Question 1: What is the linear “density” of the spectral range on the ceiling? The crown molding is common for an older (circa 1925) house.

Question 2: The glass shown is a standard 16-oz. water glass engraved with many digits of pi. (The dimensions appear somewhat distorted because of the camera angle chosen to enhance the contrast of the numerals against the dark background.)

Solution to Question 1: The spectral range of visible light from violet (~400 nm) to red (~700 nm) is ~300 nm = 3 × 10−7 m. The spectrum on the ceiling is ~15 “crown molding” widths, the latter being ~0.1 m. Hence, the linear “density” is approximately (3 × 10−7)/(15 × 0.1) = 2 × 10−7.

Solution to Question 2: There are 30 rows of digits, each with ~20 digits per line (21 to be precise), so there are ~600 digits...

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