Halley comet: The triumph of Newton mechanics and the catastrophic failure of relativity,

I leave this link for numerical and historical details.
https://en.wikipedia.org/wiki/Halley%27s_Comet
Enough to say that the Halley comet was the first general proof of the
extraordinary and simple Newton's theory of gravitation. With Newton's
theory,
the astronomer Halley (also editor and publisher of Principia) was able
to
predict the next apparition of the comet in 1758 (after his death).
Halley
met with Newton seeking advice for the behavior of his comet, and was
shocked
by the unpublished theories that Newton had. He became a fervent admirer
of Newton's work and used all of his resources and influences to get
Principia published. This sole action CHANGED THE WORLD, giving birth to
modern science.
Einstein's general relativity had strong support by influencers, still
has. Yet,
GR fail miserably when trying to solve any problem in astronomy, except
the highly propagandized (and still theoretical hack) for a tiny
discrepancy on the gross calculation of the advance of Mercury's
perihelion, and THAT'S IT. NOT ANY OTHER EXPLANATION about the problem
of planets and other celestial bodies revolving around the Sun.
Excuses abound, to hide the pile of crap that relativity is:
Mathematical Complexity:
General relativity involves solving complex equations, and applying it
to a system like Halley's Comet would require significant computational
efforts for uncertain results, which under Newton are almost
non-existent.
N-body problem: GR can't be used to solve a problem with too many
variables:
- Influence of giant planets.
- Perturbations due to small planets and celestial bodies.
- Changes in the mass of the comet as it approaches the Sun.
- Precession in the highly eccentric orbital path (e close to 1)
Also, the highly complex non-linear equations that are the basis of GR
can't be analytically solved by any means. Not even a linearization of
them can be used (PPN) that may take account of so many details.
Conclusion: GR is a failed geometrical theory that has no practical use
IN THE REALM OF REAL PHYSICS. Newton's theory still reigns UNCHALLENGED.