Paolo Casati (in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

, Paulus Casatus) (1617 – 22 December 1707) was an Italian Jesuit mathematician. He belonged to the jesuit scientific school founded in the Provincia Veneta by

Giuseppe Biancani Giuseppe Biancani, SJ (Latin: Josephus Blancanus) (1566–1624) was an Italian Jesuit astronomer, mathematician, and selenographer, after whom the crater Blancanus on the Moon is named. He was a native of Bologna. Works His ''Aristoteli ...

, and represented later by

Niccolò Cabeo Niccolò Cabeo, SJ (also known as Nicolaus Cabeus; February 26, 1586 – June 30, 1650) was an Italian Jesuit philosopher, theologian, engineer and mathematician. Biography He was born in Ferrara in 1586, and was educated at the Jesuit co ...

Niccolò Zucchi Niccolò Zucchi (; December 6, 1586 – May 21, 1670) was an Italian Jesuit, astronomer, and physicist. As an astronomer he may have been the first to see the belts on the planet Jupiter (on May 17, 1630), and reported spots on Mars in 1640. H ...

Giovanni Battista Riccioli Giovanni Battista Riccioli, SJ (17 April 1598 – 25 June 1671) was an Italian astronomer and a Catholic priest in the Jesuit order. He is known, among other things, for his experiments with pendulums and with falling bodies, for his discussion ...

and Francesco Maria Grimaldi.

Biography

Born in

Piacenza Piacenza (; egl, label= Piacentino, Piaṡëinsa ; ) is a city and in the Emilia-Romagna region of northern Italy, and the capital of the eponymous province. As of 2022, Piacenza is the ninth largest city in the region by population, with over ...

to a

Milanese Milanese (endonym in traditional orthography , ') is the central variety of the Western dialect of the Lombard language spoken in Milan, the rest of its metropolitan city, and the northernmost part of the province of Pavia. Milanese, due to ...

family, he joined the Jesuits in 1634. After completing his mathematical and theological studies, he moved to

Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus (legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ...

, where he assumed the position of professor at the

Collegio Romano The Roman College ( la, Collegium Romanum, it, Collegio Romano) was a school established by St. Ignatius of Loyola in 1551, just 11 years after he founded the Society of Jesus (Jesuits). It quickly grew to include classes from elementary school t ...

. He was given the chair in mathematics after teaching philosophy and

theology Theology is the systematic study of the nature of the divine and, more broadly, of religious belief. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of analyzing the ...

Casati in Sweden

In 1651, Casati was sent on a mission to Stockholm in order to gauge the sincerity of Christina of Sweden's intention to become

Catholic The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...

. He subsequently returned to his post at Rome. In 1677, he moved to the Jesuit College in

Parma Parma (; egl, Pärma, ) is a city in the northern Italian region of Emilia-Romagna known for its architecture, music, art, prosciutto (ham), cheese and surrounding countryside. With a population of 198,292 inhabitants, Parma is the second mos ...

, where he remained until his death. Casati was a friend and correspondent of the famous florentine librarian

Antonio Magliabechi Antonio di Marco Magliabechi (or Magliabecchi; 29 October 1633 - 4 July 1714) was an Italian librarian, scholar and bibliophile. Biography He was born at Florence, the son of a burgher named Marco Magliabechi, and Ginevra Baldorietta. Although ...

, and other scientists like Carlo Rinaldini, Giovanni Antonio Rocca and

Daniello Bartoli Daniello Bartoli, SJ (; 12 February 160813 January 1685) was an Italian Jesuit writer and historiographer, celebrated by the poet Giacomo Leopardi as the "Dante of Italian prose" Ferrara He was born in Ferrara. His father, Tiburzio was a chemis ...

Casati's ''Terra machinis mota''

The astronomical work ''Terra machinis mota'' (1658) imagines a dialogue between Galileo,

Paul Guldin Paul Guldin (born Habakkuk Guldin; 12 June 1577 ( Mels) – 3 November 1643 (Graz)) was a Swiss Jesuit mathematician and astronomer. He discovered the Guldinus theorem to determine the surface and the volume of a solid of revolution. (This theor ...

, and Marin Mersenne on various intellectual problems of

cosmology Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosopher ...

geography Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, an ...

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

and geodesy. For example, they discuss how to determine the Earth's dimensions, floating bodies, the phenomena of capillarity, and also describe the experiment on the

vacuum A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or " void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often di ...

made by Otto von Guericke in 1654. The work is remarkable for the fact that it represents Galileo in a positive light, in a Jesuit work, only 25 years after Galileo's condemnation by the Church.

Casati and Theories on the Vacuum

Casati, Paolo – De igne, 1686 – BEIC 3880799

Casati discussed the hypothesis of horror vacui, that nature abhors a vacuum, in his thesis ''Vacuum proscriptum'', published in

Genoa Genoa ( ; it, Genova ; lij, Zêna ). is the capital of the Italian region of Liguria and the sixth-largest city in Italy. In 2015, 594,733 people lived within the city's administrative limits. As of the 2011 Italian census, the Province of ...

in 1649. Casati confuted the existence of both vacuum and atmospheric pressure, but he did not rely entirely on scientific observation, and refers to Catholic thought in order to back his claims. The absence of anything implied the absence of God, and hearkened back to the void prior to the story of creation in the book of Genesis (see Vacuum: historical interpretation).

Named after Casati

The crater Casatus on the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

is named after him.

Other works

*''Fabrica et uso del compasso di proportione'' (1664), a work explaining the construction and use of proportional compasses *''Le ceneri dell'Olimpo ventilate'' (1673), a dialogue about meteorology *''De gli horologi solari'' (unpublished manuscript): about sundial construction * * *''Exercitationes matheseos candidatis exhibitaæ'' (1698) (unpublished manuscript): a collection of algebraic and geometrical subjects.

Sources

*
The scientific works of Paolo Casati (1617-1707)
* {{DEFAULTSORT:Casati, Paolo 17th-century Italian mathematicians 18th-century Italian mathematicians 17th-century Italian physicists 17th-century Italian Jesuits 1617 births 1707 deaths Jesuit scientists Catholic clergy scientists Italian Roman Catholics