public void update( final double ct ) {		
		// get the array of entities
		final Entity[] entities = getEntities();
		
		// update all entities
		for( final Entity entity : entities ) {
			entity.update( ct );
		}
		
		// check for collisions
		for( final Entity entityA : entities ) {
			for( final Entity entityB : entities ) {
				if( ( entityA != entityB ) && entityA.isAlive() && entityB.isAlive() ) {
					if( entityA.intersects( entityB ) ) {
						// allow each entity to handle the collision
						entityA.handleCollsion( entityB );
						entityB.handleCollsion( entityA );
						
						// did entity A die?
						if( !entityA.isAlive() ) {
							remove( entityA );
						}
						
						// did entity B die?
						if( !entityB.isAlive() ) {
							remove( entityB );
						}
					}
				}
			}
		}
	}