Abstract
The concept of the earth as a gigantic ball surrounded by space is a basic component of the modern world view. Unless children understand this idea, they cannot understand the answers to commonly asked questions such as: “Why do we have day and night?” In addition, the closely related concept that the “down” direction always points towards the earth’s center is important in understanding the answers to further questions such
as: “Why don’t people who live near the South Pole fall off?” and “Why don’t space satellites fall?” Research on children’s concepts of the earth’s shape and gravity is consequently of great interest to those concerned with how and when to introduce many topics in the astronomy and geography curriculum.
