Refraction calculator
Light bends toward the normal entering a denser medium, and past a critical angle it does not get out at all.
Vacuum 1; air 1.000293; water 1.333; crown glass 1.52; diamond 2.417.
Angle of refraction
22.030 11degrees
- Critical angle Zero when going into a denser medium, where no critical angle exists.
- 0.000 00 degrees
- Brewster angle
- 53.123 23 degrees
- Light speed in the second medium
- 224 900 570
- Totally internally reflected
- 0
Show the working
- Refractive index of the first medium = 1
- Refractive index of the second medium = 1.333
- Angle of incidence = 30
- sin2 = 1 * sin(rad(30)) / 1.333 = 0.375 094
- Angle of refraction = abs(0.375 094) <= 1 ? deg(asin(0.375 094)) : 0 = 22.0301
- Totally internally reflected = abs(0.375 094) > 1 ? 1 : 0 = 0
- Critical angle = 1 > 1.333 ? deg(asin(1.333/1)) : 0 = 0
- Light speed in the second medium = c / 1.333 = 224 901 000
- Brewster angle = deg(atan(1.333/1)) = 53.1232
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- n1 sin(theta1) = n2 sin(theta2)
- critical angle = arcsin(n2/n1) when n1 > n2
- Brewster angle = arctan(n2/n1)
Diamond's high index gives a critical angle of only 24.4 degrees, which is why a cut stone traps and returns so much light.