Document Type
Article
Publication Date
2024
DOI
10.1119/5.0178537
Publication Title
Physics Teacher
Volume
62
Issue
6
Pages
543
Abstract
The article titled "Shadow hands" discusses a statement made by authors Dave Lynch and Bill Livingston in their book "Color and Light in Nature." The authors state that when you cast a shadow with your hand onto a piece of paper, the sharpness of the shadow's edge diminishes as you raise your hand above the surface. This fuzzy outer edge of the shadow is called the penumbra, and its width divided by its distance from your hand is always a constant fraction of about 1/112. The article poses two questions related to this statement and asks readers to explain it using elementary geometry. The article also mentions Fermi Questions, which are brief questions with answers and estimation techniques.
Rights
© 2024 The Author.
Included in accordance with publisher policy.
Original Publication Citation
Adam, J. (2024). Shadow hands. Physics Teacher, 62(6), 543. https://doi.org/10.1119/5.0178537
ORCID
0000-0001-5537-2889 (Adam)
Repository Citation
Adam, John, "Shadow Hands" (2024). Mathematics & Statistics Faculty Publications. 267.
https://digitalcommons.odu.edu/mathstat_fac_pubs/267