The channelling of radiation or particles into a beam. Jets are emitted in beams along the rotation axis of an accretion disk around protostars and at the centres of active galaxies. The radio emission from pulsars appears to be emitted along the object’s magnetic axes. Other examples of beaming include secondary cosmic-ray showers, which are observed mostly around the zenith due to the increased atmospheric absorption at large zenith angles. See also Relativistic Beaming.