Voigt effect

The Voigt effect is like when you look at a straw in a glass of water, and it looks like it's bending. But really, it's just the way the light is getting through the water and the straw.

When light goes through different materials, like water or glass, it can change direction a little bit. This is called refraction. Sometimes, when light goes through a material that isn't spread evenly, like when it goes through a crystal or something, it can get bent even more. This is called birefringence.

The Voigt effect is a special kind of birefringence that happens when the material is stretched or compressed. It's kind of like when you pull or squash a rubber band, and it gets longer or shorter. When you do that, the atoms in the rubber band move around, and they change the way the light goes through it.

Scientists use the Voigt effect to study lots of things, like how rocks and crystals change under pressure. It can even be used to help make better glasses, by changing the way light goes through them so that they don't create a lot of glare.