We present an extension of the fast-multipole method of Greengard and Rokhlin to the case of the long-range interactions between parallel edge (in arbitrary orientations) and screw dislocations. By finding complex potentials from which the stress terms can be calculated, and expanding those potentials in multipole series, we convert a computationally difficult O(N2) poroblem into a much faster O(N) approach. To reach sufficient numerical accuracy, only a few terms are needed in the multipole expansions (four screws and six for edges) so that the interactions between millions of dislocations can be calculated in a few minutes on a workstation. We present results of a study of the relaxed configurations of 16384 edge dislocations of arbitrary orientations.

High-school physics students grappling with the delights of capacitors, inductors and resistors will be groaning into their exercise books. Electronics experts in California have finally succeeded in proving the existence of a fourth fundamental unit of electronic circuits: the 'memristor'.

A black hole 600 million times the mass of the Sun has been kicked out of the centre of a distant galaxy, according to research from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany.

"The quantum hydrodynamic model is employed to study the nonlinear structure of non-planar dust acoustic waves in quantum dusty plasmas consisting of electrons, ions, and negatively/positively charged dust particles. A Kadomstev–Petviashvili equation is derived in cylindrical geometry. Based on the analytical solution, it is found that the Nebulon structure is significantly modified by the quantum effects including quantum diffraction effect and quantum statistical effect. "

"Promoting and increasing rates of energy efficiency is a promising method of reducing CO2 emissions and avoiding the potentially devastating effects of climate change. The question is: How do we induce a cultural or behavioural change whereby people nationally and globally adopt more energy efficient lifestyles? We propose a new family of mathematical models, based on a statistical mechanics extension of discrete choice theory, that offer a set of formal tools to systematically analyse and quantify this problem. An application example is to predict the percentage of people choosing to buy new energy efficient light bulbs instead of the old incandescent versions; in particular, through statistical evaluation of survey responses, the models can identify the key driving factors in the decision-making process, for example the extent to which people imitate each other. These tools and models that allow us to account for social interactions could help us identify tipping points that may be used to trigger structural changes in our society. The results may provide tangible and deliverable evidence-based policy options to decision-makers. We believe that these models offer an opportunity for the research community, in both the social and physical sciences, and decision-makers, both in the private and public sectors, to work together towards preventing the potentially devastating social, economic and environmental effects of climate change. "

A test pdf of feynman paper

physics institute