Porcupines can NOT throw their quills. Porcupine vision is poor, but they have an excellent sense of smell. Porcupines make shrill screeches, whines, and low grunts. Porcupines are vegetarians, and they eat a large variety of plants, shrubs and trees. Baby porcupines are called porcupettes..
Freebase (0.00 / 0 votes) Rate this definition: Divergence. In vector calculus, divergence is a vector operator that measures the magnitude of a vector field's source or sink at a given point, in terms of a signed scalar. More technically, the divergence represents the volume density of the outward flux of a vector field from an infinitesimal volume around a given point. For example, consider air as it is heated or cooled. The relevant vector field for this example is the velocity of the moving air at a point.
The beam divergence of an electromagnetic beam is an angular measure of the increase in beam diameter or radius with distance from the optical aperture or antenna aperture from which the electromagnetic beam emerges.The term is relevant only in the far field, away from any focus of the beam.eam divergence is often used to characterize electromagnetic beams in the optical regime, for cases in which the aperture from which the beam emerges is very large with respect to the wavelength.