The Polarised Sky

A hidden pattern bees can see

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Scattered skylight is polarised, most strongly 90° from the Sun.
• Ideal degree of polarisation: $P = \sin^2\theta / (1 + \cos^2\theta)$.
• Insects (and perhaps Vikings) navigate by the pattern.

Steps

1. Scattered light is sorted
2. At sunset
3. Half polarised
4. Navigating by the pattern
5. Sixty degrees
6. Forty-five degrees