When you view your right hand in a mirror, it appears as a left hand. Writing is reversed, as is the direction of any spinning object: clockwise becomes counterclockwise and vice versa. In many ways, it appears as though things are flipped left-to-right, but not up-to-down. That’s not the true reason for what you see, however. (Credit: Hong Kong Science Museum)

Why do mirrors flip left-and-right but not up-and-down?

If you look into a mirror, you’ll notice that left-and-right are reversed, but up-and-down is preserved. The reason isn’t what you think.

If you’ve ever looked in a mirror, you’ve likely noticed that everything you see is flipped. When you raise your left hand, your reflection…