1. Physics competitions: aims and realizations

One aim of physics competitions is to increase the interest of young students, primarily at upper secondary level, to physics and natural sciences in general. A competition has motivational aspects known usually from sports events or games—comparing one's own ability with others, of course with the desire to be better and to win. If competitions reach nationwide and even international levels, additional stimulation is created.

Competitions provide greatest attraction to possible winners, to the group of gifted people in a particular field. This implies that science contests are excellent tools for the promotion of talented students. Traditional teaching has been shown to have problems in supporting this group of students. Very often teachers are overstretched with the demands of teaching both low- and high-level students. Extracurricular activities are therefore a good chance to relieve the teacher, and to give ...

We report on the competition problems given at the 39th International Physics Olympiad held in Hanoi, Vietnam, which consist of three theoretical and one experimental problems. The abbreviated solutions are presented. The distribution of marks for the problems is also shown.

The International Young Physicists' Tournament (IYPT) is a worldwide, annual competition for secondary school students. This is our solution to problem number 10, The Kaye effect, as presented in the final round of the 21st IYPT in Trogir, Croatia. The Kaye effect occurs when a thin stream of shampoo or a different adequate non-Newtonian liquid is poured onto a surface. Suddenly, a jet leaves the heap that is formed by the shampoo and begins to 'dance' around the primary jet like a lasso. The phenomenon ends when the 'dancing' jet hits the primary jet and subsequently collapses. We started our investigations based on available literature (Kaye 1963 Nature 197 1001, Versluis et al 2006 J. Stat. Mech., Collyer and Fischer 1976 Nature 261 682). We made experiments with a similar experimental set-up in which we could determine the velocities of both shampoo streams as well as the angle of the 'dancing' stream. From there on, we develop...

In the project laboratory, a group of students are given a well-defined task but the path to the solution is entirely left to the students. The paper reports on some basic strategies in designing successful project tasks that are based on modified problems from International Young Physicists Tournament (IYPT). In addition, an integration of first-year project laboratory in in-service teacher training is also briefly presented.

In conceiving a special section for European Journal of Physics, a number of selection criteria will usually operate. Primarily, the chosen theme needs to be a subject area that is sufficiently broad to offer a range of opportunities for pedagogic exploration. Although the teaching of science must always lag a little behind forefront research, many of the most exciting developments occur just as the wisdom in a new subject area is consolidated and systematized. At such a juncture, as new topics are being added to the curriculum, there is fresh scope to reflect on how best to approach the art of instruction, and to consider what principles might be conveyed in any new course of lectures. The result is often a double bonus; the pleasure of introducing new material reflecting current developments and imminent technologies is compounded by the discovery of new contexts for the delivery and grounding of fundamental concepts.

The compilation of papers that follows, f...

Scenario planning may assist us in harnessing the benefits of nanotechnology and managing the associated risks for the good of the society. Scenario planning is a way to describe the present state of the world and develop several hypotheses about the future of the world, thereby enabling discussions about how the world ought to be. Scenario planning thus is not only a tool for learning and foresight, but also for leadership. Informed decision making by experts and political leaders becomes possible, while simultaneously allaying the public's perception of the risks of new and emerging technologies such as nanotechnology. Two scenarios of the societal impact of nanotechnology are the mixed-signals scenario and the confluence scenario. Technoscientists have major roles to play in both scenarios.

We present three experimental themes and one discussion theme that proved to be suitable for introducing nanoscience through topics that can be integrated into the existing introductory physics or teacher training courses. The experimental themes include two teaching models of an atomic force microscope (AFM) and an experiment with an elastic optical grating. They are all based on simple experiments that give also quantitative results and can be explained using basic physics theory.

Photonic crystals are periodic dielectric structures with an index of refraction periodicity of the order of the wavelength of light. They are emerging as a key building block for many applications in nanotechnology that involve controlling the flow of light. In this paper, the basic physical principles and applications of photonic crystals are presented, as well as descriptions of some of the many chemical and physical strategies that have been used for their fabrication.

Monodisperse noble metal nanoparticles are of tremendous interest for numerous applications, such as surface-enhanced Raman spectroscopy, catalysis or biosensing. However, preparation of monodisperse metal nanoparticles is still a challenging task, because typical preparation methods yield nanoparticle ensembles with broad shape and/or size distributions. To overcome this drawback, tailoring of metal nanoparticles with laser light has been developed, which is based on the pronounced shape- and size-dependent optical properties of metal nanoparticles. I will demonstrate that nanoparticle tailoring with ns-pulsed laser light is a suitable method to prepare nanoparticle ensembles with a narrow shape and/or size distribution. While irradiation with ns-pulsed laser light during nanoparticle growth permits a precise shape tailoring, post-grown irradiation allows a size tailoring. For example, the initial broad Gaussian size distribution of silver nanoparticles on quartz substrates with...

We show that when natural light is incident to a linear lossless polarizing element, the polarized intensity in transmission equals the polarized reflected intensity. The result appears to be quite general, and is not restricted to cases where the reflected and transmitted light are orthogonally polarized. We discuss some simple examples and give supporting experimental evidence, where the polarizing element is a structurally chiral film. Leading in to our main results we review, for undergraduates and teachers of polarization optics, the theory of Stokes parameters and the theory of propagation in structurally chiral media. Our main result will also be of interest to specialists.