If "gravitation exists in other celestial bodies", why not between bodies on the surface of the earth
This conjecture is simply a false premise leading to a faulty conclusion.
Help me a bit, what "false premise"?
From Wiki "
The gravitational pull of the stars, for example, causes observable tidal effects on Earth."
Gravitation (whether under GR or simply Newtonian) causes a force between masses. "Celestial bodies" have mass, the flat earth has mass and objects on earth have mass,
hence there must be "gravitational pull" between the flat earth and objects on it. the the variation of gravity with altitude has no reported daily or monthly variation.
I am not really sure what you are arguing here.
The Sun, moon and other "Celestial bodies" rotate at rates one revolution in about 24 hours (sun, planets and stars) and about 29 days for the moon.
Hence any "gravitational pull" from these objects should show variations with similar periodicity.
Gravity on earth also varies with latitude. This is explained on the Globe by the rotation and differing radii.
Please provide evidence for this claim.
Evidence of what? That "Gravity on earth also varies with latitude." This has been known for around 400 years since Christiaan Huygens found unexplained variations in the rate of pendulum clocks. Temperature variations were important, but were compensated for. Robert Hooke and Isaac Newton determined the variations were due to a variation in "g".
There are numerous related questions, but this will do for a start.
I think we should probably muddle through this first round of cobbled together thoughts before even considering discussing much else.
And, no I have not personally verified all of this! Mind you I could come up with numerous points of the Flat Earth model that have not been personally verified, but are simply inferred to preserve the initial hypothesis.
By the way I find this a bit odd. The Wiki says "The traditional theory of gravitation (e.g. Newton's Law of Universal Gravitation, General Theory of Relativity, etc) is incompatible with the Flat Earth Model". How does that fit with:
What physics makes this distinction and how?
GR and SR. By describing gravitation in detail.