  Precision measurements of the possible coupling of spin to other scalars,
vectors and pseudovectors has proven to be a sensitive way to search for new
particle physics beyond the standard model. Indeed, in addition to searching
for exotic spin-spin interactions, studies have been undertaken to look for
couplings of spin to gravity, the relative velocity between particles, and
preferred directions. Several laboratory experiments have established upper
bounds on the energy associated with various fermion spin-orientations relative
to Earth. Here, we combine these results with a model of Earth in order to
investigate the possible long-range spin-velocity interactions associated with
the exchange of ultralight ($m_{z'}<1$ neV) or massless scalar or vector
bosons. We establish stringent bounds on the strength of these couplings
between electrons, neutrons, protons and nucleons.
