in powder toy if you turn on radial gravity and make a solid mass it should simulate a planet. which means that if you made a hole all the way through the "planet" and droped dust particals in the whole it should fall all the way through the "planet", return to the hight you droped it on the other side of the "planet" and then fall back through the whole and since powder toy is a vacume with no friction or wind resistance this process should repeat itself untill you change something, since the only force acting on the dust would be gravity, all due to the law of conservation of energy. currently in the game if you perform the experament i decribed the dust will just collect at the center of the "planet."
okay, over time I might agree with that but if you perform this experament you will see that it dosent do what I say should happen even once.
in vertical, the gravity source is at the bottom. in radial the gravity source is a point near or at the center. if stuff were to pass right through that then the vertical mode would also have to follow that rule- but you don't want the particles to be bouncing back up onto the screen!
Do any particles lose energy to drag in extreme negative pressure? (i.e. -256)