  While wormholes are as good a prediction of Einstein's theory as black holes,
they are subject to severe restrictions from quantum field theory. In
particular, holding a wormhole open requires a violation of the null energy
condition, calling for the existence of exotic matter. The Casimir effect has
shown that this physical requirement can be met on a small scale, thereby
solving a key conceptual problem. The Casimir effect does not, however,
guarantee that the small-scale violation is sufficient for supporting a
macroscopic wormhole. The purpose of this paper is to connect the Casimir
effect to noncommutative geometry, which also aims to accommodate small-scale
effects, the difference being that these can now be viewed as intrinsic
properties of spacetime. As a result, the noncommutative effects can be
implemented by modifying only the energy momentum tensor in the Einstein field
equations, while leaving the Einstein tensor unchanged. The wormhole can
therefore be macroscopic in spite of the small Casimir effect.
