Why do rainbows form semicircles?
Show answer & explanation
Answer: Light refracts at specific angle
Rain falls in arc patterns — Wrong. Rain falls straight down. Rainbow's arc comes from refraction angle—light bends 40-42° inside raindrops, creating circular arc centered opposite sun.
Light refracts at specific angle ✓ — Correct! Rainbows form at specific angle: light enters raindrop, refracts (bends), reflects internally, refracts again exiting—total deviation ~42° (red) to 40° (violet). All raindrops at this angle from antisolar point contribute to rainbow—forms cone/circle with your eye at apex. Ground blocks lower half—you see semicircle. From airplane, you see full circle! Double rainbows have secondary reflection (50-53°, reversed colors)!
Gravity bends light downward — Wrong. Gravity doesn't bend visible light significantly (only in extreme cases like black holes). Rainbow arc comes from refraction geometry—42° angle.
More Physics in Daily Life questions
- In a warm office that already reads 26 C, which change can make people feel cooler without lowering the thermostat?
- Why might 26 C feel acceptable in a breezy naturally ventilated summer building but too warm in a sealed winter office?
- On a warm humid day, why can the same 27 C room feel much worse once you start sweating?
- Why can moving air make a 27 C room feel cooler without changing the thermometer?
- Which hidden factor can make a desk beside a cold window feel chilly even when the thermostat across the room still reads 22 C?
- In the same 22 C room, why might someone who just climbed stairs feel warm while someone sitting in a T-shirt feels chilly?