Imagine yourself as a child lying on your back, gazing up into a cloudless sky, and blowing soap bubbles through a plastic ring. As a bubble drifts up into the sky, you watch it rise, and this brings your attention to the sky. While you are looking at the bubble, it pops, and you keep your attention right where the bubble had been. Your awareness now lies in empty space. -B. Alan Wallace, "Tibetan Buddhism From the Ground Up"