Why do stars appear to have points?
Show answer & explanation
Answer: Diffraction in eye/camera
Distance creates pointed shape — Wrong. Distance makes stars appear as points due to size, but the 'pointed' starbursts come from diffraction, not distance.
Diffraction in eye/camera ✓ — Correct! Stars appear as point sources due to distance, but the 'star points' (diffraction spikes) come from light diffracting around edges. In eyes, the iris creates subtle points. Cameras with aperture blades (usually 5-9) create pronounced starbursts—light bends around each blade edge. Refractor telescopes produce cross-shaped spikes from support vanes!
Atmosphere distorts the light — Wrong. Atmosphere causes twinkling, but pointed spikes come from diffraction at the aperture (iris or camera), not atmospheric effects.
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