A survey of armature transition mechanisms

Over the last two decades, several mechanisms of armature transition have been postulated. Each mechanism has been subjected to experimental and analytic examination with the objective of "explaining" transition. However, no single mechanism has emerged as the consensus cause of transition. In this paper, we take the position that all the mechanisms that have been identified, and perhaps others which have not yet been, contribute to and may be mutually influenced by those processes leading to the onset of transition. Our inability to correlate transition with a single mechanism, or model, results from the multiplicity of mechanisms at work. We examine all the mechanisms identified to date, suggest several additional ones, and explore a more complex transition world in which each transition event is potentially caused by a different mechanism or combination of mechanisms. With this picture, control of transition requires that we control all of the mechanisms which can result in transition, not just one.