Each layer in the Earth's crust changes in fundamental ways the closer it is to the planet's core. There are four layers of the Earth, and each layer has a different density, composition, and thickness. Three hundred years ago, English scientist Isaac Newton created the foundation for current scientific thought about the density of the Earth’s layers.
Answer: the main purpouse of physical maps usually show the most important political boundaries, such as state and country boundaries. So, this is true.
