What are sand clocks?

A sand clock is like a tiny timer made of grainy sand that flows from one side to the other.

Imagine you have a jar with little sand grains, and when you tip it over, the sand starts to fall through a small hole in the middle. Just like how water flows from a bottle, the sand moves slowly, taking time to go all the way down. That’s what makes a sand clock special, it shows how much time has passed by how much sand has fallen.

When you turn over a sand clock, the top part starts filling up, and the bottom part begins emptying out. Each grain of sand takes its own little time to move, so after a while, all the sand will have changed places. That means it’s been exactly as long as the sand clock was designed for, like 1 minute, or maybe even an hour!

People use sand clocks when they need to know how much time has passed without looking at a watch. They are fun and simple, just like counting your breaths while playing hide-and-seek!