Twistor space, Minkowski space and the conformal group (Q1074893)

Although twistors describe the geometry of Minkowski space, the symmetry of compactified Minkowski space is not that of twistor space, but the latter is four-one homomorphic to the part of the former which is connected to the identity. To clarify this puzzle it is shown here that a better definition of a symmetry group for twistors is the group of transformations of projective space which preserve orthogonality; this is isomorphic to the Minkowski symmetry group.