Operating System Independent Physics Simulations Osvaldo Aquines, Héctor González, Pablo Pérez Universidad de Monterrey (Mexico) Abstract

In his research on the cognitive development, Jerome Bruner [1] proposed three modes of representation: Enactive representation (action-based), Iconic representation (image-based) and Symbolic representation (language-based). These modes occur sequentially in the natural learning process. The Enactive representation is particularly important since it implies many senses. In the context of physics the Enactive representation would be the direct interaction with the phenomena, namely a laboratory. Unfortunately, in most physics courses due to classroom size, time, budget, etc. the course is focused in the development of the theory and solving equations (covering mostly the Iconic and Symbolic representation) and if there is a laboratory, it occurs at a different time and place. By this the student gets in a highly abstract reasoning process without a physical reference to relate it. Computer based physics simulations offer the teaching process the opportunity to integrate the three modes of representation in the same classroom session, providing a more solid and integral learning process for the student. Nevertheless, nowadays there are many types of computing devices and several operating systems, and most of the actual simulations are operating system dependent and require specific libraries. These requirements limit their use to a certain type of devices and platforms. The offered complimentary alternative is a set of Java coded crossplatform physics simulations which can be used in any computing device on any the available operating systems: from personal computers, tablets and smartphones on Linux, Windows, iOS or Android. They enable the student to interact with the desired phenomena at all times and places. Learning games and challenging scenarios can be proposed and left as homework, since the simulations can be accessed continuously and by this engaging the student in the development of knowledge. Since they help him become the centre and administrator of his own learning process, they contribute to active learning and knowledge ownership. As well, making the interaction with the phenomena more persistent, a deeper insight of the concept is reached.

Keywords Physics Simulations, JavaScript, Virtual laboratory, Cognitive tools

.

1. Introduction The traditional teaching of Physics is mostly based in the lecture by the teacher. It is primordially focused in stating physics laws with their respective formulas and afterwards solving exercises in the abstract level leaving behind the association with the phenomenon that is described by the physics principles. This delay in the association is quite serious because in a natural learning process, the interaction with the phenomenon is the fundamental component and it should be the first to happen, as told by Jerome Bruner [1] in his research on the cognitive development. In some cases, the interaction with the phenomenon takes place in a laboratory, but having the disadvantage of happening in different time and space from the development of theory leaving again association behind. Furthermore, physics laboratories are expensive and limited to very specific scenarios, so not all of the theory can be associated with the actual described phenomena. To address this issue, computer simulations have been developed and have shown great success in helping students visualize physical phenomena and associate it with the theory. Nevertheless the actual options [3],[4] are limited to certain computing devices and require the use of specific libraries, limiting their use to certain spaces and occasions. Nowadays there are many types of devices and operating systems, and to be more effective, learning strategies should be accessible in all that range of computing options. The proposed alternative is a set of Java coded cross-platform physics simulations. These simulations are contained in the Newtondreams project [5] developed in the Physics and Mathematics Department at Universidad de Monterrey. Since they are operating system independent and do not require any specific libraries, they can be accessed by students anywhere at any time in their smartphones, tablets, computers, etc. The intention is to provide open access cognitive tools to help the student to get deeply involved with the simulated phenomena. These tools are meant to be used in learning activities to provide effective learning strategies. In the words of Jonassen [2]: “Cognitive tools, if properly conceived and executed, should activate cognitive and metacognitive learning strategies”. In section 2 we will describe how physics simulations help to follow a natural learning process [1] in physics courses. We will then proceed to section 3 discussing how physics simulations can be efficient cognitive tools. The development and initial implementation of the simulations contained in the Newtondreams Project will be presented at section 4. Afterwards, on section 5 we will talk about why physics simulations should be operating system independent in the present era. Finally on section 6, conclusions will be discussed.

2. Physics simulations and the natural learning process In a natural learning process (as described by Brunner [1]) three modes of representation should happen sequentially: First, the physical interaction (Enactive), secondly representation or association with images (Iconic), and finally the description using language (Symbolic). In traditional physics courses the transfer of knowledge relies mostly in the Iconic (diagrams) and

Symbolic (stating physics laws and using their respective equations) modes, and leaving the Enactive (a laboratory) afterwards in a different time and space. As an example, we will use parabolic motion of projectiles. In a regular course the session starts by showing that the only active force on the projectile is due to gravity g that acts in the vertical axis. That is why its vertical movement is accelerated (according to Newton´s second law). Then, remembering Newton’s law of inertia, a body should continue in constant movement if no external force is acting on it , that is why the horizontal movement is constant, which in a physics course is normally stated as Vx = constant. Then the main equations of parabolic motion are defined:

y = y o + voy t − x = vox t

1 2 gt 2

(1)

v y = voy − gt Later on, a set of exercises are solved using the equations obtaining, maximum height, horizontal displacement, time of flight, etc. This classical approach usually leaves the association with the phenomena behind. Students rarely get to visualize the change in velocity on the vertical component versus the constant movement in the horizontal. A highly abstract reasoning process should be followed by the student to be able to relate the content seen in the classroom with actual projectile motion. It is here where physics simulations help to follow a natural learning process. Using a different approach, the classroom session may start directly interacting with the simulated phenomenon. Figure 1 shows a parabolic motion simulation which has three main input parameters: Initial height, speed and angle. The student, with guidance from the teacher, proceeds to experiment what happens if the initial speed is larger, what happens at different angles, etc. The simulation shows the vertical and horizontal components of the object´s velocity at every moment. In such way the student can visualize that the horizontal component stays the same, and then he can infer that horizontal motion is constant. On the other hand it is observable how the vertical component of the velocity is changing, illustrating the student how unlike horizontal motion, vertical motion is accelerated. Using this approach, the interaction with the phenomenon gives the student the chance to develop a more profound knowledge of it and provides a solid basis to proceed later with the development of theory and solution of numerical exercises.

Figure 1. Computer simulation of parabolic projectile motion for using an initial velocity vo=35 m/s and an angle θ=66° respect to the horizontal axis. The horizontal and vertical components at different times are shown to illustrate the difference between vertical (accelerated) and horizontal (constant) motion. The image is superimposed to show the evolution of the movement.

3. Physics simulations as cognitive tools Physics simulations can be powerful cognitive tools (as described by Jonassen [2]) with the proper execution. For this purpose we can design a learning strategy based on the generation of new knowledge departing with the individual’s actual conceptions. Both Piaget [6] with schemas and Wittrock [7] with generative processing state that during the learning process, the individual links the new information with his previous knowledge. As an example let’s take periodic motion using the harmonic oscillator, particularly, the spring mass system. To reach the students prior knowledge, the teacher may start with trigger questions to refresh the student´s knowledge of Hooke´s law (or simply the behavior of a spring): • What do you think that would happen if you hang the mass from the spring? • What will happen if you now hang a larger mass? Should the spring stretch the same, more, less? Afterwards, the student can check his predictions using the simulation (Figure 2) and compare results. With guidance from the teacher, the student can infer or simply remember Hooke´s law.

Figure 2. Computer simulation of a mass-spring system showing the stretch of a k=1000N/m spring casued by a 2kg mass hanging on it. The mass of the spring is neglected.

After that, the student can proceed to take the mass away from equilibrium, the teacher can now ask: • What would happen now if you stretch the mass-spring system from its equilibrium position? Does the string stay the same? How does it react to this modification? • What will happen if you now release the mass spring system from the stretched position? Does it stay there? Does it return calmly to the equilibrium position? How far will it move? • After releasing it, will it ever return to the stretched position? Again, with the guidance of the teacher, the student may foresee the effect of the restorative force of the spring. In best case scenarios, the student might already realize that the motion is repetitive. Then, the student can proceed observe the actual phenomenon with aid of the simulator (Figure 3): • Release the mass-spring system from the stretched position and let it move • It is returning to its departure point? • Let it oscillate for a while; observe how long does it take to return to its departure point. Does it always take the same time to go back and forth?

Figure 3. Computer simulation showing oscillations of a 2kg mass on a k=1000N/m spring. The illustrated amplitude is 2.5cm.

At this point the teacher can introduce the concept of periodicity and define the period as the time it takes to complete one full oscillation and state that it is constant. To reinforce, the teacher can help the student relate the concept with other repetitive processes in daily life which have a defined cycle and period: The hours of the day, the newspaper delivery, etc.

4. Why do physics simulations need to be operating system independent? The actual physics simulations projects [3],[4] contain mainly applications for PC´s (Personal Computers) which require specific libraries. Actually, there are each time less PC users and more tablet and smartphone users. The Gartner [8] company reported that in 2013 2.3 million of ultra-mobile devices (tablets smartphones and else) and only 0.3 million PC´s. Cross-platform simulations extend the reach of learning strategies by making the cognitive tools accessible to a wider audience. Traditionally in a course session, tablets and smartphones are tagged as distractors, now we can take advantage of them by integrating them in learning process (Figure 4) .

Figure 4. Students using operating system independent physics simulations on several computing devices. For this particular case, the mass spring system simulation is shown.

The operating system independent simulations contained in the newtondreams project are programmed in HTML/JavaScript. Since HTML/JavaScript is embedded in all web browsers, these simulations do not have any special requirements and can be run in any operating system independently of its type and release. They are open access and since they are programmed with basic libraries. Therefore, the student can profit from them at any time and place increasing his interaction with the simulated phenomena. Learning scenarios can be designed for the classroom session or homework.

5. The Newtondreams Project The Netwondreams Project [5] is a set of Java coded cross-platform physics simulations. It started on 2013 at the Physics and Mathematics Department at Universidad de Monterrey (UDEM) to help students achieve an integral learning and engage them in Physics courses (specifically Physics for Engineering I, II and Electricity and Magnetism). The faculty noticed that newer generations of students struggled having a passive role in the classroom and could easily get distracted by their smartphones and other handheld devices. Additionally, many times students just learned formulas, to solve specific exercises but didn´t grasp the physics concepts involved in them. Another issue was that the course curriculum was very ambitious and classroom sessions were limited. With this in mind it was decided that a cognitive tool [2] should be developed to help students be actively involved in the classroom session and help them follow a natural learning process [1] to achieve a deeper understanding of physics principles. The tool had to be accessible, attractive to students, and illustrative. Therefore, it was decided to develop Operating System Independent Physics Simulations. The purpose was for students to use them in their handheld devices without having to download any additional libraries. Also, since students had many brands of handheld devices and operating systems on them, simulations had to be cross-platform. The first simulation made was parabolic motion. Its implementation was simple letting students play with the simulation after the lecturer had introduced the principles of parabolic motion, but before arriving to the equations of motion. The main purpose was for students to visualize that the movement along the vertical axis is accelerated and at the horizontal axis it moves at constant speed. For this purpose the x and y components of the velocity are illustrated as arrows so that the student can observe their behavior along the trajectory of the projected object (Figure 1). It was observed that students got engaged with the lecture and the concept of simultaneous independent movements was better understood. The second application was the spring mass harmonic oscillator. Although the simulation is intentioned for harmonic oscillation, it was initially implemented in energy conservation. First, students would observe how a spring´s stretch depended on the mass hanged on it (Figure 2). Afterwards, they were told to predict the behavior of the system after stretching it from equilibrium position and then releasing it. Finally, they would confirm their predictions with the simulation. They noticed how the spring- mass system oscillated continuously when friction was not present, and could visualize how energy is transformed from potential to kinetic during the process (Figure 3). For this case greater guidance from the instructor was required, since the simulation didn´t present energy plots. Nevertheless students got motivated and the lecturer could more easily illustrate energy conservation in a closed system. Actually, more simulations are being developed for fluid mechanics, electricity and many other topics. Further work is to conduct quantitative and qualitative research to systematically analyze the effects of using these physics simulations as cognitive tools.

6. Conclusion Helping teachers to integrate theory and the physical phenomenon in the same classroom session, Operating System Independent Physics Simulations can be used as cognitive tools to provide a comprehensive learning. Students become highly motivated since they are actively involved in the development of knowledge. Handheld devices, which are everyday more accessible, become part of the course allowing students to be constantly in touch with the simulated phenomenon, and so integral learning is not limited to certain spaces and times. The Newtondreams Project provides a set of open access platform independent simulations for teachers, students and any individual willing to have an active learning experience. Further work is to conduct quantitative and qualitative research to systematically analyze the effects of using Operating System Independent Physics Simulations as cognitive tools.

References [1] Bruner, J. (1976). The Process of Education, Harvard University Press [2] Jonassen, D.H., (1978). What are cognitive tools?. In (1992) Piet A.M. Kommers, David H. Jonassen & J. Terry Mayes Cognitive tools for learning, NATO ASI series, Series F: Computer and Systems Science,Vol. 81. SpringerVerlag. [3] ComPADRE Resources and Services for Physics Education, http://www.compadre.org/ [4] PhET Interactive Simulations, https://phet.colorado.edu/ [5] The Newtondreams Project, www.newtondreams.com [6] Piaget, J. & Inhelder, B. (1969). The psychology of the child (H. Weaver, Trans). New York, Basic Books [7] Wittrock, M. C. (1974). Learning as a generative process. Educational Psychologist, 11 [8] Gartner, D.H., (July 7, 2014). Gartner Says Worldwide Traditional PC, Tablet, Ultramobile and Mobile Phone, http://www.gartner.com/newsroom/id/2791017 Osvaldo Aquines, Hector Gonzalez, Pablo Perez Department of Physics and Mathematics Universidad de Monterrey Av Morones Prieto 4500 Pte. San Pedro Garza García N.L. C.P. 66238 Mexico e-mail: [email protected] [email protected] [email protected]