[bkcooper]

The Wikipedia article on fractional calculus mentions that fractional derivatives are not local in the same way that integer derivatives are. Is that right? That seems profoundly weird in the context of differential equations.

[danbruc]

Because the local behavior is already completely captured by integer order derivatives there is no information remaining that could go into fractional order derivatives. You could maybe just make fractional order derivatives interpolate between neighboring integer order derivatives but I guess that may cause some problems and a non-local definition just makes more sense.