void calcGravityForce() {
		double scalar;
		double dist;
		for(int i = 0; i < mass.length; i++) {
			dist = distances[i].length();
			if(Math.abs(dist) > 0.001) {			
				scalar = PhysConstantEnum.gravitationalConstant.value() * weight * mass[i] / 
						(dist * dist * dist);
				distances[i].scalarMul((float)scalar);
				gravityForce.add(distances[i]);
			}
		}
	}