@article{Edel2004, author = {Edel, Karl-Otto}, title = {Der Bologna Prozess : Anmerkung zur rechtlichen Gestaltung und Umsetzung}, series = {Die neue Hochschule}, volume = {45}, journal = {Die neue Hochschule}, number = {6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:522-opus-347}, pages = {26 -- 29}, year = {2004}, abstract = {Die Bologna-Deklaration ist eine politische Willensbekundung der Unterzeichner, die durch die informelle Versammlung der europ{\"a}ischen Wissenschaftsminister vorangetrieben wird. Wegen des fehlenden Rechtscharakters der Deklaration gibt es keine rechtliche Verpflichtung, die vereinbarten Ziele umzusetzen, keine Rechtsanspr{\"u}che oder Verpflichtungen zwischen den Teilnehmerl{\"a}ndern untereinander, insbesondere auch keinen Anspruch auf Anerkennung der Studien und Abschl{\"u}sse im Ausland. Die platte {\"U}bernahme der US-amerikanischen Abschlußbezeichnungen des gestuften Studiums stellt einen Bruch mit den Traditionen der deutschen Hochschulen dar und steht im offenen Widerspruch zu der im Bologna-Abkommen feierlich unterzeichneten Achtung vor der eigenen Kultur, Sprache und Tradition. W{\"a}hrend die durch das gestufte Studiensystem charakterisierten angels{\"a}chsischen L{\"a}nder von ihrem traditionellen System Abschied nehmen und - teilweise expressis verbis - auf das einhundertj{\"a}hrige bew{\"a}hrte deutsche Diplomstudium zugehen, verordnen Politiker unseren Hochschulen eine Roßkur mit h{\"o}chst fatalen Folgen f{\"u}r die Zukunft. Diesen Bestrebungen sollte Einhalt geboten werden, damit in Ruhe und mit {\"U}berlegung eine inhaltliche Reform begonnen werden kann, die die St{\"a}rken unseres Bildungssystems wieder innerhalb Deutschlands und weltweit zur Geltung bringt, anstatt es auf das niedrigste bekannte Niveau des Bachelors zu reduzieren.}, subject = {Bologna-Prozess}, language = {de} } @article{Edel2005, author = {Edel, Karl-Otto}, title = {Die Auswirkungen des Bologna-Prozesses und seiner Instrumentalisierung auf das akademische Qualifikationsniveau}, volume = {46}, number = {2/3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:522-opus-356}, pages = {16 -- 18}, year = {2005}, abstract = {Aus einer Gegen{\"u}berstellung der Absolventenzahlen der jeweiligen Abschl{\"u}sse in Deutschland und den USA ergibt sich der Schluß, daß durch die Einf{\"u}hrung der Bologna-Abschl{\"u}sse zusammen mit den konkreten politischen Zielvorgaben das akademische Bildungsniveau in Deutschland in einem f{\"u}r ein Industrieland gef{\"a}hrlichem Maße gesenkt werden wird.}, subject = {Bologna-Prozess ; Auswirkung}, language = {de} } @article{Edel2005, author = {Edel, Karl-Otto}, title = {Ausl{\"a}ndische Erfahrungen mit der Studienstrukturreform}, series = {Die neue Hochschule}, volume = {46}, journal = {Die neue Hochschule}, number = {4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:522-opus-368}, pages = {22 -- 27}, year = {2005}, abstract = {Trotz seiner dringenden Reformbed{\"u}rftigkeit ist auch heute noch das deutsche Diplomstudium grunds{\"a}tzlich erfolgreich und erneuerungsf{\"a}hig. In Kenntnis der neueren internationalen Entwicklungen in D{\"a}nemark, Finnland, Griechenland, Großbritannien, den USA und Indien ist es vorschnell und nicht zu akzeptieren, das seit mehr als einem Jahrhundert existierende deutsche Hochschuldiplom zum Auslaufmodell zu erkl{\"a}ren und die akademische Bildung ausschließlich auf das angeblich international - von wem auch immer - anerkannte Bachelor-Master-System umzustrukturieren.}, subject = {Studienreform}, language = {de} } @article{MukhinKonoplevOseevetal.2021, author = {Mukhin, Nikolay and Konoplev, Georgii and Oseev, Aleksandr and Schmidt, Marc-Peter and Stepanova, Oksana and Kozyrev, Andrey and Dmitriev, Alexander and Hirsch, Soeren}, title = {Label-Free Protein Detection by Micro-Acoustic Biosensor Coupled with Electrical Field Sorting. Theoretical Study in Urine Models}, series = {Sensors}, volume = {21}, journal = {Sensors}, number = {7}, publisher = {MDPI}, doi = {10.3390/s21072555}, pages = {2555}, year = {2021}, language = {en} } @article{Vollmer2020, author = {Vollmer, Michael}, title = {Below the horizon-the physics of extreme visual ranges}, series = {Applied Optics}, volume = {59}, journal = {Applied Optics}, number = {21}, publisher = {Optica Publishing Group}, doi = {10.1364/AO.390654}, pages = {F11 -- F19}, year = {2020}, language = {en} } @article{TumarkinTyurninaTyurninaetal.2020, author = {Tumarkin, Andrey and Tyurnina, Natalya and Tyurnina, Zoya and Mukhin, Nikolay and Sinelshchikova, Olga and Gagarin, Alexander and Sviridov, Sergey and Drozdovsky, Andrey and Sapego, Eugeny and Mylnikov, Ivan}, title = {Barium-Strontium Titanate/Porous Glass Structures for Microwave Applications}, series = {Materials}, volume = {13}, journal = {Materials}, number = {24}, publisher = {MDPI}, doi = {10.3390/ma13245639}, year = {2020}, language = {en} } @article{RudenkoGaponenkoLitvinovetal.2020, author = {Rudenko, Maryia and Gaponenko, Nikolai and Litvinov, Vladimir and Ermachikhin, Alexander and Chubenko, Eugene and Borisenko, Victor and Mukhin, Nikolay and Radyush, Yuriy and Tumarkin, Andrey and Gagarin, Alexander}, title = {Structural Dependent Eu3+ Luminescence, Photoelectric and Hysteresis Effects in Porous Strontium Titanate}, series = {Materials}, volume = {13}, journal = {Materials}, number = {24}, publisher = {MDPI}, doi = {10.3390/ma13245767}, year = {2020}, language = {en} } @article{RegehlyHecht2022, author = {Regehly, Martin and Hecht, Stefan}, title = {Auf dem Weg zum Replikator}, series = {Physik in unserer Zeit}, volume = {53}, journal = {Physik in unserer Zeit}, number = {3}, publisher = {Wiley-VCH GmbH}, issn = {1521-3943}, doi = {10.1002/piuz.202201637}, pages = {125 -- 131}, year = {2022}, language = {de} } @article{HirschSchmidtOseevetal.2016, author = {Hirsch, S{\"o}ren and Schmidt, Marc-Peter and Oseev, Aleksandr and Engel, Christian and Brose, Andreas and Schmidt, Bertram}, title = {Flexible free-standing SU-8 microfluidic impedancespectroscopy sensor for 3-D molded interconnectdevices application}, series = {Journal of Sensors and Sensor Systems}, volume = {5}, journal = {Journal of Sensors and Sensor Systems}, number = {1}, doi = {10.5194/jsss-5-55-2016}, pages = {55 -- 61}, year = {2016}, language = {en} } @article{VollmerMoellmann2020, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Unsichtbares sichtbar gemacht: Infrarotkameras f{\"u}r Smartphones}, series = {Physik in unserer Zeit}, volume = {51}, journal = {Physik in unserer Zeit}, number = {1}, publisher = {Wiley-VCH}, doi = {https://doi.org/10.1002/piuz.201901551}, pages = {29 -- 35}, year = {2020}, language = {de} } @article{VollmerMoellmann2020, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Wenn Licht die Biege macht}, series = {Physik in unserer Zeit}, volume = {51}, journal = {Physik in unserer Zeit}, number = {1}, publisher = {Wiley-VCH}, doi = {https://doi.org/10.1002/piuz.202001569}, pages = {46 -- 47}, year = {2020}, language = {de} } @article{FachetWitteFlassigetal.2020, author = {Fachet, Melanie and Witte, Carina and Flassig, Robert J. and Rihko-Struckmann, Liisa K. and McKie-Krisberg, Zaid and Polle, J{\"u}rgen E. W. and Sundmacher, Kai}, title = {Reconstruction and analysis of a carbon-core metabolic network for Dunaliella salina}, series = {BMC Bioinformatics}, volume = {21}, journal = {BMC Bioinformatics}, number = {1}, publisher = {BioMed Central}, doi = {10.1186/s12859-019-3325-0}, year = {2020}, language = {en} } @article{GieslerPeschWeirauchetal.2020, author = {Giesler, Jasper and Pesch, Georg R. and Weirauch, Laura and Schmidt, Marc-Peter and Th{\"o}ming, Jorg and Baune, Michae}, title = {Polarizability-Dependent Sorting of Microparticles Using Continuous-Flow Dielectrophoretic Chromatography with a Frequency Modulation Method}, series = {Micromachines}, volume = {11}, journal = {Micromachines}, number = {1}, publisher = {MDPI}, doi = {10.3390/mi11010038}, pages = {38}, year = {2020}, language = {en} } @article{Vollmer2021, author = {Vollmer, Michael}, title = {Gefrierende Gew{\"a}sser}, series = {Physik in unserer Zeit}, volume = {52}, journal = {Physik in unserer Zeit}, number = {1}, publisher = {Wiley-Blackwell}, doi = {10.1002/piuz.202001589}, pages = {19 -- 25}, year = {2021}, language = {de} } @article{AgafonovaKozyrevMukhinetal.2018, author = {Agafonova, D. S. and Kozyrev, A. B. and Mukhin, N. V. and Red'ka, D. N. and Elanskaya, G. K. and Rudenko, M. V. and Oseev, A. and Hirsch, S{\"o}ren}, title = {Impurity Phases in Polycrystalline Films of Ferroelectric Oxides of the Perovskite-Type on the Basis of Bi2SrTa2O9 and Pb(Zr,Ti)O3}, series = {Glass Physics and Chemistry}, volume = {44}, journal = {Glass Physics and Chemistry}, number = {1}, doi = {10.1134/S1087659618010029}, pages = {15 -- 20}, year = {2018}, language = {en} } @article{PtashnikMikhailovYastrebovetal.2017, author = {Ptashnik, Sergey V. and Mikhailov, Anatoliy K. and Yastrebov, Alexander V. and Petrov, Peter K. and Liu, Wei and McN Alford, Neil and Hirsch, Soeren and Kozyrev, Andrey B.}, title = {Ferroelectric thin film acoustic devices with electrical multiband switching ability}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {15289}, doi = {10.1038/s41598-017-14895-8}, year = {2017}, language = {en} } @article{OseevLucklumZubtsovetal.2017, author = {Oseev, Aleksandr and Lucklum, Ralf and Zubtsov, Mikhail and Schmidt, Marc-Peter and Mukhin, Nikolay V. and Hirsch, Soeren}, title = {SAW-Based Phononic Crystal Microfluidic Sensor—Microscale Realization of Velocimetry Approaches for Integrated Analytical Platform Applications}, series = {Sensors}, volume = {17}, journal = {Sensors}, number = {10}, doi = {10.3390/s17102187}, pages = {2187}, year = {2017}, language = {en} } @article{KutiaMukhinPetrovaetal.2020, author = {Kutia, Mykhailo and Mukhin, Nikolay and Petrova, Hanna and Oseev, Aleksandr and Bakhchova, Liubov and Schmidt, Marc-Peter and Aman, Alexander and Palis, Stefan and Tarasov, Sergey and Hirsch, Soeren}, title = {Sensor for the evaluation of dielectric properties of sulfur-containing heteroatomic hydrocarbon compounds in petroleum based liquids at a microfluidic scale}, series = {AIP Advances}, volume = {10}, journal = {AIP Advances}, number = {2}, publisher = {American Institute of Physics}, doi = {10.1063/1.5141482}, pages = {025006}, year = {2020}, language = {en} } @article{KurachkinaKonshinaOseevetal.2018, author = {Kurachkina, Margarita and Konshina, Elena and Oseev, Aleksandr and Hirsch, S{\"o}ren}, title = {Hybrid structures based on gold nanoparticles and semiconductor quantum dots for biosensor applications}, series = {Nanotechnology Science and Applications}, volume = {11}, journal = {Nanotechnology Science and Applications}, doi = {10.2147/nsa.s155045}, pages = {15 -- 21}, year = {2018}, language = {en} } @article{MukhinRedkaTarasovetal.2018, author = {Mukhin, N.V. and Redka, D. N. and Tarasov, S. A. and Oseev, A. Yu. and Hirsch, S{\"o}ren}, title = {Two-Dimensional Periodic Composite Structure for Acoustic Sensor of Volumetric Properties of Liquids}, series = {Journal of the Russian Universities. Radioelectronics}, journal = {Journal of the Russian Universities. Radioelectronics}, number = {1}, doi = {10.32603/1993-8985-2018-21-1-56-63}, pages = {56 -- 63}, year = {2018}, language = {ru} } @article{WidjajaLoeweCosta2018, author = {Widjaja, Agnes S. N. and L{\"o}we, Katharina and Costa, Felipe Salerno}, title = {Design and simulation of a concentrated solar thermal system with an integrated concrete storage for continuous heat supply}, series = {Energy Procedia}, volume = {155}, journal = {Energy Procedia}, doi = {10.1016/j.egypro.2018.11.062}, pages = {121 -- 135}, year = {2018}, language = {en} } @article{Kraska2022, author = {Kraska, Martin}, title = {Meclib: Dynamic and Interactive Figures in STACK Questions Made Easy}, series = {International Journal of Emerging Technologies in Learning (iJET)}, volume = {17}, journal = {International Journal of Emerging Technologies in Learning (iJET)}, number = {23}, publisher = {International Association of Online Engineering}, issn = {1863-0383}, doi = {10.3991/ijet.v17i23.36501}, pages = {15 -- 27}, year = {2022}, abstract = {Making and interpretation of drawings and schematics is an important skill to be developed in engineering education. The question type STACK in the Moodle learning management system combined with the interactive graphics library JSXGraph has a great potential for implementation of e-learning resources addressing these skills in formative and summative settings. The authoring process of such materials is complex due to multiple markup and programming languages like HTML, LaTeX, Maxima and JavaScript (JS) being involved. The Meclib concept mitigates this complexity and allows for efficient bulk production of material with consistent appearance and user experience. The core of Meclib is a set of pre-defined JSXGraph-based objects with an interface to Maxima, such that no problem specific JS code is required at all. The present paper outlines the basic ideas of the implementation and demonstrates the approach for some typical examples of different complexity. The focus is on applications in engineering mechanics, starting from static illustrations up to an editor for free body diagrams, with rich adaptive formative feedback.}, language = {en} } @article{TumarkinTyurninaMukhinetal.2022, author = {Tumarkin, Andrey and Tyurnina, Natalya and Mukhin, Nikolay and Tyurnina, Zoya and Sinelshchikova, Olga and Gagarin, Alexander and Sapego, Eugeny and Kretser, Yriy}, title = {Glass-ceramic ferroelectric composite material BaTiO3/KFeSi for microwave applications}, series = {Composite Structures}, volume = {281}, journal = {Composite Structures}, publisher = {Elsevier}, issn = {0263-8223}, pages = {1 -- 10}, year = {2022}, abstract = {Glass-ceramic composites consisting of potassium-iron-silicate glass and barium titanate mixed in various proportions were successfully synthesized by low-temperature sintering. The crystal structure of the obtained composite samples, the porosity and the microhardness were studied by the X-ray diffraction, the electron microscopy, the weight method, and the Vickers method. Electrical characteristics (dielectric permittivity, tunability and losses) of as-prepared and annealed in oxygen medium samples were investigated at microwaves. According to structural analysis, the synthesized samples are a mixture of KFeSi glass, ferroelectric BaTiO3, and dielectric barium polytitanates; the ratio of the latter determines the electrical properties of the composites. Depending on the content of barium titanate, the studied composite samples show a permittivity from 50 to 270 with a dielectric loss level of 0,1-0,02 in frequency range from 3 to 10 GHz. Annealing of composite samples in an oxygen-containing environment leads to an increase in their dielectric permittivity and tunability by 10-25\% and a twofold decrease in dielectric loss.}, language = {en} } @article{KombeLang'atNjoguetal.2022, author = {Kombe, Emmanuel Yeri and Lang'at, Nickson and Njogu, Paul and Malessa, Reiner and Weber, Christian-Toralf and Njoka, Francis and Krause, Ulrich}, title = {Process modeling and evaluation of optimal operating conditions for production of hydrogen-rich syngas from air gasification of rice husks using aspen plus and response surface methodology}, series = {Bioresource Technology}, volume = {361}, journal = {Bioresource Technology}, publisher = {Elsevier}, issn = {0960-8524}, pages = {1 -- 11}, year = {2022}, abstract = {Biomass gasification is recognized as a viable avenue to accelerate the sustainable production of hydrogen. In this work, a numerical simulation model of air gasification of rice husks is developed using the Aspen Plus to investigate the feasibility of producing hydrogen-rich syngas. The model is experimentally validated with rice husk gasification results and other published studies. The influence of temperature and equivalence ratio on the syngas composition, H2 yield, LHVSyngas, H2/CO ratio, CGE, and PCG was studied. Furthermore, the synchronized effects of temperature and ER are studied using RSM to determine the operational point of maximizing H2 yield and PCG. The RSM analysis results show optimum performance at temperatures between 820 °C and 1090 °C and ER in the range of 0.06-0.10. The findings show that optimal operating conditions of the gasification system can be achieved at a more refined precision through simulations coupled with advanced optimization techniques.}, language = {en} } @article{RuzankinaMukhinMermouletal.2022, author = {Ruzankina, Iuliia and Mukhin, Nikolay and Mermoul, Ali and Parfenov, Vadim and Fron, Eduard and Ferrini, Gabriele}, title = {Surface optical sensitivity enhanced by a single dielectric microsphere}, series = {Optics Express}, volume = {30}, journal = {Optics Express}, number = {24}, publisher = {Optica}, pages = {43021 -- 43036}, year = {2022}, abstract = {Single dielectric microspheres can manipulate light focusing and collection to enhance optical interaction with surfaces. To demonstrate this principle, we experimentally investigate the enhancement of the Raman signal collected by a single dielectric microsphere, with a radius much larger than the exciting laser spot size, residing on the sample surface. The absolute microsphere-assisted Raman signal from a single graphene layer measured in air is more than a factor of two higher than that obtained with a high numerical aperture objective. Results from Mie's theory are used to benchmark numerical simulations and an analytical model to describe the isolated microsphere focusing properties. The analytical model and the numerical simulations justify the Raman signal enhancement measured in the microsphere-assisted Raman spectroscopy experiments.}, language = {en} } @article{Uhl2023, author = {Uhl, Roland}, title = {Charakterisierung des Erwartungswertes am Graphen der Verteilungsfunktion}, publisher = {Technische Hochschule Brandenburg}, address = {Brandenburg an der Havel}, doi = {10.25933/opus4-2986}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:522-opus4-29862}, pages = {10}, year = {2023}, abstract = {Der Erwartungswert einer Zufallsgr{\"o}ße kann generell am Graphen ihrer Verteilungsfunktion durch eine naheliegende Gleichheit zweier Fl{\"a}cheninhalte festgelegt werden. {\"A}quivalent dazu l{\"a}sst er sich mit zwei uneigentlichen Riemann-Integralen darstellen. Davon ausgehend werden die Tschebyschow-Ungleichung und ihre Modifikation mit strikten Ungleichheitszeichen hergeleitet.}, subject = {Verteilungsfunktion}, language = {de} } @article{WangHarthPuzyrevetal.2022, author = {Wang, Jing and Harth, Kirsten and Puzyrev, Dmitry and Stannarius, Ralf}, title = {The effect of obstacles near a silo outlet on the discharge of soft spheres}, series = {New Journal of Physics}, volume = {24}, journal = {New Journal of Physics}, publisher = {IOP}, doi = {10.1088/1367-2630/ac8bea}, year = {2022}, language = {en} } @article{KuznetsovFroripSuenteretal.2022, author = {Kuznetsov, Artur and Frorip, Aleksandr and S{\"u}nter, Alar and Korsakov, Vadim and Konoplev, Georgii and Stepanova, Oksana and Roschina, Natalia and Ovsyannikov, Nikolay and Lialin, Daniil and Gerasimchuk, Roman and Dmitriev, Alexander and Mukhin, Nikolay and Hirsch, S{\"o}ren}, title = {Optical Chemical Sensor Based on Fast-Protein Liquid Chromatography for Regular Peritoneal Protein Loss Assessment in End-Stage Renal Disease Patients on Continuous Ambulatory Peritoneal Dialysis}, series = {Chemosensors}, volume = {10}, journal = {Chemosensors}, number = {6}, publisher = {MDPI}, doi = {10.3390/chemosensors10060232}, year = {2022}, language = {en} } @article{KonoplevAgafonovaBakhchovaetal.2022, author = {Konoplev, Georgii and Agafonova, Darina and Bakhchova, Liubov and Mukhin, Nikolay and Kurachkina, Marharyta and Schmidt, Marc-Peter and Verlov, Nikolay and Sidorov, Alexander and Oseev, Aleksandr and Stepanova, Oksana and Kozyrev, Andrey and Dmitriev, Alexander and Hirsch, S{\"o}ren}, title = {Label-Free Physical Techniques and Methodologies for Proteins Detection in Microfluidic Biosensor Structures}, series = {Biomedicines}, volume = {10}, journal = {Biomedicines}, number = {2}, publisher = {MDPI}, issn = {2227-9059}, doi = {10.3390/biomedicines10020207}, pages = {207}, year = {2022}, language = {en} } @article{VogelWoelferRamirezDiazetal.2020, author = {Vogel, Sven and W{\"o}lfer, Christian and Ramirez-Diaz, Diego and Flassig, Robert and Sundmacher, Kai and Schwille, Petra}, title = {Symmetry Breaking and Emergence of Directional Flows in Minimal Actomyosin Cortices}, series = {Cells}, journal = {Cells}, publisher = {MDPI}, doi = {10.3390/cells9061432}, pages = {1 -- 10}, year = {2020}, abstract = {Cortical actomyosin flows, among other mechanisms, scale up spontaneous symmetry breaking and thus play pivotal roles in cell differentiation, division, and motility. According to many model systems, myosin motor-induced local contractions of initially isotropic actomyosin cortices are nucleation points for generating cortical flows. However, the positive feedback mechanisms by which spontaneous contractions can be amplified towards large-scale directed flows remain mostly speculative. To investigate such a process on spherical surfaces, we reconstituted and confined initially isotropic minimal actomyosin cortices to the interfaces of emulsion droplets. The presence of ATP leads to myosin-induced local contractions that self-organize and amplify into directed large-scale actomyosin flows. By combining our experiments with theory, we found that the feedback mechanism leading to a coordinated directional motion of actomyosin clusters can be described as asymmetric cluster vibrations, caused by intrinsic non-isotropic ATP consumption with spatial confinement. We identified fingerprints of vibrational states as the basis of directed motions by tracking individual actomyosin clusters. These vibrations may represent a generic key driver of directed actomyosin flows under spatial confinement in vitro and in living systems.}, language = {en} } @article{GoschinVogelFlassig2022, author = {Goschin, Tobias and Vogel, Mathias and Flassig, Robert}, title = {Energy Technologies For Decarbonizing The Steel Processing Industry - A Numerical Study}, series = {IFAC-PapersOnLine}, volume = {55}, journal = {IFAC-PapersOnLine}, number = {9}, publisher = {Elsevier}, doi = {https://doi.org/10.1016/j.ifacol.2022.07.001}, pages = {1 -- 5}, year = {2022}, abstract = {This study analyzes approaches to decarbonize the energy supply of the secondary steel processing industry. Therefore, real data from a secondary steel production company is used in combination with state-of-the art low carbon energy supply technologies. Also, the use of waste heat from a pusher furnace for process integration is considered. The developed temporal process model allows holistic optimizing and expanding the steel making process system regarding techno-economic criteria. As we show, implementing the annual heat demand of a municipality shows that a nearly 100 \% self-sufficient heat supply is possible.}, language = {en} } @article{TrittelKloppHarthetal.2022, author = {Trittel, Torsten and Klopp, Christoph and Harth, Kirsten and Stannarius, Ralf}, title = {Stability and Rupture of Liquid Crystal Bridges under Microgravity}, series = {Crystals}, volume = {12}, journal = {Crystals}, number = {8}, publisher = {MDPI}, doi = {https://doi.org/10.3390/cryst12081092}, pages = {16}, year = {2022}, language = {en} } @article{KollathHajduDegenetal.2025, author = {Koll{\´a}th, Zolt{\´a}n and Hajdu, Tam{\´a}s and Degen, Tobias and Jechow, Andreas and Sztakovics, J{\´a}nos}, title = {Conversion between measurement units used for night sky quality assessment with multispectral (RGB) cameras}, series = {Journal of Quantitative Spectroscopy and Radiative Transfer}, volume = {347}, journal = {Journal of Quantitative Spectroscopy and Radiative Transfer}, publisher = {Elsevier}, doi = {10.1016/j.jqsrt.2025.109636}, pages = {1 -- 10}, year = {2025}, abstract = {In recent years, many studies have shown that light pollution adversely affects wildlife, ecosystems, and human well-being. To assess and mitigate these impacts, it is crucial that measurements of night sky quality are reliable and comparable across sites and instruments. However, the lack of standardised night sky brightness metrology and the use of a wide variety of measurement instruments with varying spectral responsivity and field-specific measurement units hinder meaningful comparison. We collected night sky spectra from 44 nights at dark locations (existing and proposed dark sky parks). Based on this observational dataset, we created a larger random set of spectra. These data served to fit conversion parameters for a wide variety of units. We demonstrate that RGB cameras, when used as multichannel measuring devices, enable the retrieval of measurements that facilitate conversions between different units. Furthermore, even airglow can be quantified from a given measurement, enabling the determination of oxygen and sodium emission line contributions. Since this contribution is not negligible, quantitative measurements of its magnitude are crucial for accurately assessing light pollution at dark-sky sites. Using our spectral measurement database, we constructed the most probable transformation from the cameras' R, G, and B channel 𝑑𝑠𝑢 values to other units, such as the astronomical Bessel V band magnitudes. The unit conversion formulas provided in this paper are valid for mildly polluted sites (existing and proposed dark sky places), in the 21-22 magV∕arcsec2 range.}, language = {de} } @article{SchumannStoilovaBortolettoetal.2025, author = {Schumann, Sophia and Stoilova, Velizara and Bortoletto, Enrico and Piva, Elisabetta and Pacchini, Sara and Mozzi, Gloria and Jechow, Andreas and Marion, Andrea and Bertotto, Daniela and Erlandson, Ann and H{\"o}lker, Franz and Greenberg, Larry and Santovito, Gianfranco}, title = {Impact of artificial light at night (ALAN) on cardiac function and acute oxidative stress physiology in migratory brown trout smolts}, series = {Environmental Pollution}, journal = {Environmental Pollution}, number = {381}, publisher = {Elsevier}, doi = {10.1016/j.envpol.2025.126593}, pages = {1 -- 9}, year = {2025}, abstract = {Light pollution poses significant ecological challenges for nocturnal animals reliant on natural light for migration, orientation, and circadian rhythms. The physiological effects of abrupt exposure to artificial light at night (ALAN) on migratory fish, such as the light experienced passing near illuminated infrastructures, remain poorly understood. This study investigates the physiological responses of brown trout (Salmo trutta) smolts to low-intensity (0.02 lx) and short-term (30 s) ALAN, simulating nocturnal migration light conditions near illuminated bridges. To evaluate the influence of social dynamics, trout were tested individually (solitary) or in groups of six. Using continuous cardiac monitoring with data storage tags, alongside analyses of oxidative stress markers and adenylate kinase (AK) activity in the heart, we identified distinct patterns of physiological responses. Solitary fish exhibited significant heart rate variability (HRV) increases following repeated ALAN exposure, suggesting impaired physiological regulation under repeated ALAN exposure. In contrast, trout in groups displayed consistently lower HRV over the entire 90-min experiment, implying that social dynamics likely influenced a sustained oxidative stress response, corroborated by increased AK activity. Oxidative stress markers further reflected social effects, with significant upregulation of key antioxidant enzymes (sod1, sod2, gpx1, gpx4) and elevated lipid peroxidation, identifying lipids as primary oxidative targets. The observed divergence between superoxide dismutase (SOD) activity and sod gene expression suggests adaptive post-transcriptional regulation to maintain redox balance under combined environmental and social stress. These findings reveal that social dynamics under ALAN can amplify physiological stress, potentially affecting migratory outcomes.}, language = {en} } @article{KalinkatJechowSchroeretal.2025, author = {Kalinkat, Gregor and Jechow, Andreas and Schroer, Sibylle and H{\"o}lker, Franz}, title = {Nocturnal pandas: conservation umbrellas protecting nocturnal biodiversity}, series = {Trends in Ecology \& Evolution}, volume = {40}, journal = {Trends in Ecology \& Evolution}, number = {8}, publisher = {Elsevier}, doi = {10.1016/j.tree.2025.05.006}, pages = {736 -- 739}, year = {2025}, abstract = {Light pollution is an emerging ecological threat. To mitigate its negative consequences, creative inter- and transdisciplinary solutions and societal interactions are needed. To this end, we introduce nocturnal umbrella species representative of light-sensitive biodiversity whose protection will safeguard vital ecosystem services and a wide range of co-occurring species.}, language = {en} } @article{VollmerEberhardt2024, author = {Vollmer, Michael and Eberhardt, Wolfgang}, title = {Ein einfaches Modell f{\"u}r die Vorhersage von CO2 Konzentrationen in der Atmosph{\"a}re in Abh{\"a}ngigkeit von globalen CO2 Emissionen}, series = {PhyDid B, Didaktik der Physik, Beitr{\"a}ge zur DPG-Fr{\"u}hjahrstagung}, volume = {1}, journal = {PhyDid B, Didaktik der Physik, Beitr{\"a}ge zur DPG-Fr{\"u}hjahrstagung}, number = {1}, publisher = {FU Berlin}, organization = {Fachverband Didaktik der Physik}, issn = {2191-379X}, pages = {379 -- 388}, year = {2024}, abstract = {Es wird das vielleicht einfachst m{\"o}gliche Modell vorgestellt, mit dem zeitabh{\"a}ngige CO2 Konzent-rationen c(t) in der Atmosph{\"a}re ausgehend von verschiedenen globalen Emissionsszenarien f{\"u}r CO2berechnet werden. Dazu wird eine einzelne inhomogene lineare Differenzialgleichung 1. Ordnung hergeleitet, deren Parameter sich aus den quantitativen Daten des global carbon project sowie Mauna Loa Daten f{\"u}r CO2 Konzentrationen errechnen. Das Modell wird erstens getestet am Zeitraum 1960 bis 2020 mit vergleichsweise guter quantitativer {\"U}bereinstimmung zu Messdaten. Zweitens wird f{\"u}r zwei typische IPCC Emissions-Szenarien ein Vergleich der Modellvorhersagen mit denen der kom-plexen IPCC Earth-System-Klimamodelle diskutiert mit qualitativer {\"U}bereinstimmung des zeitli-chen Verlaufs. Drittens werden Ergebnisse einiger ausgew{\"a}hlter neuer Emissionsszenarien pr{\"a}sen-tiert. Ungeachtet einiger Abweichungen zu komplexeren Klimamodellen zeichnet sich unser Mo-dell durch zwei wichtige Vorteile f{\"u}r die Lehre aus. Zum einen ist es sehr einfach f{\"u}r Studierende und begabte Sch{\"u}ler nutzbar, da die erforderliche L{\"o}sung der Differentialgleichung bereits mit han-dels{\"u}blicher Tabellenkalkulationssoftware wie z.B. Excel programmiert werden kann. Dadurch ge-stattet es zum anderen auch sehr einfach, den zeitlichen Verlauf von Emissionsszenarien zu ver{\"a}n-dern und innerhalb weniger Sekunden Ver{\"a}nderungen aufgrund ge{\"a}nderter Eingaben zu berechnen. Insofern eignet sich das Modell sehr gut als Einstieg in das Thema Klimamodellierung in einf{\"u}hren-den Hochschulvorlesungen zum Themenbereich Kohlenstoffkreislauf und Klimawandel. In der Schule kann es gegen Ende der Sekundarstufe 2 beispielsweise im Projektunterricht zum Themen-komplex Nachhaltigkeit in Physik und/oder Mathematik eingesetzt werden}, language = {de} } @article{KloppTrittelStannarius2024, author = {Klopp, Christoph and Trittel, Torsten and Stannarius, Ralf}, title = {Coarsening of quasi two-dimensional emulsions formed by islands in free-standing smectic films}, series = {ChemPhysChem}, volume = {25}, journal = {ChemPhysChem}, number = {12}, publisher = {Wiley}, doi = {10.1002/cphc.202400166}, pages = {1 -- 12}, year = {2024}, abstract = {We study the coarsening behavior of assemblies of islands on smectic A freely suspended films in ISS microgravity experiments. The islands can be regarded as liquid inclusions in a two-dimensional fluid in analogy to liquid droplets of the discontinuous phase of an emulsion. The coarsening is effectuated by two processes, predominantly by island coalescence, but to some extend also by Ostwald ripening, whereby large islands grow at the expense of surrounding smaller ones. A peculiarity of this system is that the continuous and the discontinuous phases consist of the same material. We determine the dynamics, analyze the self-similar aging of the island size distribution and discuss characteristic exponents of the mean island growth.}, language = {en} } @article{Vollmer2024, author = {Vollmer, Michael}, title = {Limitations of the eye and how to overcome them}, series = {Journal of Physics: Conference Series}, volume = {2750}, journal = {Journal of Physics: Conference Series}, number = {1}, doi = {10.1088/1742-6596/2750/1/012001}, pages = {1 -- 10}, year = {2024}, abstract = {Human eyes have spatial, temporal, and spectral limitations which impose constraints on our perception. With appropriate optical devices and cameras, the limitations can be easily overcome. As a consequence, a huge variety of physical phenomena can be made accessible for teaching.}, language = {en} } @article{PuzyrevTorstenHarthetal.2024, author = {Puzyrev, Dmitry and Torsten, Torsten and Harth, Kirsten and Stannarius, Ralf}, title = {Cooling of a granular gas mixture in microgravity}, series = {npj microgravity}, volume = {10}, journal = {npj microgravity}, number = {1}, publisher = {Springer}, address = {Brandenburg an der Havel}, doi = {10.1038/s41526-024-00369-5}, pages = {1 -- 9}, year = {2024}, abstract = {Granular gases are fascinating non-equilibrium systems with interesting features such as spontaneous clustering and non-Gaussian velocity distributions. Mixtures of different components represent a much more natural composition than monodisperse ensembles but attracted comparably little attention so far. We present the observation and characterization of a mixture of rod-like particles with different sizes and masses in a drop tower experiment. Kinetic energy decay rates during granular cooling and collision rates were determined and Haff's law for homogeneous granular cooling was confirmed. Thereby, energy equipartition between the mixture components and between individual degrees of freedom is violated. Heavier particles keep a slightly higher average kinetic energy than lighter ones. Experimental results are supported by numerical simulations.}, language = {de} } @article{TrittelPuzyrevHarthetal.2024, author = {Trittel, Torsten and Puzyrev, Dmitry and Harth, Kirsten and Stannarius, Ralf}, title = {Rotational and translational motions in a homogeneously cooling granular gas}, series = {npj microgravity}, volume = {10}, journal = {npj microgravity}, number = {1}, publisher = {Springer}, doi = {10.1038/s41526-024-00420-5}, pages = {1 -- 6}, year = {2024}, abstract = {A granular gas composed of monodisperse spherical particles was studied in microgravity experiments in a drop tower. Translations and rotations of the particles were extracted from optical video data. Equipartition is violated, the rotational degrees of freedom were excited only to roughly 2/3 of the translational ones. After stopping the mechanical excitation, we observed granular cooling of the ensemble for a period of three times the Haff time, where the kinetic energy dropped to about 5\% of its initial value. The cooling rates of all observable degrees of freedom were comparable, and the ratio of rotational and translational kinetic energies fluctuated around a constant value. The distributions of translational and rotational velocity components showed slight but systematic deviations from Gaussians at the start of cooling.}, language = {en} } @article{JechowBumbergerPalmetal.2024, author = {Jechow, Andreas and Bumberger, Jan and Palm, Bert and Remmler, Paul and Schreck, G{\"u}nter and Ogashawara, Igor and Kiel, Christine and Kohnert, Katrin and Grossart, Hans-Peter and Singer, Gabirel A. and Nejstgaard, Jens C. and Wollrab, Sabine and Berger, Stella A. and H{\"o}lker, Franz}, title = {Characterizing and Implementing the Hamamatsu C12880MA Mini-Spectrometer for Near-Surface Reflectance Measurements of Inland Waters}, series = {Sensors}, volume = {24}, journal = {Sensors}, number = {19}, publisher = {MDPI}, doi = {10.3390/s24196445}, pages = {1 -- 14}, year = {2024}, abstract = {In recent decades, inland water remote sensing has seen growing interest and very strong development. This includes improved spatial resolution, increased revisiting times, advanced multispectral sensors and recently even hyperspectral sensors. However, inland waters are more challenging than oceanic waters due to their higher complexity of optically active constituents and stronger adjacency effects due to their small size and nearby vegetation and built structures. Thus, bio-optical modeling of inland waters requires higher ground-truthing efforts. Large-scale ground-based sensor networks that are robust, self-sufficient, non-maintenance-intensive and low-cost could assist this otherwise labor-intensive task. Furthermore, most existing sensor systems are rather expensive, precluding their employability. Recently, low-cost mini-spectrometers have become widely available, which could potentially solve this issue. In this study, we analyze the characteristics of such a mini-spectrometer, the Hamamatsu C12880MA, and test it regarding its application in measuring water-leaving radiance near the surface. Overall, the measurements performed in the laboratory and in the field show that the system is very suitable for the targeted application.}, language = {en} } @article{DaupayevEngelHirsch2025, author = {Daupayev, Nursultan and Engel, Christian and Hirsch, S{\"o}ren}, title = {Two-to-One Trigger Mechanism for Event-Based Environmental Sensing}, series = {Sensors}, volume = {25}, journal = {Sensors}, number = {13}, publisher = {MDPI}, doi = {10.3390/s25134107}, pages = {1 -- 18}, year = {2025}, abstract = {Environmental monitoring systems often operate continuously, measuring various parameters, including carbon dioxide levels (CO2), relative humidity (RH), temperature (T), and other factors that affect environmental conditions. Such systems are often referred to as smart systems because they can autonomously monitor and respond to environmental conditions and can be integrated both indoors and outdoors to detect, for example, structural anomalies. However, these systems typically have high energy consumption, data overload, and large equipment sizes, which makes them difficult to install in constrained spaces. Therefore, three challenges remain unresolved: efficient energy use, accurate data measurement, and compact installation. To address these limitations, this study proposes a two-to-one threshold sampling approach, where the CO2 measurement is activated when the specified T and RH change thresholds are exceeded. This event-driven method avoids redundant data collection, minimizes power consumption, and is suitable for resource-constrained embedded systems. The proposed approach was implemented on a low-power, small-form and self-made multivariate sensor based on the PIC16LF19156 microcontroller. In contrast, a commercial monitoring system and sensor modules based on the Arduino Uno were used for comparison. As a result, by activating only key points in the T and RH signals, the number of CO2 measurements was significantly reduced without loss of essential signal characteristics. Signal reconstruction from the reduced points demonstrated high accuracy, with a mean absolute error (MAE) of 0.0089 and root mean squared error (RMSE) of 0.0117. Despite reducing the number of CO2 measurements by approximately 41.9\%, the essential characteristics of the signal were saved, highlighting the efficiency of the proposed approach. Despite its effectiveness in controlled conditions (in buildings, indoors), environmental factors such as the presence of people, ventilation systems, and room layout can significantly alter the dynamics of CO2 concentrations, which may limit the implementation of this approach. Future studies will focus on the study of adaptive threshold mechanisms and context-dependent models that can adjust to changing conditions. This approach will expand the scope of application of the proposed two-to-one sampling technique in various practical situations.}, language = {en} } @article{Vollmer2025, author = {Vollmer, Michael}, title = {Nachtsicht ins All mit dem bloßen Auge: Sag mir, wie weit die Sterne steh'n}, series = {Physik in unserer Zeit}, volume = {2025}, journal = {Physik in unserer Zeit}, publisher = {Wiley}, doi = {10.1002/piuz.202501751}, pages = {2 -- 10}, year = {2025}, language = {de} } @article{MushunuriAdesojiKrauseetal.2025, author = {Mushunuri, Ashwini and Adesoji, Oluyomi and Krause, Roland and May, Patrick and Lerche, Holger and Becker, Albert and Grimm, Daniela and Nothnagel, Michael and Schulz, Herbert}, title = {Genetic risk factor identification for common epilepsies guided by integrative omics data analysis}, series = {Epilepsia}, journal = {Epilepsia}, publisher = {Wiley}, doi = {10.1111/epi.70021}, pages = {15}, year = {2025}, abstract = {Objective Genetic generalized epilepsies (GGEs) comprise the most common genetically determined epilepsy syndromes, following a complex mode of inheritance. Although many important common and rare genetic factors causing or contributing to these epilepsies have been identified in the past decades, many features of the genetic architecture are still insufficiently understood. This study integrates genome-wide association study (GWAS) data from the International League Against Epilepsy Consortium on Complex Epilepsies with transcriptome-wide association studies to identify genes whose genetically regulated expression levels are associated with epilepsy. Methods To achieve this, we used multiple computational approaches, including MAGMA, a tool for gene analysis of GWAS data, and its derivatives E-MAGMA and H-MAGMA, to improve gene mapping accuracy by utilizing tissue-specific expression and chromatin interaction data. Furthermore, we developed ME-MAGMA to incorporate methylation quantitative trait loci data, providing insights into epigenetic factors. Results We identified a total of 897 false discovery rate-corrected (<.05) candidates. These include voltage-gated calcium channels, voltage-gated potassium channels, and other genes such as NPRL2, CACNB2, and KCNT1 associated with epilepsy pathogenesis that act as key players in neuronal communication and signaling in the brain. Significance In this study, we propose new candidate genes to expand the dataset of potential epilepsy-causing genes. Further research on these genes may enhance our understanding of the complex regulatory mechanisms underlying GGE and other types of epilepsy, potentially revealing targets for therapeutic intervention.}, language = {en} } @article{SataStannariusPuzyrev2025, author = {Sata, Sai Preetham and Stannarius, Ralf and Puzyrev, Dmitry}, title = {Criteria for dynamical clustering in permanently excited granular gases: comparison and estimation with machine learning approaches}, series = {Granular Matter}, volume = {27}, journal = {Granular Matter}, number = {4}, publisher = {Springer}, doi = {10.1007/s10035-025-01560-5}, year = {2025}, abstract = {When granular gases in microgravity are continuously excited mechanically, spatial inhomogeneities of the particle distribution can emerge. At a sufficiently large overall packing fraction, a significant share of particles tend to concentrate in strongly overpopulated regions, so-called clusters, far from the excitation sources. This dynamical clustering is caused by a complex balance between energy influx and dissipation. The mean number density of particles, the geometry of the container, and the excitation strength influence cluster formation. A quantification of clustering thresholds is not trivial. We generate 'synthetic' data sets by Discrete Element Method simulations of frictional spheres in a cuboid container and apply established criteria to classify the local packing fraction profiles. Machine learning approaches that predict dynamic clustering from known system parameters on the basis of classical test criteria areoposed and tested. It avoids the necessity of complex numerical simulations.}, language = {en} } @article{HarthTrittelMohammadietal.2025, author = {Harth, Kirsten and Trittel, Torsten and Mohammadi, Mahdieh and Puzyrev, Dmitry and Enezz, Mohammad and Cruz Hidalgo, Raul and Stannarius, Ralf}, title = {Granular gases of rough spheres: Velocity, rotation and collision statistics from in-situ measurements, optical data and simulations}, series = {EPJ Web of Conferences}, volume = {340}, journal = {EPJ Web of Conferences}, editor = {Alam, M. and Das, S.L. and Bose, M. and Murthy, T.G. and Chikkadi, V. and Singh, A. and Luding, S.}, publisher = {EDP Sciences}, doi = {10.1051/epjconf/202534003012}, year = {2025}, abstract = {Granular gases are not only of interest in fundamental physics, but they can also serve as a test ensembles for the validity of collision models employed in (loose) granular matter. The theoretical literature mainly addresses spheres under ideal conditions and simulations allow full access to all particle parameters, but experiments cannot fulfill these idealizations. We investigate granular gases of soft, rough spheres by combining microgravity experiments and adjusted simulations. We introduce Smart Particles with embedded autarkic micro-sensors for in-situ measurements of rotation rates and accelerations. Additionally, we extract 3D positions, translations and orientations of the particles from stereoscopic video data using Machine-Learning based algorithms. We address the partition of kinetic energy between the degrees of freedom, the angular and translational velocity as well as collision statistics. A simulation is adjusted to experiment parameters, showing good agreement of translational motion, but qualitative differences in the decay of rotational kinetic energy.}, language = {en} } @article{StannariusWangPongoetal.2025, author = {Stannarius, Ralf and Wang, Jing and Pong{\´o}, Tivadar and Fan, Bo and B{\"o}rzs{\"o}nyi, Tam{\´a}s and Hidalgo, Ra{\´u}l Cruz}, title = {Forces on a sphere suspended in flowing granulate}, series = {EPJ Web of Conferences}, volume = {340}, journal = {EPJ Web of Conferences}, editor = {Alam, M. and Das, S.L. and Bose, M. and Murthy, T.G. and Chikkadi, V. and Singh, A. and Luding, S.}, publisher = {EDP Sciences}, doi = {10.1051/epjconf/202534002019}, year = {2025}, abstract = {We investigate the forces of flowing granular material on an obstacle. A sphere suspended in a discharging silo experiences both weight of the overlaying layers and drag of the surrounding moving grains. In experiments with frictional hard glass beads, the force on the obstacle was found to be practically flow-rate independent. In contrast, flow of nearly frictionless soft hydrogel spheres added drag forces which increased with the flow rate until reaching saturation at high flow speeds. The total force grew quadratically with the obstacle diameter in the soft, low friction material, while it grew much weaker, nearly linearly with the obstacle diameter, in the bed of hard, frictional glass spheres. In addition to the drag, obstacles embedded in the flowing hydrogel spheres experience a weight force from the top as if immersed in a hydrostatic pressure profile, but negligible counter-forces from below. In contrast, the frictional hard particles create a strong pressure gradient near the upper surface of the obstacle. Numerical simulations provide additional information that is difficult to access experimentally. They reproduce the experimental results and give hints for the origin of the different force contributions. The results have considerable practical importance for the discharge of storage containers with large objects suspended in flowing granular material.}, language = {en} } @article{PreethamSataStannariusPuzyrev2025, author = {Preetham Sata, Sai and Stannarius, Ralf and Puzyrev, Dmitry}, title = {Machine learning for prediction of dynamical clustering in granular gases}, series = {EPJ Web of Conferences}, volume = {340}, journal = {EPJ Web of Conferences}, editor = {Alam, M. and Das, S.L. and Bose, M. and Murthy, T.G. and Chikkadi, V. and Singh, A. and Luding, S.}, publisher = {EDP Sciences}, doi = {10.1051/epjconf/202534012012}, year = {2025}, abstract = {Continuously excited dense granular gases in microgravity can develop spatial inhomogeneities of the particle distribution. Dynamical clustering is a phenomenon where a significant share of particles concentrate in strongly overpopulated regions. It is caused by a complex interplay between the energy influx and dissipation in collisions. The overall packing fraction, container geometry, and excitation parameters influence the gas-cluster transition. We perform Discrete Element Method (DEM) simulations for frictional spheres in a cuboid container and apply statistical criteria to the packing fraction profiles. Machine learning (ML) methods are used to study the dependence of the gas-cluster transition on system parameters. It is a promising alternative to predict the state of the system without the need for the time-consuming DEM simulations. We identify the best models for predicting the dynamical clustering of frictional spheres in a specific experimental geometry.}, language = {en} } @article{Vollmer2025, author = {Vollmer, Michael}, title = {Naked eye celestial objects and phenomena: how far can we see at night?}, series = {European Journal of Physics}, volume = {46}, journal = {European Journal of Physics}, number = {3}, publisher = {IOP Science}, doi = {10.1088/1361-6404/adbf74}, pages = {18}, year = {2025}, abstract = {How far can we see with the naked eye at night? Many celestial objects like stars and galaxies as well as transient phenomena such as comets and supernovae can be observed in the night sky. We discuss the furthest distances of such objects and phenomena observable with the naked eye during the night-time for Earth-bound observers. The physics of night-time visual ranges differs from that of daytime observations because human vision shifts from cones to rods. In addition, mostly point sources are observed due to the large distances involved. Whether celestial objects and phenomena can be detected depends on the contrast of their radiation and the background sky luminance. We present a concise overview of how far we can see at night by first discussing the effects of the Earth's atmosphere. This includes attenuation of transmitted radiation as well as its role as a source of background radiation. Disregarding the attenuation of light due to interstellar and intergalactic dust, simple maximum night-time visual range estimates are based on the inverse square law, which can be easily verified by laboratory and demonstration experiments. From the respective calculations, we find that individual stars within the Milky Way galaxy of up to 15 000 light years are observable. Even further away are observable galaxies with several billion stars. The Andromeda galaxy can be observed with the naked eye at a distance of around 2.5 million light years. Similarly, the observability of supernovae also allows a visual range beyond the Milky Way galaxy. Finally, gamma ray bursts as the most energetic events in the universe are discussed concerning naked eye observations.}, language = {en} } @article{Vollmer2025, author = {Vollmer, Michael}, title = {How far can we see at day?}, series = {European Journal of Physics}, volume = {46}, journal = {European Journal of Physics}, number = {3}, publisher = {IOP Science}, doi = {10.1088/1361-6404/adc4a0}, pages = {17}, year = {2025}, abstract = {We discuss the farthest objects on Earth observable for the unaided, healthy naked eye during the daytime, i.e., the maximum visual range for observers on Earth. Visual range depends first on the properties of the material between observer and object and its interaction processes with radiation, but second also on our visual perception system. After a rough comparison of ranges in water, glass, and the atmosphere, we focus on the physical basis of visual range for the latter. As a contrast phenomenon, visual range refers to allowed light paths within the atmosphere. It results from the interplay of geometry, refraction, and light scattering. We present a concise overview of this field by qualitative descriptions and quantitative estimates as well as classroom demonstration experiments. The starting point is the common geometrical visual ranges, followed by extensions due to refraction and limitations due to contrast, which depend on scattering and absorption processes within the atmosphere. The quantitative discussion of scattering is very helpful to easily understand the huge ranges in nature from meters in dense fog to hundreds of kilometers in clear atmospheres. Extreme visual ranges from about 300 km to above 500 km require optimal atmospheric conditions, cleverly chosen locations and times, and a sophisticated topography analysis. Even longer visual ranges are possible when looking through the vertical atmosphere. From the ISS, daytime ranges well above 1000 km are possible.}, language = {en} }