> ... is exactly the same reason why we can add displacements on a slide rule ... I know this analogy was intended to help understanding, but I'm curious - are

> ... is exactly the same reason why we can add displacements on a slide rule ... I know this analogy was intended to help understanding, but I'm curious - are most people actually familiar with slide rules work? Just for reference: I'm an engineer in my mid thirties, and I know what a slide rule is, and might even be able to correctly identify the object if it were placed in front of me, but I've never actually seen one (let alone used one), so the analogy you've made is meaningless to me. My girlfriend who's a few years younger than me and also works in tech is vaguely familiar with the concept of the device but had never heard of the term "slide rule". My father is also an engineer and only used one for one class when he was in high school.