title: Rapidly changing radio images.
abstract: Differences in total transit time can give rise to images that expand at arbitrarily high speed. Two versions of a model based on this idea can account for the varying microwave structure reported for the quasar 3C 279. Other possible examples are suggested.
authors.forename: A
authors.initials: A
authors.lastname: Cavaliere
authors.forename: P
authors.initials: P
authors.lastname: Morrison
authors.forename: L
authors.initials: L
authors.lastname: Sartori