Online communities

“Our online community provides a dynamic forum for you to discuss current topics and concerns with the wider education community.“ This quote is taken from the Teachernet website [ ], but could be claimed to apply to any number of education sites. Increasingly, online content is being complemented by with opportunities for readers to interact with each other or participate in debate. This article will look at the proliferation of such ‘online communities’. It will consider how they might be used to support teachers and school managers, how they might be most effectively used and how ‘virtual’ communication complements and overlaps with the ‘real world’. Finally it challenges the very notion of this dichotomy. What then is an online community? Simply it is community, a collection of people, who are communicating or working together online. Often the term is used to describe the software or online space – “Click here to enter our community” – but if it is a true “community” then it must involve a defined membership, however loose that definition

The Divine Liturgy as Mystical Experience

Most characterizations of mystical experience emphasize its private, esoteric, and non-sensory nature. Such an understanding is far removed from the original meaning of the term mystikos. For the ancient Greeks, the ”mystical’ was that which led participants into the awareness of a higher reality, as in the initiatory rites of the ancient mystery cults. This usage was taken over by the early Church, which similarly designated the Christian sacraments and their rites as ”mystical’ because they draw participants into a higher level of reality. I argue that the Divine Liturgy is a form of ”mystical experience’ in this sense, and that philosophers have missed a great deal by excluding such communal acts from the scope of mystical experience

Sharing the Love, Feeding the Hungry

The biblical injunction to share one’s bread with the poor is for Christians intimately linked with the Eucharist and the Eucharist with the upbuilding of the Church. We will explore New Testament and other early Christian insights into these fundamental theological connections, and examine the consequences for eucharistic celebrations today

The University of Greenwich Maths Arcade

I had been exercised for some time about how to stretch our most able students and those who have more prior mathematical knowledge, whilst at the same time support those with weaker backgrounds or who take a little longer to grasp the mathematical concepts we teach. When the opportunity came to put in a bid for University funding I devised a project designed to address these two ambitions

Optically tailored access to metastable electronic states

On irradiating a molecular system with a laser beam of ultraviolet or visible frequency, photon absorption occurs when an electronic state is at a suitable energy level relative to an initial state. Despite meeting this criterion, interesting metastable states can remain inaccessible because of symmetry constraints. In this Letter a mechanism, based on the input of an off-resonant beam, is shown to enable the population of such states. This is achievable because the laser-modified process involves different selection rules compared to conventional photon absorption. The effects of applying the stimulus beam to either a one- or two-photon process are examined

Vortex boundary-layer interactions

The interaction of a turbulent boundary layer (on a flat plate) with a strong artificially-generated longitudinal vortex, which may or may not actually enter the boundary layer, was studied. Experiments, including extensive hot-wire measurements, were completed for the case in which the vortex does enter the boundary layer, and measurements for the somewhat simpler cases in which the boundary layer and vortex remain distinct are now in progress. Contours of total pressure (recently acquired) and of turbulent kinetic energy at various downstream positions are presented to show the overall development of the vortex imbedded in the boundary layer

Interactions between spherical nanoparticles optically trapped in Laguerre-Gaussian modes

When a Laguerre-Gaussian (LG) laser mode is used to trap nanoparticles, the spatial disposition of the particles about the beam axis is determined by a secondary mechanism that engages the input radiation with the interparticle potential. This analysis, based on the identification of a range-dependent laser-induced energy shift, elicits and details features that arise for spherical nanoparticles irradiated by a LG mode. Calculations of the absolute minima are performed for LG beams of variable topological charge, and the results are displayed graphically. It is shown that more complex ordered structures emerge on extension to three- and four-particle systems and that similar principles will apply to other kinds of radially structured optical mode. © 2005 Optical Society of America