls and the engine finds no solution for this problem and therefore explodes."
Still you couldn't realize it as long as there were influences like air, gravitation etc. And if the balls were "perfectly round" you wouldn't even be able to find the correct positioning for making them stay on each other. *cough* Well.. I better stop now.
It's of course a cool program. I had some fun with creating a "room" out of this static balls, trying to get the pseudo-goo-balls out of a whole in its top with the arrowkeys...