  In this paper we introduce a proposal for the kinematics of bodies in uniform
circular motion. This model could contribute for the explanation of the two
main problems of contemporary cosmology: dark matter and dark energy. We use
one of the physical properties of space - the gravitational waves - to define a
reference frame at rest with respect to the space and to determine a mechanism
for the synchronization of clocks. So we derive through a Postulate the
so-called transformations of Lorentz and a new velocity of the bodies in
uniform circular motion. This rotational velocity could contribute to clarify
both cosmological problems. This contribution would come from effects due to a
single phenomenon: the rotational velocity of bodies with respect to the
reference frame at rest on the space. And finally, we interpret physically the
Postulate - the major point in this model - which allows, inclusive, a
comparison with the Relativity Principle and also new theoretical previews.
