💡 RefractLab — drag a light ray and feel why it bends
Step 1 of 5 · Light bends
SNELL · air → water
θ₁ 35.0°
θ₂ 25.5°
n₁ 1.000 → n₂ 1.330
θc
travel time t(x) Fermat minimum (Snell point) your guess drag the crossing point on the scene