wunder beta

🌈 How does a rainbow form?

Raindrops refract, reflect, and disperse sunlight into a personal 42-degree geometry.

lessons

~10 min

to learn

🔬 Science

subject

Adults

level

Start the course →

What you’ll learn

Sunlight sorted by raindropsExplain rainbows as refraction, reflection, dispersion at fixed angles.Raindrops redirect sunlight into your eyes near 42 degrees. The bow is geometry, not a solid arch on the land.
Order, doubles, and Alexander’s bandDescribe color order, secondary bows, and interference fringes.Primary color order is fixed; secondary reverses and sits outside. Dark bands and supernumeraries add wave details.
Myths and near relativesDebunk the pot-of-gold location and relate moonbows, fogbows, prisms.You cannot reach an end that moves with you. Related bows use similar physics with different light or drop sizes.

Questions this course answers

Why can’t you walk to the physical “end” of a rainbow?

A rainbow is angular geometry; the drops contributing change as you move, so the end recedes.

Order light’s simplified journey in a primary-bow drop

Enter, reflect once, exit, observe at the characteristic angle.

Match phenomenon to idea

Different optical paths and drop sizes make related but distinct sights.

Grounded in trusted sources

NOAA optical phenomena / rainbow education pages
Atmospheric optics educational sites (e.g. atoptics-style explanations)
University physics demos on refraction and dispersion
Classic meteorological optics texts on rainbow angles

Every Wunder lesson is built from real, reputable sources — never invented.

Related Science courses

🕳️How does a black hole form?🌀How does a hurricane form?🐋How do whales sleep without drowning?🌙How does the moon cause tides?💊How do antibiotics kill bacteria?🌱How does a seed know which way is up?🕷️How do spiders make silk?👁️How does the eye see colour?

Wunder is a personalized learn-anything platform — tell it any topic and it builds a beautiful, fact-checked course in minutes, with narration, a knowledge check, and a college-style University track.

Browse more Science courses · All topics · Home