  One of the deepest insights from the general theory of relativity is the
relational nature of spacetime. While it is a generally agreed on that the
nature of spacetime must be drastically different at the Planck scale, it has
been a common practice to assume a full pseudo-Riemannian geometry of spacetime
no matter what the physical fields present are, and to apply such geometry to
cosmology. In the spirit of preserving the relational description of spacetime,
we initiate a discussion on the applicability of general relativity all the way
to Planck scale, and propose the possibility that the full pseudo-Riemannian
geometry emerges as late as the time of electroweak phase transition when
spacetime acquires the projective structure necessary to describe the motions
of massive particles. A brief discussion of possible properties of spacetime
prior to electroweak symmetry breaking is followed by an exploration of
plausible experimental indications that such transition is real.
