# The Mass of the Earth

TEKEL: You have been weighed in the balances, and found wanting;

(Daniel 5:27) NKJV

The mass of the Earth has never been directly measured. It’s calculated using the radius of the Earth, the value of g we get from a ball drop experiment (acceleration due to gravity), and the gravitational constant, G.

We know the mass of the ball, drop it, get a value for g. Then we have to calculate the force that would be needed by the Earth to make it accelerate at that speed. If we have a value for the gravitational constant then this can be used to calculate how much mass would be necessary to cause the force which is measured by dropping the ball. The calculation is based on 2 assumptions:

1. Mass causes gravity,
2. Earth’s density is spherically symmetric.

Sadly, for popular science (SciPop) neither of these assumptions are true. If you assume that the Earth is solid and has an average density throughout in order to calculate the mass of the Earth, then you can’t then use the calculated value to prove that the Earth is solid and has an average density throughout. That’s called circular reasoning.

We can only measure what we can measure, in this case the ball drop experiment. The result we get is quite independent of the internal structure of the Earth if gravity is a field emitted from the center, which is congruent with practical applications of math.

This means that we don’t have an absolute value for the mass of the Earth, hell is at the center and there is a great gulf of open space between the lower mantle and the surface of hell. The value that we use is just a number which has been agreed upon. Yet the value we have for the mass of the Earth is used to calculate the mass of the sun, and this is then used to calculate the mass of the other planetary and stellar bodies. It turns out that we don’t know the absolute values of any of these bodies, all we have are relative values based on our 2 assumptions. Ironically, Sir Isaac Newton was fully aware of this.

Wherefore relative quantities are not the quantities themselves, whose names they bear, but those sensible measures of them (either accurate or inaccurate), which are commonly used instead of the measured quantities themselves.

– Sir Isaac Newton, Principia Mathematica p. 82