An easy circuit for measuring the power of a solar panel in physics classroom by using the microcontroller Arduino will be introduced in this article. The measured data is transferred via Bluetooth to the smartphone app ‘phyphox’ where it is displayed graphically. The circuitry enables measuring the power of a solar panel in different situations of light intensity. Several model experiments for students will be described.

Black holes are both interesting to many students and are part of several school and university curricula. However, it has not yet been documented in detail what kind of mental models of black holes students have. As such, this study qualitatively reports on the mental models of 53 university students, most of them with a non-physics major. The gestalts of the mental models found were mostly disc shaped holes or black spheres, though some funnels or ellipsoids were also described by the students. As for the functionality, students associated attractive functions with a black hole, though more elaborate descriptions such as time dilation or gravitational lensing and Hawking radiation were also named. All university students described a kind of black hole creation, though not all knew about their change in time and only described growth or could not give founded reasons for the change. Several participants showed potential problems by seeing their mental model as a direct replica of reality and assumed that black holes were literally holes. Conceptual problems regarding things “behind” the holes were raised. The results show that many rudimentary properties of black holes are known to university students without explicit education in that field, and a surprising amount of physics quantities were associated with them, although things like density or mass were described inadequately in several cases. Though mental models of black holes were not documented this extensively before, parallels in thinking with mental models in other areas of physics could be observed, making the findings consistent with literature.

Quantum technology is an emerging field of physics and engineering and important applications are expected in quantum computing, quantum sensing, quantum cryptography, quantum simulation, and quantum metrology. Thus the need for education in this field is increasing, while still remaining challenging. While the need for basic education in quantum physics is accepted in many countries, the possibilities still are limited. Concerning fundamental topics such as the superposition principle and complementarity, on the one hand, a large variety of simulations and animations are available. However, single-photon experiments are still beyond reach for any school, due to costs and technical difficulties. A promising approach seems to be a combination of cheap, easy-to-use and modular experimental kits for school which allow for wave optical experiments, in combination with quantum optical simulations. In the present article, we focus on the modularity and accessibility of an experimental kit based on 3D-printed ‘Optic Cubes’, which allow for a large variety of experiments in high school.

Kundt’s tube is a popular experiment commonly used in schools, in which standing sound waves are made visible inside a glass tube. A fine powder is stirred up in areas of high sound particle velocities, so that one can measure the wavelength of the sound waves by examining the patterns created. In this way, the ‘invisible’ can be made visible. However, when looking at educational contexts, Kundt’s tube is an experiment with several shortcomings—despite its popularity and prevalence: The glass tube is big, expensive and fragile. Additionally, during the experiment itself, the sound tends to be quite loud due to the high sound pressure needed so that communicating during the experiment becomes hard or even impossible. In this article, we propose a silent and low-cost alternative to commonly used setups which can easily be constructed by using 3D-printed parts as well as readily available ultrasonic transmitters. This makes Kundt’s tube even implementable as an experiment done by students themselves.

Congenic BB.SHR rat strains were established by crossing of spontaneously diabetic BB/OK rats and diabetes-resistant SHR rats. Chromosomal regions on which the genes Iddm 4 (BB.6s), Iddm6 (BB.Xs) and Iddm 2 (BB.LL) are located were exchanged. As a result of genetic manipulation diabetes incidence was markedly reduced from 80% in BB/OK to 50% in BB.SHR (Chr. X), to 14% in BB.SHR (Chr. 6) and to 0% in BB.LL rats. Pancreata of these newly generated BB.SHR rats were investigated histologically. In newly diagnosed diabetic rats of congenic strains pancreatic insulin content (BB.6s: p<0.05; BB.Xs p<0.01) and relative volume of insulin-positive cells (BB.Xs: p<0.001) were significantly higher than in BB/OK rats. The degree of insulitis was not different in 90-day-old and newly diagnosed diabetic animals. Surprisingly, in 30-day-old rats we observed an increase of the degree of insulitis with decreasing diabetes incidence. We suppose that by an earlier occurrence of the immunological β-cell destruction, a part of the animals is able to develop a secondary diabetes resistance. The exchange of the BB-lymphopenia gene by that of SHR-rats prevented the development of hyperglycaemia without altering the auto-reactive immune response, which could be observed in all animals investigated.