M. Vetter

Experimenting from a distance—remotely controlled laboratory (RCL)

The use of computers and multimedia, as well as the World Wide Web and new communication technologies, allows new forms of teaching and learning such as distance learning, blended learning, use of virtual libraries and many more. The herewith discussed remotely controlled laboratory (RCL) project shall offer an additional contribution. The basic idea is for a user to connect via the Internet with a computer from place A to a real experiment carried out in place B. An overview of our technical and didactical developments as well as an outlook on future plans is presented. Currently, about ten RCLs have been implemented. The essential characteristics of an RCL are the intuitive use and interactivity (operating the technical parameters), the possibility of different points of view of the ongoing experiment thanks to web cams and the quickest possible transfer of the data measured by the user. A reasonable use of sensibly chosen real experiments as remote labs allows a new form of homework and exercises, as well as project work and the execution of experiments, which usually would be a teachers prerogative only.

Remotely controlled laboratories: Aims, examples, and experience

Remotely controlled laboratories are real experiments that can be controlled by users from their computers via the Internet. We present an overview of technical and pedagogical developments, describe the diversity and potential of our experiments, and comment on their acceptance by physics instructors.

From optical spectra to phase diagrams—the binary mixture N2–CO

We investigate the T–c% phase diagram of the binary system N2–CO. From changes in IR spectra of all kinds of mode excitations (phonons, vibrons) we were able to determine the temperature of phase transitions (solid-solid, solid-liquid). The improvements in comparison to structural investigations by x-rays or electrons are the following: sample growing and handling with perfect optical and thermodynamic quality; determination of actual concentration (N2)x(CO)y from optical spectra; reduction of thermal hysteresis by careful cooling-heating cycles of the samples.

Physical aspects of matrix isolation technique: FTIR studies on CO and CO2 in O2 and N2 matrices

The matrix isolation technique is traditionally used to investigate the properties of the matrix-isolated species themselves or to solve some special questions of the theory of defects in solids. We showed here that the optical spectroscopy of real matrix-isolated molecules can be successfully used to investigate the host crystal qualities, too. We demonstrated the capacity of modern FTIR spectroscopy to study the properties of cryocrystals such as phase transitions, solubility boundaries, orientational order parameter, etc., by monitoring the behavior of the IR-active molecules, which are present in matrices under investigation as a natural contamination (40 ppb). Due to the excellent optical quality of our crystal samples, we were able to determine a part of the binary phase diagram CO–O2 (at CO concentrations less than 1 ppm) as well as to investigate the kinetics of phase transitions. Furthermore, we successfully used the spectroscopy of the matrix-isolated molecules to proof that the α-β phase transi...

Lattice phonons of solid phases (α,β,δ,ε) of carbon monoxide by optical studies

The phase diagram of solid carbon monoxide was investigated in the pressure range 0–10GPa and temperature range 30–300K by infrared and Raman spectroscopy. The tentative phase diagram known from the literature was expanded and specified in detail. The δ-phase region is divided into two subphases—δrot and δloc—similar to solid nitrogen. The pressure-temperature behavior of the elementary and combined excitations was also followed up. The vibron overtone region was carefully investigated by FTIR spectroscopy as a function of temperature at different pressures; the fundamental region was investigated by Raman spectroscopy. The features of the IR-active phonon sideband to the vibron overtone were investigated in detail in the entire pressure-temperature region. The lattice-phonon spectra were studied by Raman spectroscopy as a function of pressure (at lowest temperature) and by IR spectroscopy as a function of temperature at saturated vapor pressure.

Experimenting from a distance—determination of speed of light by a remotely controlled laboratory (RCL)

The speed of light is an essential topic in the teaching of physics at school and at university, either with respect to the type of experiment or of course with respect to its genuine inherent importance. In reality, the various available experiments are hardly ever performed in class for many reasons. Therefore, we offer this experiment as a remotely controlled laboratory (RCL). An RCL is a real experiment setup at location A which can be controlled via the Internet by a user at a distant location B. It allows several actions like in the hands-on experiment and delivers convincing results. Finally, we present experiences of the use of the RCL, describe the added value of this experiment as an RCL and give hints for implementing the RCL in teaching.

Experimenting from a Distance in the Case of Rutherford Scattering.

The Rutherford scattering experiment plays a central role in working out atomic models in physics and chemistry. Nevertheless, the experiment is rarely performed at school or in introductory physics courses at university. Therefore, we realized this experiment as a remotely controlled laboratory (RCL), i.e. the experiment is set up in reality and can be operated by a computer via the Internet. We present results of measurements and supplementary didactical material. In addition, we make suggestions on how to use the RCL in class and we describe the added value of performing this experiment as an RCL.

World pendulum?a distributed remotely controlled laboratory (RCL) to measure the Earth's gravitational acceleration depending on geographical latitude

We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy ?g ~ 0.01 m s?2). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part describes the physical origin of this phenomenon g(), that the Earths effective gravitational acceleration g depends on the angle of latitude . Then, we present all necessary formula to deduce g() from oscillations of a string pendulum. The technical part explains tips and tricks to realize such an apparatus to measure all necessary values with sufficient accuracy. In addition, we justify the precise dimensions of a physical pendulum such that the formula for a mathematical pendulum is applicable to determine g() without introducing errors. To conclude, we describe the internet version?the string pendulum as a remotely controlled laboratory. The teaching relevance and educational value will be discussed in detail at the end of this paper including global experimenting, using the internet and communication techniques in teaching and new ways of teaching and learning methods.

Millikan's oil-drop experiment as a remotely controlled laboratory

The Millikan oil-drop experiment, to determine the elementary electrical charge e and the quantization of charge Q = n · e, is an essential experiment in physics teaching but it is hardly performed in class for several reasons. Therefore, we offer this experiment as a remotely controlled laboratory (RCL). We describe the interactivity of the experiment and the quality of measurements. The added value to offer the Millikan experiment as an RCL is pointed out.