On Friday, November 1, 2019 at 12:06:15 AM UTC-7, The Starmaker wrote:
there must be a mistake somewhere..

'they' (i don't know who they are)

keep listing Gravity
as one of the forces of nature...

What year did Gravity become a ...force????

When it became a "fundamental interaction"

https://en.wikipedia.org/wiki/Fundamental_interaction

1. Gravity.
2. The weak force.
3. Electromagnetism.
4. The strong force.

These are called the four fundamental forces of nature, and they govern everything that happens in the universe.

On the other hand...

https://en.wikipedia.org/wiki/Gravity

.... relativity says otherwise.

When not dealing with relativistic speeds, Nertwon's gravitational formulae work just fine. They enabled Newton to explain the astronomical observations of Kepler.