@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} } @misc{Vollmer2012, author = {Vollmer, Michael}, title = {Beautiful phenomena in the skies: a colorful journey in the realm of atmospheric optics}, year = {2012}, language = {en} } @misc{Vollmer2012, author = {Vollmer, Michael}, title = {Surprising warm edges associated with moisture on surfaces}, year = {2012}, language = {en} } @misc{Vollmer2013, author = {Vollmer, Michael}, title = {Brilliant colors from a white snow cover}, year = {2013}, language = {en} } @misc{Vollmer2013, author = {Vollmer, Michael}, title = {Visible and invisible mirages: comparing inferior mirages in the visible and thermal infrared spectral range}, year = {2013}, language = {en} } @misc{Vollmer2013, author = {Vollmer, Michael}, title = {The magic of the invisible: using IR imaging in physics education}, year = {2013}, language = {en} } @misc{Vollmer2001, author = {Vollmer, Michael}, title = {A random walk through the cultural history of the rainbow}, year = {2001}, language = {en} } @misc{Vollmer2009, author = {Vollmer, Michael}, title = {IR imaging of gases: potential applications for CO2 cameras}, year = {2009}, language = {en} } @misc{Vollmer2009, author = {Vollmer, Michael}, title = {IR feedback loops to spotlights: thermography and contemporary dancing}, year = {2009}, language = {en} } @misc{Vollmer2010, author = {Vollmer, Michael}, title = {High speed - slow motion I: new insights for hands on experiments in mechanics}, year = {2010}, language = {en} } @misc{Vollmer2010, author = {Vollmer, Michael}, title = {High speed - slow motion II : more experiments using gases, fluids, heat and electromagnetism}, year = {2010}, language = {en} } @misc{Vollmer2010, author = {Vollmer, Michael}, title = {Measurements of sky, clouds and moon with IR cameras: effects of air mass}, year = {2010}, language = {en} } @misc{VollmerMoellmann2011, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {High speed - slow motion: fascinating phenomena observed in hands-on experiments}, year = {2011}, language = {en} } @misc{Vollmer2011, author = {Vollmer, Michael}, title = {IR imaging of CO2: basics, experiments, and potential industrial applications}, year = {2011}, language = {en} } @misc{Vollmer2011, author = {Vollmer, Michael}, title = {Low cost hands-on experiments for physics teaching}, year = {2011}, language = {en} } @misc{Vollmer2011, author = {Vollmer, Michael}, title = {Optics of glass fronts of buildings: the science of skyscraper death rays}, year = {2011}, language = {en} } @misc{Vollmer2001, author = {Vollmer, Michael}, title = {More laboratory experiments in atmospheric optics}, year = {2001}, language = {en} }