Talk:Galileo Galilei/Archive 8

Effort

The information about Protestant opposition to Copernicanism has been removed from the article on Galileo. It has not been added to any other article. This gives the impression that the effort is designed to suppress the information. It appears not to have been added to the articles on Luther or Copernicus, where it would be perfectly relevant. We are told that the details of heliocentrism were not available in 1539. They had been available for centuries, since the days of Aristarchus. —Preceding unsigned comment added by 217.41.51.240 (talk) 10:10, 10 September 2007 (UTC)

The information was not relevant here. That is why it was removed. The cited individuals all died prior to Galileo's work. If you want to update other articles with useful encyclopedic information, go right ahead. Take account of the information and references provided here; it may be useful. —Duae Quartunciae (talk · cont) 10:27, 10 September 2007 (UTC)

At the moment, the Luther and Copernicus articles are protected, making it difficult for me to edit them. —Preceding unsigned comment added by 217.41.51.240 (talk) 10:43, 10 September 2007 (UTC)

I have added indentation to your comments. You can make proposals on the talk page. That is a very good idea. Articles get protected because of edit wars, and in such cases it is really a good idea to run new ideas past the community on the talk page. There will be a lot of expertise there, and different perspectives, than will help tighten up any additions you are considering. Welcome to Wikipedia, by they way. You've picked some pretty heavy articles for your starting out! —Duae Quartunciae (talk · cont) 10:54, 10 September 2007 (UTC)

I use twenty IP numbers, giving the impression that I have just appeared on Wikipedia.

—Preceding unsigned comment added by 87.194.4.21 (talk) 09:25, 11 September

• Please sign your comments on talk pages. It is very easy to do and has many advantages. It is also considered a standard by the Wikipedia guidelines that all users should follow. You can get all the details by following the link at the beginning of this comment.
• When you use spaces to indent your comments, please include carriage returns (newlines) after every 80 or so characters of text. Without carriage returns your comment will consist of a single line and overflow the right end of the surrounding box if the text is longer than about 90 characters. This makes it unnecessarily difficult to read. If the text is much longer than that it will extend beyond the right edge of the browser page making it even more difficult to read.

—David Wilson (talk · cont) 14:02, 12 September 2007 (UTC)

SineBot signs automatically. —Preceding unsigned comment added by 87.194.4.21 (talk) 08:58, 13 September 2007 (UTC)

It should not have to. You should do it; programs are less reliable. I have put proper indentation on your two most recent comments here, replacing the leading white space. It is not just the IP address that make you look new to wikipedia. It is the way you don't follow very simple conventions for talk pages. You use white space in the front of comments, and you don't sign appropriately. Please, use the proper formatting conventions. —Duae Quartunciae (talk · cont) 10:26, 13 September 2007 (UTC)

Alleged torture

There is nothing in the article about the theory that Galileo was tortured.

The alleged torture was not mentioned in the 17th., 18th. or early 19th. centuries. Torture is treated as a possibility by A.D.White in the 1897 era. Berry quotes the exact Latin words with which Galileo was threatened with torture but says nothing about actual torture. —Preceding unsigned comment added by 87.194.34.71 (talk) 13:44, 12 September 2007 (UTC)

David Brewster, in 1855, seems to have been the first to claim that Galileo was tortured. —Preceding unsigned comment added by 86.145.50.66 (talk) 13:46, 14 September 2007 (UTC)

Do you have any specific suggestions to make on the content of the article? As far as I know the idea that Galileo was tortured has not been taken seriously by any professional historian of science for at least 50 years, and probably not since the publication of Favaro's monumental edition of his works nearly 100 years ago. Galileo's dispute with the Church is now extremely well-documented by copious and widely available copies of primary sources and many reliable secondary sources. The fact that Galileo was never tortured has been established about as firmly as it is possible for any negative historical proposition ever can be.

I believe the current article does need a short summary of what went on during Galileo's trial, including an accurate explanation of why he was threatened with torture. Contrary to a widely held misconception this was not done to force him to recant (he had already done that), but to test the sincerity of his preceding testimony.

A short account of the evolution of historical views of Galileo's conflict with the Church, including 19th-century accusations that he had been tortured, might be worth including in the Galileo affair article. The definitive reference here is Maurice Finocchiaro's Retrying Galileo, 1633–1992. Until I've read it I wouldn't consider attempting to write such an account myself.

—David Wilson (talk · cont) 15:38, 14 September 2007 (UTC)

Church controversy in lead

I have amended some recent edits to the lead by Michelet (see below). In my amendments I have tried to retain as much as possible of the gist of them which are indisputably accurate. However it seems to me that the result is a highly unbalanced lead which gives unnecessary weight to the Church controversy. I preferred the lead as it stood before Michelet's edits, and I think it would be much better if the extra material were moved to an appropriate part of the body of the article or to the Galileo affair article (if indeed it is not already there, which I haven't yet checked).

The main reason for my amendments to the edits is that parts of them were inaccurate. Specifically:

"[The geocentric view] was considered by scholars to be backed by the Scripture"

This is an at least disputable over-generalisation and uses a form of wording that needs to be backed up by reliable sources. I have replaced it with a less general statement and provided a good source.

"... and his defense of heliocentrism as being an indisputable truth, ..."

This is a standard furphy of the less reliable apologetics literature. I have never been able to find support for the claim in the primary or any reputable secondary literature. At the very least it is not NPOV. At the time of the condemnation of Copernicanism in 1616 Galileo's defence of Copernicanism had consisted of:

• Three brief remarks in The Starry Messenger indicating that Galileo himself was convinced that the Copernican model was largely correct.
• The following statement from his Letters on Sunspots

"And perhaps this planet also [viz. Saturn], no less than horned Venus, harmonises with the great Copernican system, to the universal revelation of which doctrines propitious breezes are seen to be directed towards us, leaving little fear of clouds or crosswinds."

• Several letters written in response to alarming, scripturally motivated attacks on both Copernicanism and himself personally, including his denuncation to the Inquisition by two Dominican friars at the beginning of 1615. These writings consisted of:

his Letter to Castelli. This was private letter, although copies of it were circulated amongst Galileo's friends and supporters, and one of these eventually wound up in the hands of his enemies;

the Letter to the Grand Duchess Christina, an expanded version of his Letter to Castelli. Galileo started this in late 1614 or early 1615 in response to the alarming incidents which had occurred at that time. He had intended to circulate this widely amongst his friends and supporters, and possibly even to have it published. However, Copernicanism was condemned by the Congregation of the Index before he had had a chance to do so, and it does not seem to have circulated much, if at all, at that time. It was not published until 1636;

a response to Bellarmine's Letter to Foscarini. This was never published in Galileo's lifetime and he does not appear to have sent copies to anyone;

a long letter to Cardinal Alessandro Orsini containing a discourse on the tides, which Galileo had set down in writing at the Cardinal's request;

much of his correspondence for the year 1615. Some of this is also contained in volume 5 of the Edizione Nazionale of his works.

• A round of lobbying in person in Rome at the end of 1615 and beginning of 1616 in an attempt to clear himself of suspicions of unorthodoxy and to stave off an anticipated condemnation of Copernicanism.

With the exception of the less important items of correspondence, English translations of all the above-mentioned writings have been given by Stillman Drake in Discoveries and Opinions of Galileo and Maurice Finoccharo in The Galileo Affair--a documentary history. I have read them all, and not one of them contains any claim by Galileo that the evidence for Copernicanism is conclusive, let alone that it was an "indisputable truth." Neither have I seen this claim made in any other works by professional Galilean scholars that I have read, including Stillman Drake's Galileo at Work: His Scientific Biography and Galileo: A Very Short Introduction, Michael Sharratt's Galileo--Decisive Innovator and Richard Blackwell's Galileo, Bellarmine, and the Bible.

"... resulted in his first condemnation of 1616 ..."

Neither Galileo himself nor any of his works were condemned in 1616. He was merely warned that the Inquisition had determined that heliocentrism was false and contrary to Scripture and that as a consequence he could not hold or defend it. It is possible (or perhaps probable—there is much controversy over this point) that he was also served with a formal injunction not to teach it "in any way whaterver, either orally or in writing".

" ... according to which he was to present the heliocentric model as being only an hypothesis. ..."

This is at least misleading because of the ambiguity of the word "hypothesis" as it was understood at the time. The decision of the Inquisition meant that the only way Copernicanism could be discussed that would be acceptable to the Church was as a convenient mathematical fiction that was nevertheless false.

"The publication of his Dialogue Concerning the Two Chief World Systems was judged in 1633 to be an infringement of the 1616 court decision,..."

There was no "court" case in 1616. During 1615 the Inquisition investigated two complaints against Galileo, but found insufficient evidence to charge him with anything. As a consequence of its investigations (and perhaps other incidents) the Congregation of the Index issued the edict in which Copernicanism was condemned. —David Wilson (talk · cont) 16:37, 30 September 2007 (UTC)

It seems to me that the two inquisition decisions are presented as though the church wanted to defend the Ptolemaic system, which is at best hasty presentation, and probably a POV construction, justifying my "bold" modifications.

As I understand it, the sketch is (1) Galileo had a very high idea of himself (he could, of course) and was very polemical in his defending the Copernican views, which upset his opponents. (2) Ptolemaic oriented scholars being reduced at quia magister dixit, transfered the (scientific and scholar) debate in the theological field by backing the Ptolemaic system on its coherence with the scriptures. (3) The church (inquisition) being asked to investigate a charge of heresy, had to give an answer by examining both the cosmology and the theology. (4) Bellarmino examined the Copernican cosmology and concluded (correctly) that it was indeed useful for practical usage, but not backed by a decisive proof. (5) The 1616 decision therefore ordered Galileo to present Copernican theory as an hypothesis (under prison penalty), and warned him that this theory contradicted the literal meaning of scriptures. (6) The dialogue publication 17 years later was both a POV presentation of the Copernican theory, and felt as an insult by the pope (up to then his protector): the 1616 threat was applied, and Galileo sentenced to prison (which the pope immediately changed to assigned residence).

Indeed, the distinction between "truth", "error" and "working hypothesis" is a modern one, and the way inquisition formulated it is black-and-white (quite normal for Dominicans, btw ;o): since Copernican views have not been proven "true", they were to be considered "false" - in-between status was apparently nonexistent at that time; but the prohibition had been not to teach them as being true, which was the best they could formulate it. These reflections on what is Truth and what is certain and what is proven in science and philosophy lead to Cartesianism, btw, so in its very special way, the Galileo affair has also been very beneficial to science...

The big picture, as I understand it (by reading the article, mostly), is that the church was involved in a scholar dispute, first issued a moderate decision in 1616, and then sanctioned Galileo for not respecting it in 1633. This clearly shows the problem of having an interference between research and juridical sanction, but for the Catholic church it was not a problem of faith per se (Bellarmino was open-minded and ready to accept a decisive proof, had Galileo presented one)- the link between faith and cosmology was made by scholars because of scholar disputes, not the other way around, and presenting it as an opposition "of the Church" (as an institution, because of catholic dogmas) seems POV and not backed by facts.

Galileo went twice before the inquisition, and in both cases, the real question is: what was the charge? Inquisition could not care less about Copernicus or Ptolemy, this was outside its jurisdiction. IMHO, the first 1616 charge had been statements about "truth" that could be interpreted as challenging the faith, and the second 1633 charge was simply not to respect the 1616 decision - a kind of "contempt of court", hence the expression.

Now, there is no reason of course to upset the equilibrium of the article. The 1616-1633 affairs can be introduced in the main article, and detailed in the Galileo affair one, no problem. Feel free to correct me - English not being my native language, I won't object to corrections anyway ;o) and I must take time to read the links you provided. Michelet-密是力-Me laisser un message 06:53, 1 October 2007 (UTC)

Michelet wrote:

It seems to me that the two inquisition decisions are presented as though the church wanted to defend the Ptolemaic system, ...

If you can put your finger on exactly what it is in the article that gave you this impression then it definitely needs to be corrected, since it is certainly false that the Church "wanted to defend the Ptolemaic system". I am however completely baffled as to what could have given you that impression. The Ptolemaic system is only mentioned twice in the article—once (slightly inaccurately) as a target of Galileo's opposition after his discovery of the moons of Jupiter, and a second time as making incorrect predictions about the phases of Venus. I can't see how either of those references implies that "the church wanted to defend the Ptolemaic system."

Neither does stating the fact that the Church banned Copernicanism in 1616 at all imply that it wanted to defend the Ptolemaic system. The decree of the Congregation of the Index which instituted the ban merely described the "false Pythagorean doctrine ... that the earth moves and the sun is motionless" as "altogether contrary to Holy Scripture". Thus any physical theory that was both heliodynamic and geostatic would have been acceptable to the Church. At the time there were at least two other of these available besides the Ptolemaic—namely, Tycho Brahe's geoheliocentric theory and the Eudoxan/Callipan/Aristotelian theory of concentric spheres.

... presenting it as an opposition "of the Church" (as an institution, because of catholic dogmas) seems POV and not backed by facts.

The earlier lead of the article did not claim or imply that the Church's opposition to heliocentrism was "dogma". It stated, quite correctly, that in 1616 the Church had condemned Copernicanism as contrary to Scripture. The decision to do so was taken at a meeting of the Inquisition presided over by the Pope on February 25th, 1616, and promulgated by the Congregation of the Index on March 5th. These events and their consequences are copiously documented in any number of good secondary sources by eminent experts on the history of the affair (the collection of articles in McMullin (2005) for example). Your objection to this wording appears to be based either on misinformation or original research.

Since the earlier lead was concise and accurate, and the current one is not, I have now restored a slightly amended version of the earlier one with citations to two reliable modern secondary sources. If you wish to alter the wording again, please discuss it here first.

—David Wilson (talk · cont) 20:00, 1 October 2007 (UTC)

Your formulation of the lead is incorrect and unfortunately leads to a POV presentation: "the Catholic Church's prohibiting the advocacy of heliocentrism as potentially factual, because it considered this contrary to Scripture" exactly means that the reason of Galileo's problem is that the catholic church condemns a scientific theory because it is contrary to the scriptures - which is POV and has not been the case. Please check the documents of the Galileo trial (available in the reference I provided and you supressed), not second-hand interpretations (like the one in the reference you preserved), which are potentially biaised. Michelet-密是力-Me laisser un message 06:40, 2 October 2007 (UTC)

Thank you for your restraint in your last edits of 16:31, October 2. While the wording is not quite as tight as I would like, it is at least accurate and reasonably concise.

I'm afraid I am having trouble following how you arrive at your conclusion that what I wrote was not NPOV. The statement which I had placed in the lead represents a POV shared by a large number of experts in the subject, two of whom I cited. I know of no expert on the subject who would disagree with it (please feel free to cite one, if you know of any). That you disagree with it is irrelevant. You are of course perfectly entitled to include contrary POVs in the article if you can provide reliable authorititave secondary sources to show that they are held by a significant number of experts (or even just a single prominent expert) in the subject. You are not entitled to delete or modify a properly attributed and documented significant POV simply because you disagree with it.

I am quite familiar with the documents in the web-site you linked to. As I have already mentioned above, I have actually read the whole of the book of Finocchiaro's from which they have been extracted. I am completely baffled as to why you think any of those documents contradict the claim that the reason the Church condemned Copernicanism was because it regarded heliocentrism as contrary to Scripture. Let's look at the text of some of those documents (bolding mine):

From the Consultants' report on February 24th, 1616

"(1) The sun is the center of the world and completely devoid of local motion.

Assessement: All said that this proposition is foolish and absurd in philosophy, and formally heretical since it explicitly contradicts many places the sense of Holy Scripture, according to the literal meaning of the words and according to the common interpretation and understanding of the Holy Fathers and the doctors of theology"

Now this is merely an advisory opinion of the Consultants, which the Church was free to accept or reject as it saw fit. However, on the following day a meeting of the Inquisition presided over by the Pope did accept a slightly watered down version of this report and required that Galileo be officially warned of the consequences of that decision (see the Inquisition Minutes of February 25th). One of these consequences was a an official decree of the Congregation of the Index which read in part:

"This Holy Congregation has also learned about the spreading and acceptance by many of the false Pythagorean doctrine, altogether contrary to the Holy Scripture, that the earth moves and the sun is motionless, which is also taught by Nicholaus Copernicus's On the Revolutions of the Heavenly Spheres and by Diego de Zuniga's On Job. .... Therefore, in order that this opinion may not creep any further to the prejudice of Catholic truth, the Congregation has decided that the books by Nicolaus Copernicus ... and Diego de Zuniga ... be suspended until corrected; but that the book of the Carmelite Father Paolo Antonio Foscarini be completely prohibited and condemned; and that all other books which teach the same be likewise prohibited, according to whether with the present decree it prohibits, condemns, and suspends them respectively."

In the certificate Bellarmine gave to Galileo on May 26th he describes the officially mandated warning which he gave to Galileo in these terms:

" .. he has only been notified of the declaration made by the Holy Father and published by the Sacred Congregation of the Index, whose content is that the doctrine attributed to Copernicus (that the earth moves around the sun and the sun stands at the center of the world without moving from east to west) is contrary to Holy Scripture and therefore cannot be defended or held."

And from the Inquisition's sentence of Galileo on June 22nd 1633:

"Furthermore, in order to completely eliminate such a pernicious doctrine, and not let it creep any further to the great detriment of Catholic truth, the Holy Congregation of the Index issued a decree which prohibited books treating of such a doctrine and declared it false and wholly contrary to the divine and Holy Scripture.

"And whereas a book has appeared here lately, printed in Florence last year, whose inscription showed that you were the author, ... , the said book was diligently examined and found to violate explicitly the above-mentioned injunction given to you; for in the same book you have defended the said opinion already condemned and so declared to your face, ..."

On the face of it seems to me that these documents are completely consistent with the claim that the Church did condemn Copernicanism on the grounds that it was contrary to Scripture, and, as I have already said, I am completely baffled as to why you would think otherwise.

But in any case, these documents are translations of primary sources. Conclusions based on the interpretation of such sources are required by Wikipedia policy to be supported by reliable secondary sources.

- which is POV and has not been the case.

How do you know it "has not been the case"? So far you have presented no evidence except your own unsupported and completely baffling interpretation of a small selection of primary sources.

... not second-hand interpretations (like the one in the reference you preserved), which are potentially biaised.

Any sources are "potentially" biased. I see no reason to accept your otherwise unsupported and completely baffling interpretation of a small selection of primary sources, when it contradicts a large number of very good secondary sources by experts on the subject. I gave secondary sources because the statement which they were supporting can only be justified by synthesis and evaluation of a large number of facts derived from primary sources, which is exactly what these secondary sources do. Sources cited in support of such statements are required by Wikpedia policy to be reliable secondary sources. The authors of the cited sources are Michael Sharratt and Ernan McMullin, both widely acknowledged experts on Galileo. They are also both Catholic priests, so I see no reason to cast aspersions on their knowledge of the motives and actions of the Catholic Church.

—David Wilson (talk · cont) 17:43, 2 October 2007 (UTC)

Hi, David,

The evidence is, for instance, in the very quotations you gave: "this proposition is foolish and absurd in philosophy, and formally heretical since it explicitly contradicts many places the sense of Holy Scripture, according to the literal meaning of the words and according to the common interpretation and understanding of the Holy Fathers and the doctors of theology". Just read it, emphasis should not only be on the points that attract your attention. What do they say? Three very different things.

• First, "this proposition is foolish and absurd in philosophy", which must probably be understood as "natural philosophy" at that time. This relates to the problem that Galileo's propositions were unconfirmed and insufficiently backed by decisive evidence - which is was factual at that time, and remained so for two centuries - no decisive proof. In other words, there was no "reason" to adhere to the Copernican system given the available data, and given the commonly accepted cosmology.
• Second, "it explicitly contradicts many places the sense of Holy Scripture, according to the literal meaning of the words" which is once again factual, and can of course still be verified. The word "literal" is important, since it is a long established tradition (in catholic Bible studies) to distinguish different level in scripture interpretation. The literal meaning of scriptures could be reinterpreted in view of factual evidences (as Bellarmino -inquisitor, but also cardinal, saint, doctor of the Church...- commented), as long as there was a reason to do so - but point 1 was, there was not such reason at that time.
• Third, "this proposition is [...] formally heretical". Indeed: if someone pretending to be a catholic goes on suggesting that what is written in the scriptures is false, and is not backed by good (scientific) reasons to do so, the possible reason might be that the argument is in fact used in the theological field, to back some kind of theological contest - this is the definition of an heresy. But they did not even admit that it was heretical, just stated that the form of it was - it could, indeed, be interpreted as a sign of heretical intends. This justified indeed that inquisition examined the case (which was the question they had to answer), otherwise it would just have been yet another dispute between scholars. This statement is essentially correct, though it would be judged as far-fetched in present times (and the "formally" term suggests it was felt far-fetched even at that time). But please note the justification given: once the assessment on cosmology has been made and inasmuch as the theory appears to be not reasonable, then (only) the question of heresy becomes legitimate and may be answered (concluding it is formally heretical, given the context).

You can do exactly the same analysis, for instance, on the text of Galileo's retraction, or on most of the documents of the Galileo affair.

Now, if you account for that decision by saying "the Catholic Church's prohibiting the advocacy of heliocentrism as potentially factual, because it considered this contrary to Scripture", two important points are omitted in the Church's judgment - the first, and the third. By omitting the first point, the Church is presented as neglecting evidence to preserve the scriptures, which is ridiculous (obscurantism, and so on). By omitting the third, the Church is presented as arbitrarily interfering in scientific debates with no reason (arbitrary,...), when there was a very logical (and legal) reason to do so. (And as to the second point, omitting the "literal" precision suggests the Church considers the literal sense only, like fundamentalists would, which has never been the case). In both cases, a POV presentation of the Church's position is favored - hence my criticism.

This POV may be shared by a number of experts - who cares? It is still POV, detrimental for the Church, and not backed by factual evidence - so this has not its place on wikipedia, and let's have a NPOV presentation of the case, according to local policies. Though you may want, of course, to sate that "the idea that Galileo was condemned by the church because he endangered the literal reading of the scriptures" has been widely spread amongst scholars. Good point, and obviously factual - but then, why was such a false opinion so widespread? Make your guess. This may justify a section of its own, but it would probably be attacked under the "no personal work" rule, so... ;o) best to have a break on that.

Michelet-密是力-Me laisser un message 22:03, 2 October 2007 (UTC)

Ex cathedra

The doctrine of papal infallibility / speaking ex cathedra wasn't defined until the First Vatican Council in the 19th century, and as such, I'm removing it from the article (as it would've had no impact on Galileo's teachings.)

--Falkan 23:06, 14 October 2007 (UTC)

Vandalism

 There is so much vandalism in the Galileo article that it should be at least semi-protected. —Preceding unsigned comment added by 81.149.255.133 (talk) 10:53, 15 October 2007 (UTC)

Previous semi-protection was lifted on October 8th. I have now requested that it be reimposed.

—David Wilson (talk · cont) 14:51, 16 October 2007 (UTC)

Request for assistance

there is information about Galileo also in Zaza language however in would list sees one not please assistance...

http://diq.wikipedia.org/wiki/Galileo_Galilei

I legend vilen now thanks for its assistance. A Zaza. —Preceding unsigned comment added by 62.245.207.18 (talk) 18:57, 21 October, 2007 (UTC)

Done (I think—assuming I have correctly understood the request).

—David Wilson (talk · cont) 16:25, 21 October 2007 (UTC)

Banning of Sidereus Nuncius

We say:

• He was formally rehabilitated in 1741, when Pope Benedict XIV authorized the publication of Galileo's complete scientific works (a censored edition had been published in 1718) ... ’’.

Did this "complete" publication include Sidereus Nuncius? I have a reference that says it was banned from 1616 until 1822. I have no idea what was special about 1822, and the book’s own article doesn’t shed any light. -- JackofOz 02:21, 22 October 2007 (UTC)

1822 probably refers to an edition of the Index Librorum Prohibitorum. —Preceding unsigned comment added by 87.194.4.21 (talk) 09:36, 22 October 2007 (UTC)

The 1616 date is certainly nonsense, and I strongly suspect the 1822 date is too. None of Galileo's works was banned, censured or censored^{[see correction below]} in any way until after his trial in 1633. At that time the Dialogue was listed in the Index as being absolutely prohibited (unlike Copernicus's De Revolutionibus of which appropriately censored versions were not prohibited). The Inquisition also issued an order prohibiting everything Galileo had ever written, or would write in the future, from being printed or reprinted. As I understand it, this would not have prohibited Catholics from owning or reading previously printed copies of those works, as would have been the case if they had been placed on the Index.

Judging from Coyne's description in McMullin (2005, p.347), the edition of Galileo's works approved by Benedict XIV did indeed include Sidereus Nuncius. He writes:

The imprimatur of Benedict XIV was granted under the condition that the stipulations of the Paduan Inquisitor, who had requested the imprimatur, be observed. The result was that the publication in 1744 of the "complete works" had to exclude the Letter to Christina and the Letter to Castelli. Furthermore, the Dialogue had to be printed in volume 4, accompanied by the 1633 sentence and the text of Galileo's abjuration, and it had to contain a preface emphasizing its "hypothetical" character.

What happened in 1822 was that Pope Pius VII granted an imprimatur (i.e. permission to print) to a work by a Catholic Canon, Giuseppe Settele, which treated heliocentrism as a physical fact rather than a mathematical fiction, was published, after having been granted an imprimatur (i.e. permission to be printed) by Pope Pius VII two years earlier. This effectively ended the Catholic Church's opposition to heliocentrism—although the Dialogue and De Revolutionibus nevertheless remained on the Index until it was next revised in 1835.

The assertion that Galileo was "formally rehabilitated in 1741" is at least a non-NPOV exaggeration, in my opinion, and should be revised. George Coyne, for instance, in the article of his mentioned above, criticizes claims of such an early "rehabilitation" of Galileo by the Church as inaccurate.

—David Wilson (talk · cont) 19:03, 22 October 2007 (UTC)

Correction

Above, I wrote:

None of Galileo's works was banned, censured or censored in any way until after his trial in 1633.

In saying that none of Galileo's works was censored in any way, I was thinking only of post-publication censorship. However, before any works could be published in Catholic countries in Galileo's time they had to be submitted to a censor for approval. Galileo was required to make changes to both his Letters on Sunspots and his Dialogue before the censors would give him permission to publish them. So at least some of his works were in fact "censored" before his trial. —David Wilson (talk · cont) 15:15, 4 November 2007 (UTC)

Galilei singing songs for timing?

"For measurements of particularly short intervals of time, Galileo sang songs with whose timing he was familiar." I've heard of this theory, but I understood that it was only a theory, with little other evidence than that we don't know how he did those measurments so accurately. There should at least be a citation, or I will add to the article that this is a theory. Ornilnas 20:21, 28 October 2007 (UTC)

I don't have the reference, but I recall reading this in either Physics Today or The Physics Teacher as something that he mentioned in private correspondence. I agree it should have a citation. And the point is not so much that the timing is familiar, as that anyone with musical training can sing a song so that it has a consistent timing, thus being able to arrive at distance being proportional to the square of time. I have tried this with undergraduate physics classes, and the results are generally quite accurate.--SarahLawrence Scott 20:10, 3 November 2007 (UTC)

Stillman Drake's account on pages 88 and 89 of Galileo at Work strongly suggests that Galileo's purported use of musical rhythm to equalise short intervals of time, though reasonably plausible, is nevertheless no more than conjecture. He writes: "Galileo's procedure, as I reconstruct it, was this" (emphasis mine), and then proceeds to explain how he believes Galileo might have conducted his experiments. Immediately before this reconstruction he argues that by using this method Galileo could easily have specified time intervals which differed by no more than 1/64th of a second. In an end note he refers to experiments performed independently by himself and another colleague which apparently support his argument.

A telling observation, though, is that Drake cites no primary source in which Galileo is known to have mentioned this procedure—which he surely would have done if he had known of any. I would therefore be very wary of any claim that Galileo himself had described the procedure, unless the claimant were to provide a specific verifiable reference to some primary source where he did so.

—David Wilson (talk · cont) 14:41, 4 November 2007 (UTC)

This idea that Galileo would use music in his experiments with great success is supported (but not by any means proven) by the fact that his father was a learned musician.68.8.219.254 (talk) 18:03, 3 March 2008 (UTC)

Citation for "bell and ball" label

The article includes the following:

However, Galileo did perform experiments involving rolling balls down inclined planes, one of which is in Florence, called the bell and ball experiment

There should be a citation for this terminology. I'm not sure what specifically it's referring to, and have been unable to find references to a "bell and ball" experiment on the web other than those that seem to be derived from this Wikipedia entry. --SarahLawrence Scott 20:03, 3 November 2007 (UTC)

I suspect "bell and ball experiment" refers to an exhibit in the Institute and Museum of the History of Science in Florence. According to the description of the exhibit, it was constructed in the early nineteenth century and "[n]o documents survive proving that Galileo performed this specific experiment." It's possible that the editor responsible for the text in the article did not mean to imply that Galileo had carried out that specific experiment himself, although that certainly seems to me to be the most natural way to read it. But since the reference to the experiment seems to me to serve no useful purpose anyway, I shall delete it.

—David Wilson (talk · cont) 13:30, 4 November 2007 (UTC)

Odd

The words "His relevance" have appeared in the main article. It would be very odd if a Wikipedia article were written about an irrelevant person. —Preceding unsigned comment added by 87.194.4.21 (talk) 09:56, 5 November 2007 (UTC)

Indeed it would. However, I'm afraid I don't see the point of this observation. For a section devoted to explaining Galileo's significance in the history of science the heading "His relevance" seems entirely reasonable to me, although I think "His significance" would be more apt. I would query have no problems with the creation of this section, however, on the grounds that but the material it contained was written specifically for the lead (from which it was removed), and that still seems to me to be the proper place for it. —David Wilson (talk · cont) 15:20, 7 November 2007 (UTC)

The editor involved seems to be interested in the Galileo article for unscientific reasons. —Preceding unsigned comment added by 87.194.4.21 (talk) 09:33, 7 November 2007 (UTC)

Please assume good faith on the part of other editors rather than speculating about whether they might be harbouring questionable motives. I intend to invite the editor responsible for this change to come here and discuss it. Before I do, however, I suggest that the discussion will be much more likely to reach a mutually satisfactory conclusion if you were to delete the above comment. If you do so, I will in turn delete this one of mine (or you can do it yourself if you wish, provided you delete your own at the same time).

—David Wilson (talk · cont) 15:20, 7 November 2007 (UTC)

I have commented out this heading for the time being to discourage edits which might make the text unsuitable for putting back into the lead. —David Wilson (talk · cont) 13:59, 8 November 2007 (UTC)

Why is he called by his first name?

How did Galilei come to be known by his first name? We don't refer to Newton as 'Isaac' or Huygens as 'Christiaan'. Just wondering. --Chetvorno^TALK 09:36, 22 November 2007 (UTC)

Important Italians were referred to by their first name only. —Preceding unsigned comment added by 87.74.1.47 (talk) 15:12, 24 November 2007 (UTC)

Thank you, sir. --Chetvorno^TALK 08:35, 24 May 2008 (UTC)

E pur si muove

I nearly went crazy trying to remember what it was that Galileo supposedly said after being forced to renounce the Copernican system. I think it's interesting and makes him seem like less of a cop-out for rolling over as the Church demanded. It gives him a nice "begrudged old man" feel, I suppose, which made him interesting to me.

Since it's not exactly proven to be true, I figured I shouldn't just throw it on there, but I think it should be place at the end of the discussion of his trial. —Preceding unsigned comment added by Circuitries (talk • contribs) 18:17, 23 November 2007 (UTC)

See E pur si muove!, I'm not sure that we should have legends in the article, whether or not it gives us a nice feeling. I suppose there maybe a case for mentioning it, if only to discount it, as it's such a well-known supposed quote. Mikenorton (talk) 18:27, 23 November 2007 (UTC)

Diagramma della Verità

Galileo's book Diagramma della Verità (meaning Diagram of Truth) was a secretive work of scientific facts that was too explosive to share with public then. It was smuggled out of Italy and published in Holland. Only one copy has survived (in the Vatican Archives) till date after the book-burning orgy of the Church. —Preceding unsigned comment added by 172.215.212.158 (talk) 08:00, November 28, 2007

From a google search, it would appear that Diagramma della Verità is a completely fictional work invented by the best-selling author Dan Brown in his novel Angels and Demons. At any rate, it's not a work that seems to be known to any professional Galileo scholars whose works I have read. For any Wikipedia article to treat it as if it were a real work by Galileo, a much more reliable source than Angels and Demons would be needed.

—David Wilson (talk · cont) 14:47, 28 November 2007 (UTC)

Ja'far al-Sadiq

Jafar was the pioneer of heliocentric theory in late 8th century refuting Ptolemy. Galileo merely built on his work eight hundred years later. —Preceding unsigned comment added by 172.207.208.120 (talk) 20:52, 11 December 2007 (UTC)

172.207.208.120 seems to have over-looked Pythagoras and Aristarchos of Samos. —Preceding unsigned comment added by 87.194.4.21 (talk) 10:07, 12 December 2007 (UTC)

The single source cited in the WP article Ja'far al-Sadiq in support of the claims about al-Sadiq's supposed scientific discoveries appears to be a self-published work. If the extracts quoted on this web-site are accurate, it also makes many completely unsourced exceptional claims, several of which would seem to disqualify it from being considered a reliable source. To cite just one, it asserts that al-Sadiq "refuted" the theory of geocentrism at age 11, and the argument against geocentrism which it attributes to him is nonsensical. Given that al-Sadiq appears to have been a highly respected Islamic scholar, it doesn't seem likely that he would have proposed such an obviously fallacious argument as a refutation of the then universally held notion of geocentrism.

The source purports to be an English translation from a Persian (presumably Farsi) translation of a French original, claimed to have been a "thesis" published by a "Research Committee", variously described as being eiher "of Strasbourg" or "of Strasbourg University". I would remain highly sceptical of these claims until someone can provide a traceable citation of the supposed French original.

—David Wilson (talk · cont) 14:39, 12 December 2007 (UTC)

Galileo wasn't the first to propose heliocentrism; as was mentioned above, it was proposed in Greece around the time of Ptolemy, if not before. The difference is that Galileo supported the theory by science, while the earlier ones were just unsupported speculation.

Also, "built on" implies that Galileo was aware of the work of Jafar. Is there any support for that claim? If not, it would be better to say that he "independently developed" the theory. But again, that ignores the crucial difference between philosophizing and scientific analysis. Paul Koning (talk) 15:30, 12 December 2007 (UTC)

As far as I know Galileo only mentions Aristarchus and Copernicus as the inventors of heliocentrism. In my opinion it would be better not to say that Ja'far developed heliocentrism at all (either independently or otherwise)—unless a reliable source can be found to support the claim that he did in fact do so. He is not mentioned in J.L.E. Dreyer's A History of Astronomy from Thales to Kepler or C.M.Linton's From Eudoxus to Einstein, both of which contain extensive material on Islamic astronomy. —David Wilson (talk · cont) 17:28, 12 December 2007 (UTC)

Image of phases of Venus

None of the browsers I have on my computer would display the previous version of the image of the phases of Venus (Phases-of-Venus2.svg), so I have replaced it with Phases-of-Venus.svg, which is displayed properly by the browsers I have. I was unable to work out why the latter version displays properly while the former doesn't, but it may be something to do with the fact that all of the browsers I have are now getting pretty long in the tooth.

The phases of Venus, observed by Galileo in 1610

Before the image is reverted back to the former version, it might be worth checking how many Wikipedia readers have the same problem. If your browser displays nothing but duplicate copies of the text "The phases of Venus, observed by Galileo in 1610" in the box on the right please indicate this below.

—David Wilson (talk · cont) 14:47, 16 December 2007 (UTC)

The phases of Venus, observed by Galileo in 1610

I keep getting bugs with Inkscape. Or was an insomniac operator headspace problem?

A jpg seems to be working.

—Preceding unsigned comment added by Sagredo (talk • contribs) 05:36, December 17, 2007

Yep, the jpg displays just fine in my browser. Thanks for all your work on the image---I like it much better than the original. However, I'd like to suggest one small improvement. Blotting out the earth has resulted in a large dark space being left below Venus's orbit. I think the image would be improved if most of this were to be cropped so that just enough space is left for the "not to scale" message to fit comfortably. Alternatively, you could just put the earth back in. I don't have any particularly preference for either of those alternatives.

—David Wilson (talk · cont) 01:39, 17 December 2007 (UTC)

Scrub that. On viewing the image with a decent monitor, I see that the earth's still there. Unfortunately, the contrast between dark colours on the ancient monitor I have on my home computer is so poor that the earth (and the writing--except for the "not to scale" notice in the full-size version) is totally invisible. —David Wilson (talk · cont) 05:16, 17 December 2007 (UTC)

Date Ambiguity

Page has "In the week of January 7, 1610 Galileo discovered three of Jupiter's four largest satellites (moons): Io, Europa, and Callisto.".

In the USA, the week is held to start on Sunday. The ISO 8601 week, used internationally, starts on Monday. Others have other weeks.

The exact dates should if known be given.

Also, for dates between 1581 and 1753 at least, dates need also a statement of whether Julian or Gregorian.

82.163.24.100 (talk) 15:50, 16 December 2007 (UTC)

Film about Galileo's trial

There is an esthetically and intellectually outstanding film about Galileo's trial. I do not want to mess with this good article, but I suggest to a leading author to see this film and to add a reference to it. From the French version of the article:

2005 : Galilée ou l'amour de Dieu de Jean-Daniel Verhaeghe avec Claude Rich dans le rôle de Galilée et Jean-Pierre Marielle dans celui du pape Urbain VIII.

The film is in French and I do not know an English version of it, yet for many that should no be a barrier.

--Lupo Manaro (talk) 16:31, 26 December 2007 (UTC) Films are basically fiction and not an original source. —Preceding unsigned comment added by 87.194.4.21 (talk) 09:27, 27 December 2007 (UTC)

Ratzinger

The part on the Feyerabend quote might be inaccurate. According to the Italian Wikipedia article, Ratzinger actually went on to criticize Feyerabend. This is not mentioned in this article, giving the impression that Ratzinger endorsed Feyerabend's view. If the Italian Wikipedia is correct, then quite the opposite is true. --87.8.61.190 (talk) 20:16, 22 January 2008 (UTC)

It is quite true that Ratzinger did not endorse Feyerabend's views in his speech. I had tried to disabuse readers of that impression by rewording the original text, and adding the following remarks at the end:

The Cardinal did not clearly indicate whether he agreed or disagreed with Feyerabend's assertions. He did, however, say "It would be foolish to construct an impulsive apologetic on the basis of such views".

but if the reader still gets an impression that Ratzinger was endorsing Feyerabend's views, then obviously the text needs further work. Can you put your finger on precisely what it was that gave you the impression?

I disagree with the claim that Ratzinger specifically criticised Feyerabend's views. He opens the section of his speech labelled "Crisis of the Faith in Science" in the printed English version with the following words:

The resistance of creation to its manipulation by men has become a new factor in the intellectual situation in the last decade. It is impossible to evade the questions of the limits of science and of the criteria it must follow. The change in the way in which the case of Galileo is evaluated seems to me characteristic of the change of climate.

He then goes on to say that in the eighteenth century the Galileo affair was elevated into "nothing less than the myth of the Enlightenment" with Galileo as the "victim of the medieval obscurantism in which the Church persists". He then cites Ernst Bloch, Paul Feyerabend, Carl Friedrich von Weizsäcker, and an anonymous interviewer as modern challengers of this view (without indicating either agreement or disagreement with any of them). He then winds up this section of his speech with the following remarks:

It would be foolish to construct an impulsive apologetic on the basis of such views; faith does not grow out of resentment and skepticism with respect to rationality, but only out of a fundamental affirmation and a spacious reasonableness; we shall come back to this point. I mention all this only as a symptomatic case that permits us to see how deep the self-doubt of the modern age, of science and technology goes today.

I see nothing there which seems to me to constitute a criticism of any of the specific views he had previously quoted. At best, there is a vague insinuation that some (or possibly all) of them were based on a rejection of rationality and therefore not soundly argued. But the conclusions of an unsound argument can nevertheless be true, and I can find nowhere in Ratzinger's speech where he seems to me to distance himself from any of the comments which he cites.

All the above English quotations from Ratzinger's speech are taken from Brian McNeil's translation from the German, cited in the article. Another English translation of this entire section of the speech can be found here (this translation appears to be from the Italian edition).

—David Wilson (talk · cont) 07:28, 23 January 2008 (UTC)

Thank you for the detailed discussion. I think the current version of the article is much clearer. --82.60.157.60 (talk) 19:31, 26 January 2008 (UTC)

Popular Culture

This isn't a massive point, and I'd do it myself, but the page has been locked. The German power metal band Blind Guardian did a song called Age Of False Innocence off their album A Night At The Opera which was about Galileo. Sky God94 (talk) 22:45, 17 February 2008 (UTC)

Galileo not contrary to Aristotle: Proposed Edit

The article currently claims

"A biography by Galileo's pupil Vincenzo Viviani stated that Galileo had dropped balls of different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass (excluding the limited effect of air resistance). This was contrary to what Aristotle had taught: that heavy objects fall faster than lighter ones, in direct proportion to weight."

But contrary to what the article currently claims, Aristotle did not claim that the time of descent through any given distance in gravitational free-fall in a vacuum would be proportional to their weight (W), but rather that it would be independent of their weight and the same for all bodies, namely instantaneous i.e infinite speed. (See Physics 215af [Corrected from erroneous 225a--Logicus (talk) 14:37, 29 February 2008 (UTC)]) This was because in Aristotle's dynamics bodies have no inherent resistance to their motion, other than their gravity in the special case of sublunar bodies in cases of their violent motion i.e. anti-gravitational motion such as projectile motion. Thus in gravitational fall, which is driven by gravity, if there were no external resistance due to any medium, such as air or water, for example, the total resistance R = 0, and thus speed must be infinite given Aristotle's mathematical law of natural motion that average speed v @ W/R, which becomes v @ W/0 in the case of free-fall, whereby v is infinite. ('@' = 'is proportional to' here.)

But this conclusion was subsequently avoided by Philoponus's rejection of Aristotle's law and his replacement law v @ W - R, whereby v @ W when R = 0 and so is proportional to weight. (It was also alternatively avoided by Aquinas's alternative Averroist solution, according to which all bodies have an inherent non-gravitational resistance to all motion proportional to their mass (m), which resistance came to be called 'inertia', and so whereby v @ W/R becomes v @ W/m in pure free-fall without any other resistance to motion, where m > 0, and so whereby its average speed is not infinite.

Thus, as is evident from the literature, the sin of Philoponus is mistakenly attributed to Aristotle in such claims as made here.

I provisionally propose the italicised sentence be replaced by the following:

'This was contrary to what Philoponus had taught, that in a vacuum heavy objects would fall faster than lighter ones, in direct proportion to their weight, and in accordance with the Aristotelian view that in a vacuum all bodies would fall with the same speed.' --Logicus (talk) 15:41, 24 February 2008 (UTC)

I think you must mean 215a, rather than 225a. But Aristotle clearly states that, in a vacuum, nothing could move at all. Given that an object's place is defined as the innermost surrounding surface of whatever contains it, an object in a vacuum, being contained by nothing at all, would not have a place at all, and hence could not be subject to a change of place, i.e. to a local motion. Aristotle did not postulate mathematical laws at all, so you really can't speculate about what speed would result from dividing a quantity by zero, especially when he already gives you the answer: "not a single thing can be moved, if there is a void" (214b31). Motion is only possible because there isn't a void; and then, in actual cases of motion, Aristotle maintains that the speed will be determined jointly by the resistance of the medium and the object's weight: "We see the same weight or body moving faster than another [...] because, other things being equal, the moving body differs from the other owing to excess of weight or lightness" (215a25-28). So a heavier body in the same medium will indeed fall more quickly. Hce1132 (talk) 16:13, 24 February 2008 (UTC)

Logicus to Hce: Thanks for pointing out Physics reference error, should have been 215a25f. Reject your other points later.--Logicus (talk) 19:16, 25 February 2008 (UTC)

I also don't understand Logicus's objection. Objects falling from the Tower of Pisa are falling through air (a resistant medium), so opinions about what happens in a vacuum would seem to me to be irrelevant anyway. As far as I can see, the objection would be completely met by replacing the final sentence of the text with something like:

"This was contrary to what Aristotle had taught: that heavy objects fall through a resistant medium faster than lighter ones in direct proportion to their weight."

—David Wilson (talk · cont) 22:55, 25 February 2008 (UTC)

Logicus to David Wilson: Thanks David, but your comment, "Objects falling from the Tower of Pisa are falling through air (a resistant medium), so opinions about what happens in a vacuum would seem to me to be irrelevant anyway." is surely a misreading of the sentence you refer to, for which what happens in a vacuum is the ONLY logically relevant comparison. Again the sentence says "...Galileo had dropped balls of different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass (EXCLUDING the limited effect of air resistance)", which presumably means 'to demonstrate that their time of descent was independent of their weight (excluding the limiting effect of air resistance and any other resistant medium).', and so is in effect to demonstrate what their time of descent would be in a vacuum, which excludes all resistant media. So in effect the sentence means '...to demonstrate that their time of descent in a vacuum would be independent of their mass.' Thus the only logically valid comparison is with what Aristotle predicted for the time of gravitational fall in a vacuum, which was that it would be instantaneous i.e. of infinite speed for all bodies of whatever weight.

But I now see my proposed edit overlooked the fact that it would then contradict the also mistaken claim of the last sentence of this whole paragraph that Philoponus maintained the time of gravitational fall is independent of weight, whereas he maintained it is proportional to specific weight or density, as did Benedetti and Galileo in his 1590 Pisan De motu, and as does modern physics in such as Stoke's Law for terminal speed of gravitational fall in a fluid medium. I fear the whole paragraph is quite mistaken and must be rewritten.

Perhaps the most important thing to grasp here is that Aristotle on gravitational fall in a fluid medium was essentially empirically right and vindicated by modern physics. Whilst I do not agree precisely with Major Hardcastle in Nature and Toulmin and that lobby that says Aristotle meant the terminal velocity in a fluid medium in claiming that in a plenum heavier bodies fall faster than lighter ones, nevertheless on Stoke's law he would still surely come out empirically right about the average speed of the whole motion from rest.--Logicus (talk) 19:18, 26 February 2008 (UTC)

Logicus to Hce1132 of 24 Feb: I comment on the remainder of your above claims re-quoted below with the following insertions in square brackets:

But Aristotle clearly states that, in a vacuum, nothing could move at all.

[ No, he deals with two different dynamical cases of motion in a void in Physics 4.8, namely natural motion in a vacuum with a natural place (i.e. gravitational fall in a vacuum) in 215a25f and unforced motion in a pure void even without any natural places in 215a19-22. He predicts the first would be infinitely fast or instantaneous, and the second would be endless or interminable. It is the second that is widely regarded by commentators as a statement of (what is most misleadingly known as) 'the law of inertia' or Newton's first law of motion, and was so regarded by Newton himself, who wrote:

"All those ancients knew the first law [of motion] who attributed to atoms in an infinite vacuum a motion which was rectilinear, extremely swift and perpetual because of the lack of resistance...ARISTOTLE was of the same mind, since he expresses his opinion thus …in Book IV of the Physics, text 69, [i.e. Physics 4.8.215a19] speaking of motion in the void where there is no impediment he writes: 'Why a body once moved should come to rest anywhere no one can say. For why should it rest here rather than there ? Hence EITHER it will not be moved, OR it must be moved indefinitely, UNLESS something stronger impedes it [My caps].' " [From one of Newton's Scientific Papers in The Portsmouth Collection, first published in Hall & Hall's 1962 Unpublished Scientific Papers of Isaac Newton.]

The fact that Aristotle regarded both endless motion and also instantaneous motion as oxymoronic or impossible is logically irrelevant to the fact that he endorsed the counterfactual conditional 'law of inertia' that 'if there were unforced motion in a void, then it would be interminable unless it met some impediment'.]

Given that an object's place is defined as the innermost surrounding surface of whatever contains it, an object in a vacuum, being contained by nothing at all, would not have a place at all, and hence could not be subject to a change of place, i.e. to a local motion.

[ Where does Aristotle state this argument ?]

Aristotle did not postulate mathematical laws at all,

[ No, rather he founded mathematical dynamics. Physics 7.5 (mathematical rules for the average speed of violent motions) and 4.8 are typically cited as its main locus. His general mathematical law of motion is traditionally summarised algebraically as v @ F/R, which becomes v @ W/R for natural motion in which gravitational (W)eight is the motor and v @ F/W for violent motion, in which (W)eight is the resistance. The positivist myth that Aristotle had no mathematical quantitative science - a key component of the 17th century Scientific Revolution mythology created by such as Koyre, Burtt and others in their extremely silly thesis that the mathematisation of nature was a historical novelty of the 17th century - was surely decisively scotched by Tom Heath's 1949 'Mathematics in Aristotle', and also see, for example, Hussey's 'Aristotle's Mathematical Physics: A Reconstruction' in Judson's 2000 'Aristotle's Physics' and Grant's 1996 'The foundations of modern science in the middle ages' e.g. p62 on his mathematical laws of dynamics, for example, although both of the latter two are also wrong on some key points in my view. (Drabkin's 1938 'Notes on the laws of motion in Aristotle' is an earlier classic. Dijksterhuis also.) The most illogical expression of this non-quantitative claim is to be found in the extreme positivist claim that 'Aristotle had no mathematical quantitative dynamics, but his (alleged) law that the average speed of gravitational free-fall is directly proportional to weight was refuted by the facts.' i.e. he had no mathematical dynamics and his mathematical dynamics was refuted.]

so you really can't speculate about what speed would result from dividing a quantity by zero,

[ I am not speculating. An infinite (i.e. unbounded) speed results, or as Aristotle expressed it, a speed 'beyond any ratio'. And this was also how his mathematical law of motion v @ F/R was historically interpreted, as evident in its major empirical problem being regarded by Philoponus and others as its prediction of the infinite speed of celestial motion because in the heavens F > 0 but R = 0, yet even the stellar sphere, the fastest of all, took 24 hrs to complete one revolution, rather than instantaneously.]

especially when he already gives you the answer: "not a single thing can be moved, if there is a void" (214b31). Motion is only possible because there isn't a void; and then, in actual cases of motion, Aristotle maintains that the speed will be determined jointly by the resistance of the medium and the object's weight: "We see the same weight or body moving faster than another [...] because, other things being equal, the moving body differs from the other owing to excess of weight or lightness" (215a25-28).

So a heavier body in the same medium will indeed fall more quickly.

[ As is also predicted by modern physics for two bodies of the same shape and size, such as by Stokes' Law for the terminal velocity of gravitational fall in a fluid medium, and as was also predicted by Philoponus, Benedetti and by Galileo in his Philoponan 1590 Pisan 'De Motu' ! ]--Logicus (talk) 19:16, 27 February 2008 (UTC)

Thank you for this. I would actually go along with the majority of what you say here: but I'm still not comfortable with your proposed edit. Partly because, like David Wilson, I'm inclined to feel that what may or may not happen in a vacuum is simply irrelevant to the case at hand. But partly also because your proposal strikes me as misleading. Strictly speaking, you might be right that Aristotle's opinion, that interminable or instantaneous motion is impossible, is logically irrelevant to that counterfactual claim about what would happen in a void (I'm not altogether certain that this is correct, but let's go along with it). But, rhetorically, the way you've phrased the proposed edit gives the impression that he believed such a thing could actually happen. That chapter of the Physics (as I presume you would agree) is designed as a sequence of reductio ad absurdums of the hypothesis of a void, resting precisely upon the impossibility of things like interminable or instantaneous motion. All this gets lost in your proposal, and, even though you're not actually saying it, I fear that a reader would come away with the mistaken impression that Aristotle believed not only that a void was genuinely possible but also that all bodies would fall in it with the same finite speed. Hce1132 (talk) 20:02, 28 February 2008 (UTC)

Logicus to Hce1132 (& Wilson): Thanks for your overall agreement Hce1132, and I mostly agree with what you say here. But first can I point out you seem to overlook that I have anyway already withdrawn my proposal because this whole paragraph of the article needs rewriting because of its crucial errors about Philoponus and Benedetti, who both maintained like Aristotle that speed of gravitational fall of a body in a fluid medium depends upon and increases with a body’s specific weight or density, which of course it also does according to modern physics, whereas the article gives the misleading impression this is somehow incorrect, which thus promotes lousy physics education with unscientific fairy tales.

Secondly, contrary to what you and Wilson say, what happens in a vacuum, that is, when air resistance is discounted as the article clearly says, is central to the comparison made. But the article currently comparfes chalk and cheese in respect of contrasting what Galileo allegedly predicted about gravitational fall DISCOUNTING ANY RESISTANCE, and which is thus free-fall in a vacuum, with what Aristotle predicted about fall in a fluid medium, rather than with his prediction for fall in a vacuum. Galileo predicted free-fall (i.e. gravitational fall in a vacuum) would be the same finite speed for all bodies independent of their weight, and Aristotle that it would be infinitely fast for all bodies independent of their weight, and Philoponus said it would be of finite speed and proportional to density or specific weight, or what he called their ‘natural’ weight. So my main point remains, that it was Philoponus’s dynamics, and in fact Galileo’s own 1590 dynamics, and not Aristotle’s as the article mistakenly claims, that Galileo was in disagreement with on the issue of whether the speed of fall in a vacuum is independent of weight or not. He later changed his own 1590 view that speed of fall in a vacuum is dependent upon specific weight to the view that it is the same for all bodies independently of their specific weight.

Thus Wilson’s proposed edit is wrong in making a dynamically invalid comparison because the article as currently framed here is concerned with comparing what Galileo predicted about the speed of gravitational fall when the effect of the resistant medium is discounted (i.e. note it says “EXCLUDING the limited effect of air resistance”) with what Aristotle predicted in the same circumstances, whereas Wilson’s proposed edit invalidly compares it with what Aristotle predicted about fall in a resistant media.

So instead of Wilson's

"This was contrary to what Aristotle had taught: that heavy objects fall through a resistant medium faster than lighter ones in direct proportion to their weight.", in which case Galileo would have been wrong and Aristotle right

[Logicus correction: Logicus’s claim here that Aristotle would have been right is wrong. In fact Aristotle was wrong here because although he was right that heavier objects fall faster through a resistant medium than lighter ones inasmuch as there is a monotonically increasing relationship between speed and specific weight, nevertheless their speed is not “in direct proportion to their weight” as he, Philoponus and Galileo 1590 claimed. --Logicus (talk) 21:30, 1 March 2008 (UTC)]

the edit should be

"This was contrary to what Galileo had taught at Pisa University according to his 1590 De Motu, namely, following Philoponus and contrary to Aristotle, that heavy objects would fall through a vacuum faster than lighter ones in direct proportion to their specific weight."

Clarifying the main problem here: Your quotation from Physics is of course actually the main evidence that Aristotle held to the modern view that the speed of gravitational fall of a body in a fluid resistant medium depends upon and increases with its specific weight or density. For as he says

“We see the same weight or body moving faster than another [...] because, OTHER THINGS BEING EQUAL, the moving body differs from the other owing to excess of weight or lightness" (215a25-28).”

Hence for all other things to be equal, the two bodies must therefore be of the same shape and size. Hence they can only differ in weight by virtue of being of different density or specific weight. This entails Aristotle is saying the speed of gravitational fall of bodies in a resistant medium increases with their specific weight or density. And modern physics agrees with him on this spercific point, as did Philoponus, Benedetti, and Galileo in his 1590 De Motu, if not with the claim that it is proportional to density.

It is most important to first get the elementary logic and physics of the dynamical situations being compared here right before we can possibly get the history of science right. The traditional problem here has been that historians of science have confounded these issues of scientific discovery with logical malcomparisons and bad elementary physics, such as logically malcomparing what Galileo predicted about gravitational free-fall with what Aristotle predicted about gravitational fall in a resistant medium, and then further mistakenly claiming Aristotle was wrong about the latter to boot, when in fact he was right on a modern physics analysis of the ilk behind Stoke's law, for example. This is all to create the false impression Aristotle was a mistaken fool as portrayed by Enlightenment-positivist historiography of science. (But if you turn to the Wikipedia article on Stoke's law, you will see that the terminal speed of fall in a medium must increase with the density or specific weight of the body that occurs in its numerator) --Logicus (talk) 15:52, 29 February 2008 (UTC)

Just a couple of points before (as someone who really doesn't relish disputes) I bow out. First, I don't see the relevance of modern physics, Stokes Law and such like. This article is about what Galileo and, in this instance, Aristotle believed to be the case, not about what actually is the case. Second, in establishing what they did in fact believe, that is of course the job of historians of science, and yet you seem to be of the opinion that most historians of science have got it wrong. Perhaps so: but this is not the place for original research. If you can find reliable, peer-reviewed sources to back up your perspective on this stuff, then by all means cite them, together with citations for the opposing viewpoints so that readers can make up their own minds. If not, then go ahead and write something yourself, send it to a peer-reviewed journal, and then, once it appears, feel free to cite it here. Hce1132 (talk) 19:29, 29 February 2008 (UTC)

Logicus wrote:

Thanks David, but your comment, "Objects falling from the Tower of Pisa are falling through air (a resistant medium), so opinions about what happens in a vacuum would seem to me to be irrelevant anyway." is surely a misreading of the sentence you refer to, for which what happens in a vacuum is the ONLY logically relevant comparison.

No, not "surely" at all. An experiment can constitute a test for a theory for any conditions under which it predicts an outcome differing negligibly from that which it predicts for the actual conditions of the experiment. Thus, since the modern theories of free fall, and those of Galileo's given in De Motu and the Discorsi, all predict that the results of performing the experiment Viviani describes in a vacuum would be negligibly different from those obtained under the actual conditions of the experiment, then one can indeed regard the experiment as a test of those theories' predictions for a vacuum. But there's no reason at all why one cannot just as well regard it as a test of the theories' predictions for the actual conditions of the experiment—namely for bodies falling through air.

For Aristotle's theory, however, the case is entirely different. If we accept Logicus's interpretation, according to which Aristotle predicted that free fall in a vacuum would occur instantaneously, and regard the experiment described by Viviani as a test of that theory, then the experiment would decisively refute it. Objects dropped fom the observation platform of the Leaning Tower of Pisa take at least 3 seconds to fall to the ground, and this is easily distinguished from an instantaneous fall. An obvious (and entirely reasonable) rejoinder of a supporter of Aristotle's theory would be that the 3 second delay is caused by the resistance of the medium (namely air) through which the object has to fall. Now, according to Galileo's interpretation of Aristotle's theory, it predicts that the average speed achieved by an object dropped through air from the Leaning Tower will be proportional to its weight. But this means that since a lead ball (for instance) weighing 2 kilograms takes about 3 seconds to fall the distance, one weighing half a kilogram would have to take 12 seconds, rather than about the same time of 3 seconds which is actually observed.

So if the interpretation of Aristotle's theory adopted by Galileo is correct, then his theory of free fall through air makes a completely erroneous prediction. And since our hypothetical supporter of Aristotle has already appealed to the effects of air resistance as influencing the results of the experiment, it would be totally unreasonable for him or her to try and evade Galileo's argument by now turning around and claiming that the experiment was only meant to test what would happen in a vacuum.

But all this is largely beside the point anyway. The first sentence of the text which Logicus is objecting to merely claims to be reporting what Viviani had given as Galileo's purpose for allegedly performing the experiment. We don't need to speculate about that because we can simply check the claim against what Viviani actually wrote:

And then, to the great consternation of all the philosophers, by means of experiments and convincing demonstrations and arguments, he established the falsity of very many conclusions of the same Aristotle, which right up to that time had been held as obvious and indubitable; such as, amongst others, that the speed of bodies of the same material, but different weights, falling through the same medium, do not stand in the proportion of their weights, as asserted by Aristotle, but rather all such bodies move with the same velocity. He demonstrated this with repeated experiments performed from the height of the bell-tower of Pisa in the presence of the other lecturers and philosophers and all the students;

(Favaro's Edizione Nazionale of Galileo's works, 19:606—translation mine)

A couple of interesting points about this account are that Viviani gives Galileo's conclusions only for bodies of the same material and fails to mention the assumption that the effects of air resistance are negligible. This indicates that he was probably giving an accurate historical account of the faulty arguments Galileo would have actually been using at the time he was alleged to have performed the experiment, rather than those he would have given after he had arrived at the mature theory of the Discorsi.

I do not agree with Logicus's proposed changes to the sentence he has objected to, partly because of the facts stated above, but also because there are at least some reputable scholars who share Galileo's opinion about what Aristotle's theory predicts for natural motion through a medium (e.g. Stillman Drake, in Galileo at Work, p.9, Michael Sharratt, in Galileo: Decisive Innovator, p.31, and Robin Waterfield, in the Introduction to his translation of the Physics, p.xliii). Of these three scholars, Drake is the only one who gives any hint that there might be some controversy about this. In a footnote, he says "At any rate that [i.e. his opinion about Aristotle's theory] was the prevailing opinion concerning Aristotle's teaching held by Peripatetics of Galileo's time."

Nevertheless, if there really is a genuine scholarly controversy about this, then of course the article should not convey the impression that Galileo's interpretation of Aristotle was the correct one. But, in my opinion, all that would be needed would be to rephrase the sentence Logicus has objected to to say something like the following:

A biography by Galileo's pupil Vincenzo Viviani stated that Galileo had dropped balls of different masses, but the same material, from the Leaning Tower of Pisa to demonstrate that their time of descent through the atmosphere was independent of their weight. According to Galileo, Aristotle's theory had predicted that their time of descent through the atmosphere would be inversely proportional to their weight, and therefore that it was refuted by this experiment.

with an appropriate footnote saying something like: "Scholars disagree about whether Galileo had interpreted Aristotle's theory correctly. The interpretations of Drake (1978, p.9), Sharratt (1996, p.31) and Waterfield (1996, p.xliii), for instance, coincide with Galileo's, while Bloggs (1945, p.2), Nurk (2008, p.1436) and Sempronio (1900, p.10) argue against that interpretaion."

P.S: I notice that just as I finished writing this, Logicus added another long post. None of the points he raises in that post should be necessarily be expected to be addressed in any of my above comments. —David Wilson (talk · cont) 16:54, 29 February 2008 (UTC)

David thanks for this, some of which is most useful, especially your Viviani translation that confirms Viviani did not claim Galileo was trying to demonstrate the time of fall is independent of weight, contrary to his belief at Pisa that it depends upon specific weight, but as many historians of science have claimed he did.

A historically more informative version of your proposed sentence might be:

'A biography by Galileo's pupil Vincenzo Viviani stated that Galileo had dropped balls of different weights, but of the same material, from the Leaning Tower of Pisa to demonstrate that their time of descent through the atmosphere was independent of their absolute weight. According to Galileo when at Pisa University in 1590, the time of descent of heavy bodies in a vacuum would be proportional to their specific weight as Philoponus and others had claimed, whereas he claimed without any textual evidence that Aristotle had predicted that their time of descent through the atmosphere would be inversely proportional to their absolute weight, and therefore that this prediction would be refuted by this experiment.'

But given its Philoponus and Benedetti errors and others, I think a wholly different approach is needed to this whole paragraph. I’ll maybe try and draft something that improves on it and makes it much more interesting and informative about the development of Galileo’s dynamics from his Pisan dynamics that I hope you will find basically acceptable.

I should also perhaps point out that it is anyway silly being so concerned with the errors of Aristotle's original dynamics, since by the time of the 17th century Aristotelian dynamics in the form of Kepler's Thomist inertial variant, for example, according to which v @ F/m, would predict the speed of gravitation fall in a void is the same for all bodies independent of their weight because this becomes v @ W/W for gravitational fall.--Logicus (talk) 22:12, 1 March 2008 (UTC)

GA nomination

This article passes, as, compared against the six good article criteria:

1. Well written?: Outstanding prose, but some minor WP:MOS issues. Those don't particularly affect a GA nomination, per se, but if you're going for FA, I'd recommend you correct them.

2. Factually accurate?: Yes. Well-sourced.

3. Broad in coverage?: Yes.

4. Neutral point of view?: Yes.

5. Article stability? Yes.

6. Images?: Yes.

Spectacularly done. If you feel that this review was in error, feel free to have it reassessed. Nousernamesleft^{copper, not wood} 23:52, 28 February 2008 (UTC)

Factually incorrect that Philoponus held speed in free-fall is independent of weight

The article currently claims that

“John Philoponus had argued [that a body’s time of descent in free-fall is independent of its weight] over one thousand years earlier (as well as the Oxford Calculators several centuries before Galileo).”

But this claim about Philoponus is both unsourced and also false on David Furley’s 2004 translation of his Physics, and the claim about the Oxford Calculators is also unsourced.

On Philoponus, I had always understood since the 1970s that contrary to Aristotle, Philoponus maintained the speed of gravitational fall in a vacuum would be proportional to specific weight or density, the view also propounded by Galileo in his 1590 De Motu when he taught at Pisa University. I am not aware of any subsequent scholarship having changed this view to that depicted in the article. Thus as Furley’s 2004 translation of Philoponus’s Physics has it:

"But if bodies in themselves have more or less downward tendency, they will obviously have such a difference among themselves even if they move in a void and the same distance in a void will be traversed in less time by the heavier and in more by the lighter, not because of being more or less obstructed, but because of having a greater or lesser downward tendency in proportion to the difference in their natural weight." Physics 679.19-23 [p335 The Philosophy of the Commentators 200-600 AD Richard Sorabji 2004 Duckworth]

This at least demonstrates Philoponus did not maintain the speed of fall in a vacuum would be independent of weight as the article claims he did. I further understand that ‘natural’ weight here is to be interpreted to mean specific weight or density rather than absolute weight.

This result that speed of free-fall is proportional to natural weight follows from the fact that Philoponus maintains the resistance of the medium is to be subtracted from the motive force or weight, so that v @ W – R, rather than dividing it as in Aristotle’s v @ W/R. Thus when R = 0 as in a vacuum, speed is proportional to weight rather than infinite (if weight is not infinite).

Galileo subsequently came to reject this Philoponan theory that the speed of free-fall would be proportional to weight, a view falsely attributed to Aristotelian dynamics, and instead to maintain that the speed of free-fall is a universal constant and independent of weight. (He was of course grossly mistaken inasmuch as in Newtonian dynamics it is a variable and dependent upon the attracting gravitational mass and distance.)

But Galileo is typically misrepresented by Enlightenment-positivist historians of science as overthrowing an incorrect Aristotelian view that the speed of free-fall is proportional to weight with a modern correct view. Thus the incorrect view of Philoponan dynamics that was overthrown is misrepresented as being the Aristotelian view that was overthrown. It was Philoponan dynamics, not Aristotelian dynamics, that held the speed of free-fall would be proportional to weight, and that was rejected. This all fosters the mistaken view that Philoponan dynamics overthrew Aristotelian dynamics, whereas the truth is the very contrary.

At least the current claim should be flagged as unsourced. --Logicus (talk) 17:35, 29 February 2008 (UTC)

Modern play about Galileo

I have written a modern play about Galileo, which would likely be of interest to Wikipedia readers; it could appear under the "Galileo in popular culture" heading. It is available at http://www.geocities.com/savitz_1999/Galileo.pdf . I do not have editing privileges, but if someone who does could add a link to it, that would be greatly appreciated. Sincerely, Dr. Scott Savitz Scottsavitz (talk) 01:51, 31 March 2008 (UTC)

Galileo

He should be knighted for discovering and inventing so many things.

—Preceding unsigned comment added by 203.25.195.1 (talk) 15:31, April 3, 2008

Delete the diagram on 'Classical Mechanics' ?

In the 'Physics' section of the article the diagram on Classical Mechanics as reproduced here

is both mistaken and misleading and irrelevent to the text of this article, so should be deleted.

In itself it is mistaken because its sub-legend 'Newton's second law of motion' is historically mistaken and if anything should be rather 'The second law of motion of classical mechanics'.

This is certainly not Newton's second law stated in the Principia, which was that THE change of motion [referred to in the first law] is proportional to the motive force impressed, i.e. Dmv @ F, or F --> Dmv (where 'D' = 'the absolute change', Delta, '@' = 'is proportional to', and '->' is the logical symbol for if... then...).

The misrepresentation of Newton's second law as F = ma or similar has the logical consequence that a = F/m and thus a = 0 when F = 0, whereby Newton's first law would be logically redundant just as Mach claimed it was.

But Newton's second law only deals with changes of motion produced by impressed force such as mentioned in the first law, and does not itself assert there is no change of motion without the action of impressed force as the law F = ma does, where F denotes impressed force rather than inertial force. And in fact both Galileo's 1590 Pisan impetus dynamics and Kepler's 'inertial' dynamics, both of which claimed motion would terminate without the continuing action of what Newton called 'impressed force', denied this principle.

But the logical function and historical purpose of Newton's first law is precisely to assert this principle, that there is no change of motion unless (i.e. If not) compelled by impressed force, and thus whereby Dmv <=> F, rather than just F --> Dmv. (Here <=> is the logical equivalence symbol for 'if and only if', and '-->' the symbol for 'If...then...') Thus Mach’s logical criticism was wrong by virtue of his ahistorical misinterpretation of Newton’s second law as F = ma.

--Logicus (talk) 18:30, 16 April 2008 (UTC)

More Galilean fairy-tales ?

Galileo Galilei is forever remembered as the scientist who invented the telescope, turned it skyward, and started a controversial battle with the Roman Catholic Church. He is known to have proved that the earth revolves around the sun and invalidated many of the theories of the ancient Greek philosopher, Aristotle. What many people do not know is that Galileo was also an incredible mathematician, physicist, engineer, and inventor, who was a descendant of a noble family in Florence. Galileo Galilei was born on February 15, 1594, in Pisa, Italy. His father, Vincenzio Galilei, was a musician and mathematician who contributed greatly to music theory, and wrote a prominent treatise on music called “Seconda Pratica.” His brother, Michelangelo, was a musician of the Grand Duke of Baviera. He also had three sisters; Virginia, Anna, and Livia. Galileo’s father encouraged him to study a subject that would be relevant to society, and not the philosophers that Galileo was so interested in. So, in 1581, Galileo began studying medicine at the University of Pisa. However, he had little interest in the subject, and left without obtaining a degree in 1585, and began to study Euclid and Archimedes. He wrote a treatise in 1586 called The Little Balance, and in 1589, he was appointed Chair of Mathematics in Pisa, at the same university he had dropped out of just four years earlier. Aristotle, the Greek philosopher, stated that heavier objects fall faster than lighter ones. Galileo, with his new vocation, immediately disproved the theory by dropping two cannonballs of different weight off the Tower of Pisa, and watched as they hit the ground at the same time. In 1591 he wrote a treatise, On Motion, which explained his observations. However, Galileo stated that objects of different sizes only fall at the same rate only if they are made of the same substance, a theory which was later proved incorrect. In 1592, Galileo became the Chair of Mathematics at Padua. It was in this prestigious position that he researched some of his biggest scientific ideas yet. In 1597, Galileo wrote a letter to his colleague, Jacopo Mazzoni, telling him that he was sure that the earth went around the sun, and that he was afraid to make his opinion public. The reason he was afraid was because Copernicus, just a few decades earlier, had been declared a heretic by the Catholic Church for stating that the universe was heliocentric, or revolving around the sun. The heliocentric theory was declared by the church as being contradictory to the scriptures. Twelve years later, something happened that was detrimental to the Aristotelian theory of astronomy. Kepler’s Star, as it was called back then, is now known as the Supernova of 1604. Although it was cloudy the day it happened, a few days later the bright star was visible to the naked eye, after Galileo did some math using parallax equations, he determined that the supernova was in the distant area that Aristotelian philosophers believed was unchangeable. Contrary to common knowledge, Galileo did not actually invent the telescope. The telescope was first invented in Holland, and was used as a child’s toy. As soon as Galileo found out about a device that could make distant objects seem close, he set to work making his own. Using a concave lens behind a convex lens, Galileo was able to create the best telescope of its time. Although there were many others attempting to make such a device, Galileo was able to construct a nine-power telescope that was better than any other. After a small demonstration to government officials, the telescope was immediately patented, and Galileo’s salary was doubled as a reward. With his telescope, Galileo was able to make major discoveries in astronomy. First, he discovered that there were mountains and craters on the moon. This was significant because Aristotle believed that all heavenly bodies were pure orbs of light. Second, thousands more stars could be seen. And last, four satellites could be seen revolving around Jupiter. Galileo thought that if Jupiter had four moons, then it was not inconceivable to say that Earth revolved around the sun. Later he discovered that Venus had phases just like the moon. In 1610, he recorded his observations in a new treatise, the Sidereus Nuncius. Galileo, after his important discoveries, was appointed Mathematician and Philosopher of the Grand Duke of Tuscany, and In 1613 he made his Copernicanism public. He was warned soon after, by the church, to abandon his heretical ideas. Galileo stopped writing about astronomy for a while, although he still strongly believed that the universe was heliocentric. When the new pope, Urban VIII, became head of the church in 1623, Galileo thought that he could then keep writing about Copernicanism, and in 1631, his famed Dialogue on the Two Chief World Systems was published. The publisher decided to make one thousand copies, a very large sum for the time. When Pope Urban VIII found out about this, he found the document that was ordered in 1616 that prohibited him from writing about Copernican theory, and summoned Galileo to court. He was made to kneel and formally recant his views. After he did this, it is said that he muttered the phrase “Eppur si muove” or “yet it does move.” This is considered to be a myth by most historians, since there is no mention of him saying that until a century later. Galileo was sentenced to house arrest for the rest of his life. He continued to study physics, and completed his book, the Discourses and Mathematical Discoveries, which was a summary of all his discoveries. Since he was not allowed to write anything about science, the book had to be smuggled out of his house, and in 1638, it was published in Holland, and on January 8, 1642, he died at the age of 77. Although many people still say that Galileo proved that the Earth revolves around the sun, he actually never did. In fact, to this day there is no scientific proof that our solar system is sun-centered (although it is significantly more probable). In N. Martin Gwynne’s Galileo versus the Geocentric Theory of the Universe, it states: “Ever since the Copernican theory of heliocentricity was adopted as fact by the scientific community, attempts have been made to devise scientific experiments to prove it. Many of them have been ingenious and some of them should have worked. Remarkably, not only has not one of them produced the proof but the results of all of them are consistent with the hypothesis that the earth is at rest.” (p. 10)

Since all movement is relative, there is not a very effective method of proving the geocentric or the heliocentric theory. Galileo made many lasting impressions on modern science. In physics, Galileo started to grasp the ideas that Isaac Newton did later. He rejected the theory that force is needed to keep something moving. One of his biggest discoveries was that the distance traveled by a falling object is proportional to the square of the time it takes to fall. In the Two New Sciences, Galileo wrote his discoveries, including the law of falling bodies, which is still used today. Galileo also discovered that the path of and object through space is a parabola. This contributed to modern warfare because it made it possible to calculate the trajectory of cannonballs or bullets, a phenomenon that many other scientists were trying to explain at that time. Galileo made plenty of other discoveries in physics. He made several advancements in the laws of equilibrium, flotation, and the tides. He even wrote a treatise that was far ahead of his time period about how machines only convert energy, and they do not create it. In engineering, Galileo was known for his science of structures. He proved that the dimensions of buildings are crucial to their stability. Galileo tested many materials that were necessary to building structures with the laws of levers. He applied his knowledge of levers to ship-making when he discovered that oars are like levers, and the water is the fulcrum. This made it possible to find the most efficient way to place the oars on a ship. In addition to the nine-power telescope, Galileo also invented the sector, the hydrostatic balance, the thermometer, and a water pump. The sector was a tool for measurement that Galileo sold to his students, and the hydrostatic balance was able to weigh objects in water. Because Galileo did not take the atmospheric pressure into account, the thermometer was very inaccurate. Although it did not work very well, it is considered historic because it was one of the first instruments with units of measurement. Galileo also invented a water pump that, unlike other pumps, required only one horse to move water. Galileo made enormous contributions to astronomy. He observed the phases of Venus, Jupiter’s moons, and spots on the sun. Since the argument that Venus and Mercury did not have phases like the moon was a commonly known disproof of heliocentricity, Galileo’s discovery of the phases of Venus was a key element in convincing people that his theory of the universe was correct. In fact, Copernicus had run into this same dilemma, and had used the hypothesis that the suns rays went through these planets to defend his theory. The discovery of Jupiter’s four moons was also a great benefit to Copernicanism. The moon’s obvious revolution around Earth was used by the church to refute Galileo’s beliefs. However, the four moons around Jupiter, which Galileo named Io, Europa, Ganymede, and Callisto, were proof that other planets have moons, and therefore the earth could still revolve the sun even though it had the moon revolving around it. The ancient Chinese were the first to discover spots on the sun when they observed it on the horizon. Galileo, however, was able to see that the sunspots were moving. This, he said, proved that the sun is rotating. Galileo made may other astronomical discoveries. He was the first to see the rings around Saturn. He said that they resembled “ears” or “handles.” He also was the first to state that the Milky Way was made up of stars, and not the band of one material that was previously accepted. Galileo was very adamant about his views. With a talent for polemics that he learned from his father, he was quick to debate anyone that disagreed with him. Many believe that his blindness in his old age was a result of his dedication to finding out more about he spots on the sun. Even house arrest could not stop him from writing. It was not until decades later that a heliocentric universe was accepted as fact, and Galileo was immortalized as one of the greatest astronomers of all time. —Preceding unsigned comment added by 74.71.82.110 (talk) 17:18, 3 May 2008 (UTC)

Influence

How is it possible that islamic influence is not mentioned in this article without islamic astronomical observatory there would be no gellileo at all why hide history facts. —Preceding unsigned comment added by 86.162.66.11 (talk) 15:39, 31 May 2008 (UTC)

Perhaps you are looking for Islamic astronomy? One could say the same, if not more so, about Greek, early Persian and Indian influences on Islamic observations.—RJH (talk) 20:39, 10 June 2008 (UTC)

International Year of Astronomy

2009 is the International Year of Astronomy, marking the 500th anniversary of Galileo's first astronomical observations and the publication of Johannes Kepler's Astronomia nova. I think it would complement the occasion nicely if this page were brought up to FA status by 2009 and received front page coverage on August 25. Anyway, just a thought for those who may have an interest. Thanks.—RJH (talk) 17:56, 8 June 2008 (UTC)

August 25 2009? Gimme danger (talk) 22:27, 8 June 2008 (UTC)

Yup. Or perhaps November 30, 2009, the anniversary of when he began observing and illustrating the Moon.[1]—RJH (talk) 17:00, 9 June 2008 (UTC)

Great idea. I've just used RJH's ideas to nominate this article for the History of Science Collaboration of the Month. --SteveMcCluskey (talk) 16:07, 10 June 2008 (UTC)

{{editsemiprotected}}On 29 JAN 2009 the Holy See Press Office announced various initiatives marking the year of astronomy. Archbishop Gianfranco Ravasi, president of the Pontifical Council for Culture explained that the United Nations decided to make 2009 the "year of astronomy" in order "to commemorate 400 years since the first astronomic discoveries" gives pride of place to Galileo. After stating that "the Church wishes to honour the figure of Galileo, innovative genius and son of the Church", the archbishop explained that "the time is now ripe for a fresh consideration of the figure of Galileo and of the entire Galileo case".

Not done: please be more specific about what needs to be changed. Also, please supply a reference. —Ms2ger (talk) 13:03, 1 February 2009 (UTC)