[galaxyLogic]

> Javascript code doesn't just stop executing for no reason,

I would say it stops unless there is something keeping it running.

Think about your single-page-web-app. When you click on some widget on it a click-handler triggers and executes that code. But then it stops. When the user doesn't interact with your web-app no JavaScript is typically executing, unless you have set up a repeating polling loop with setInterval().