Fractional Calculus...? What?!?! I came across this Wiki article a couple of days ago: http://en.wikipedia.org/wiki/Fractional_calculus As a student who just finished an undergrad major in math, the idea of a "fractional derivative" or "fractional integral" is mind blowing! Up until I read the article, I pretty much thought that the differential and integral operators were "fixed." Let f:R -> R be a fcn. Geometrically speaking, if the derivative of a fcn f at a point p in its domain is the rate of change of the fcn at that point and the integral of a fcn over an interval in the domain is the "area under the curve," how can I interpret the fractional derivative and fractional integral?