Fractional Calculus

In reviewing emails of current published papers I came across the idea of "fractional calculus."

Frankly, I had never heard of such a thing so I did some searches. The link above is to Wikipedia which has a good discussion of this. Here's another good link.

It seems that fractional calculus is the generalization of standard calculus to fractions of derivatives. We usually talk about the "first derivative" of a function, and the "second derivative" of a function. So, why not talk about the "one and a half derivative" of a function. Seems like we could do that.

In fact, that can be done. Just what that means and why you would want to do it is something for another day. Today, it's interesting that it can be done.