OK. This is going to sound crazy, but the direction of down where you are is not the same as the direction of down where I am.

Why?

Because everything on Earth gets pulled towards the center of the Earth. And yes Martha, the Earth is round. If where you stand on Earth is different than where I’m standing, then the direction to the center of the Earth (and out the other side) is different for you and me.

A person in Hawaii and a person in Botswana are directly through the Earth from each other. Their directions for “down” are opposite!

The activity at the end of chapter 1 of my book Why Stuff Falls Down lets you build a “Toy Earth” and demonstrate this for yourself. Not only that, see how our round Earth creates day and night, and the seasons!