@article{VollmerMoellmann2008, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Infrarotkameras: es gibt mehr zu sehen als unsere Augen wahrnehmen}, series = {In: Naturwissensschaftliche Rundschau 61 (2008) 11, 557—565}, journal = {In: Naturwissensschaftliche Rundschau 61 (2008) 11, 557—565}, pages = {557 -- 565}, year = {2008}, language = {de} } @article{VollmerMoellmannArnold2008, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter and Arnold, Frank}, title = {Ins eigene Segel blasen. M{\"u}nchhausen-Effekt und Schubumkehr}, series = {In: Physik in unserer Zeit 39 (2008) 5, 241-245}, journal = {In: Physik in unserer Zeit 39 (2008) 5, 241-245}, doi = {10.1002/piuz.200801172}, pages = {241 -- 245}, year = {2008}, abstract = {Kann man sich mit seinem Segelboot fortbewegen, indem man ins eigene Segel bl{\"a}st? Der Impulssatz erlaubt diesen an M{\"u}nchhausen erinnernden Effekt. Das demonstriert ein vereinfachtes Gedankenexperiment, bei dem der Segler durch den Werfer eines Balls und das Segel durch eine starre Wand ersetzt wird. Allerdings ergibt die naive Theorie, die Luftmolek{\"u}le als ball{\"a}hnliche Korpuskeln auffasst, einen zu hohen Impuls des reflektierten Luftstroms. Eine realistische Beschreibung liefert die moderne Str{\"o}mungstheorie. Ihre Resultate sind experimentell erfolgreich umsetzbar. Technisch angewendet wird das Prinzip in der Schubumkehr von Flugzeugtriebwerken.}, language = {de} } @incollection{ChiaverinaVollmer2006, author = {Chiaverina, Chris and Vollmer, Michael}, title = {Learning physics from the experiments}, series = {In: Informal learning and public understanding of physics : third international GIREP seminar 2005 ; selected contributions ; [5 - 9 September 2005, Ljubljana, Slovenia] / ed.: Gorazd Planinšič ... Ljubljana : Faculty of Mathematics and Physics, 2006}, booktitle = {In: Informal learning and public understanding of physics : third international GIREP seminar 2005 ; selected contributions ; [5 - 9 September 2005, Ljubljana, Slovenia] / ed.: Gorazd Planinšič ... Ljubljana : Faculty of Mathematics and Physics, 2006}, publisher = {Faculty of Mathematics and Physics}, address = {Ljubljana}, year = {2006}, language = {en} } @article{Vollmer2005, author = {Vollmer, Michael}, title = {Diffraction revisited : position of diffraction spots upon rotation of a transmission grating}, series = {In: Physics education 40 (2005), 562-565}, journal = {In: Physics education 40 (2005), 562-565}, pages = {562 -- 565}, year = {2005}, language = {en} } @article{Vollmer2005, author = {Vollmer, Michael}, title = {Hot gases : transition from line spectra to thermal radiation}, series = {In: American journal of physics 73 (2005), 215-223}, journal = {In: American journal of physics 73 (2005), 215-223}, pages = {215 -- 223}, year = {2005}, abstract = {The question of how the line spectrum of atoms is transformed into the continuous spectrum of thermal radiation of a gas by repeated absorption and emission of photons is addressed. We consider a simple model of a hydrogen-like gas in thermal equilibrium where only the Lyman-α transition is allowed and calculate the spectra for increasing thickness of the gas. The transition from line spectra for optically thin samples to the spectra of thermal radiation for optically thick samples is demonstrated. We estimate the emissivities for hot gases and study the line width of spectral lines due to self-absorption processes.}, language = {en} } @article{CowleyLavenVollmer2005, author = {Cowley, L. and Laven, Ph. and Vollmer, Michael}, title = {Rings around sun and moon : coronae and diffraction}, series = {In: Physics Education 40 (2005) 1, 51-59}, journal = {In: Physics Education 40 (2005) 1, 51-59}, pages = {51 -- 59}, year = {2005}, language = {en} } @article{VollmerMoellmannKarstaedt2004, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter and Karst{\"a}dt, Detlef}, title = {Microwave oven experiments with metals and light sources}, series = {In: Physics Education 39 (2004), 500-508}, journal = {In: Physics Education 39 (2004), 500-508}, pages = {500 -- 508}, year = {2004}, abstract = {Don't put metal objects in the microwave' is common safety advice. But why? Here we describe demonstration experiments involving placing household metallic objects in a microwave oven. These allow a better understanding of the interaction of microwaves with materials. Light bulbs and discharge lamps can also be used in instructive demonstrations.}, language = {en} } @article{VollmerMoellmannKarstaedt2004, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter and Karst{\"a}dt, Detlef}, title = {More experiments with microwave ovens}, series = {In: Physics education 39 (2004) 4, 346 - 351}, journal = {In: Physics education 39 (2004) 4, 346 - 351}, pages = {346 -- 351}, year = {2004}, abstract = {Microwave ovens can be used to perform exciting demonstrations that illustrate a variety of physics topics. Experiments discussed here show superheating, visualize the inhomogeneous heating that takes place in a microwave and also show how to use a mobile phone to detect radiation leaking from the oven. Finally eggs can give some spectacular (though messy) explosions. In all cases please note the safety advice given.}, language = {en} } @article{ParkerVollmer2004, author = {Parker, Kerry and Vollmer, Michael}, title = {Bad food and good physics : the development of domestic microwave cookery}, series = {In: Physics Education 39 (2004) 1, 82-90}, journal = {In: Physics Education 39 (2004) 1, 82-90}, pages = {82 -- 90}, year = {2004}, abstract = {This article forms the second of two papers on the subject of microwave cookers. In the first paper Michael Vollmer describes the physics behind the production of microwaves in the magnetron of the oven, the waveguide and the interaction between the microwaves and the food. This article looks at the physics of cooking, and how the appliance and the food industries have developed products which are now part of many of our students' lifestyles. We include many interesting demonstrations that illustrate this history and which could be used to teach many principles of physics.}, language = {en} } @article{Vollmer2004, author = {Vollmer, Michael}, title = {Physics of the microwave oven}, series = {In: Physics education 39 (2004) 1, 74-81}, journal = {In: Physics education 39 (2004) 1, 74-81}, pages = {74 -- 81}, year = {2004}, abstract = {This is the first of two articles about the physics of microwave ovens. This article deals with the generation of microwaves in the oven and includes the operation of the magnetrons, waveguides and standing waves in resonant cavities. It then considers the absorption of microwaves by foods, discussing the dielectric relaxation of water, penetration depths of electromagnetic waves in matter and, in considering the possible chemical changes during the microwave heating, multi-photon ionization or dissociation.}, language = {en} }