At what point can it be said astronomy replaced astrology? Even Newton believed in astrology so it must be after he lived?

I think they're independent of each other; you can meet people today who are aware of both, but only subscribe to one or the other...

Astrology has grown out of our persona - where we've *always* thought our lives must be directed by higher sources of intelligence or fate - and has remained with us steadfastly for generations... In it's shadow, Astromony has grown from just *watching* planets and stars, to astrophysics where we analyze and describe what it is we're actually seeing... As science has moved from its toe-hold in teachings for humanity, to the way we learn about ourselves, I think it's off-set the astrology bandwagon - but there's still 4 wheels on that wagon going down the highway.... Probably when space and rocketry were getting closer - guessing, the 30's, the 40's, and the 50's - is when the two were on equal footing with the mainstream public; I would guess it was the advent of manned space travel in the 1960's that finally had us seeing science for it's advantages and repeatable outcomes that finally surpassed the astrology folks... but again: Astrology ain't dead.

But I think we might be better off if it was...

As the guys say, Astronomy didn't replace Astrology. Rather, I would say Astronomy was born from Astrology. Of course, their purposes are so extremely different today, but when Astronomy was very young, it was the same people that worked on both and the two were highly influenced by one another.

But while lots of common people continue to believe in Astrology, we could say that Astronomy "replaced it" in the sense that astronomers today (and not common people) have pretty much abandoned belief in Astrology. I think this is the point you're heading to. In that sense, I think that while even Newton had some mystic beliefs, astronomers were willing to give up their superstition when an experiment showed they were wrong. Kepler did that. And this was the case for a long time before Newton. Yet, none of these guys gave such a strong hit as Newton himself. Newton may have had some superstition, but the impact of what he discovered and explained was huge, because he made it clear nothing supernatural was necessary for Astronomy to work. He caused lots of astronomers after him be a lot less superstitious. Probably he was the last "very important" astronomer (he was a lot more than "very important", but just for the sake or grouping) to have significant mystical beliefs that would have an effect on their scientific thinking.

First there was Astrology. That was based on the movements of Sun, Moon & five planets that everybody with eyes could see in the sky, So it was needed to know their positions in the sky ( amongst the stars for those other than the Sun) and that is Astronomy. It came out of need for some other purpose that has its own life.

At what point can it be said astronomy replaced astrology? It was no repalcement. It is like you take a dilapidated neighbour's jalopy that he was using for hauling corn, grain or hay from his farm to turn into a car that could run on city streets. That needs lot of work.

Newton supplied the first spark. Physics was the progenitor. Most of the Laws of Physics can't be verified on Earth in an overwhelming field of its own gravity. Against this back ground it was remarkable that Newton surpassed all that limitation & propounded his thesis on Gravity. It needed to be verified & that was possible in the sky(or Space) only. Kepler did that & it came to be tagged as Astronomy as it was about celestial bodies; otherwise it is only Physics. It is how it all began.

At least in the English-speaking world, among *most* of the educated elite, I would say that astronomy replaced astrology sometime before 1700, perhaps as early as 1660 (founding of the Royal Society), or even during the 1640's. Isaac Newton published "Principia Mathematica" in 1687; even though he had some mystic beliefs, the respected scientists of his time generally were anti-astrology.

Around 1897 when the "mystery airship" was being sighted, leading to HG Wells to write "War of the Worlds", when it was "claimed" (by professional astronomers no less) that there were canals on Mars. That's when the whole space boogers myth started. It rapidly displaced astrology as the number nuttiness for the scientifically illiterate masses.

Sadly, not much has changed since then.

Cheers!

Have you looked in the news paper lately. I don't think astrology has been replaced at all. In fact there are reports that President Regan's wife believed in it.

The one didn't replace the other. They are two completely different things.