Quasilinear Drift Of Cosmic Rays In Weak Turbulent Electromagnetic Fields

A general quasilinear transport parameter for particle drift in arbitrary turbulence geometry is presented. The new drift coefficient is solely characterized by a nonresonant term and is evaluated for slab and two-dimensional turbulence geometry. The calculations presented here demonstrate that fluctuating electric fields are a key quantity for understanding quasilinear particle drift in slab geometry. It is shown that particle drift does not exist in unpolarized and purely magnetic slab fluctuations. This is in stark contrast to previous models, which are restricted to slab geometry and the field line random walk limit. The evaluation of the general transport parameter for two-dimensional turbulence geometry, presented here for the first time for dynamical magnetic turbulence, results in a drift coefficient valid for a magnetic power spectrum and turbulence decay rate varying arbitrarily in wavenumber. For a two-component, slab/two-dimensional turbulence model, numerical calculations are presented. The new quasilinear drift, induced by the magnetic perturbations, is compared with a standard drift expression related to the curvature and gradient of an unperturbed heliospheric background magnetic field. The considerations presented here offer a solid ground and natural explanation for the hitherto puzzling observation that drift models often describe observations much better when drift effects are reduced.Comment: 23 pages, 6 figures, accepted for publication in Ap

John Calvin – Verbi Divini Minister

Ministering the Word of God was a first priority for John Calvin. Through researching his frequent references to the ministry in his sermons and Bible commentaries, it was possible to arrive at a better understanding of his views on the office of pastor and teacher (pastor et doctor). Although the ministry is no imperium, the people of God should honour the servants of Christ on the ground of the dignity of their Master. The ministry is a servitude, but not without authority, so that by it the glory of God may excel among his people and in the world. This is also the ultimate goal of the minister’s preaching, and to this end it should be clear and to the point. This article particularly pursues Calvin’s views on the requirements for a sound proclamation of the Gospel. It is argued that Calvin’s particular consideration of the broader context of a biblical passage in his exegesis points to the fact that he had already established the sound hermeneutic rule of ascertaining the intention of the author and the understanding of the first readers to get to the true meaning. Thus, in his preaching the application of Biblical truths was topical and to the point

L. J. du Plessis as “Politieke Profeet”

In I960, after serious differences of opinion with the Party leaders on matters of policy, the late Prof. L. J. du Plessis was expelled from the National Party. Since then, some of his views have become accepted policy, and others, such as for example the idea of a constellation of Southern African states, enjoy natio­nal scrutiny at the moment. In the present quest for a new constitutional dis­ pensation for South Africa, his views are still valuable. An issue for which he gained wide notoriety especially among the political leaders of the day, was his uncompromising rejection of the element of white supremacy in the policy of the National Party. In this he clashed especially with Dr. Verwoerd. His views on the problems of South African politics as well as the foundational bases on which these views rested, are discussed in this article