I don't know wheather or not this is important here, but I want to tell you this the same."I had something else in mind."
Come on, tell us!
Cat
As I said before, this is abstraction, for this reason I don't know if I can say this...
Frankly speaking, I don't believe that our Universe has three dimensions, for me the Universe can have a lot more dimensions like the Universe according to string theory, for this reason my thought isn't something new after all. Anyways, returning to our previous speech, the graph in question could have more dimensions by adding another dimension to a drawn three-dimensional graph. This is my thought, I know this could seem strange (and it is), but if physics is the application of math, everything is possible.
I nearly forgot, I want to say that this graph can describe a point, but even a curve, in a four-dimensional Universe, this is useless but we can do it...