Prism Physics: How Glass Separates White Light

A prism splits white light because different colors travel at different speeds through glass.
This effect is called dispersion—the spreading of light into its component wavelengths.
Violet light bends the most, while red light bends the least, creating the familiar spectrum.
The sharp edges of a triangular prism enhance this separation of colors.
Isaac Newton famously used a prism in the 1660s to show that white light is a mix of colors.
Each wavelength has a slightly different refractive index in glass, causing unequal bending.
Rainbows are nature’s version of prism physics, with raindrops acting like tiny prisms.
The order of colors in a prism is always the same: red, orange, yellow, green, blue, indigo, violet.
Optical instruments like spectrometers use prisms to analyze light from stars and lamps.
Prisms don’t create color—they reveal the hidden spectrum already inside white light.