The TEUTATES-Project: Tablet-PCs in Modern Physics Education N. Dahlmann1, S. Jeschke1, H. Scheel2, C. Thomsen2 1
Technische Universität Berlin, Institute of Mathematics, Center for Multimedia in Education and Research, D-10623 Berlin, Germany (
[email protected]) 2 Technische Universität Berlin, Institute of Solid State Physics, Center for Multimedia in Education 2 and Research, D-10623 Berlin, Germany 1
Abstract: The overall objective of the TEUTATES approach is to implement a flexible mobile learning concept for a modern physics education at universities, focusing on enhanced access to a broad variety of experiments. Within a blended learning concept, Tablet-PCs allow an extended experimental part of the education right from the beginning. Different types of experiments – remote and virtual – are introduced. Executed within web-interfaces, experiments can be implemented and accessed regardless of the location of the laboratory and the experimenter. Additionally, experiments can be performed which otherwise would not be accessible for reasons of expense, security, or availability. Students work individually or in small groups, designing and executing different types and realisations of experiments including the investigation of the underlying theoretical models. Through its highly interactive approach, TEUTATES contributes to a modern pedagogy for university teaching which aims at creative thinking and high level learning, encouraging students to become active learners challenged by complex problems and situations, seeking collaboratively a variety of solutions. Information and Communication Technologies (ICT) are applied to learning purposes and modern pedagogics such as project-based learning, problem oriented learning, principles of non-linear learning, co-operative and cross-cultural learning.
Keywords: tablet PCs, mobile teaching, remote experiments, virtual laboratories, physics education
1
INTRODUCTION
“Hands-on-training” has always been considered an essential part of the learning and teaching experience in natural and engineering sciences. However, presently the physics education of engineering students often suffers from a lack of comprehensive experimental components due to the large number of students in combination with limited experimental resources. The integration of Tablet-PCs into physics education opens up new perspectives and allows to increase the experimental part of the education right from its start. Executed within web-interfaces, experiments can be implemented and accessed regardless of location of laboratory and experimenter. Additionally, experiments can be performed which otherwise would not have been accessible for reasons of expense, security, or availability. Experiments of two principle kinds come into place: Virtual Laboratories are interactive, explorative learning tools, which emulate scientific hands-on experiments in virtual spaces by modelling and simulations, using the metaphor of a “real” scientific laboratory as a guiding line. They are capable of simulating various physical models and thus allow for investigation of experimental set-ups, which were infeasible in traditional laboratories. The complementary Remote Experiments are real experiments, remotely controlled from outside the laboratory by users anytime and anywhere. However, enabling students to learn for experiments requires more than just offering the experimental setups: performing experiments includes taking notes, drawing setup sketches, writing protocols, analysing the measured data, and visualising the results. Here, within a blended learning concept, the potential of Tablet-PCs comes into place.
FIGURE 1: Physics class, projection of remote experiments in lecture hall, TU Berlin
2
EXPERIMENTS IN VIRTUAL AND REMOTE LABORATORIES
2.1
Remote Experiments
A Remote Experiment consists of two vital parts, namely the experiment itself, which is supposed to be conducted remotely, and the method being used to provide the necessary remote controls. For the Remote Experiments at the TU Berlin, National Instruments LABVIEW is used to control the hardware and collect the experimental data. LABVIEW also possesses a convenient web-interface, which enables the remote-experimenter to perform any necessary adjustments. In order to view and control the experiment, a freely available web browser plug-in has to be downloaded and installed. Due to the modular programming structure of LABVIEW, remote experiments can easily be combined or extended. Prof. C. Thomsen and research group [11] at the TU Berlin have already set up several remote experiments and several others are about to follow. A selection of these Remote Experiments is presented for illustration purposes: •
Solar cells A solar – or photovoltaic – cell is a semiconductor device consisting of a p-n junction diode: two electrically contacted semiconductors, one positively doped, the other negatively, form a diode, which allows a current in one direction but not in the other. By illuminating the junction with visible light, free carriers will be generated and accumulated – thus, solar cells are capable of generating electrical energy. One important property of a solar cell is its “efficiency”, the ratio of the electrical-power output to the light-power input, as represented by its current-voltage (I/V) characteristics. Measuring the I/Vcurves of a solar cell – in the dark and when illuminated – within a remote experiment enables the students to determine the efficiency of the solar cell. Running this experiment using different solar cells
allows the investigation of material dependences (in Fig. 1 the solar cell experiment is demonstrated within a physics lecture).
2.2
•
Resonant circuit Resonance is an important phenomenon in technical applications. It can cause the damage of mechanical systems, e.g. bridges under the influence of strong winds or synchronous pedestrian walk (London Millennium Bridge), or can ensure the functioning of a system, as in an ordinary radio. Systems of electronic devices also show resonance phenomena: an LC-oscillator is a serial connection of an inductance and a capacitor. Between these devices, the electrical current alternates at a certain angular frequency. Applying a sinusoidal external voltage, the system will oscillate with the excitation frequency with a frequency-dependent amplitude. The frequency associated with the maximum amplitude is referred to as resonance frequency. Within our remote experiment, students can access an LC-Oscillator via the Internet to measure the amplitude in dependency of the stimulating frequency, thus determining the resonance frequency.
•
Magnetism & phase transitions The goal of the “magnetism” experiment is to gain insight into the phenomenon of phase transitions and the behaviour of ferromagnetic substances [9]. A magnetic coil generates a magnetic field proportional to the current passed through it, controlled by the computer. The magnetic field in turn magnetises a ferromagnetic core whose magnetisation is measured by a Hall probe. A standard multimeter that provides a digital output port then digitises the measured value and transmits it back to the computer. By running the experiment, a student explores the non-linear dependency of the probes’ magnetisation with respect to the external field. Thus, the student will become aware of the fact that ferromagnetic materials show a so-called “hysteresis loop”, a characteristic behaviour for materials featuring phase transitions.
•
Raman scattering Raman scattering is a powerful light scattering technique used to diagnose the internal structure of solids, liquids and gases [7]. In a light scattering experiment, light of a known frequency and polarisation is scattered off a sample. Most photons are elastically scattered, having the same wavelength as the incident photons (Rayleigh scattering). However, a small fraction of light is inelastically scattered at optical frequencies different from the frequency of the incident photons. This “Raman shift” is therefore an intrinsic property of the sample. Using a laser as light source, the Raman Remote Experiment allows students to collect Raman spectra of different samples, for example silicon and diamond, but also of carbon nanotubes and other solids or nano structures. The design of the Remote Experiment allows changing the samples, modifying the polarisation of the laser light and its intensity via remote control. Both parts of this experiment are depicted in Fig. 2 and 3.
•
Fourier transform spectrometer Fourier spectrometers are used to determine spectra [5]: light from a suitable source is split into two beams by a semi-transparent mirror, one is reflected off a fixed mirror and one off a moving mirror which introduces a time delay – in short, the Fourier transform spectrometer is just a Michelson interferometer with a movable mirror. The beams interfere, allowing the temporal coherence of the light to be measured at each different time delay setting. By measuring signal at many discrete positions of the moving mirror, the spectrum can be reconstructed using a Fourier transform of the temporal coherence of the light. Essential target of the experiment is the understanding of the Michelson interferometer and of interference. The second important attribute is the comprehension and use of Fourier transformation. For our remote experiment, a HeNe-laser will be used as light source enabling students to get a first hands-on experience with laser technology.
Virtual Laboratories
Virtual laboratories have revolutionised education and research as they allow a direct experimental access to abstract objects and concepts. The Virtual Laboratory VIDEOEASEL [8] (developed at the TU Berlin) is capable of simulating various models from the field of statistical mechanics, problems of thermodynamics, wave phenomena and chemical reactions. Measurements are performed by tools, freely plugged into the experiment by the user, allowing observation of magnetisation, entropy, free energy or other measurable quantities during the experiment. When experiments of higher complexity are performed, the experimental results can be automatically exported into computer algebra systems (e.g. Maple or Mathematica) for further analysis. To enhance co-operative work between students, or students and their teachers, VIDEOEASEL is able to support
distributed measurement processes on the same experimental setup, including remote access from outside the university (for technical details see [3]). Again we highlight some selected experiments, which can be performed within the VIDEOEASEL lab:
FIGURE 2: The remote experiment in the laboratory…
FIGURE 3: ... and the experimentors outside the lab, using Tablet-PCs to perform experiments
•
Ising model & ferromagnetism The Ising model is a prominent lattice gas model used to investigate phase transitions and describe ferromagnetic behaviour. A typical experiment is the measurement of the hysteresis loop: after starting the Ising simulation, the user attaches a probe (by selecting a region) to measure its magnetisation (cf. Figure 4). The user interface now allows the variation of parameters of the model, for example the external field. By plotting magnetisation over external field (cf. Fig. 8), one finds the desired hysteresis loop; by varying the temperature the phase transition of the model becomes observable. However, the Virtual Lab is also able to run experiments that are hardly feasible in reality: by changing the boundary conditions of the Ising model during runtime, one can investigate the impact of the boundary configuration on the spontaneous magnetisation of the model and compare the behaviour with the theoretical result of the Peierls argument [10].
FIGURE 4: VIDEOEASEL Java Front-End for an experiment about the Ising model, measurement of the magnetisation
FIGURE 5: VIDEOEASEL Java-Applet integrated in a web-page; displaying an experiment on the 2nd Law of thermodynamics
•
Irreversibility of time The dynamics of single molecules are difficult to investigate in “real” experiments but form an interesting field for experiments in virtual laboratories: molecular dynamics simulate the trajectories of individual molecules by integrating the equations of motion, i.e., assuming Newtonian mechanics. This means, that in principle, time is reversible. Consider, for example, if one changed the sign of all molecular velocities at some point, then all molecules should end up at their initial positions after the appropriate number of time steps. This is clearly not the case in physical systems, where time is irreversible – a consequence of the second law of thermodynamics (cf. Fig. 5). This discrepancy – time reversibility for molecular dynamics, but irreversibility in real systems – is referred to as Loschmidt’s paradox and can be observed within the VIDEOEASEL lab.
•
Self-organisation and periodic reactions Self-organisation refers to a process in which the degree of internal organisation of a system, normally an open system, increases automatically without being guided or managed by an outside source. A prominent example is the so-called “Belousov-Zhabotinsky” reaction (cf. Fig. 6), a reaction-diffusion system showing oscillating – spatially and temporally – chemical reactions. A simulation experiment within a virtual lab allows the students to get a deep understanding of the fundamentals of selforganising systems. Additionally, students may investigate the idea of self-organisation in connection with the second law of thermodynamics (“ever-decreasing order”) gaining the insight that selforganisation can only occur far away from thermodynamic equilibrium.
•
Discretisation of partial differential equations In physics, partial differential equations as wave equation or heat equation play a very important role for a large number of applications (different types of wave propagation and heat conduction phenomena). Beyond a few “toy models” of fundamental and/or theoretical interest, most of these applications have to be solved numerically for realistic physical models for complexity reasons. Students have to learn how to describe those partial differential equations within numerical models. In particular, the appropriate discretisation plays a fundamental role. Within virtual laboratories, partial differential equations can be modelled, and their impact can be investigated within different physical settings (cf. Fig. 7). Numerical effects resulting from discretisation and rounding parameters become apparent.
FIGURE 6: VIDEOEASEL Java Front-End for an experiment about the Belousov-Zhabotinsky Reaction 2.3
FIGURE 7: VIDEOEASEL Java Front-End for an experiment about the heat conduction equation
Comparison
The examples described illustrate the typical setup of Remote Experiments as well as according experiments within a Virtual Laboratory. In both scenarios, the experimenter regulates a set of parameters controlling the experiment and interacting with it, e.g. by a motor, the magnetic field, or – in case of the Virtual Laboratory – also by manipulating the boundary conditions. Additionally, a set of measurement tools is provided collecting data from the running experiment, e.g. the temperature, the magnetisation, a rotation frequency, the mechanical
force, etc. Thus, the different approaches possess a number of similarities, but also enrich each other through their differences: one the one hand Remote Experiments allow for the investigation of real objects including hands-on measurement experience, which does obviously not hold true for Virtual Laboratories. On the other hand, Virtual Laboratories are capable of mapping the complete process of constructing an experiment, whereas this kind of flexibility is clearly limited in remote experiments [2]. The accomplishment of experiments in eLearning scenarios can be measured in many aspects – ranging from the actual quantification of a physical measurement and operating experience with real experimental setups to the examination of the corresponding theoretical model – of the learning process in the academic education of natural and engineering scientists. Even though the two systems are not identical (which model is capable of exactly describing physical reality?) the combination of a remote and “real” experiment and a sound simulation supports the process of understanding in an outstanding manner which is vital for the learning and teaching process in natural sciences and engineering. 3
The Integration of Tablet-PCs & Expected Outcomes
The usage of Tablet-PCs forms the basis of the TEUTATES project: preserving the advantages of traditional teaching methods in modern eLearning scenarios, TEUTATES enables training scenarios based on different types of remote and virtual experiments. However, while the TEUTATES approach is based on the metaphor of the traditional laboratory, it is enriched by a wide range of multimedia enhancements: students can note test protocols, including experimental setup sketches, tables and diagrams graphically on the Tablet-PC. They are enabled to complete their records by embedding external material, e.g. images from the web or interactive applets. Experimental results determined by other researchers can be included for the purpose of comparison and questioning of own results. In the future, through integration of handwriting recognition, computer algebra systems will be queried for their numeric or symbolic results and function plots. Students may even send queries to remote web services (CGI scripts) to running interactive simulations and visualisations from arbitrary sources. Furthermore, modern synchronous and asynchronous communication and co-operation tools will come into place, transforming the traditional image of “isolated” laboratories into networked collaborative working environments for natural sciences. Providing a steadily increasing number of remote and virtual experiments, continuously available to a broad target audience of students and teachers independently of physical location, the expected results can be summarised as follows: •
Students of all engineering fields will gain enhanced, comprehensive access to “hands-on”-experiments.
•
The education of engineering students in the field of physics will be transformed from teacher-led to more contemporary student-centric learning scenarios.
•
State-of-the-art computer algebra systems, numerical software packages, and visualisation tools will become integral parts of modern sophisticated education for all fields of technological studies.
•
Mobile learning and teaching scenarios will impact education, research and the organisational structures of the different fields of studies.
•
Students will be supplied with the opportunity to get acquainted with modern scientific software at an early stage of their education, thus, enhancing their motivation while simultaneously improving their skills required in the modern scientific workplace.
•
Engineers and computer scientists are expected to acquire new competencies, as advanced mathematical comprehension and the development of soft skills will be supported.
FIGURE 8: Magnetisation and Free Energy over external field for T>Tc, as collected by Maple.
4
Conclusion and Outlook
Giving enhanced access to a broad variety of experiments, students can design and execute different types and realisations of experiments – individually as well as in small groups – and investigate the underlying theoretical models. With annually 1,000 students from 10 different fields of engineering, the course “Physics for Engineering Students”, taught in the first and second semester, is one of the largest classes of the TU Berlin. In an extended implementation of this course design, approximately 1,500 students will be reached per academic year. Integration of state-of-the-art computer algebra systems, numerical software packages, and visualisation tools enable students to analyse their experimental data and treat their results further. Thus, students gain the opportunity to get acquainted with modern scientific software at an early stage of their academic education, enhancing their motivation and improving their scientific skills. Through its highly interactive approach, TEUTATES contributes to a modern pedagogy for university teaching, which aims at creative thinking and high level learning, encouraging students to become active learners challenged by complex problems and situations, collaboratively seeking a variety of solutions. Information and Communication Technologies (ICT) are applied to learning purposes and modern pedagogies such as project-based learning, problem oriented learning, principles of non-linear learning, cooperative and cross-cultural learning. The TEUTATES approach is part of the program of the MuLF center (Center for Multimedia in Education and Research, [1, 12]) of the TU Berlin. It contributes in facilitating and strengthening a modern eLearning-based education as well as cooperative learning activities in experimental and theoretical physics. Through its generic approach TEUTATES is not restricted to the teaching of physics only, but is envisioned as an important prototype for a modern teaching concept in all fields of natural sciences and engineering. Broad access to virtual laboratories as well as to the remote experiments is an essential part of the eLearning dissemination strategy of the MuLF center. TEUTATES aims at providing all results of the project to non-profit organisations following an “OpenSource, OpenContent, OpenAccess” strategy. Universities, research institutes, schools and other non-profit organisations should have free access to all software components and all scientific results gained in the process of the project including the right for further development. They are free to publish the advancements with non-profit intention only (GPL-like license models).
References: [1] C. Thomsen and S. Jeschke (Heads): Center for Multimedia in Education and Research. http://www.mulf.tu-berlin.de/ [2] S. Jeschke, T. Richter, H. Scheel, R. Seiler and C. Thomsen: “The Experiment in eLearning: Magnetism in Virtual and Remote Experiments”. Conference Proceedings ICL 2005, Interactive computer aided learning, Villach/Austria, September 2005. Kassel University Press. [3] S. Jeschke, T. Richter and R. Seiler: “VideoEasel: Architecture of Virtual Laboratories on Mathematics and Natural Sciences”. Proceedings of the 3rd International Conference on Multimedia and ICTs in Education, June 7-10, 2005, Caceres/Spain, Badajoz/Spain, June 2005. FORMATEX. [4] S. Jeschke, C. Thomsen and I. Piens: “CERES – Classroom eLearning & eResearch Support”. Application HP Technology for Teaching, University Grants Program, April 2005. [5] U. Kuhlmann, H. Jantoljak, N. Pfänder, P. Bernier, C. Journet, and C. Thomsen: “Infrared active phonons in single-walled carbon nanotubes”. Chem. Phys. Lett., 294:237, 1998. [6] R. Peierls: “On Ising’s model of ferromagnetism”. Proc. Camb. Philos. Soc. 32, S. 477-82. 1. edition, 1936. [7] S. Reich, C. Thomsen and J. Maultzsch: “Carbon Nanotubes: Basic Concepts and Physical Properties”. Wiley-VCH, Berlin, 2004. [8] T. Richter: „VideoEasel“. http://www.math.tu-berlin.de/~thor/videoeasel . [9] K.P. Schmidt, A. Gössling, U. Kuhlmann, C. Thomsen, A. Löffert, C. Gross and W. Assmus: “Raman response of magnetic excitations in cuprate ladders and planes”. Phys. Rev. B, 72:094419, 2005. [10] C. Thomsen and H.E. Gumlich: „Ein Jahr für die Physik“. Wissenschaft und Technik Verlag, Berlin, 2. edition, 1998. [11] C. Thomsen, H. Scheel and S. Morgner: “Remote Experiments in Experimental Physics”. Proceedings of the ISPRS E-Learning 2005, June 1-3, Potsdam/Germany, June 2005. [12] C. Thomsen, R. Seiler, S. Jeschke, and S. Morgner: „MULTIMEDIA in Lehre und Forschung an der TU Berlin“. Draft-paper (MuLF-Center), January 2004.
