Optical rotatory dispersion

Optical rotatory dispersion is a big, fancy word that describes how light reacts when it passes through different substances, like liquids or gases. You know how when you look through a glass of water, the straw can look like it's bending? That's kind of what happens with light when it passes through different things.

When light from the sun or a light bulb passes through a substance, it can get twisted or turned a little bit. That's because the substance has molecules in it that are shaped like spirals. These spirals can make the light twist as it passes through.

Scientists use a special tool called a polarimeter to measure how much the light has twisted. By studying how much the light twists at different wavelengths, they can learn a lot about the substance that the light passed through. They can figure out things like how many molecules of the substance are in the liquid or gas, and what shape those molecules are.

So optical rotatory dispersion is all about how light gets twisted and turned by different substances, and how scientists use that to learn more about the substances. It might sound complicated, but it's really just a fancy way of saying "light bending and twisting in cool ways when it passes through stuff."