Related Experiment Video
Updated: Jun 17, 2026

A Modified Mirror Test as a Visual Guide for the Self-awareness Trait in Wild Antarctica Penguins, Pygoscelis adeliae
Published on: July 8, 2025
Abstract:
The optical test for the flatness of a plane mirror in conjunction with a concave spherical mirror has been analyzed in terms of the hyperboloid to which it can be thought to be referenced. This geometrical approach renders obvious the requirement to make two tests, the second after rotating the plane mirror 90 degrees about its normal. The expression for the separation of the astigmatic foci for a long radius of curvature, nearly flat, mirror is in agreement with previous derivations.
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