  We compute the static potential in a non-commutative theory including a term
due to UV/IR-mixing. As a result, the potential decays exponentially fast with
distance rather than like a power law Coulomb type potential due to the
exchange of massless particles. This shows that when quantum effects are taken
into account the introduction of non-commutativity not only modifies physics at
short distances but has dramatic macroscopic consequences as well. As a result,
we give a lower bound on the scale of non-commutativity (if present at all) to
be compatible with observations.
