A light pillar is like a big shiny stick of light that seems to come from the ground or the sky. It looks like a shiny tower that goes straight up and down, even though nothing is really there!
The way it happens is that tiny ice crystals in the air reflect light from street lights, car headlights, or other bright sources of light. These little ice crystals act like tiny mirrors, bouncing the light around until it forms a tall, glowing column in the sky.
Even though it looks pretty cool, it is not really magic or anything like that. It's just a simple natural phenomenon caused by the way that light and ice interact in the air. So remember, the next time you see a light pillar, it's just a reflection of light by ice crystals, but it still looks pretty amazing!