Why Is the Sky Blue? Rayleigh Scattering Explained
Why the sky is blue, explained simply: how sunlight scatters off air molecules, why short wavelengths scatter more, red sunsets and why it isn’t violet.
Topic
Light & Waves
Color, scattering, refraction and sound.
How Rainbows Form
How rainbows form: refraction, dispersion and reflection inside raindrops, why the colours appear in order, why rainbows are arcs and double rainbows.
Snell’s Law and Refraction
Refraction and Snell’s law explained: why light bends between materials, refractive index, n₁ sin θ₁ = n₂ sin θ₂, total internal reflection and a calculator.
The Doppler Effect Explained
The Doppler effect explained: why a passing siren changes pitch, the formula, redshift and blueshift of light, and uses in radar, medicine and astronomy.