# Welcome to a Model for examining gravity from the surface of the Earth to the center.

Author: Greg Wallace
Updated: 21 Sept 2016.

In short form, it is called MODELBS which stands for Model Below Surface.

This modelling program will attempt to examine the way Newton forces act on a small standard 1kg object and the changes as the small object is taken at intervals toward the center of a large object.
It uses gravity as the main force and includes Mass in Front and Mass Behind.
It takes into account the density of the various layers of the Earth.
An assumption was that gravity at the center is zero due to an object being pulled equally in all directions and this is proven in the model.
A big question being searched is whether density at the center can be zero or null and this is not concluded.

The following diagram shows the concept of the model. This is an original work while acknowledging that some data comes from other sources such as radius of Earth, mass of Earth, layers, densities of layers, temperatures and gravity and pressure formulae.

What has come from doing this model as a semi-conclusion is that the standard gravity formula is calibrated to work at the surface of the Earth and where the Earth is a sphere and where there are angular vectors. It would not work for a cube Earth!!. Gravity at the surface of the Earth has to take into account side vectors. The standard gravity formula works as the small object is taken at a greater distance from the Earth, and at a distance, it does not matter what the shape of the large object is.

The model shows that Newton forces of gravity are pretty much linear as the small object is taken inside the large object (Earth).
The Earth is a good place to start because we know much more about its properties such as radius, mass, average density and even info about the various layers of the Earth including temperature.
Not resolved is how to better introduce pressure into the model.
More may come....