Marvelous Items

These are items that we find to be marvelous.  We don't pretend to fully understand them (yet) but we think they are interesting/important.

Weierstrass function 

In mathematics, the Weierstrass function is an example of a pathological real-valued function on the real line. The function has the property of being continuous everywhere but differentiable nowhere. It is named after its discoverer Karl Weierstrass.