Introduction

If someone were to ask me about the Earth, this is how the conversation might go.

Them: “How would you describe the Earth?”

Me: “It’s round.”

Them: “No, really.”

Me: “It’s mostly green and brown, and there is blue water. There are lots of plants and animals. In some places there are mountains and canyons. In other places there are deserts. In still other places there are jungles and beaches.”

Them: “Anything else?”

Me: “Okay. At the North and South Poles there is ice and snow all year round. There are a lot of people on this planet. Many live in cities, but a lot also live in suburbs and on farms. There are some places that no people live. Why do you ask?”

Them: “Just interested to know how you see it. What about the Earth, the ground itself?”

Me: “It’s hard.”

Them: “So you mean, it is solid?”

Me: “Yes.”

Them: “Does the ground move?”