It will help to have an idea of the volume of material in the Earth's mantle because it appears that Earth has shrunk since it was first created, a process known as radial shrinkage.
Radial Shrinkage
Functional Orbital Mechanics
Any opposition to the popular science (SciPop) heliocentric cosmological model will be greeted with the general refrain of "it must be true because it works."
Based on Gravitational Interaction
Having a value for Earth's average density is critical to the popular science (SciPop) model for its internal structure because we can't see inside the Earth, we can only infer what we think it's structure may be.
Passive Aggressive Special Pleading
Here's an example of a Christian who sounds like an atheist, using the scientific paradigm and tactics of atheism. "Being a geophysicist, I do not take the pillars of the Earth literally."
Where is the Gravity in a Comet?
We upset a compromised Christian when we told them they they were defending the mainstream science paradigm (SciPop). It started when we confronted them about a statement that they make on their website.
The Volume of the Great Deep
When Noah's flood took place all of the waters of the great deep burst forth and flooded the Earth. If we know the volume of water and the radius of the Earth at this time, then we may calculate how deep the water was.
The Volume of Earth’s Mantle
It's very useful to know the volume of material in the Earth's crust and mantle, but before we move on it's also worthwhile to note that the Earth's crust and mantle have several Biblical synonyms.
Present Day Earth
With a few pieces of information we can take what we know about the Earth today and deduce what the Earth was like in the past. This is the alternative to using Uniformitarianism to assume that things were the same in the past.
Uniformitarianism
People presume to disprove God by cobbling together some math based on Uniformitarianism ideals that were popularized by Charles Lyell, a contemporary of Charles Darwin.
August 3rd
There was enough water in the great deep to flood the Earth 1,200 km deep. 15 cubits was when the crew of the ark stopped taking soundings. Mount Everest formed 101 years AFTER Noah's flood during Peleg's tectonics.