Re: Decker's new book

101
mikeh wrote: In the Definitiones, the tractate that Lazzarelli translated, there is an interesting sentence, in section 17 (out of 19):
Around the sun are the eight spheres that depend from it: the sphere of the fixed stars, the six of the planets, and the one that surrounds the earth.
Not bad, for Greco-Egyptian magicians. I suppose the young Copernicus read this part.
I have wondered if Copernicus might not have been inspired by observing rotating globes in parades, which, after 1443, seem to have become a regular feature in Italy. Copernicus was in Italy long enough, and in big enough cities like Bologna, Padua and Rome (1500), to have seen at least one such procession with triumphal floats.

Philine Helas, to whom I owe the information on the subject, does not suggest this idea, but it strikes me that while the rotating globe is just a gimmick (the person standing on it doesn't turn around the Earth to demonstrate mastery of the World (perhaps because it would take too much effort to keep standing rigidly on a moving cart while turning 360 degrees constantly), rather the globe turns to show viewers the whole world - as well as to astonish them with an innovative machine), it is simultaneously demonstrating a heretical idea (what would have been a heretical idea, had anyone thought of it), the very idea that Galileo was forced to recant 100 years later - that the Earth moves. The Brunelleschi-Toscanelli-Piero de' Ricci invention (Helas' idea, which I mentioned at the end of this post here viewtopic.php?f=23&t=392&p=14473&hilit=helas#p14473 ) is not trying to suggest a new cosmology - as I said, it is just a fancy new machine - but it could, for the right mind, have inspired the thought "What if the Earth really IS turning on its axis? Doesn't that solve a host of problems?"

So it could be that, indirectly, the Copernican revolution owes something to the triumphal parades, particularly Alfonso's, which as far as I know is the first time the rotating globe was demonstrated.
Image

Re: Decker's new book

102
The quotation from Tractate XVI, the one translated by Lazzarelli, goes much further than just the idea of the rotating globe, although to be sure that was heretical enough. The passage I quoted moves the center of the universe to the sun rather than the earth.

I have been researching where Copernicus got his ideas from. All I have is what he himself says in De Revolutionibis (http://www.webexhibits.org/calendars/ye ... nicus.html). First, in the preface:
:
For a long time, then, I reflected on this confusion in the astronomical traditions concerning the derivation of the motions of the universe’s spheres.I began to be annoyed that the movements of the world machine, created for our sake by the best and most systematic Artisan of all, were not understood with greater certainty by the philosophers, who otherwise examined so precisely the most insignificant trifles of this world. For this reason I undertook the task of rereading the works of all the philosophers which I could obtain to learn whether anyone had ever proposed other motions of the universe’s spheres than those expounded by the teachers of astronomy in the schools. And in fact first I found in Cicero that Hicetas supposed the earth to move. Later I also discovered in Plutarch that certain others were of this opinion. I have decided to set his words down here, so that they may be available to everybody:
Some think that the earth remains at rest. But Philolaus the Pythagorean believes that, like the sun and moon, it revolves around the fire in an oblique circle. Heraclides of Pontus, and Ecphantus the Pythagorean make the earth move, not in a progressive motion, but like a wheel in a rotation from west to east about its own center
Therefore, having obtained the opportunity from these sources, I too began to consider the mobility of the earth. And even though the idea seemed absurd, nevertheless I knew that others before me had been granted the freedom to imagine any circles whatever for the purpose of explaining the heavenly phenomena. Hence I thought that I too would be readily permitted to ascertain whether explanations sounder than those of my predecessors could be found for the revolution of the celestial spheres on the assumption of some motion of the earth..

Since he refers to the "world machine", it is possible that he is prompted to that thought by seeing machines that rotated a globe in triumphal processions. But of course the Ptolemaic view also postulated a "world machine" in the sense in which he means the word "world" here, namely, the machine of the cosmos, rotating around the earth. However what he says is that he read diligently in the works of the philosophers. Also, he says in what I quoted that he got his idea of the earth's moving from classical sources. I have not found an online version of Copernicus that actually gives Copernicus's specific sources here, but I did spend a little time tracking down the Plutarch citation. It is pseudo-Plutarch, De Placidus Philosophorum, Book III, Ch. 11 and 13. Ch 11 is at http://www.perseus.tufts.edu/hopper/tex ... apter%3D11; Ch. 13 is at http://www.perseus.tufts.edu/hopper/tex ... apter%3D13.

Later in the work Copernicus cites a "letter from Lysis to Hiparchus" on the same subject. Hipparchus was a well-known ancient astronomer, featured in Raphael's "School of Athens". This letter had been published in Greek in Venice of 1499, in a good edition by Aldus Manutus, but the one that Copernicus translated was from another "very defective" print "which also appeared in Venice in 1499", according to Jeremi Wasiutinski in The Solar Mystery 2004, p. 207, citing L. A. Birkenmajer, Mikolaj Kopernik. Studya nad pracami Kopernika oraz materyaly biograficzne 1900, pp. 121-125.

Reading further, I find that Copernicus actually quotes from the Corpus Hermeticum itself, in Book One, Chapter Ten:
At rest, however, in the middle of everything is the sun. For in this most beautiful temple, who would place this lamp in another or better position than that from which it can light up the whole thing at the same time? For, the sun is not inappropriately called by some people the lantern of the universe, its mind by others, and its ruler by still others. (Hermes) the Thrice Greatest labels it a visible god, and Sophocles’ Electra, the all-seeing. Thus indeed, as though seated on a royal throne, the sun governs the family of planets revolving around it. Moreover, the earth is not deprived of the moon’s attendance. On the contrary, as Aristotle says in a work on animal , the moon has the closest kinship with the earth. Meanwhile the earth has intercourse with the sun, and is impregnated for its yearly parturition.
The label "visible god" comes from Tractate One, the Poimandres. But given Copernicus's diligence, I would imagine that he read every word of the Corpus--it is not even very long, 92 pages in Copenhaver's translation.(Consider that his library at his death contained the complete works of Plato, as translated by Ficino, and also Bessarion's Calumniator, both rather ponderous tomes; the Calumnator was valuable if only for its long quotations from Greek sources, with Latin translation. My source here is Wasiutinski p. 503.)

So although I have read absolutely nothing in the literature on Copernicus to this effect--in fact, the discussions I have read say precisely the opposite, that Copernicus's theory is not found in an ancient source--it seems to me highly probable that he got the idea for a sun-centered cosmos, or at least found confirmation there for his own suspicions, from this tractate translated by Lazzarelli and published by Symphorien Champier in 1507 (Copenhaver p. xlix, 200). According to Wikipedia, Champier was based in Lyon. (How Champier might have got a copy of Lazzerelli's translation is discussed by Copenhaver in his book on Champier, p. 170, at http://books.google.com/books?id=JjqgAA ... Lazzarelli.) It is not as though the Corpus was an obscure document; it was still the book of the hour, and one Copernicus himself cites. It is true Copernicus does not cite this tractate; but he may have lost the book, or merely borrowed it, and forgotten where he read it. Or he might have seen Lazzarelli's manuscript itself, as he was in Rome in 1500. Or he might have seen the original Greek, his skill in which he was perfecting at that time. I notice in Wasiutinski 's list (p. 503) that Copernicus owned the works of one of Lazzarelli's chief sponsors, Pontano ("Joannes Jouianus Pontanus"), published Venice 1503.

For quick reference here it is again, from Tractate 16, section 17, p. 61 of Brian Copenhaver, Hermetica:
Around the sun are the eight spheres that depend from it: the sphere of the fixed stars, the six of the planets, and the one that surrounds the earth.
Last edited by mikeh on 12 Jan 2014, 00:30, edited 2 times in total.

Re: Decker's new book

103
1495 wurde Kopernikus zum Kanoniker der ermländischen Domschule in Frauenburg ernannt.[5] Sein Onkel Watzenrode schickte ihn an die Universität Bologna, wo er zum Wintersemester 1496/1497 ein Studium beider Rechte begann. In Bologna studierte Kopernikus neben Griechisch bei Urceus Codrus auch Astronomie und lernte bei Domenico Maria da Novara neuere Theorien zur Bewegung der Planeten kennen. Er erwarb sich dort den Titel eines Magister artium.[6]
1500 verließ Kopernikus Bologna und verbrachte anlässlich des Heiligen Jahres einige Zeit in Rom, bevor er 1501 nach Frauenburg zurückkehrte. Er erbat eine Genehmigung für eine Verlängerung seines Studienaufenthaltens in Italien und begann noch im gleichen Jahr ein Medizinstudium an der Universität Padua. Parallel dazu setzte er sein Jurastudium fort. Während dieser Zeit wurde Kopernikus das Amt eines Scholastikers der Breslauer Kreuzkirche übertragen, das er nicht persönlich ausübte, jedoch bis kurz vor seinem Tod innehielt.[7]

Zum Doktor des Kirchenrechts (Doctor iuris canonici) wurde er am 31. Mai 1503 an der Universität Ferrara promoviert.[8] Einen akademischen Grad in Medizin erwarb Kopernikus nicht. 1503 kehrte er ins Ermland zurück und begann zunächst als Sekretär und Arzt für seinen Onkel Lucas Watzenrode, den Fürstbischof des Ermlandes, zu arbeiten.
http://de.wikipedia.org/wiki/Nikolaus_Kopernikus
Domenico Maria da Novara bezeichnete sich als Schüler von Regiomontanus, der in Wien Mathematik und Astronomie gelehrt hatte. Zu Beginn des 16. Jahrhunderts waren Astronomie und Astrologie nicht klar geschieden. Novara verstand sich als jemand, der die mathematische Basis für persönliche und politische Prognostik durch präzise Beobachtung schuf.[1]

Er galt als hervorragender Beobachter; er hatte Zweifel am damaligen ptolemäischen geozentrischen Weltsystems, wie Randbemerkungen in Büchern zeigen.[2] Diese Zweifel dürfte er seinem begabten Schüler beim Studium der Lehren von Regiomontanus und Georg von Peuerbach übermittelt haben. Die beiden Autoren hatten einen ausführlichen Kommentar zum Almagest des Claudius Ptolemäus verfasst, der 1496 in Venedig neu herausgegeben worden war.

Domenico Maria da Novara gilt als Lehrer und Mentor von Nikolaus Kopernikus.[3] Laut Kopernikus De revolutionibus orbium coelestium beobachteten beide gemeinsam am 9. März 1497 eine Bedeckung des Sterns Aldebaran durch den Mond sowie am 9. Januar 1500 und am 4. März 1500 eine Konjunktion des Saturns mit dem Mond.
http://de.wikipedia.org/wiki/Domenico_Maria_da_Novara
Domenico Maria Novara (1454–1504) was an Italian scientist.

Life

Born in Ferrara, for 21 years he was professor of astronomy at the University of Bologna, and in 1500 he also lectured in mathematics at Rome. He was notable as a Platonist astronomer, and in 1496 he taught Nicholas Copernicus astronomy. He was also an astrologer, perhaps for financial gain, as was common at the time.

At Bologna, Novara was assisted by Copernicus, with whom he observed a lunar occultation of Aldebaran. Copernicus later used this observation to disprove Ptolemy's model of lunar distance.

Copernicus had started out as Novara's student and then became his assistant and co-worker. Novara in turn declared that his teacher had been the famous astronomer Regiomontanus, who was once a pupil of Georg Purbach. Novara was initially educated in Florence, at the time a major center of Neoplatonism. He studied there under Luca Pacioli, a friend of Leonardo da Vinci.

Novara's writings are largely lost, except for a few astrological almanacs written for the university. But Copernicus' De revolutionibus orbium coelestium (published in 1543, long after Novara's death) records that on 9 March 1497 Novara witnessed Copernicus' first observation. Both men were described as "free minds and free souls," and Novara believed that his[citation needed] findings would have shaken Ptolemy's "unshakable" geocentric system.

Novara died in 1504 at Bologna.
http://en.wikipedia.org/wiki/Domenico_M ... da_Ferrara

*************

It seems plausible, that Domenico Maria da Novara already had gathered "contradictions" and that Copernicus profited from it.

Compare:
http://books.google.de/books?id=C_a1kTv ... ra&f=false

****************

Genealogy of Alfonso V of Aragon and Naples
(the one with the turning globe in his triumphal procession)


Alfonso X, the Wise (a great astronomer)
http://en.wikipedia.org/wiki/Alfonso_X_of_Castile

Sancho IV of Castile
http://en.wikipedia.org/wiki/Sancho_IV_of_Castile

Ferdinand IV of Castile
http://en.wikipedia.org/wiki/Ferdinand_IV_of_Castile

Alfonso XI of Castile
http://en.wikipedia.org/wiki/Alfonso_XI_of_Castile

Henry II of Castile
http://en.wikipedia.org/wiki/Henry_II_of_Castile

John I of Castile
http://en.wikipedia.org/wiki/John_I_of_Castile

Ferdinand I of Aragon
http://en.wikipedia.org/wiki/Ferdinand_I_of_Aragon

Well, Alfonso V. had the same name as his great ancestor, who nearly became German emperor. And who made a lot for early astronomy.
Sicily had been ruled as independent kingdom by Aragon. In 1409 it became part of Aragon.
Naples was ruled by Anjou, which had also Sicily till 1282 (then still Alfonso the Wise lived; he died 1284).

In 1442 Alfonso V. of Aragon took Naples, and the triumphal celebration had been in 1443. There was political reason to remember the time about 160 years ago (Sicilian Vesper and Alfonso the Wise).
from http://en.wikipedia.org/wiki/Alfonso_X_of_Castile

Astronomy
Monument to Alfonso X in La Puebla del Río, province of Seville.

As an intellectual he gained considerable scientific fame based on his encouragement of astronomy, which included astrology at the time and the Ptolemaic cosmology as known to him through the Arabs. He surrounded himself with mostly Jewish translators who rendered Arabic scientific texts into Castilian at Toledo. His fame extends to the preparation of the Alfonsine tables, based on calculations of al-Zarqali, "Arzachel". Because of this work, the lunar crater Alphonsus is named after him. One famous, but apocryphal, quote attributed to him upon his hearing an explanation of the extremely complicated mathematics required to demonstrate Ptolemy's theory of astronomy was "If the Lord Almighty had consulted me before embarking on creation thus, I should have recommended something simpler."[8] Gingerich (1990) says that a form of this alleged quotation was mentioned (but rejected) as early as the 16th century by the historian Jerónimo de Zurita, and that Soriano Viguera (1926) states that "nothing of the sort can be found in Alfonso's writings."[9] Nevertheless, Dean Acheson (U.S. Secretary of State, 1949-1953) used it as the basis for the title and epigraph of his memoir Present at the Creation[10]
Translations

From the beginning of his reign, Alfonso employed Jewish, Christian and Muslim scholars at his court, primarily for the purpose of translating books from Arabic and Hebrew into Latin and Castilian, although he always insisted in supervising personally the translations. This group of scholars formed his royal scriptorium, known as the Escuela de Traductores de Toledo (Toledo School of Translators). Their final output promoted Castilian as a learning language both in science and literature, and established the foundations of the new Spanish language. This evolved version of the Castilian language also acquired significant relevance in the royal chancery, where it came to replace Latin, which until then was the language commonly used by the royal diplomacy in Castilla and León.[11]

The very first translation, commissioned by his brother, Fernando de la Cerda— who had extensive experience, both diplomatic and military, among the Muslims of southern Iberia and north Africa— was a Castilian version of the animal fable Kalila wa-Dimna,[12] a book that belongs to the genre of wisdom literature labeled Mirrors for Princes: stories and sayings meant to instruct the monarch in proper and effective governance.

The primary intellectual work of these scholars centered on astronomy and astrology. The early period of Alfonso's reign saw the translation of selected works of magic (Lapidario, Picatrix, Libro de las formas et las ymagenes) all translated by a Jewish scholar named Yehuda ben Moshe (Yhuda Mosca, in the Old Spanish source texts). These were all highly ornate manuscripts (only the Lapidario survives in its entirety) containing what was believed to be secret knowledge on the magical properties of stones and talismans. In addition to these books of astral magic, Alfonso ordered the translation of well-known Arabic astrological compendia, including the Libro de las cruzes and Libro conplido en los iudizios de las estrellas. The first of these was, ironically, translated from Latin (it was used among the Visigoths), into Arabic, and then back into Castilian and Latin.[13] Most of the texts first translated at this time survive in only one manuscript each.
Maybe there was some early Spanish understanding, which assumed heliocentric theories ... but possibly never reached Italy in an "official manner".
We've also Kabbala in Spain very early and even very early attempts to spread it in Italy during 13th century. But it became topic there in late 15th century.
Last edited by Huck on 11 Jan 2014, 17:35, edited 2 times in total.
Huck
http://trionfi.com

Re: Decker's new book

104
In all of this it seems that there may have been "murmurings" of a change in the Ptolemaic system among the astronomers of the 15th century. It could well be that if Toscanelli had anything to do with the rotating globe machine of Alfonso's triumph, that it was a polemical gesture aimed at the knowing few, those "with eyes to see." All he had to do was get someone to build it (Helas suggests Brunelleschi), and he could demonstrate the idea, without having to argue it.

But Toscanelli, Cusanus, Regiomontanus (if they indeed had this idea in mind), Novara, Copernicus and Galileo are far from solving the basic problems of cosmology. The rotating Earth and Sun-centered system are just the beginning. This would take Kepler and finally Newton, who built, of course, on the theoretical and empirical findings of their predecessors.
Image

Re: Decker's new book

105
I've added a few considerations to my post before.

**********

Generally one shouldn't overlook, that Italy got a Spanish pope in 1455 (likely with some realationship to Alfonso V. who still lived), and a second Spanish pope in 1492 (rather sure with some relationship to the successes of Isabella and Ferdinand in Spain and Granada - it was taken 1492).

There was also ...

http://en.wikipedia.org/wiki/Avignon_Pope_Benedict_XIII (counted as Anti-pope)
Huck
http://trionfi.com

Re: Decker's new book

106
Huck wrote:I've added a few considerations to my post before.
Being aware that some Greeks had other cosmologies, including heliocentrism, is one thing. I'm sure that some Muslim as well as Christian scholars throughout the middle ages, perhaps especially in Spain, knew about them. But knowing these fragments, and developing them, are very different things. If any Muslim astronomers had developed a heliocentric theory, however rudimentary, or had a rotating Earth as part of that explanation, I have no doubt that researchers into the history of astronomy would have found them and pointed them out. They love this kind of thing, and every historian of science knows the value of Arabic translations of classical sources.

Copernicus seems to have been the first person to develop these ideas into a system. My only other thought is that I find it intriguing to speculate on whether Toscanelli also had the idea to develop the rotating Earth part, and that it might have made it into a demonstration in Alfonso's triumph.
Image

Re: Decker's new book

107
Ross G. R. Caldwell wrote:
Huck wrote:I've added a few considerations to my post before.
Being aware that some Greeks had other cosmologies, including heliocentrism, is one thing. I'm sure that some Muslim as well as Christian scholars throughout the middle ages, perhaps especially in Spain, knew about them. But knowing these fragments, and developing them, are very different things. If any Muslim astronomers had developed a heliocentric theory, however rudimentary, or had a rotating Earth as part of that explanation, I have no doubt that researchers into the history of astronomy would have found them and pointed them out. They love this kind of thing, and every historian of science knows the value of Arabic translations of classical sources.

Copernicus seems to have been the first person to develop these ideas into a system. My only other thought is that I find it intriguing to speculate on whether Toscanelli also had the idea to develop the rotating Earth part, and that it might have made it into a demonstration in Alfonso's triumph.
There's the idea, that Toscanelli knew a Chinese visitor in Europe. But I don't know, if China had any heliocentric idea.

Image


Nicole Oresme ...
(c. 1320–1325 – July 11, 1382)
http://en.wikipedia.org/wiki/Nicole_Oresme

... had the idea, that the earth is (possibly) cycling.
"In his Livre du ciel et du monde Oresme discussed a range of evidence for and against the daily rotation of the Earth on its axis."
He mainly belonged to Navarra, that's at least "close to Spain".
And it fits with a cycling globe at the triumphal chariot of Alfonso.

Cusanus thought about similar ideas.
Huck
http://trionfi.com

Re: Decker's new book

108
I think I understand your strategy here, Huck. You are arguing with Helas, through me. You are trying to say that the Spanish (Aragon, actually, so Catalans) might have come up with the idea, and that Toscanelli might have had nothing to do with it.

But in fact Florence - the merchant's guild of Florence - was responsible for the part of the procession that included Caesar and most of the rappresentazioni. The Catalans had a part, which was a mock battle between them and the Turks. Finally another rappresentazione, of a tower guarded by the cardinal Virtues and the Archangel Michael, was probably sponsored by the city itself (the top of Alfonso's arch no doubt represents this same idea - the tower represents the city, the virtues sum up the qualities of he who would hold it, and the angel the divine protection upon which it relied).

I'm not sure of all the details of how Florence assumed such a prominent role in staging the triumph, but generally they had good reason to show a good face to Alfonso, due to the alliance of Naples and Milan, and Florence's traditional favor for Anjou. René d'Anjou himself may still have been in Florence when the triumph in Naples occurred in 1443, but I'll have to check the dates to be sure.

Here is Burckhardt's description, to refresh your memory. His point of view is outdated, but the main details are correct -
Alfonso the Great, on his entrance into Naples (1443), declined the wreath of laurel, which Napoleon did not disdain to wear at his coronation in Notre-Dame. For the rest, Alfonso's procession, which passed by a breach in the wall through the city to the cathedral, was a strange mixture of antique, allegorical, and purely comic elements. The car, drawn by four white horses, on which he sat enthroned, was lofty and covered with gilding; twenty patricians carried the poles of the canopy of cloth of gold which shaded his head.

The part of the procession which the Florentines then present in Naples had undertaken was composed of elegant young cavaliers, skillfully brandishing their lances, of a chariot with the figure of Fortune, and of seven Virtues on horseback. The goddess herself, in accordance with the inexorable logic of allegory to which even the painters at that time conformed, wore hair only on the front part of her head, while the back part was bald, and the genius who sat on the lower steps of the car, and who symbolized the fugitive character of fortune, had his feet immersed in a basin of water Then followed, equipped by the same Florentines, a troop of horsemen in the costumes of various nations, dressed as foreign princes and nobles, and then, crowned with laurel and standing above a revolving globe, a Julius Caesar, who explained to the king in Italian verse the meaning of the allegories, and then took his place in the procession. Sixty Florentines, all in purple and scarlet, closed this splendid display of what their home could achieve.

Then a band of Catalans advanced on foot, with lay figures of horses fastened on to them before and behind, and engaged in a mock combat with a body of Turks, as though in derision of the Florentine sentimentalism. Last of all came a gigantic tower, the door guarded by an angel with a drawn sword; on it stood four Virtues, who each addressed the king with a song. The rest of the show had nothing specially characteristic about it.
Helas bases her speculation on the fact that the Florentine Piero de' Ricci composed Caesar's speech, and no doubt had a lot more to do with staging the Florentine part. Piero de' Ricci also wrote a sonnet for Toscanelli, which implies that they were friends. Since Toscanelli knew Brunelleschi, and since Brunelleschi was of course famous for his mechanical and engineering feats, she surmises that the wondrous new contraption of the rotating globe was Toscanelli's idea, made by Brunelleschi, all at the suggestion of Piero de' Ricci, who wanted something remarkable for Caesar's part of the triumph. Or, Toscanelli, knowing of de' Ricci's planning for the triumph, suggested to him that having Julius Caesar on a rotating globe might be a fine idea.

Implied in the latter scenario, that it was Toscanelli's idea, is that Toscanelli had a reason to be thinking of a rotating globe. I don't think that the Magisterium of the Church had ever pronounced such an idea heretical - in Galileo's context there were other forces at work besides astronomical theories - but Toscanelli, like Copernicus after him, must have experienced ridicule from his colleagues if he seriously proposed it, and therefore knew the resistance it would elicit were he to publish it. I guess it might have cost him his reputation and teaching appointments in the worst case. So he remained silent, but nevertheless demonstrated the idea, for those who might have open enough and educated enough minds to appreciate what was really being shown.
Image

Re: Decker's new book

109
Ross G. R. Caldwell wrote: René d'Anjou himself may still have been in Florence when the triumph in Naples occurred in 1443, but I'll have to check the dates to be sure.
No. King's chronology in Child Valerio says that he arrived in Florence, via Pisa, on July 19, 1442. He stayed in Florence until after 20 September (when Eugene recognized him as rightful King of Naples, despite the fact that he had lost it). He left Florence sometime in the next 3 weeks, and arrived in France on 23 October, 1442 (all on page 256 of King).

So he was not in Florence in February, 1443.
Image

Re: Decker's new book

110
Ross G. R. Caldwell wrote:I think I understand your strategy here, Huck. You are arguing with Helas, through me. You are trying to say that the Spanish (Aragon, actually, so Catalans) might have come up with the idea, and that Toscanelli might have had nothing to do with it.
I haven't a strategy, I'm just looking around, what I find in this context. I don't know Helas.

Toscanelli was close friend to Cusanus, likely they discussed a lot of things. Your idea isn't impossible.

Nonetheless: We have a lot of progress on the Iberian peninsula, especially the Portuguese ship travel development in first half of 15th century. We have, that the German emperor Fredrick III (with very special interest in astronomy and astrology) found it interesting to marry a Portuguese princess (1452) ... this, after the very progressive and successful duke of Burgundy, Philipp the Good, also had married a Portuguese princess (1430) and had made good experiences with it, though his bride had the already advanced age of 33.
Alfonso of Aragon V. had an active role in the arrangement of the marriage of Fredrick III, Fredrick visited him in Naples in 1452 cause of that.

In the much later political development we've a strong Habsburg-Spanish alliance as very successful and the most dominating West European force during 16th century.

Sea travels outside of the Mediterranean Sea had more practical advantage by astronomy and cartography as it was needed for the well known ship routes inside.

Generally cartography (possibly also some astronomy) was (at least occasionally) object to secrecy.
Huck
http://trionfi.com