  We suggest a new scenario of gravitation in which gravity at the fundamental
level is described by a Riemannian (i.e. locally Euclidean) theory without the
notion of time. The Lorentzian metric structure and the notion of time emerge
as effective properties at long distances. On the other hand, at short
distances, higher derivative terms compatible with the Riemannian
diffeomorphism become important and the system is described by a power-counting
renormalizable Riemannian theory.
