
Galileo and Heliocentricity: A Rough Guide (2014) - Hooke
https://thonyc.wordpress.com/2014/05/29/galileo-the-church-and-heliocentricity-a-rough-guide/
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throw1002a
I highly recommend (sci-fi author) Micheal Flynn's (long-ish) chronological
timeline on the series of events that led the general consensus going from
Ptolemaic system to heliocentrism:

* [http://tofspot.blogspot.com/2013/10/the-great-ptolemaic-smac...](http://tofspot.blogspot.com/2013/10/the-great-ptolemaic-smackdown-table-of.html)

We tend view things in hindsight and judge people with our 20/20 view, when
events really unfolded over a period of time, and so people made decisions
with imperfect knowledge.

Two things that people forget or don't know: (a) Galileo was technically
wrong, since he insisted on Copernicus' circular orbits, and it was Kepler
that got it right (with elliptical orbits). And (b), it was not until 1806
that the Earth's motion was demonstrated through parallax (150+ years after
Galileo died), at which point heliocentrism was more than simply an untested
hypothesis.

Regarding (a) and (b) together: people when from Ptolemy to Kepler by the
1690s not because they had proof that it was true, but mainly because it made
the answer easier. Ptolemy worked reasonably well mathematically at predicting
orbits, it just took a damn long time.

~~~
mjw1007
Maybe we couldn't distinguish "the earth goes around the sun" from "the sun
goes around the earth" until 1806, but we could tell that the other planets
have the sun, rather than the earth, as their primary much earlier than that.

Isn't that the most important difference between the systems?

~~~
throw1002a
@namarie got it right. Per Part 3 in the series:

 _In the second episode, we saw a slew of new telescopic discoveries during
1610-1611; viz., the mountains on the moon, the Medicean stars, and (more
decisively) the phases of Venus. Now the first two do not demonstrate
geomobility, not do they undermine geostationarity. The first indicates that
the moon is not incorruptible. But this is agreed to by theology, and it
undermines only Aristotelian physics. The second indicates that some heavenly
bodies -- Cosmo, Franco, Carlo, and Lonzo -- circle Jupiter and not the Earth.
This bothers Aristotelian physicists, but not Tychonic astronomers. Only the
phases of Venus KOs Old Man Ptolemy._

 _But eliminating Ptolemy does not prove Copernicus any more than eliminating
Darwin would prove ID. There may be [and were!] other alternatives. When
Ptolemy was ptossed, astronomers flocked... to the Tychonic and Ursine systems
-- because none of the telescopic observations have so far established the
motions of the Earth._

* [http://tofspot.blogspot.com/2013/09/the-great-ptolemaic-smac...](http://tofspot.blogspot.com/2013/09/the-great-ptolemaic-smackdown-great.html)

In Part 2 Flynn outlines the seven major models in play:

* Heraclidean. Geo-heliocentric. Mercury and Venus circle the Sun; everything else circles the Earth.

* Ptolemaic. Geocentric, stationary Earth.

* Copernican. Heliocentric, pure circles with lots of epicycles.

* Gilbertian. Geocentric, rotating Earth. (proposed by William Gilbert in De magnete)

* Tychonic. Geo-heliocentric. Sun and Moon circle the Earth; everything else circles the Sun.

* Ursine. Tychonic, with rotating Earth.

* Keplerian. Heliocentric, with elliptical orbits.

* [http://tofspot.blogspot.com/2013/08/the-great-ptolemaic-smac...](http://tofspot.blogspot.com/2013/08/the-great-ptolemaic-smackdown-down-for.html)

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mannykannot
This series is rather spoiled by the author's determination to trash Galileo's
reputation. While he definitely has a point about simplistic, hagiographical
accounts of Galileo's contributions, especially those that present
geocentrists as being blind to the obvious, he goes on about it at length,
introducing some rather weak and self-serving arguments along with the valid
ones.

~~~
mcv
I don't see this as spoiled by any kind of determination to trash Galileo's
reputation. Pointing out the reality of Galileo's situation is exactly the
point, and to people who believe Galileo's fairy tale, of course that's going
to hurt his reputation.

This account is actually more careful and nuanced than other accounts of the
Galileo trial that I've come across.

Another possibly useful insight into Galileo is that he ridiculed Kepler for
suggesting that the planets would have elliptical orbits. Galileo could never
make his heliocentric model fit the observations, and meant he couldn't
convince anyone that it was correct, because it wasn't. Kepler basically saved
heliocentrism by proposing a model that worked, and Galileo mocked him for it,
because he found non-circular orbits as ridiculous as others found his
heliocentric model.

Galileo did a lot of important other work, but in the past his role in proving
the heliocentric worldview has incorrectly been painted as unrealistically
saintly. He was about as wrong as he was right, and he was self-centered and
careless.

~~~
Iv
I am careful about Galileo. You see a lot of Catholics trying to rewrite
history by presenting the Galileo trial as a simple scientific debate where
Galileo lacked proofs of his hypothesis.

Actually I find it very suspicious that the author of this article skips the
trial altogether.

We have the minutes. We have the judgement. Even if Galileo was an ambitious
asshole Ith political afterthoughts, one important fact remains: The Church
used the literal interpretation of the Bible to contradict a scientific
theory.

This is the main point and the main problem of the Galileo trial and why it is
significant. Galileo deserved opposition in a debate, not condemnation in a
religious tribunal. It happened and the blame is solely on the dogmatism of
the church. From this point, science diverged more and more from religious
teaching and stopped seeing the church as an ally.

~~~
mcv
I haven't seen any Catholics yet trying to rewrite this history. I have seen
atheists correcting incorrect beliefs about this period of history. I'm
protestant and not a fan of the RC church hierarchy, but I do care about an
accurate representation of history, and the Galileo trial is muddled with
fairy tales and misinterpretations, because people don't know the context.

But whatever your religious beliefs are, Galileo did lack proof. His model was
wrong. His idea was correct (though originally from Copernicus, of course).
But without proof, and without a correct model (which Kepler later provided)
there was no way at the time they could know it was correct. There was simply
no scientific basis yet to accept it over the existing geocentric model.

The RC Church's position on science was not homogenous. Various officials have
said that if an interpretation of the bible ever conflicted with verifiable
observations, then clearly the interpretation of the bible must be incorrect.
Obviously not everybody agreed, but heliocentrism did have its supporters
within the church. It was not considered heresy until Galileo made his
position impossible and alienated his biggest fan (pope Urban). In any case,
Galileo's theory here, his model, was simply incorrect, and they knew it.
There was a solid scientific basis to contradict it. They did pile on a bunch
of other accusations, but that's primarily because he angered the wrong
people.

Galileo did receive opposition in debate. His problem is that he didn't accept
it. He wanted everybody to accept his model, despite the lack of a scientific
basis for it.

~~~
Luc
> But whatever your religious beliefs are, Galileo did lack proof. His model
> was wrong.

You know who else lacked proof? It didn't bother you just as it didn't bother
the inquisition. Maybe try using the same standards for those theocrats as you
apply to Galileo.

~~~
Sharlin
The whole point is that geocentricism wasn't just dogma, it also happened to
match observations. It was the null hypothesis, if you will, and Galileo
failed to disprove the null hypothesis.

~~~
Luc
The fact that a man had to fear for his life for having an opinion doesn't
bare mentioning? All Galileo had to do was follow the rules as set out by the
Inquisition, and all would have been well.

It was all Galileo's fault!

~~~
mcv
Is it a fact that he had to fear for his life? We're not talking about the
Spanish Inquisition or an accusation of witchcraft here. He was questioned and
got house arrest.

Of course it's still not good to get punished for dissing the pope according
to our modern freedom of speech, but in those days, insulting rulers was still
frowned upon. And Galileo went well beyond simply having an opinion; he
insulted the pope. Not merely by ignoring the pope's instruction to present
both alternatives in a balanced way, but by putting arguments from the pope (a
good friend before this) in the mouth of a character called "Fool" (Simplico).

~~~
Luc
No. Galileo feared for his life more than once during decades of persecution.
He was lucky to avoid torture. Read Heilbron's biography, or even just
Wikipedia.

This notion that Galileo insulting the pope was some sort of rhyme and reason
for his persecution is wrong. It's commonly accepted that Galileo had no
intention of insulting the pope, and the pope didn't take it as an insult
(Heilbron goes into much detail) . There is some minor evidence involving the
rumour that someone suggested to the pope that it looked bad, but this is not
at all the central reason for his persecution.

Did you get this from the Dava Sobel book? It's takes an awful license with
history. Her Longitude book is the same, it's just wrong in so many aspects
while presenting itself as accurate.

