@inproceedings{VollmerMoellmann2013, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {The magic of the invisible: using IR imaging in physics education}, series = {In: InfraMation proceedings / Infrared Training Center. - Vol. 14 (2013)}, booktitle = {In: InfraMation proceedings / Infrared Training Center. - Vol. 14 (2013)}, year = {2013}, language = {en} } @article{VollmerMoellmann2013, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Characterization of IR cameras in student labs}, series = {In: European journal of physics 34 (2013) 6,}, journal = {In: European journal of physics 34 (2013) 6,}, doi = {doi:10.1088/0143-0807/34/6/S73}, pages = {S73 -- S90}, year = {2013}, abstract = {The content of a student lab course is described which deals with characterization of the most important parameters governing the performance of infrared cameras. In detail, the parameters describing the temperature resolution, spatial resolution and time resolution of commercial IR cameras are analysed using simple lab experiments. Understanding the respective performance of the system is the prerequisite for applying infrared thermal imaging to quantitative measurements in physics and technology.}, language = {en} } @article{MangoldShawVollmer2013, author = {Mangold, Klaus and Shaw, Joseph A. and Vollmer, Michael}, title = {The physics of near-infrared photography}, series = {In: European journal of physics 34 (2013) 6, S51-S71}, journal = {In: European journal of physics 34 (2013) 6, S51-S71}, doi = {doi:10.1088/0143-0807/34/6/S51}, pages = {S51 -- S71}, year = {2013}, abstract = {The physics behind the sometimes strange effects and 'unnatural' appearance of near-infrared (NIR) photographs is discussed in terms of reflection, absorption and transmission of NIR radiation with the respective objects. Besides discussing how NIR cameras work, several visible and NIR photograph pairs are presented, which include vegetation, natural water, clouds, the sky, and humans. In addition, some physics-oriented experimental NIR images are presented which clearly demonstrate some of the basic physics behind some of these awesome sights.}, language = {en} } @article{MoellmannVollmer2013, author = {M{\"o}llmann, Klaus-Peter and Vollmer, Michael}, title = {Fourier transform infrared spectroscopy in physics laboratory courses}, series = {In: European journal of physics 34 (2013) 6, S123-S137}, journal = {In: European journal of physics 34 (2013) 6, S123-S137}, doi = {doi:10.1088/0143-0807/34/6/S123}, pages = {S123 -- S137}, year = {2013}, abstract = {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.}, language = {en} } @article{Vollmer2013, author = {Vollmer, Michael}, title = {Infrared}, series = {In: European journal of physics 34 (2013) 6, S49}, journal = {In: European journal of physics 34 (2013) 6, S49}, doi = {doi:10.1088/0143-0807/34/6/S49}, pages = {S49}, year = {2013}, language = {en} } @article{EtkinaPlaninšičVollmer2013, author = {Etkina, Eugenia and Planinšič, Gorazd and Vollmer, Michael}, title = {Light cone: Engaging students of all levels in processes that physicists use in research}, series = {In: American journal of physics 81 (2013) 11, 815-822}, journal = {In: American journal of physics 81 (2013) 11, 815-822}, doi = {10.1119/1.4822176}, pages = {815 -- 822}, year = {2013}, abstract = {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.}, language = {en} } @article{VollmerMoellmann2013, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {James Bond und die zerplatzenden Christbaumkugeln}, series = {Physik in unserer Zeit 44 (2013) 6, 304-306}, journal = {Physik in unserer Zeit 44 (2013) 6, 304-306}, doi = {10.1002/piuz.201390109}, pages = {304 -- 306}, year = {2013}, abstract = {Rohe Eier oder wassergef{\"u}llte Christbaumkugeln platzen beim Eindringen des Projektils einer Luftpistole. Dieser Vorgang l{\"a}sst sich einfach durch die sehr geringe Kompressibilit{\"a}t des Wassers und eine damit verbundene starke Druckerh{\"o}hung erkl{\"a}ren (Physik in unserer Zeit 2013, 44(5), 251). Eine genaue Analyse aller Vorg{\"a}nge sollte aber auch Fragen beantworten wie: Spielen vorhandene Luftblasen in der Fl{\"u}ssigkeit eine Rolle? Wie lange dauert es bis zum Aufplatzen, und muss die wassergef{\"u}llte Kugel eigentlich fest verschlossen sein?}, language = {de} } @article{VollmerMoellmannSchlichting2014, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter and Schlichting, Hans Joachim}, title = {Double pane windows—elastic deformations, gas thermodynamics, thermal and optical phenomena}, series = {In: European Journal of Physics 35 (2014) 4, 045023}, journal = {In: European Journal of Physics 35 (2014) 4, 045023}, doi = {10.1088/0143-0807/35/4/045023}, year = {2014}, abstract = {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.}, language = {en} } @article{VollmerMoellmann2014, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Schnelles Verblassen leuchtender Spuren}, series = {In: Physik in unserer Zeit 45 (2014) 5, 252-253}, journal = {In: Physik in unserer Zeit 45 (2014) 5, 252-253}, doi = {10.1002/piuz.201490088}, pages = {252 -- 253}, year = {2014}, abstract = {Wohl jeder, der schon einmal mit Physik zu tun hatte, kennt die meist gr{\"u}nlichen Leuchtspuren von Oszillographen. Sie erm{\"o}glichen es, zeitabh{\"a}ngige Signale zu visualisieren und quantitativ auszumessen, insbesondere auch dann, wenn die Ph{\"a}nomene sehr schnell ablaufen. Die Reaktionsdynamik der leuchtenden Phosphore auf den Bildschirmen wird mit Hochgeschwindigkeits-Videos deutlich sichtbar.}, language = {de} } @article{VollmerMoellmann2014, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Wenn es knallt und kracht}, series = {In: Physik in unserer Zeit 45 (2014) 3, 148-149}, journal = {In: Physik in unserer Zeit 45 (2014) 3, 148-149}, doi = {10.1002/piuz.201490046}, pages = {148 -- 149}, year = {2014}, abstract = {An die Knallgasprobe erinnert sich wohl noch jeder aus dem Chemieunterricht. Die Zeitskala, auf der Wasserstoff und Sauerstoff reagieren h{\"a}ngt 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 gef{\"u}llt werden.}, language = {de} } @article{VollmerMoellmann2014, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Achtung Solarofen : Kaustiken von Hochhausverglasungen}, series = {In: Physik in unserer Zeit 45 (2014) 3, 134-139}, journal = {In: Physik in unserer Zeit 45 (2014) 3, 134-139}, doi = {10.1002/piuz.201401360}, pages = {134 -- 139}, year = {2014}, abstract = {Konkav gew{\"o}lbte Glasfassaden von Großbauten k{\"o}nnen bei ung{\"u}nstiger Orientierung zur Sonne zum Brennspiegel werden. Unfreiwillig ber{\"u}hmt 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 k{\"o}nnen dort hohe Bestrahlungsst{\"a}rken auftreten. Simulationen und Experimente mit Modellen best{\"a}tigen dies.}, language = {de} } @article{VollmerMoellmann2014, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Das farbenpr{\"a}chtige Glitzern frischen Schnees}, series = {In: Physik in unserer Zeit 45 (2014) 2, 97-98}, journal = {In: Physik in unserer Zeit 45 (2014) 2, 97-98}, doi = {10.1002/piuz.201490031}, pages = {97 -- 98}, year = {2014}, abstract = {Regenb{\"o}gen, Halos, Koronen, Himmelsfarben - es gibt eine Vielzahl farbenpr{\"a}chtiger Ph{\"a}nomene 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 zun{\"a}chst anderer Natur zu sein, l{\"a}sst sich aber auf analoge Weise erkl{\"a}ren.}, language = {de} } @article{VollmerMoellmann2014, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Physikalische Zauberei : die Kette im Ring}, series = {In: Physik in unserer Zeit 45 (2014) 1, 44-45}, journal = {In: Physik in unserer Zeit 45 (2014) 1, 44-45}, doi = {10.1002/piuz.201490004}, pages = {44 -- 45}, year = {2014}, abstract = {Ein einfacher physikalischer Zaubertrick besteht darin, eine Kette {\"u}ber den Handr{\"u}cken zu legen und danach von unten einen Ring {\"u}ber 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 h{\"a}ngen bleiben.}, language = {de} } @article{NugentShawVollmer2015, author = {Nugent, Paul W. and Shaw, Joseph A. and Vollmer, Michael}, title = {Colors of thermal pools at Yellowstone National Park}, series = {Applied Optics Vol. 54 (2015 ) 4, pp. B128-B139}, journal = {Applied Optics Vol. 54 (2015 ) 4, pp. B128-B139}, doi = {10.1364/AO.54.00B128}, pages = {B128 -- B139}, year = {2015}, abstract = {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.}, language = {en} }