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In introductory electric circuits in middle school, students often carry strongly held alternative conceptions. Common to many of these is an idea of electric current as some kind of substance that originates from the battery and moves toward electronic components. Learners often argue that current influences those one by one as they are encountered (sequential reasoning), splits into equal parts at junctions independently of resistances (local reasoning), or moves toward a component from both connectors of the battery, only affecting the components if a “positive current” and a “negative current” meet there (clashing currents). Also, these learners might argue that the battery always delivers the same amount of electric current or that current is used up in, e.g., a light bulb.

Recent studies suggest chain adsorption in the melt may be responsible for a number of property changes in thin films by making correlations between the residual adsorbed layer thickness hads(t) measured after a given solvent washing procedure as a function of annealing time t of the film at an elevated temperature prior to this solvent rinse. This procedure, frequently called "Guiselin's experiment", refers to the thought experiment proposed in a 1992 theoretical treatment by Guiselin that assumed chain segments in contact with the surface are irreversibly adsorbed whereby unadsorbed chains could be washed away by solvent without disturbing the adsorbed substrate contact points in the melt. In the present work, we review this recent literature, identifying and experimentally testing a common protocol for forming adsorbed layers hads(t) from solvent washing melt films. We find hads(t) curves to be far less reproducible and reliable than implied in the literature, strongly dependent on solvent washing and substrate cleaning conditions, and annealing at elevated temperatures is unnecessary as densification of films sitting at room temperature makes the glassy film harder to wash off, leaving behind hads of comparable thickness. This review also summarizes literature understanding developed over several decades of study on polymer adsorption in solution, which experimentally demonstrated that polymer chains in solution are highly mobile, diffusing and exchanging on the surface even in the limit of strong adsorption, contradicting Guiselin's assumption. Preformed adsorbed layers of different thicknesses hads are shown to not affect the average glass transition temperature or physical aging of 30 nm thick films. In summary, a number of open questions and implications are discussed related to thin films and polymer nanocomposites.

Numerous computer simulations have shown that local dynamics associated with the glass transition can be slower next to rough interfaces compared with smooth interfaces. Even though the impact of surface roughness has been frequently considered computationally and theoretically, almost no experimental studies exist investigating these effects. Using a hydrogen fluoride vapor treatment, we created silica substrates with an increase in roughness that left the surface chemistry unchanged. The local glass transition temperature Tg near silica substrates with an increase in roughness was measured using fluorescence, finding an increase in local Tg of 10 K with an increase in the root-mean-square roughness Rrms from 0.5 nm to 11 nm. Characterization of the substrate roughness needed to create an experimental change in local Tg was found to be quite large, leaving the mechanism for this observed behavior uncertain. We discuss possible causes associated with polymer chains being more readily able to make surface contacts and adsorb to roughened interfaces.

A symposium organized by the GTG PERU-Physics education Research at University In this article we present a summary of initiatives that have been undertaken by a subset of the European Physics Education community to try to help students develop conceptual understanding. The contributions to this article represent a broad spectrum of ideas and research strategies that range from innovative teaching methods, to empirical applied psychology studies. Future physics professionals: scientists, teachers, engineers, analysts etc. are a diverse set of people and therefore the methods used to help them improve their understanding should be wide ranging. However, common themes emerge that we suggest as teaching implications namely: that more attention should be paid to how we develop students’ ability to reason; how building self-confidence can be hugely beneficial to closing knowledge gaps and how the split-attention effect acts to limit students’ working memory.

Learning is known to be a highly individual process affected by learners’ individual previous experience and self-directed action. Especially during laboratory courses in university science, technology, engineering and mathematics (STEM) education, all channels of knowledge construction become relevant: students have to match their theoretical background with experimental hands-on experience, leading to an intensive interaction between theory and experiment. Realizing augmented reality scenarios with see-through smartglasses allows to display information directly in the user’s field of view and creates a wearable educational technology, providing learners with active access to various kinds of additional information while keeping their hands free. The framework presented here describes the use of augmented reality learning environments in introductory STEM laboratory courses aiming to provide students additional information and real-time feedback while sustaining their autonomy and the authenticity of their action. Based on principles of the cognitive-affective theory of learning with media (CATLM), we hypothesize that this tool can structure students’ hands-on experiences and guides their attention to cue points of knowledge construction.

Im Gegensatz zu Geschwindigkeiten, konnen wir Beschleunigungen nur sehr schwer einschatzen, was ihre objektive Messung besonders interessant macht. Die Moglichkeiten sind dabei sehr vielfaltig und reichen von Beschleunigungsmessungen im Bereich der Technik, uber Beschleunigungen im Sport bis hin zu Beschleunigungen im Tierreich. Bemerkenswert und didaktisch besonders interessant ist dabei, dass die meisten Bewegungen in Natur und Technik mit naherungsweise konstanter Beschleunigung ablaufen. Dies bietet die Moglichkeit, bei der experimentellen Erarbeitung gleichmasig beschleunigter Bewegungen auf reale Alltagssituationen zuruckzugreifen, anstatt auf aufwendige und kontextfreie Laborexperimente (Abschn. 2.1.1.2).

Beleuchtungsstarkesensoren (ALS = Ambient Light Sensor) werden in Smartphones und Tablet-PCs integriert, um durch eine Messung des Umgebungslichtes die Bildschirmhelligkeit des Gerats an diese anzupassen. Mithilfe spezieller Apps kann die Beleuchtungsstarke in Echtzeit angezeigt oder auch zeitabhangig dargestellt werden. In diesem Beitrag wird ein Versuch dargestellt, der den ALS eines Tablet-PCs nutzt, um die Abstrahlungscharakteristik I(ϑ) eines Smartphones zu ermitteln.

Fundamental concepts of thermodynamics rely on abstract physical quantities such as energy, heat and entropy, which play an important role in the process of interpreting thermal phenomena and statistical mechanics. However, these quantities are not covered by human visual perception, and since heat sensation is purely qualitative and easy to deceive, an intuitive understanding often is lacking. Today immersive technologies like head-mounted displays of the newest generation, especially HoloLens, allow for high-quality augmented reality learning experiences, which can overcome this gap in human perception by presenting different representations of otherwise invisible quantities directly in the field of view of the user on the experimental apparatus, which simultaneously avoids a split-attention effect. In a mixed reality (MR) scenario as presented in this paper—which we call a holo.lab—human perception can be extended to the thermal regime by presenting false-color representations of the temperature of objects as a virtual augmentation directly on the real object itself in real-time. Direct feedback to experimental actions of the users in the form of different representations allows for immediate comparison to theoretical principles and predictions and therefore is supposed to intensify the theory–experiment interactions and to increase students' conceptual understanding. We tested this technology for an experiment on thermal conduction of metals in the framework of undergraduate laboratories. A pilot study with treatment and control groups (N = 59) showed a small positive effect of MR on students' performance measured with a standardized concept test for thermodynamics, pointing to an improvement of the understanding of the underlying physical concepts. These findings indicate that complex experiments could benefit even more from augmentation. This motivates us to enrich further experiments with MR.

During the last decade the development of modern digital media such as smartphones and tablet computers has enabled new experimental possibilities in STEM education. Besides these now nearly ubiquitous devices, the fields of virtual reality (VR) and augmented reality (AR) also made huge progress and reached education. In this paper we introduce an AR experiment alongside the basic idea of this column and following prior work. In the experiment high school students use smartglasses and real-time measurement data to study Kirchhoff’s circuit laws in electrical DC circuits.

Amagnetic linear accelerator (or Gauss accelerator) is a device that uses the conversion of magnetic energy into kinetic energy to launch an object with high velocity. A simple experimental implementation consists of a line of steel spheres in which the first one is a permanent magnetic sphere. If another steel ball collides with the magnetic sphere from the left, the rightmost steel sphere is ejected at a much larger velocity than the impacting steel sphere. Several approaches have been published to determine the velocity of the ejected sphere, for example by using photogates or by measuring the impact position of the ejected sphere after falling from a table. All of these approaches have in common that the measurement of the velocity is a static process. This article describes an approach in which video motion analysis on tablet computers is used to measure simultaneously the time course of the velocity of the impacting steel sphere as well as the ejected steel sphere, thus giving students insight into the dynamics of the processes that lead to a higher kinetic energy of the ejected sphere.Amagnetic linear accelerator (or Gauss accelerator) is a device that uses the conversion of magnetic energy into kinetic energy to launch an object with high velocity. A simple experimental implementation consists of a line of steel spheres in which the first one is a permanent magnetic sphere. If another steel ball collides with the magnetic sphere from the left, the rightmost steel sphere is ejected at a much larger velocity than the impacting steel sphere. Several approaches have been published to determine the velocity of the ejected sphere, for example by using photogates or by measuring the impact position of the ejected sphere after falling from a table. All of these approaches have in common that the measurement of the velocity is a static process. This article describes an approach in which video mot...

The importance of coupled oscillations for natural and engineering sciences is undisputed. But due to the complex processes behind the phenomena, its educational arrangement remains challenging.

The importance of Scanning Tunneling Microscopy (STM) in today’s research and industry leads to the question of how to include such a key technology in physics education. Manfred Euler has developed an acoustic model experiment to illustrate the fundamental measuring principles based on an analogy between quantum mechanics and acoustics. Based on earlier work we applied mobile devices such as smartphones and tablets instead of using a computer to record and display the experimental data and thus converted Euler’s experimental setup into a low-cost experiment that is easy to build and handle by students themselves.

In the field of Virtual Reality (VR) and Augmented Reality (AR) technologies have made huge progress during the last years and also reached the field of education. The virtuality continuum, ranging from pure virtuality on one side to the real world on the other has been successfully covered by the use of immersive technologies like head-mounted displays, which allow to embed virtual objects into the real surroundings, leading to a Mixed Reality (MR) experience. In such an environment digital and real objects do not only co-exist, but moreover are also able to interact with each other in real-time. These concepts can be used to merge human perception of reality with digitally visualized sensor data and thereby making the invisible visible. As a first example, in this paper we introduce alongside the basic idea of this column an MR-experiment in thermodynamics for a laboratory course for freshman students in physics or other science and engineering subjects which uses physical data from mobile devices for analyzing and displaying physical phenomena to students., This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in The Physics Teacher 55, 376 (2017) and may be found at doi: http://dx.doi.org/10.1119/1.4999739