circle with any negative attraction causes ring to disappear

[jon_joy_1999]

I've got a scene here: [link at end] that contains just the standard killer planes, no killer objects, no thyme scripting, no brains. the ring is attached to the background via the center hinge, and the white dot is fixated to the background (I think) via the central fixate. check these matters yourself, and tell me if you see different things. if things are as I understand them, press play, and tell me what magic I had to make my space station environmental ring DIE
http://www.algodoo.com/algobox/details.php?id=60108

[jon_joy_1999]

the central dot is supposed to have a negative attraction force, to provide a psuedo-gravity inside the ring

[emilk]

Algodoo attraction (and repulsion) always work on the center of mass of an object. For a ring, this means the center of the ring. To get more accurate attraction, segment the rings into several objects.