A light beam travels from air (refractive index = 1.00) into glass (refractive index = 1.50) at an angle of 30 degrees. What is the angle of refraction inside the glass?

Tue, 05 May 2026 08:47:02 +0000

**A light beam travels from air (refractive index = 1.00) into glass (refractive index = 1.50) at an angle of 30 degrees. What is the angle of refraction inside the glass?** Curious about how light bends when it moves from the open air into a glass surface? When a beam of light enters glass at a 30-degree angle from the air, its path shifts due to a fundamental optical principle—refraction—and understanding this reveals important insights for both science and everyday technology. Refractive index measures how much light slows and bends when passing between materials. Air has a refractive index of 1.00, while typical glass registers at 1.50. When light moves from a lower to higher refractive index medium, it bends *toward* the normal—the imaginary line perpendicular to the surface. Based on Snell’s Law, this bending can be calculated precisely. To determine the new angle of refraction inside the glass, apply the formula:
n₁·sin(θ₁) = n₂·sin(θ₂)
where n₁ = 1.00 (air), θ₁ = 30°, and n₂ = 1.50 (glass). Plugging in values:
1.00 × sin(30°) = 1.50 × sin(θ₂)
0.5 = 1.50 × sin(θ₂)
sin(θ₂) = 0