High-velocity jets of fluid are encountered in both natural and man-made settings. The geyser, the fireman's hose, and the rocket exhaust are notable examples. Study of the fluid mechanics literature reveals the axisymmetric fluid jet as a fundamental fluid configuration that is rich in physical features. It is the purpose of this paper to discuss a few basic, but important, aspects of the behaviour of a water jet and ways that they may be directly observed by the senses, without recourse to sophisticated measuring devices, to the benefit of science and engineering students of all ages. These are observations which may be readily performed in undergraduate laboratories or even as homework assignments.
Laser-induced break-up of water jet waveguide