In gravity theories with extended supersymmetry (extended supergravities), a graviphoton is normally a superpartner of the graviton that behaves like a photon, and is prone to couple with gravitational strength, as was appreciated in the late 1970s. Unlike the graviton, it may provide a repulsive (as well as an attractive) force, and thus, in some technical sense, a type of anti-gravity. Under special circumstances, in several natural models, often descending from five-dimensional theories mentioned, it may actually cancel the gravitational attraction in the static limit. Joël Scherk investigated semirealistic aspects of this phenomenon, stimulating searches for physical manifestations of this mechanism.