density may be hard to imagine, but think of it like temperature.
How about I think of it as what is is; the amount of mass within a given volume?
Honestly what would prompt you to consider
density as a dimension unto itself?
If you have a pool full of unevenly heated liquid and you wanted to know the location and temperature and time of that liquid you would have five dimensions at one point. (x,y,z,t,temp) You could plot all of this at once on a graph for any fixed value of t (give the point a color for temperature).
Given a sufficient number of points, "temp" is redundant - I can figure it out from x,y,z, and t. Since temperature
is, after all, nothing more than motion over time.
At any rate I don't really see how this analogy makes a compelling case for treating density as a dimension.
™ Version 4.2
