Moiré pattern

Do you know when you look at a net or a mesh, you see lines that go one way and then lines that go the other way? Those lines are called a grid. When you put one grid on top of another, you can see something very cool happening!

It's called a moiré pattern! It looks like the grids are moving and making a brand new pattern.

This happens because the lines in the two grids are different and when they overlap, they create a new pattern that's different from both of the grids!

This can happen with other patterns too, like when you look at striped clothing on a TV screen, sometimes it looks like the stripes are moving or changing. That's the moiré pattern in action!

So cool, right?