  The vector nature of magnetic fields and the geometrical interpretation of
gravity introduced by general relativity, guarantee a special coupling between
magnetism and spacetime curvature. This magneto-geometrical interaction
effectively transfers the tension properties of the field into the spacetime
fabric, triggering a variety of effects with profound implications. Given the
ubiquity of magnetic fields in the universe, these effects could prove
critical. We discuss the nature of the magneto-curvature coupling and
illustrate some of its potential implications for cosmology.
