public BouncyBallSimulation(Planet simulatedPlanet, Ball bouncyBall) {
		if (simulatedPlanet == null) {
			throw new IllegalArgumentException("The simulated planet can not be missing!");
		}
		if (bouncyBall == null) {
			throw new IllegalArgumentException("The bouncy ball can not be missing!");
		}
		bouncyBall.addHitGroundListener(this);

		this.simulatedPlanet = simulatedPlanet;
		this.bouncyBall = bouncyBall;
	}