Okay, nobody here disputes the usefulness of Newton's laws of gravity.
Excuuuuuze me?
Newton's law of gravity is the most heavily-slandered piece of science here on the Flat Earth Forums. Mostly it takes the form of "gravity doesn't exist." Frequently anyone who dares suggest that behaviors of objects in Earth's gravitation can be perfectly described by F=Gm
1m
2/r
2 is promptly pilloried because "Gravity isn't a force," and because objects fall towards Earth with an acceleration of 9.8 m/s/s because the Earth and Universe are doing the UA zoom "to infinity... and beyond!"
I'd say this counts as "disputing the usefulness of Newton's laws."
I know perfectly well that Einstein's equations are necessary for calculating high-energy stuff like black holes and gravitational lensing, yadda yadda, but you can't beat an algebra equation for describing routine real-world phenomena like trajectories and bouncing balls, versus the tensor calculus needed for Einstein's stuff.
From the University of New South Wales in Sydney, comes
this discussion of the limitations of Newton:
Although [Newton's theory of Universal Gravitation] is an excellent theory, it does not agree with experiment if one investigates extremely large fields, or moderately large fields with very high precision. In other words, it is wrong. However, it is such an excellent approximation that Newtonian gravity is what we use to calculate in almost all circumstances, while recognising that it is just a very convenient approximation to more exact theories.
There's a good reason why every gravity problem in an engineering textbook can be
correctly solved using algebra (plus trig and calculus), even if using by Einstein's formulas and tensors you'll get the same answers, to a very high degree of precision. That reason is that Newton's equations are
useful, even if they've been eclipsed by more-accurate ones from Einstein.
We are only disputing his correctness.
You conveniently forget that several planets were
discovered mathematically using Newton's equations. When you write of "disputing correctness"
exactly how many digits of precision do you want when calculating things here on earth, like the
apparent force of gravity exerted by a Zetetic Armchair? Why don't Flat Earthers propose dropping the "Universal" from the name Newton's Law of Universal Gravitation? The formula still works for 99% of real-world applications outside high-energy physics.
But nobody disputes that his equations can be useful. Please quit with the straw men. 
Name the author of the quote: "He was wrong about there being a force. He was wrong about gravity, whether the equations work in most cases or not; it only takes one example where they don't work out to prove that they are fundamentally wrong." That was none other than Roundy the Truthinessist!
"Nobody disputes" indeed!
Dude, you need some glasses.
Almost
every Flat Earther on these boards disputes the usefulness of Newton's equations,
simply because then they'd have to admit that the entire Flat Earth must have no mass.Boo-yah.