Publications
For further details, click on the respective titles.
Monographs
-
Grebe-Ellis, J. & Quick, T.: Optik - Physik fĂĽr Lehramtsstudierende, Band 3, De Gruyter Brill (in preparation)
Abstract: The third volume of the textbook series Physik fĂĽr Lehramtsstudierende addresses core topics in optics and follows a methodological approach grounded in phenomenological observation and the experience of seeing. Optical concepts and relations are developed step by step from observable phenomena, with systematic attention to the conditions under which these phenomena occur. Models of light are introduced as interpretative frameworks that structure and deepen understanding without losing their connection to experience-based descriptions of optical phenomena. In this way, the volume supports the development of a robust understanding of optical processes and provides pre-service teachers with a solid foundation for both disciplinary insight and the didactic mediation of optics-related content.
-
Quick, T. (2015): Phänomenologie der optischen Hebung, Berlin: Logos Verlag
Summary: Objects viewed in optically denser media such as water appear lifted perpendicularly toward the refracting interface. The phenomenon has been known since antiquity; following Goethe it is referred to as optische Hebung (optical lifting) and is often used in school optics lessons as an introduction to refraction optics. The latter, however, does not primarily address optical lifting but rather the refraction of light— for essentially historical reasons. Over the past years, physics education research has discussed how “lifting of sight” and “bending of light” can be conveyed as methodologically different yet equally valid and generalizable perspectives on the same complex of optical phenomena. A number of disciplinary, didactical, and methodological/epistemological questions have remained open, e.g. regarding astigmatic conditions of image formation, methodologically instructive differences in historical approaches to the refraction problem, and the mathematical description of the image curves of optical lifting. The aim of this work is to address these questions within a phenomenology of optical lifting. (Table of contents)
Book chapters and journal articles
-
Grebe-Ellis, J. & Quick,T. (2026): From Pinhole Imaging to Planetary Orbit: A Year-Long Solar Angular Measurement with a Pinhole Camera, American Journal of Physics 2/94: xx-xx
Abstract: We present a year-long experiment using a pinhole camera to determine the Sun’s angular size, employing a flat mirror to project large-scale solar images of about $50-60$ cm in diameter. Our analysis resolves the annual angular variation of 65 arcseconds, reflecting Earth’s elliptical orbit. Additionally, we observed atmospheric seeing effects (the effects of atmospheric turbulence) and sunspots visible with the naked eye. The project offers an accessible platform for high school and undergraduate students to engage in scientific inquiry.
-
Grebe-Ellis, J. & Quick, T. (2025): The Study of Shadows – Kepler’s 'Light Figures' and Pinhole Imaging, Physics Education 5/60: 11p
Abstract Kepler’s theory on pinhole camera imaging is still valid today, its development is well documented and provides an exciting context for optics lessons. Kepler presented a generalized concept of ’light figures,’ describing the formation of soft shadow images through the interaction between extended apertures and extended light sources. The work marks the culmination of Kepler’s extensive engagement with the ’Moon puzzle.’ In this paper, we examine Kepler’s theory and depiction of ’light figures’ from both historical and experimental perspectives. We provide an overview of Kepler’s theory and its historical context, and present experiments that illustrate Kepler’s theoretical insights, specifically designed for educational use. In this way, a generalized concept of soft shadow imaging can be integrated into optics education, drawing on an authentic historical context. (Volltext)
-
Quick,T. & Grebe-Ellis, J. (2025): Kepler's Moon Puzzle – A Historical Context for Pinhole Imaging, American Journal of Physics 3/93: 215–222
Abstract: In 16th-century European astronomy, determining the sizes of the Sun and Moon using a pinhole camera was common. However, calculating the Moon´s diameter from the concave segment of the partially obscured Sun yielded puzzling results due to a lack of a comprehensive theory of the influence of the aperture on the image. This inconsistency led Tycho Brahe to question prevailing assumptions in celestial mechanics. Recognizing this, Johannes Kepler conducted measurements during a solar eclipse in Graz July 10, 1600, and soon developed a theory of the pinhole camera that remains valid today. In this article, we recount the historical episode leading to Kepler´s theory through original works, complemented by a series of illustrative experiments for classroom use. This historical case study offers a rich context for reflecting on Nature of Science aspects within physics education. (Full text)
-
Quick,T. & Grebe-Ellis, J. (2024): Das Mondrätsel und die Erfindung der modernen Optik, PhyDid B – Didaktik der Physik. Beiträge zur DPG-Frühjahrstagung 2024 in Greifswald.
Abstract: In 16th-century European astronomy, it was common to determine the sizes of the Sun and Moon using a pinhole camera. However, deriving the Moon’s diameter from the concave edge segment of the partially covered Sun yielded puzzling values as long as no pinhole-camera theory existed that correctly accounted for the influence of the aperture stop. After noticing these inconsistencies, the young Johannes Kepler conducted measurements during a solar eclipse in Graz on July 10, 1600. Only a few days later, he presented in his notes a fully developed theory of the pinhole camera that is still valid today. In the following contribution, we trace the historical path toward this theory based on selected original works by Kepler and Brahe and present a series of illustrative experiments suitable for classroom use. The episode from the history of optics also serves as an exemplary case study for reflecting on NOS aspects in physics education. (Full text)
-
Quick,T. & Grebe-Ellis, J. (2024): The Eye Caustic of a Ball Lens, European Journal of Physics 4/45: 1-23
Abstract: Lens phenomena, such as caustics, image distortions, and the formation of multiple images, are commonly observed in various refracting geometries, including raindrops, drinking glasses, and transparent vases. In this study, we investigate the ball lens as a representative example to showcase the capabilities of Berry’s eye caustic as an optical tool. Unlike the conventional paraxial approximation, the eye caustic enables a comprehensive understanding of image transformations throughout the entire optical space. Through experimental exploration, we establish the relationship between the eye caustic and traditional light caustics. Furthermore, we provide mathematical expressions to describe both the caustic and the image transformations that occur when viewing objects through the ball lens. This approach could be of interest for optics education, as it addresses two fundamental challenges in image formation: overcoming the limitations of the paraxial approximation and recognizing the essential role of the observer in comprehending lens phenomena. (Full text)
-
Grebe-Ellis,J. & Quick, T. (2023): Soft Shadow Images, European Journal of Physics 4/44: 1-23
Abstract: In traditional optics education, shadows are often regarded as a mere triviality, namely as silhouettes of obstacles to the propagation of light. However, by examining a series of shadow phenomena from an embedded perspective, we challenge this view and demonstrate how in general both the shape of the object and light source have significant impact on the resulting soft shadow images. Through experimental and mathematical analysis of the imaging properties of inverse objects, we develop a generalized concept of shadow images as complementary phenomena. Shadow images are instructive examples of optical convolution and provide an opportunity to learn about the power of embedded perspective for the study of optical phenomena in the classroom. Additionally, we introduce the less-known phenomenon of the bright shadow. (Full text)
-
Quick, T., Grebe-Ellis, J., & Passon, O. (2015): Ein genauer Blick auf die optische Hebung. PhyDid A – Physik und Didaktik in Schule und Hochschule 1/14: 26-44
Summary: School textbooks and optics teaching materials provide differing and often contradictory explanations of where the lifted image of an object under water is seen. In the limiting case of a point-like pupil, two image points arise for the same object point: the image is astigmatic. While the sagittal image is seen directly above the object point, the meridional image should at the same time appear shifted toward the observer. This contradicts monocular observations, in which the lifted image is seen exclusively directly above the corresponding object. After a critical discussion of different representations and solution approaches to the problem of optical lifting, an experiment is presented that succeeds in separating the images on the centimeter scale. Finally, the extent to which image brightness constitutes a previously unconsidered property of the images is discussed. (Full text)
-
Hümbert, S.; Quick, T. & Grebe-Ellis, J. (2013): „Ich sehe was, was du nicht siehst...“ – Experimente zur optischen Bestimmung der Ergänzungsfarben im Nachbild. PhyDid B - Didaktik der Physik - Beiträge zur DPG-Frühjahrstagung
Summary: Afterimages provide an easily accessible opportunity to engage with the active side of visual perception and with characteristic regularities of color vision. To approach with students the connection between a fixated color and the “complementary color” produced in successive contrast, we designed a series of simple experiments in which complementary colors seen in afterimages can be identified optically on a computer using RGB values. The experiments also make it possible to examine various influences on subjective color perception, such as background and ambient color/brightness or color contrast. Data collected in a small study are evaluated colorimetrically, related to the complementary colors calculated for the initial color stimuli, and compared with similar studies. In addition, we discuss in what way the presented experiments are suitable for introducing the topic “color” as an enriching context in teacher education. (Full text)
-
Quick, T. (2012): Ăśber den Wolken ... . Grundschule Sachunterricht 53 (1):21-27
Ready for take off – an airplane accelerates, races along the runway, takes off, climbs to 10,000 m and flies. Very different from birds, which must flap their wings to stay airborne. Flying is a topic that fascinates children and that they want to learn more about. In this teaching unit, students learn which four forces contribute to airplanes being able to fly and what airplanes have in common with birds. (Full text)
-
Quick, T; Grebe-Ellis, J. (2011): Wo wird das Bild einer unter Wasser liegenden Münze gesehen? PhyDid B – Didaktik der Physik. Beiträge zur DPG-Frühjahrstagung 2011 in Münster.
Summary: A look into school and university optics textbooks shows that there are different and often incorrect representations of where the lifted image of an object under water is seen. Physically, in the limiting case of a point-like pupil, two image points arise for the same object point: the image is astigmatic. While the sagittal image is seen directly above the object point, the meridional image would at the same time appear shifted toward the observer. This contradicts monocular observations, in which the lifted image is seen exclusively directly above the corresponding object. After discussing different representations of the topic, an experiment is presented in which the separation of the image points on the centimeter scale succeeds using a microscope. The contribution concludes with a consideration of differing image brightness. (Full text)
-
Quick, T. (2011): Die Erde - Unser Heimatplanet. Grundschule Sachunterricht 51 (3): 20-26
Our Earth has existed for about 4.5 billion years; the first humans have inhabited it for about 2.5 million years—numbers that are hard to imagine, and that at the same time speak to an impressive continuity in maintaining life-sustaining conditions on planet Earth. Which conditions these are is something children can learn in this teaching unit. (Full text)
-
Quick, T. (2011): Einmal Neptun und zurĂĽck. Grundschule Sachunterricht 51 (3): 27-31
Dormant volcanoes, red deserts, “landscapes” shrouded in poisonous clouds—no author needs to invent these places; they exist on the planets of our solar system. Children and adults alike are fascinated by them. The article provides suggestions for how children can expand their knowledge about the eight planets. (Full text)
-
Quick, T. (2011): Warum hängen Planeten nicht an der Leine? Grundschule Sachunterricht, 51 (3): 32-33
It is one of our certainties that objects can fall to the ground. Whether it is a book, some coins, or a cup: if we do not hold them, they fall downward. We have experienced gravity many times in everyday life; it is familiar to us, and there seems to be nothing mysterious about it. What children can already learn about gravity in primary school is discussed in this article. (Full text)
-
Quick, T.; Grebe-Ellis, J. (2010): Eine mathematische Beschreibung von Helligkeitsverläufen in Schattenbildern In: D. Höttecke (Hrsg.), Entwicklung naturwissenschaftlichen Denkens zwischen Phänomen und Systematik. Gesellschaft für Didaktik der Chemie und Physik. Jahrestagung in Dresden 2009. Münster: LIT-Verlag, S. 404 – 406
Summary: Shadows are images. This becomes apparent to anyone who pays attention to how differently the shadow of the same object looks when illuminated by differently shaped light sources. The conditions under which both—the shadow-casting object and the light source—become effective in the shadow image can be formulated by considering, for the location of the shadow image, the occlusion relations between object and light source as a function of their relative distance. In an earlier article on the emergence and transformation of complementary shadow images (Grebe-Ellis 2007), the hypothesis was put forward that the characteristic transformation the shadow image undergoes while the object is shifted between light source and projection screen can be described using convolution. The refinement and elaboration of these considerations in the context of a thesis (Quick 2008) confirm this hypothesis. Conditions, possibilities, and limitations of the developed approach are presented using examples.
-
Quick, T., Müller, M. & Grebe-Ellis, J. (2009): Mathematische Beschreibung von Schattenbildern im Kontext der phänomenologischen Optik. In: Nordmeier, V. & Grötzebauch, H. (Hrsg.): Didaktik der Physik. Beiträge zur Frühjahrstagung der DPG 2009 in Bochum, Berlin: Lehmanns Media
Summary: Shadows are images. This becomes apparent to anyone who pays attention to how differently the shadow of the same object looks when illuminated by differently shaped light sources. The conditions under which both—the shadow-casting object and the light source—become effective in the shadow image can be formulated by considering, for the location of the shadow image, the occlusion relations between object and light source as a function of their relative distance. In an earlier contribution on the emergence and transformation of complementary shadow images by Grebe-Ellis, the hypothesis was put forward that the characteristic transformation the shadow image undergoes while the object is shifted between light source and projection screen can be described using convolution and at the same time provides an illustrative example of this type of transformation (cf. [1]). The refinement and elaboration of these considerations in the context of a thesis confirm this hypothesis (cf. [2]). (Full text)
Talks and poster presentations
- Kepler and the Moon Puzzle: On the Historical Development of Pinhole Camera Theory (9th Summer School on Lehrkunstdidaktik, Wuppertal 2025)
- Experiencing, Narrating, Understanding: Phenomenological Perspectives in Historical Narratives of Science as a Contribution to NOS-Oriented Teaching (OpenEyes 2025, Wuppertal)
- Measuring Images of the Sun – A Workshop Report (Physicists’ Working Days, Dornach 2025)
- The Moon Puzzle and the invention of modern optics (DPG 2024, Greifswald)
- A phenomenological study of image transformations of a ball lens (Arbeitstage Physiker:innen, Dornach 2024)
- Images of the ball lens (DPG 2022)
- Sagittal or meridional – which image do we see? A clarification on optical lifting (DPG teacher training “Light, Image and Color”, 2016)
- The eye caustic – an instrument for describing image optics (DPG 2013)
- Meridional and sagittal image in experiment (DPG 2011, poster presentation)
- Where is the image of a coin under water seen? (DPG 2010)
- Why don’t planets hang on a leash? (Children’s University talk, Lüneburg 2010)
- Image curves of optical lifting (Arbeitstage fĂĽr Physiker und Physiklehrer in Kassel)
- Brightness distributions in shadow regions (GDCP 2009, poster symposium contribution)
- Brightness distributions in shadow regions (DPG 2009)