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Updated: Jun 15, 2026

06:23
The 4 Mountains Test: A Short Test of Spatial Memory with High Sensitivity for the Diagnosis of Pre-dementia Alzheimer's Disease
Published on: October 13, 2016
Abstract:
Regardless of profile, whether flat topped or pointed, to the summit observer all mountain peaks cast triangular shadows when the sun is low. A theory for such anomalous shadows is developed. The shadow apex angle is shown to depend only on the ratio of the breadth of the mountain to its height.
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