Dispersion of White Light — VIBGYOR

Shine a narrow beam of sunlight through a glass prism and something surprising happens: instead of one white patch, you get a full band of colours on the screen — Violet, Indigo, Blue, Green, Yellow, Orange, Red (remember it as VIBGYOR).

This happens because white light is actually a mixture of all seven colours, and each colour bends by a slightly different amount when it passes through the prism. Violet bends the most, red bends the least — so they spread apart and separate into a visible band called a spectrum. This splitting is called dispersion.

Isaac Newton proved this wasn't the prism 'creating' colour: he passed the spectrum through a *second*, inverted prism, and all seven colours recombined back into plain white light — showing dispersion is reversible, and white light really is made of those seven colours all along.

This exact effect is also what creates a rainbow: tiny water droplets in the air after rain act like millions of little prisms, dispersing and internally reflecting sunlight before it reaches your eye.