Which way *does* it curl? And is it related to the tippy top problem?
A curling stone curves in the same direction relative to its spin and
velocity as a curveball. It is melting and refreezing ice (called
"regelation") as it moves down the ice sheet. It is a complicated
system, but it looks simple. It is my opinion that it is unrelated to
the tippy top phenomenon since the stone does not precess, but I've
had no success with any other approach either.