Showing posts with label Physics. Show all posts
Showing posts with label Physics. Show all posts

Monday, February 28, 2022

Octocentenary of the Universitas Patavina

Octocentenary

University of Patavium {Padova /  Padua}, Veneto / Cis-Alpine Gaul {Gallia Cis-Alpina / Gallia Citerior}, Italian peninsula.

1222. MCCXXII.



`I invite the reader’s attention to the much more serious consideration of the kind of lives our ancestors lived, of who were the men, and what the means both in politics and war by which Rome’s power was first acquired and subsequently expanded; I would then have him trace the process of our moral decline, to watch, first, the sinking of the foundations of morality as the old teaching was allowed to lapse, then the rapidly increasing disintegration, then the final collapse of the whole edifice, and the dark dawning of our modern day when we can neither endure our vices nor face the remedies needed to cure them. 
 
The study of history is the best medicine for a sick mind; for in history you have a record of the infinite variety of human experience plainly set out for all to see; and in that record you can find for yourself and your country both examples and warnings; fine things to take as models, base things, rotten through and through, to avoid.'

-- Titus Livius, Book I, `Ab urbe condita'.
 
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University of Padua


The University of Padua dates, according to some anonymous chronicles (Muratori, "Rer. Ital. Script.", VIII, 371, 421, 459, 736), from 1222, when a part of the Studium of Bologna including professors and students withdrew to Padua. The opinion that Frederick II transferred the Studium of Bologna to Padua in 1241 is groundless. But even before this emigration there were professors of law at Padua, as Gerardus Pomadellus (c. 1165), afterwards Bishop of Padua; furthermore, his predecessor, Bishop Carzo, was called sacrorum canonum doctor. The contract proposed by the commune of Vercelli to the Rectors of the students of Padua in 1228 shows that besides both laws and dialectics, medicine and grammar were taught there. The students were divided into four nationalities: French, Italian, German, and Provencal. This contract stipulated that all or part of the university (14 professors and sufficient students to occupy 500 houses) should be transferred to Vercelli for at least eight years. The university, however, was not suspended on that account, as is evident from the Life of St. Antonio. But the tyranny of Ezzelino (1237-56) caused its decadence. From 1260 it revived under the commune which established the rights of the professors and students, and the salaries (300 lire for legists and 200 for canonists); the examinations were held before the bishop, who also granted teachers' licenses. In 1274 Padua had the decrees of the Council of Lyons, equal with the Universities of Paris and Bologna. In 1282, on account of certain communal laws against the clergy and the university, Nicholas IV threatened to deprive Padua of its Studium, but the commune relented, and the Studium acquired great renown, rivalling Bologna, especially in jurisprudence. From the beginning of the fourteenth century the school of medicine was also famous. The professors in this faculty introduced Averroism in philosophy. The theological faculty was instituted by Urban V in 1363. In the same year the Collegium Tornacense was founded, the first of its kind in Padua. There were other institutes from 1390, as the college of St. Marco for six medical students, the college of Cardinal Pileo (1420) for twenty (afterwards twelve) students.

The professors of this first period included the jurisconsults, Alberto Galeotto, Guido Suzzara, Jacopo d'Arena, Riccardo Malombra, Albrado Ponte, Rolando Piazzola, Jacopo Belvisio, Bartol Saliceti, and the celebrated Baldo; the canonists, Ruffino and Jacopo da Piacenza, Lapoda Castiglionchio, and the canonist and theologian, Francesco Zabarella, afterwards cardinal; in medicine, Bruno da Longoburgo, Pietro d'Albano, Dino del Garbo, Jacopo and Giovanni Dondi (also excellent mechanicians), Marcilio, Giovanni and Guglielmo Santa Sofia, Jacopo da Forlè, and Biagio Pelacani. Philosophy was often taught, as elsewhere, by professors of medicine, mostly averroists, like Petrus Aponensis and Mundinus. The most distinguished philosophers who were not physicians were Pier Paolo Vergerio (1349-1414), afterwards Bishop of Capo d'Istria, a learned humanist and a student of antiquity; the Franciscan Antonio Trombetta, a famous Scotist. From the fifteenth century there were in theology and metaphysics two courses, one Thomistic, with professors preferably Dominican, and the other Scotist, with professors chiefly from the Friars Minor. Famous in the beginning of the sixteenth century were the controversies between the averroist philosopher, Achillini, and the Alexandrist, Pietro Pomponazzi. The doctrines of the latter (who had gone to Bologna), especially on the soul were opposed, among others, by Agostino Nifo, another professor of Philosophy at Padua. The humanist Girolamo Fracastoro taught philosophy there.

Among the professors of letters were: Rolandino, historian of Padua (thirteenth century), and Giovanni da Ravenna, friend of Petrarch; the humanists Gosparino Barzizi, Francisco Filelfo, Vittorino da Feltre, a distinguished pedagogical writer and educator, Lauro Quirino; the Greeks Demetrio Chalcocondylas, Alessandro Zenos, Nicolas Leonicos, Marino Becichem, Romolo Amasacus, and Nicolo Caliachius; Giovanni Fascolus, Francesco Robortellos, the historian Sigonius, the great French Latinist Marc. Ant. Mauretus, Justus Lipsius, and the great Latin lexicographers of the eighteenth century, Jacopus Faciolatus, and Egidio Forcellini. Astronomy, or astrology, was taught already in the fourteenth century. The most noted professors were in the fifteenth century, Georg Pearbach, and his disciple Johann Müller, called Regiomontanus; in the sixteenth century, Giovanni Battista Capuano and Galileo Galilei, who also taught mechanics and other physical sciences. Chief among the theologians was the French Dominican Hyacinthe Serry (1698), who introduced there the new method of basing theology more on Scriptural and patristic arguments than on philosophical speculations, in which he encountered much opposition from the Conventual Fra Nicola Buico. Among the jurisconsults, after the closing of the university (1509-17), were the canonist Menochius, Alciatus, Lancelotti, and Pancirolo, famous also for his knowledge of Roman antiquities.

A characteristic of the University of Padua, even in the eighteenth century, was its internationalism, as seen from the list of professors about Facciolati; it was attended especially by Germans. When Venice passed under Austrian domination (1814) the university was transformed, like that of Pavia. At present it has the ordinary four faculties, besides a school of applied engineering and a school of pharmacy and obstetrics. Various astronomical institutes, bacteriological, physiological, hygienic, and pathological; chemical, physical and geodetic laboratories; an anthropological museum; a botanical garden; and an astronomical observatory complete the equipment of the university. It has 128 chairs, 68 professors, 20 paid, and 107 private, tutors. In 1906, there was established near the university an institution for the education of Catholic young men. University education in Italy is strictly governmental, and without it all professional possibilities are closed to young men. At some seats of learning, Catholic Clubs were started to help them against the peril to their faith and morals, but they failed. The small Pensionata, situated in the neighborhood of Padua, between the Basilica and the church of Sta. Juliana, was transformed into a large establishment. The students attend a weekly conference which treats of points of faith affecting modern conditions of life and science.


Sources

Colle, Storia scientifico letteraria dello Studio di Padova (Padua, 1824); Facciolatus, Fasti gymnasii Patavini (Padua, 1757); Favaro, Lo Studio di Padova e la Rupublica Veneta (Venice, 1889); Cenni storici sulla R. Università di Padova (Padua, 1873).

APA citation. Benigni, U. (1911). University of Padua. In The Catholic Encyclopedia. New York: Robert Appleton Company. http://www.newadvent.org/cathen/11387a.htm

MLA citation. Benigni, Umberto. "University of Padua." The Catholic Encyclopedia. Vol. 11. New York: Robert Appleton Company, 1911. <http://www.newadvent.org/cathen/11387a.htm>.

 

Thursday, December 26, 2019

On harm to the eye due to observing a solar eclipse

An annular (not total) solar eclipse is due to occur in India on 26 Dec. 2019, after total ones on 11 Aug. 1999 amd 22 Jul. 2009.


1. Are piercing and dangerous rays or EM waves of a peculiar nature emitted during a solar eclipse?

A solar eclipse is an obscuring, interposing, occluding, or occultation, of the sun by another celestial body. The EM waves emitted then are exactly of the same nature as from the sun in plain sight, unobscured, or, even better, merely a portion of it. During a total (not annular) eclipse, the solar corona comes to view (as the ring), because the sun itself is obscured; but the EM waves emitted then are always there, only that they are more evident than with an unobscured sun.

2. How does observing the sun normally, i. e., unobscured, compare with observing it under (partial) eclipse?

It is exactly the same. Even in normal circumstances, one does not stare at the sun; and deliberately doing so contrary to natural instinct harms the eye. What is peculiar about observing the sun in eclipse is two-fold:

a. Exposure: When in eclipse, the sun appears less bright than normal, and thus the natural instinct in the observer of looking away from it after a minuscule amount of time is suppressed in the mind due to an error in cognition; thus the tendency to stare at it for longer times, normally impossible to tolerate. All the same, the EM waves emitted are just as dangerous as from the unobscured sun; partial obscuring or occultation of the sun does not reduce the harm of the rays emitted from its visible portion.

b. Aperture: Again, since the sun appears less bright than normal, the iris dilates the pupil to an uncustomary extent, and more of incident EM waves are let in to the retina than usual.

Both these causes result in greater irradiation of the retina and harm to the sensory cells (retinopathy). Some describe it as the burning of the retina by solar rays, but this is only a metaphor; no pain is felt, as testimonies show; only gradually is it realised by the observer that the sight has been impaired; and the harm comes more from the UV and higher frequencies above the visual spectrum than from the IR and lower frequencies which carry heat.

In my opinion, only these two things (and not any kind of peculiar rays or EM waves radiated just during an eclipse) give any particularity to watching the sun under eclipse; and these arise on the side of the observer, not on the side of the sun or the moon.

Of course, during totality (not partiality or annularity), which lasts at most a few minutes (the longest duration is about 7 1/2 minutes), it is completely secure and harmless to look at the sun, unaided. But one must be careful because, the immediately preceding and succeeding instants are particularly harmful for observation, when the phænomenon of the diamond ring occurs, the diamond being the minuscule portion of the sun emerging into visibility.

3. What are the ways to observe a solar eclipse?

Only through filters which are absolutely guaranteed to eliminate solar rays of harmful frequency and intensity.

Solar eclipses have been known since antiquity. Yet it must be remembered that classical man had extraordinary knowledge of astronomy, certainly better than the average or even `educated' man of today, and was able to predict rather than merely watch solar eclipses and other astronomical phænomena. Doubtless, initial observations led to damage to the eye, and further attempts must have been more careful.

Watching reflections on a mirror is not safe, as the attenuation is not usually sufficient to remove the danger. Watching reflections on water is also not absolutely safe, though the image has greater attenuation than a mirror. The pin-hole camera {Camera obscura} is the most appropriate one for home observations.
https://www.livescience.com/59721-solar-eclipse-viewer-photo-tutorial.html

4. A false story about Galileo Galilei turning blind due to solar observations persists.
https://aty.sdsu.edu/vision/Galileo.html

5. Antiquity also had many views of a different approach and nature on solar eclipses.
https://www.timeanddate.com/eclipse/solar-eclipse-myths.html

6. A battle was fought between the Lydians and the Medes at the banks of the River Halys in Anatolia/Asia Minor/Asiatic Greece on 28 May 585 B. C. A solar eclipse, predicted by Thales of Miletus, occurred, and the battle was called off. Herodotus writes: `Afterwards, on the refusal of Alyattes to give up his suppliants when Cyaxares sent to demand them of him, war broke out between the Lydians and the Medes, and continued for five years, with various success. In the course of it the Medes gained many victories over the Lydians, and the Lydians also gained many victories over the Medes. Among their other battles there was one night engagement. As, however, the balance had not inclined in favour of either nation, another combat took place in the sixth year, in the course of which, just as the battle was growing warm, day was on a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it actually took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.' The River Halys was agreed upon as the border between the two nations, and Aryenis the daughter of Alyattes, King of Lydia, was married to Astyages the son of Cyaxares, King of Media. This may be the earliest recorded prediction of an eclipse, and in general, a scientific phænomenon, and also the earliest historical event known precisely by date.

7. A chronology of principal solar eclipses in India:


1868
18 Aug. -> Total solar eclipse, Central India (Belgaum, Kolhapur, Gulbarga, Hyderabad, Masulipatnam, Guntur, Vijayawada, Kakinada).


1871
12 Dec. -> Total solar eclipse, S. India (Mangalore, Coimbatore, Dindigul, Trichinopoly).


1872
6 Jun. -> Annular solar eclipse, S. India (Trichur, Mysore, Coimbatore, Salem, Madras).


1898
22 Jan. -> Total solar eclipse, N. India, Buxar.


1980
16 Feb. -> Total solar eclipse, Central India (Hubli, Raichur, Nalgonda, Konark). First total solar eclipse of the XXth century to be observed in India. https://www.iiap.res.in/?q=solareclipse


1995
24 Oct. -> Total solar eclipse, N. India (Rajasthan, Iradatganj, Calcutta). Deepavali.


1999
11 Aug. -> Total solar eclipse in Central India (Srikakulam).


2009
22 Jul. -> Total solar eclipse in N. India (Bhavnagar, Surat, Ujjain, Indore, Bhopal, Sagar, Jabalpur, Kashi/Benares, Allahabad, Gaya, Patna, Tawang, Guwahati, Dibrugarh). Longest total solar eclipse of the XXIst century. https://www.iiap.res.in/eclipse_varanasi


2010
15 Jan. -> Annular solar eclipse in S. India, Trivandrum. Longest annular solar eclipse of the IIIrd millennium.


2019
26 Dec. -> Annular solar eclipse in S. India, English Malabar (Cannanore, Ceylon).


2020
21 Jun. -> Annular solar eclipse in N. India, Uttarakhand. Summer solstice.

Further keywords and labels: Antumbra, Astronomy, Celestial mechanics, Eclipse, Electromagnetic waves, Eye, Light, Natural philosophy, Occultation, Optics, Physics, Rays, Sight, Solar eclipse, Solar rays, Thales of Miletus, Umbra, Waves, Solar system, Planets, Sun, Moon, Earth, Planetary motion.