The knowledge of the orbiting planets around the Sun was empirical knowledge long before Newton was a glimse in his parents eyes. Newton just put mathematical equations on the motions and assumed the Sun to hold the planets in their orbits.
Well yes, sort of. In modern terms he
hypothesised it. This is actually how science works. He found that if he assumed gravity, it correctly retrodicted the motions of the planets and, together with his other laws, also explained many other phenomena.
The model stood for hundreds of years because it
worked and it still works for situations where relativistic effects are not significant. It works for predicting the motions of asteroids and comets and it works so well we can land a probe on a comet using it.
If we try to use something else, like electromagnetism, to do the calculations, it
doesn't work.
That is actually all that that is required for a good scientific theory; that it makes correct predictions of experiments and observation. There is no other test in science. Philosophically, it is possible to view science as being nothing but "capturing the observations". That is, if you have a framework that successfully retrodicts all the observations to date, and has proved useful in predicting new ones so far, that is all science is for.
Of course anybody claiming the science isn't telling us something about how the universe works has their work cut out to explain the success of the established theories.
As I tried to explain before, this is what you need to do if you want to claim Newton and Einstein were wrong. Strictly, of course, Einstein
did show that Newton was wrong but also explained the success of Newtonian gravity using his new theory.
This is cosmological gibberish. Have you analyzed the logics in these sentenses before you wrote this? Or are you just refferring from a textbook?
@joelr is correct. The logic is both sound and well tested in experiments and observations.