Variables and constants

Over the weekend, I was writing about how utterly random everything starts to seem when traveling. But "random" isn't the word I'm looking for here. A better word, I think, is "variable". Variable, as in changeable, mutable, unfixed. As opposed to solid, fixed, determined. Or in math terms, constant.

So, back to algebra class. A constant is a fixed value in an equation. It's always the same. X=3, Y=2, represented by a single Cartesian point on the graph. You are here, at this fixed point in space. Constants are easy, reliable. If you know all of your values, the answer to the equation is always the same. For x + y, if x=3 and y=2, you'll always end up with the answer "5", as opposed to, say, "7", "99.5", "dolphin", or "blueberry ice cream".  We humans like constants...