Tune shift with amplitude of the system. When the tune reaches resonant values, it can be unstable, and thus a tune-shift with amplitude can limit the stability region, or dynamic aperture. In classical mechanics, a simple example of a system with tune shift with amplitude is a pendulum. In accelerator physics, both the transverse and the longitudinal dynamics show tune shift with amplitude. A simple model of the transverse dynamics is of an oscillator with a single sextupole, it is referred to as the Hénon map. Another model for this case is the Standard Map. An important example is the typical case of distributed
Metaphor grasp a concept" and "to gather what you've understood" use physical action as a metaphor for understanding. The audience does not need to visualize the action; dead metaphors normally go unnoticed. Some distinguish between a dead metaphor and a cliché. Others use "dead metaphor" to denote both. A mixed metaphor is a metaphor that leaps from one identification to a second inconsistent with the first, e.g.: This form is often used as a parody of metaphor itself: An extended metaphor, or conceit, sets up a principal subject with several subsidiary subjects or comparisons. In the above quote from "As You