Simple experimental method was developed to examine magnetic self-assembly of macroscopic magnetic spheres of 3mm and 5mm diameters in the lack of external magnetic field. Magnetic force driven aggregation was followed up by video recording and was analysed in detail to identify the processes that lead to the creation of clusters (chains, pairs, circles, etc). Self-aggregation of randomly distributed single spheres, pairs and triplets were examined with this method as well. Applying several liquid media with different viscosity helped to characterize the aggregation processes regarding the kinetic energy of collisions. The results were compared with results of previous experimental works and computer simulations of aggregation of magnetic nanoparticles and magnetic-dipolar systems. Besides to earlier described rings and chains that represent the lowest potential energy of the system of ideal magnetic dipoles in two dimensions, we observed several other structures during the experiments. The most frequently appearing clusters were investigated by direct minimization of the potential energy function of these structures.

This article describes the collaborative efforts between Tecnam, Rolls‐Royce, and Rotax to equip a 4‐seat Tecnam P2010 aircraft with a parallel hybrid‐electric powertrain, the first of its kind ever developed for general aviation, to help reduce fuel consumption while maintaining, and even extending, the aircraft range. The High Power, High Scalability Hybrid Powertrain project set out to design, build, ground‐test and demonstrate in a flight campaign such a propulsion system. Creating a parallel hybrid‐electric drive system, which brings together the electric and combustion engine worlds, creates a completely new set of challenges in the design, assembly, operation, and safety assurance of aircraft which must be addressed for a successful business proposition. The article reflects on some of the challenges faced as this innovative and scalable powertrain was developed on the road to minimise emissions in the aviation industry.

While experimenting with the more and more popular neodymium magnetic ball sets, the author developed a method, by which models of atomic nuclei can be created. These macroscopic models visually represent several features of nuclei and nuclear phenomena, which can be a useful mean during the teaching of nuclear physics. Even though such macroscopic models are unable to depict the true quantum physical nature of nuclear processes, they can be much more useful didactically than the previously used disordered sets of balls, to represent the atomic nucleus.

We built a simple structure of seven dipole neodymium magnetic balls, a magnetic spinner that easily rotates around its central ball. This proved to be a very simple magnetic oscillator-rotator with a dipole-like field. After capturing videos of its rotating movements in different magnetic fields, video analysis has provided us with the rotation angle-time function of the motion, either in the case of a stationary magnetic field (damped oscillation) or an alternating magnetic field (forced oscillations). We were able to obtain a numerical solution for the differential equation describing the motion, a solution which was in tune with the special phenomena observed. It was especially interesting—and can be utilised in physics education—that the oscillation of the system was very strongly dependent on the initial conditions and seemed to be quite chaotic. The rotation angle, angular speed functions and their representation in phase space have shown the characteristics of chaotic behaviour, especially in the case of coupled oscillations. Thus, this kind of chaotic movement can be demonstrated very simply, even in classroom conditions by the use of such magnetic systems. At the same time, such models might help in the scientific understanding of magnetic nanostructures—their self-assembly and motions in alternating magnetic fields—which is the basis of practical applications such as magnetic hyperthermia.