TY - JOUR A1 - Möllmann, Klaus-Peter A1 - Vollmer, Michael T1 - Fourier transform infrared spectroscopy in physics laboratory courses JF - In: European journal of physics 34 (2013) 6, S123-S137 N2 - nfrared spectrometry is one of the most important tools in the field of spectroscopic analysis. This is due to the high information content of spectra in the so-called spectroscopic fingerprint region, which enables measurement not only of gases, but also of liquids and solids. Today, infrared spectroscopy is almost completely dominated by Fourier transform infrared (FTIR) spectroscopy. FTIR spectroscopy is able to detect minute quantities in the ppm and ppb ranges, and the respective analyses are now standard tools in science as well as industry. Therefore FTIR spectroscopy should be taught within the standard curriculum at university to physicists and engineers. Here we present respective undergraduate laboratory experiments designed for students at the end of their third year. Experiments deal first with understanding the spectrometer and second with recording and analysing spectra. On the one hand, transmission spectra of gases are treated which relate to environmental analytics (being probably the most prominent and well-known examples), and on the other hand, the focus is on the transmission and reflection spectra of solids. In particular, silicon wafers are studied—as is regularly done in the microelectronics industry—in order to characterize their thickness, oxygen content and phonon modes. Y1 - 2013 U6 - https://doi.org/doi:10.1088/0143-0807/34/6/S123 SP - S123 EP - S137 ER - TY - JOUR A1 - Vollmer, Michael T1 - Infrared JF - In: European journal of physics 34 (2013) 6, S49 Y1 - 2013 U6 - https://doi.org/doi:10.1088/0143-0807/34/6/S49 SP - S49 ER - TY - JOUR A1 - Etkina, Eugenia A1 - Planinšič, Gorazd A1 - Vollmer, Michael T1 - Light cone: Engaging students of all levels in processes that physicists use in research JF - In: American journal of physics 81 (2013) 11, 815-822 N2 - A cone of light appears in a tank of water when a laser pointer shines through the water onto a white piece of paper upon which the tank is sitting. We describe how students can understand the origins of this cone by constructing multiple explanations, then proposing and designing experiments to test their explanations. This process is the foundation of the Investigative Science Learning Environment (ISLE) framework, designed to engage students in the reasoning activities similar to those that physicists use to construct and apply new knowledge. We describe typical student ideas and provide a list of equipment and suggestions for facilitating student exploration relating to optics. We also explain the formal physics behind the phenomena that are involved in the experiment. Finally, we suggest how the ISLE framework can be used to help instructors find problems and experiments that engage students in devising and testing multiple explanations. Y1 - 2013 U6 - https://doi.org/10.1119/1.4822176 SP - 815 EP - 822 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - James Bond und die zerplatzenden Christbaumkugeln JF - Physik in unserer Zeit 44 (2013) 6, 304-306 N2 - Rohe Eier oder wassergefüllte Christbaumkugeln platzen beim Eindringen des Projektils einer Luftpistole. Dieser Vorgang lässt sich einfach durch die sehr geringe Kompressibilität des Wassers und eine damit verbundene starke Druckerhöhung erklären (Physik in unserer Zeit 2013, 44(5), 251). Eine genaue Analyse aller Vorgänge sollte aber auch Fragen beantworten wie: Spielen vorhandene Luftblasen in der Flüssigkeit eine Rolle? Wie lange dauert es bis zum Aufplatzen, und muss die wassergefüllte Kugel eigentlich fest verschlossen sein? Y1 - 2013 U6 - https://doi.org/10.1002/piuz.201390109 SP - 304 EP - 306 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter A1 - Schlichting, Hans Joachim T1 - Double pane windows—elastic deformations, gas thermodynamics, thermal and optical phenomena JF - In: European Journal of Physics 35 (2014) 4, 045023 N2 - Double pane windows are common objects which can enrich physics teaching at undergraduate level at least in five different fields. First, having sealed inner spaces filled with gas, one can discuss gas law problems upon changes of pressure and/or temperature. Second, when discussing temperature differences between inside and outside, one needs to take into account the associated heat transfer mechanisms which define the pane temperatures, enclosing the gas. Third, using elastic properties of the glass, one may treat deformations of the window panes upon those changes or additional manually applied external pressure. Fourth, the reflective properties of glass combined with the pane deformations result in concave or convex mirrors, which when illuminated by the Sun, may lead to focal points on projection areas such as facing houses. Fifth, such areas receive an increased irradiance which leads to associated thermal effects. Starting from the most obvious daily life phenomenon, the fascinating caustics of reflected sunlight on streets or walls, all of these double pane window phenomena are investigated experimentally as well as theoretically. Y1 - 2014 U6 - https://doi.org/10.1088/0143-0807/35/4/045023 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Schnelles Verblassen leuchtender Spuren JF - In: Physik in unserer Zeit 45 (2014) 5, 252-253 N2 - Wohl jeder, der schon einmal mit Physik zu tun hatte, kennt die meist grünlichen Leuchtspuren von Oszillographen. Sie ermöglichen es, zeitabhängige Signale zu visualisieren und quantitativ auszumessen, insbesondere auch dann, wenn die Phänomene sehr schnell ablaufen. Die Reaktionsdynamik der leuchtenden Phosphore auf den Bildschirmen wird mit Hochgeschwindigkeits-Videos deutlich sichtbar. Y1 - 2014 U6 - https://doi.org/10.1002/piuz.201490088 SP - 252 EP - 253 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Wenn es knallt und kracht JF - In: Physik in unserer Zeit 45 (2014) 3, 148-149 N2 - An die Knallgasprobe erinnert sich wohl noch jeder aus dem Chemieunterricht. Die Zeitskala, auf der Wasserstoff und Sauerstoff reagieren hängt davon ab, ob die beiden Reaktionsgase zu Beginn getrennt oder gemischt vorliegen. Dies zeigt sich deutlich in Hochgeschwindigkeits-Aufnahmen von Experimenten, bei denen Luftballons entweder mit reinem Wasserstoff oder aber mit Knallgas gefüllt werden. Y1 - 2014 U6 - https://doi.org/10.1002/piuz.201490046 SP - 148 EP - 149 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Achtung Solarofen : Kaustiken von Hochhausverglasungen JF - In: Physik in unserer Zeit 45 (2014) 3, 134-139 N2 - Konkav gewölbte Glasfassaden von Großbauten können bei ungünstiger Orientierung zur Sonne zum Brennspiegel werden. Unfreiwillig berühmt gewordene Beispiele sind das Vdara-Hotel in Las Vegas und das “Walkie-Talkie”-Hochhaus in London. Dieser Effekt tritt auch nur an bestimmten Tagen bei passendem Sonnenstand auf. Da die Fassaden keine perfekten Parabolspiegel sind, produzieren sie keinen scharfen Brennpunkt, sondern aufgeweitete Brennflecke, sogenannte Kaustiken. Trotzdem können dort hohe Bestrahlungsstärken auftreten. Simulationen und Experimente mit Modellen bestätigen dies. Y1 - 2014 U6 - https://doi.org/10.1002/piuz.201401360 SP - 134 EP - 139 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Das farbenprächtige Glitzern frischen Schnees JF - In: Physik in unserer Zeit 45 (2014) 2, 97-98 N2 - Regenbögen, Halos, Koronen, Himmelsfarben – es gibt eine Vielzahl farbenprächtiger Phänomene in der Natur, verursacht durch Reflexion, Brechung oder allgemein gesprochen durch Streuung des Lichts an Wassertropfen, Eiskristallen oder Aerosolen. Das farbige Glitzern einer Schneeschicht scheint zunächst anderer Natur zu sein, lässt sich aber auf analoge Weise erklären. Y1 - 2014 U6 - https://doi.org/10.1002/piuz.201490031 SP - 97 EP - 98 ER - TY - JOUR A1 - Vollmer, Michael A1 - Möllmann, Klaus-Peter T1 - Physikalische Zauberei : die Kette im Ring JF - In: Physik in unserer Zeit 45 (2014) 1, 44-45 N2 - Ein einfacher physikalischer Zaubertrick besteht darin, eine Kette über den Handrücken zu legen und danach von unten einen Ring über die Kette zu schieben. Der Ring kann entweder von der zweiten Hand oder der die Kette haltenden Hand gehalten werden. Er wird sodann losgelassen und soll (mit einem Knoten) in der Kette hängen bleiben. Y1 - 2014 U6 - https://doi.org/10.1002/piuz.201490004 SP - 44 EP - 45 ER - TY - JOUR A1 - Nugent, Paul W. A1 - Shaw, Joseph A. A1 - Vollmer, Michael T1 - Colors of thermal pools at Yellowstone National Park JF - Applied Optics Vol. 54 (2015 ) 4, pp. B128-B139 N2 - Abstract The brilliant visible colors of various hot springs and pools in Yellowstone National Park are explained with a combination of scattering from the water and from microbial mats that coat the bottoms of these thermal features. A simple 1D radiative transfer model was used to simulate the colors recorded in visible photographs and the spectrum of light making up these colors. The model includes attenuation in water by absorption and molecular scattering as well as reflection characteristics of the microbial mats and surface reflection of the water. Pool geometries are simulated as simple rough cones scaled to have depths and widths that match published data. Thermal images are also used to record the spatial distribution of water skin temperature. The measurements and simulations confirm that colors observed from shallow-water features arise primarily from the spectral properties of the microbial mat, which is related to the water temperature, while colors observed from deeper water arise primarily from the wavelength-dependent absorption and scattering in the water. Y1 - 2015 U6 - https://doi.org/10.1364/AO.54.00B128 SP - B128 EP - B139 ER - TY - GEN A1 - Vollmer, Michael T1 - Beautiful phenomena in the skies: a colorful journey in the realm of atmospheric optics Y1 - 2012 ER - TY - GEN A1 - Vollmer, Michael T1 - Surprising warm edges associated with moisture on surfaces Y1 - 2012 ER - TY - GEN A1 - Vollmer, Michael T1 - Brilliant colors from a white snow cover Y1 - 2013 ER - TY - GEN A1 - Vollmer, Michael T1 - Visible and invisible mirages: comparing inferior mirages in the visible and thermal infrared spectral range Y1 - 2013 ER - TY - GEN A1 - Vollmer, Michael T1 - The magic of the invisible: using IR imaging in physics education Y1 - 2013 ER - TY - GEN A1 - Vollmer, Michael T1 - A random walk through the cultural history of the rainbow Y1 - 2001 ER - TY - GEN A1 - Vollmer, Michael T1 - IR imaging of gases: potential applications for CO2 cameras Y1 - 2009 ER - TY - GEN A1 - Vollmer, Michael T1 - IR feedback loops to spotlights: thermography and contemporary dancing Y1 - 2009 ER - TY - GEN A1 - Vollmer, Michael T1 - High speed - slow motion I: new insights for hands on experiments in mechanics Y1 - 2010 ER -