What Would Happen If the Earth Was Hollow and How Do We Know It’s Not?

OK, we are going think about a hollow Earth— but we need to stop for a moment and talk about gravity. Let’s model gravity as an attractive force between objects that have mass (instead of modeling it as a curvature in space-time). With that, we can calculate the gravitational force per unit mass due to some other tiny mass. This would be called the gravitational field (it’s the vector g with units of Newtons per kilogram). The gravitational field due to this tiny little mass depends on both the value of the mass (m) and how far you are from that mass (r). It’s a vector that points towards the mass and we can write it as the following expression. <a href="https://rjallain.medium.com/what-would-happen-if-the-earth-was-hollow-8e2e71d463b5">Website</a>