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Abstract

Discusses a well-known optical refraction problem where the depth of an object in a liquid is determined. Proposes that many texts incorrectly solve the problem. Provides theory, equations, and diagrams. (MVL)
... The virtual image that forms when light from an object refracts from a transparent medium into air is a study area that is specifically covered in the applications section of the 'refraction of light' topic in the Thai high-school physics curriculum. Although there are many teaching strategies that can be used to locate the position of a virtual image arising from refraction [12][13][14][15], the students in our study had significant problems in trying to qualitatively determine the position of a virtual image. These problems arose because students appear to have poor understanding of light propagation and basic refractive principles [16]. ...
... The problem is compounded by the fact that some of the textbooks used by Thai students incorrectly show the virtual image position as being vertically above the object that is viewed at an angle (i.e. when light from an object immersed in water is refracted at an angle at the water's surface to the observer's eye). The same error has also been noted in high-school physics textbooks from Australia and India, and it appears that this error is common in textbooks from many countries [15]. ...
... strategies use complicated mathematical formulations [14][15][16]. Some researchers (and some textbooks) only consider the situation where the observer looks vertically down directly toward the object (i.e. ...
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... Rays labeled violet and red in Fig. 3 starting at the point source and emerging into the air form separated images of colors violet and red, as shown in the figure. The images corresponding to different colors are in the straight extrapolation of rays into the water, according to details shown in Fig. 2 and discussed in Ref. 2. In order to simplify the arguments, we are going to ignore the small vertical displacement of the image corresponding to different colors and retain just the lateral displacement shown in Fig. 3, which is a simplified picture showing a white source, rays, and images corresponding to colors in the borders of the visible spectrum. ...
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... Man kann so den Astigmatismus der schrägen Abbildung durch die ebene Grenzfläche beobachten. Für Vertiefungen hierzu und allgemein zum Thema Hebung-Brechung sei auf entsprechende Literatur verwiesen5678. Damit sind zum einen und in aller Kürze wesentliche Merkmale im Phänomenkontext " Hebung und Brechung " vergegenwärtigt. ...
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