It came and then it went. It went and then it came. To and fro, back and forth, never ending. What is this thing that simply goes and comes, comes and goes? This is the question asked. Is it a pendulum? The tides? The orbits of the moon? The planets? The galaxy? The universe itself? Is it a tiny atom, vibrating in its place? An electron? What is this thing that comes and goes, goes and comes? This is the question asked. The answer is simple.