7. The Great Ptolemaic Smackdown: Time and Tides Wait Not

Previously on the Smackdown

The faces of Venus

Previous episode: Comet Chameleon

The discovery of the phases of Venus by a variety of telescopists in the early 1610s has put paid to the long, happy consensus science of the Ptolemaic model, which now languishes on the ash-heap of history.  The Aristotelians are gleeful, since Ptolemaic astronomy was at serious odds with Aristotelian physics.  (Much like today's quantum mechanics is at odds with relativity.)  However, they should hold their gobs, since several bits of Aristotelian Physics have also come under telescopic doubt: the Moon has mountains, Jupiter has moons, the Sun gots freckles, and comets have most unhappy orbits. 

None of this proves the Earth is mobile or that the Sun is at the center of the World.  The stationary Earth remains unimpeached and her alleged dual motions are falsified in the Popperian sense by a) a lack of visible parallax among the fixed stars (which falsifies the Earth's revolution) and b) a lack of discernible Coriolis effects (which falsifies the Earth's rotation). There are other counterarguments, as well, which await the development of such concepts as inertia. TOF would discuss inertia, but it's hard to get started. 

Meanwhile, Galileo has been suckered by the Pigeon League into dabbling in Scriptural interpretation, never a good idea for an amateur during a Protestant Revolution.  He's been cleared of suspicion of heresy in a confidential investigation, but in the process Copernicanism has attracted the notice of the Authorities -- who are mostly lawyers and politicians.  Galileo tried to re-interpret Scripture because of his commitment to Copernicanism-as-physically-real and -- much as people react to a mass shooting by concern over guns (rather than, say, lunatics) -- the Authorities react to this free-lance exegesis by a concern over heliocentrism.

A decree of the Index had removed Copernicus' book from circulation for a few years pending a couple of corrections to statements that seem to assert the physical reality of the model.  Galileo has been cautioned not to hold or teach the theory other than as a mathematical model.  However, the late Cardinal Bellarmino had written that if a demonstration could be shown, there would be little problem in clearing up the  Scriptural issues. The Church has never insisted on strict literalism.  But while the Church, holding that Truth is One, would have no problem reading a scripture non-literally if the literal reading could be certainly demonstrated false, they are not about to do so for the sake of a plausible mathematical hypothesis.  Given the history of science, this would hold exegesis hostage to phlogiston, or any other scientific fashion. 

So all Galileo needs to do now is present empirical evidence that the Earth has a dual motion.  Piece of cake.

Or is it? 

6. The Great Ptolemaic Smackdown: Comet Chameleon

Previously on the Smackdown...

1. Galileo's enemies have managed to suck him into a theological discussion, never a good idea for a private individual during a Protestant Revolution.  The lawyers and politicians who run things have almost no understanding of and little interest in natural science. They see it only as a hairy nuisance getting some folks riled up and they want to make it go away.  Even the Lynceans are mostly naturalists and lack deep understanding of astronomy.
2. Galileo has been asked politely to prove that the Earth really does move before he demands that the Church reinterpret the Scriptures.  But the Tuscan mathematician is an irascible and impatient sort.  He sees things so clearly that the demand for proof seems like pig-headedness and, alas, he starts to see proofs where they are not.  
3. The upshot is that in 1616 Copernicus' book has been withdrawn from publication -- the third edition has just come out -- to await corrections.  That it was not banned outright is evidence that the authorities have no problem with heliocentrism per se, only with the assertion that it is physical fact (and therefore etc.)  Two other books that delved into Scripture in the name of Copernicanism -- those by Foscarini and by de Zuñiga -- have been banned, indicating what really matters to the Holy Office. 
4. Galileo is okay with this, because he believes that before long he will have the physical proofs Bellarmino wants.  Then he will Write a Book.  

We must not suppose that Galileo brought everything on himself by his arrogant personality, though that surely isn't helping.  (Lots of people are talking up geomobility without raising a stink.   Kepler, for example, has been appointed Imperial Mathematician by the Catholic Emperor.*)  Galileo has been systematically hounded by a band of Aristotelian enemies led by Ludovico delle Colombe, who have more or less compelled him to answer in theological terms.  He genuinely frets that if they keep it up they will badger his beloved Church into taking a theological stance on a matter of empirical fact. 

(*) Imperial Mathematician.  At this point, Kepler has been given permission to move to Linz and work on the Rudolphine Tables, a practical manual for applying his weird elliptical astronomical model. 

But neither should we suppose that the Church authorities are "out to get" Galileo due to some deep-seated science-hating hostility of science haters.  Everyone thinks they are on the side of science, and none of them -- not even Galileo -- think of science in the way we do today.  The authorities are rather well-disposed toward Galileo, especially those like Bellarmino, the Barberinis, del Monte, and others of "the Tuscan clan" within the Curia, who cut him every break they can.  Bellarmino gave him a heads up on the decree of 1616 so that he would not be taken by surprise and publicly embarrassed, and had no trouble providing Galileo with a certificate saying that Galileo himself had not been accused of anything.  Once the corrections to Copernicus' book are made, he is welcome to use and discuss it as a mathematical model.  It's only that until he has proof, he cannot say it is physical fact.   

Although Bellarmino showed an understanding of what we today recognize as scientific method, we can't say that he issued the decree out of tenderness for the purity of scientific methodology.  Many scientific theories have been proclaimed -- and accepted -- in advance of their proofs -- Maxwell, Darwin, Einstein, etc.  But it has not yet quite sunk into the 17th cent. Zeitgeist that the heavens are a physical place in which physical discoveries can be made.  Though it is beginning to change, astronomical theory is still instrumentalist: a specialized branch of mathematics whose purpose is to devise models that accurately predict heavenly events.  In fact, the heavenly bodies are so distant and so devoid of sensible properties -- only location, speed, brightness, diameter can be seen -- that it is unlikely that any physical theory regarding them can ever finally be proven.*

(*) finally proven.  In the Late Modern Age, we have extended that to all of science.  Nothing is ever proven.  From time to time things are falsified.  Had Galileo known of Popper, he would have despaired. 

As of 1617, Galileo has returned to Florence to work on his Big Book; Kepler is in Linz developing the Rudolphine Tables; Scheiner is working on his own magnum opus on the sunspots; Simon Marius has discovered the Andromeda Nebula -- no one will know it's a galaxy until much later.  But TOF's Astute Reader will note that no progress has yet been made on establishing the dual motions of the Earth.  If we assume the Earth moves, we can make accurate predictions of the heavens; but if we assume she does not, the Tychonic model also makes accurate predictions.  The Copernican and Tychonic models are mathematically equivalent, differing only in the origin of their reference frames.  To decide which reference frame to privilege will require physics, not math.

Wussup?

In 1617:

• René Descartes (21) has just graduated college and will shortly enlist in the army.  He is about to meet... 
  
• Isaac Beeckman (29), a student of Willebrord Snel, who will anticipate much of Galileo's mechanics.
• Marin Mersenne (29), newly ordained, is teaching theology and philosophy at Nevers and will set up a correspondence network among the scientists of Europe that will include Galileo, Descartes, Beeckman, Gassendi, and Peiresc.  He will help translate Galileo's works into French.
• Pierre Gassendi (25) is about to be ordained.  
• Nicolas-Claude Fabri de Peiresc (39) has discovered the Orion Nebula. 
• Joseph Gaultier de la Vallette (55) had with Peiresc observed the moons of Jupiter back in 1610, shortly after Galileo and Marius, and had been the second to see the Orion Nebula.
• Old Simon Stevin (69) had in 1586 dropped two balls of differing weights from the church tower in Delft, proving that they fell at the same rate.  He also discovered "Pascal's" Law. As science advisor to Maurice of Nassau, he may well have been present when Lippershey demonstrated his telescope in 1608. 
• Nicholas Zucchi (30), a friend of Kepler, has invented a reflecting telescope in 1616 using a borrowed parabolic mirror and some lenses.  The primitive design did not provide a way to keep the head of the user from intercepting most of the rays needed to form the focal image, but he will use it to discover the belts of Jupiter in 1630 and examine the spots on the planet Mars ten years later. At the urging of another Jesuit scientist, Paul Guldin, Zucchi will present a reflecting telescope to an enthusiastic Kepler.

All of these save Gaultier and Beeckman have Lunar craters named for them, as do Clavius, Tycho, Galileo, Kepler, Marius, Fabricius, Scheiner, and Harriott.  All those things that seemed so important 400 years ago, all the disputes over who was right and who was wrong and who was first are vanished now into the democracy of the dead and the landscape of the moon. 

Then came...

5. The Great Ptolemaic Smackdown: Here's Mud in Yer Eye

Previously on the Smackdown...

1. For sound empirical reasons the consensus science of 1400 years had been that the Earth is stationary at the bottom of the world and the Church Fathers anciently interpreted Scripture in the light of this settled science.
2. In the early 1600s, a series of telescopic discoveries made nearly simultaneously by Harriot, the Fabricii, Marius, Galileo, Scheiner, Lembo, et al., had broken Ptolemaic astronomy beyond repair.  But falsifying Ptolemy does not affirm Copernicus.  The Tychonic model seemed the best alternative at the time.  After all, if a geomobile theory were factual, it would require an entirely new physics, and no one had one handy.
3. One discovery -- the sunspots -- triggered a flamewar of epic proportions between Fr. Christoph Scheiner SJ, a mathematician in Ingolstadt, and Galileo Galilei, a mathematician-courtier of the Florentine Grand Duke. This will have Dire Consequences later. 
4. Die-hard Aristotelian Lodovico delle Colombe attacks the new discoveries in a paper, some philosophers refuse to look through a telescope, some look but see nothing.(*)  Galileo ignores or mocks them.  Then della Colombe's "Liga" engineers a series of attacks, first by Lorini, then more scandalously by Caccini, finally by a formal complaint filed by Lorini with the Holy Office.  The Office dismisses the complaint without prejudice.  
   
   (*) see nothing.  With good reason.  The first telescopes did not produce great images. 

 Curses, foiled again.

In today's episode....

4. The Great Ptolemaic Smackdown: The Down 'n Dirty Mud Wrassle

Previously on the Smackdown...

1. We have seen that there were sound empirical reasons for accepting the consensus science of a stationary earth, in particular the lack of stellar parallax and of Coriolis effects.  
2. In particular, the Church Fathers had interpreted Scripture in the light of this settled science, since like everyone else they assumed the scientists had gotten it right.  This consensus has stood for 1400 years. 
3. In the early 1600s, a series of telescopic discoveries had shaken Aristotelian cosmology and one (the phases of Venus) had broken Ptolemaic astronomy beyond repair.  These discoveries were being made nearly simultaneously by mathematicians all over Europe: Harriot, Fabricius pere et fils, de Peiresc, Marius, Galileo, Scheiner, Lembo, and others.
4. Since the earth was "clearly" stationary, most astronomers shifted to the Tychonic or Ursine models.   A few -- mostly humanists rather than scientists -- rallied around the Copernican model.  Kepler's elliptical model for some reason flew below the radar. 
5. One discovery -- the sunspots -- resulted in a flamewar of epic proportions between Fr. Christoph Scheiner, a mathematician in Ingolstadt, and Galileo Galilei, a mathematician-courtier of the Florentine Grand Duke. 

It is 1613, and Galileo has published his Letters on Sunspots, after the censors have removed all of his appeals to Scripture.  (They did not object to his straight-up endorsement of Copernicanism.)  Meanwhile, Galileo's enemies are preparing an attack.  Several men of a severely Peripatetic persuasion have formed a "league" (as they have called themselves) under Ludovico delle Colombe.  Learning of this, Galileo calls them the "Pigeon League" (since colomb means "dove").  Ludovico, he says, never opens his mouth without saying something stupid.  Galileo's love of a witty put-down could get him in trouble some day.

"But my most holy intention, how clearly it would appear if some power would bring to light
the slanders, frauds, stratagems, and trickeries that were used eighteen years ago in Rome in
order to deceive the authorities!"  

-- Letter: Galileo to Peiresc (22 Feb 1635)

3. The Great Ptolemaic Smackdown: The Great Galileo-Scheiner Flame War of 1611-13

Previously on the Smackdown...

...we have seen that the immobility of the earth was 'settled science' and 'the consensus' for excellent empirical reasons, while geomobile theories had been falsified on several grounds, most decisively on the lack of stellar parallax (which falsified the earth's revolution) and the lack of Coriolis effects (which falsified the earth's rotation).  We now know that these falsifications (like all falsifications) have been falsified by what we might call the Duhem Effect.   

Popperian falsification is known in logic as modus tollens.  

M: If A, then Y. 
m: But not-Y
/.: not-A

But there is never just one A, so what we always have is:

M: If A and B, then Y.
m: But not-Y
/.: Either not-A or not-B 

Thus, it is never evident on the face of it which of the prior assumptions -- and there will be more than two! -- has been falsified when Y fails of observation.  The problem is, it's hard to know what unspoken assumptions you are assuming.  The lack of stellar parallax was thought to falsify A (Earth goes round the sun) but it actually falsified B (the stars are millions of miles away).  In fact, they are billions of miles away and the parallax is too small for eyesight to detect even with a 20x telescope. The stellar distance was believed to be fact, based on the brightness and diameter of stellar disks.  But it turned out (in the 19th cent.!) that the "disks" were optical illusions caused by aberration and the stars differed in intrinsic brightness. But we are still here in the 17th century.

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

But eliminating Ptolemy does not prove Copernicus any more than eliminating Darwin would prove ID.  There may be [and were!] other alternatives.  When Ptolemy was ptossed, astronomers flocked... to the Tychonic and Ursine systems -- because none of the telescopic observations have so far established the motions of the Earth.  Of the seven models of the world that were in play at the beginning of the century, four are still in the running, although the kumbersome Kopernican was fading fast:

1. Heraclidean 
2. Ptolemaic
3. Copernican
4. Gilbertian
5. Tychonic
6. Ursine
7. Keplerian

It was a new, modern age.  Everything was changing.  Who knew what might happen next?

The Sun Gots Freckles!