Barnaba Oriani
Encyclopedia
__FORCETOC__
Barnaba Oriani (July 17, 1752 – November 12, 1832) was an Italian
priest
, geodesist, astronomer
and scientist
.
), the son of a mason, and died in Milan.
After getting his elementary education in Garegnano, he went on to study at the College of San Alessandro in Milan, under the tutelage and with the support of the Order of Barnabus
, which he later joined. After completing his studies in the humanities
, physical and mathematical
sciences, philosophy
, and theology
, he was ordained as a priest in 1775.
When Napoleon I
established the Republic of Lombardy, Oriani refused to swear an oath against the monarchy, and the new republican government modified the oath of allegiance on his behalf. He was retained in his position at the observatory and was made president of the commission appointed to regulate the new system of weights and measures.
When the republic became a Napoleonic kingdom, Oriani was awarded the Iron Crown
and the Legion of Honour, was made a count
and senator, and was appointed to measure the arc of the meridian between the zeniths of Rimini
and Rome
.
Oriani was a devoted friend of the Theatine monk, Giuseppe Piazzi
, the discoverer of Ceres
. Oriani and Piazzi worked together for thirty-seven years, cooperating on many astronomical observations.
).
A very capable astronomer, Oriani's work began to attract considerable attention. His research in the areas of astronomic refraction
, the obliquity of the ecliptic
and orbital theory were of considerable noteworthiness in themselves; but his greatest achievement was his detailed research of the planet Uranus
, which had been discovered by Sir William Herschel
in 1781. Oriani devoted significant time to observations of Uranus, calculating its orbital properties, which he published as a booklet of tables in 1793.
After others had shown that Uranus was not on a parabolic
orbit but rather in a roughly circular orbit, he calculated the orbit in 1783. In 1789, Oriani improved his calculations by accounting for the gravitational effects of Jupiter
and Saturn
.
In addition to his continual contributions to the Effemeridi, he published a series of memoirs on spherical trigonometry
: the Memorie dell' Istituto Italiano, 1806–10, and the Istruzione suelle misure e sui pesi, 1831.
For his work in astronomy, Oriani was honored by naming asteroid
(4540) "Oriani". This asteroid had been discovered at the Osservatorio San Vittore
in Bologna, Italy on November 6, 1988.
The series expansion
he obtained was effective at up to 85 degrees from the zenith. Unlike previous approximations, however, Oriani's two-term expression did not depend on a hypotheses regarding atmospheric temperature or air density
in relation to altitude
. Thus, the effects of atmospheric curvature are only dependent upon the temperature and pressure at the location of the observer.
Oriani's theorem explains why Cassini's
uniform-density model works well except near the horizon—the atmospheric refraction from the zenith to a zenith distance of 70° is not dependent on the details of the distribution of the gas.
Barnaba Oriani (July 17, 1752 – November 12, 1832) was an Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
priest
Priest
A priest is a person authorized to perform the sacred rites of a religion, especially as a mediatory agent between humans and deities. They also have the authority or power to administer religious rites; in particular, rites of sacrifice to, and propitiation of, a deity or deities...
, geodesist, astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
and scientist
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
.
Life
Oriani was born in Garegnano (now part of MilanMilan
Milan is the second-largest city in Italy and the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza ,...
), the son of a mason, and died in Milan.
After getting his elementary education in Garegnano, he went on to study at the College of San Alessandro in Milan, under the tutelage and with the support of the Order of Barnabus
Barnabites
The Barnabites, or Clerics Regular of Saint Paul is a Roman Catholic order.-Establishment of the Order :It was founded in 1530 by three Italian noblemen: St. Anthony Mary Zaccaria The Barnabites, or Clerics Regular of Saint Paul (Latin: Clerici Regulares Sancti Pauli, abbr. B.) is a Roman Catholic...
, which he later joined. After completing his studies in the humanities
Humanities
The humanities are academic disciplines that study the human condition, using methods that are primarily analytical, critical, or speculative, as distinguished from the mainly empirical approaches of the natural sciences....
, physical and mathematical
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
sciences, philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
, and theology
Theology
Theology is the systematic and rational study of religion and its influences and of the nature of religious truths, or the learned profession acquired by completing specialized training in religious studies, usually at a university or school of divinity or seminary.-Definition:Augustine of Hippo...
, he was ordained as a priest in 1775.
When Napoleon I
Napoleon I
Napoleon Bonaparte was a French military and political leader during the latter stages of the French Revolution.As Napoleon I, he was Emperor of the French from 1804 to 1815...
established the Republic of Lombardy, Oriani refused to swear an oath against the monarchy, and the new republican government modified the oath of allegiance on his behalf. He was retained in his position at the observatory and was made president of the commission appointed to regulate the new system of weights and measures.
When the republic became a Napoleonic kingdom, Oriani was awarded the Iron Crown
Iron Crown of Lombardy
The Iron Crown of Lombardy is both a reliquary and one of the most ancient royal insignia of Europe. The crown became one of the symbols of the Kingdom of Lombards and later of the medieval Kingdom of Italy...
and the Legion of Honour, was made a count
Count
A count or countess is an aristocratic nobleman in European countries. The word count came into English from the French comte, itself from Latin comes—in its accusative comitem—meaning "companion", and later "companion of the emperor, delegate of the emperor". The adjective form of the word is...
and senator, and was appointed to measure the arc of the meridian between the zeniths of Rimini
Rimini
Rimini is a medium-sized city of 142,579 inhabitants in the Emilia-Romagna region of Italy, and capital city of the Province of Rimini. It is located on the Adriatic Sea, on the coast between the rivers Marecchia and Ausa...
and Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
.
Oriani was a devoted friend of the Theatine monk, Giuseppe Piazzi
Giuseppe Piazzi
Giuseppe Piazzi was an Italian Catholic priest of the Theatine order, mathematician, and astronomer. He was born in Ponte in Valtellina, and died in Naples. He established an observatory at Palermo, now the Osservatorio Astronomico di Palermo – Giuseppe S...
, the discoverer of Ceres
1 Ceres
Ceres, formally 1 Ceres, is the smallest identified dwarf planet in the Solar System and the only one in the asteroid belt. With a diameter of about 950 km, Ceres is by far the largest and most-massive asteroid, comprising about a third of the mass of the asteroid belt. Discovered on 1 January 1801...
. Oriani and Piazzi worked together for thirty-seven years, cooperating on many astronomical observations.
Astronomy
Given his strong interest in astronomy, Oriani was appointed on the staff of the Observatory of Brera in Milan in 1776, becoming assistant astronomer in 1778 and director in 1802. In 1778 he began publishing various in-depth dissertations on astronomical objects, the Effemeridi di Milano (Ephemerides of MilanEphemeris
An ephemeris is a table of values that gives the positions of astronomical objects in the sky at a given time or times. Different kinds of ephemerides are used for astronomy and astrology...
).
A very capable astronomer, Oriani's work began to attract considerable attention. His research in the areas of astronomic refraction
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
, the obliquity of the ecliptic
Axial tilt
In astronomy, axial tilt is the angle between an object's rotational axis, and a line perpendicular to its orbital plane...
and orbital theory were of considerable noteworthiness in themselves; but his greatest achievement was his detailed research of the planet Uranus
Uranus
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...
, which had been discovered by Sir William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
in 1781. Oriani devoted significant time to observations of Uranus, calculating its orbital properties, which he published as a booklet of tables in 1793.
After others had shown that Uranus was not on a parabolic
Parabolic trajectory
In astrodynamics or celestial mechanics a parabolic trajectory is a Kepler orbit with the eccentricity equal to 1. When moving away from the source it is called an escape orbit, otherwise a capture orbit...
orbit but rather in a roughly circular orbit, he calculated the orbit in 1783. In 1789, Oriani improved his calculations by accounting for the gravitational effects of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
and Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
.
In addition to his continual contributions to the Effemeridi, he published a series of memoirs on spherical trigonometry
Spherical trigonometry
Spherical trigonometry is a branch of spherical geometry which deals with polygons on the sphere and the relationships between the sides and the angles...
: the Memorie dell' Istituto Italiano, 1806–10, and the Istruzione suelle misure e sui pesi, 1831.
For his work in astronomy, Oriani was honored by naming asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
(4540) "Oriani". This asteroid had been discovered at the Osservatorio San Vittore
Osservatorio San Vittore
The Osservatorio San Vittore is an astronomical observatory in Bologna, Italy. It has made a number of asteroid discoveries....
in Bologna, Italy on November 6, 1988.
Oriani's theorem
In De refractionibus astronomicis, Oriani showed that astronomical refraction could be expanded as a series of odd powers of (tan Z), where Z is the observed zenith distance. Such a series had previously been derived by J. H. Lambert, who dropped all but the first term. However, Oriani investigated the higher terms; and he found that neither of the first two terms depended on the structure of the atmosphere.The series expansion
Taylor series
In mathematics, a Taylor series is a representation of a function as an infinite sum of terms that are calculated from the values of the function's derivatives at a single point....
he obtained was effective at up to 85 degrees from the zenith. Unlike previous approximations, however, Oriani's two-term expression did not depend on a hypotheses regarding atmospheric temperature or air density
Density of air
The density of air, ρ , is the mass per unit volume of Earth's atmosphere, and is a useful value in aeronautics and other sciences. Air density decreases with increasing altitude, as does air pressure. It also changes with variances in temperature or humidity...
in relation to altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
. Thus, the effects of atmospheric curvature are only dependent upon the temperature and pressure at the location of the observer.
Oriani's theorem explains why Cassini's
Giovanni Domenico Cassini
This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer...
uniform-density model works well except near the horizon—the atmospheric refraction from the zenith to a zenith distance of 70° is not dependent on the details of the distribution of the gas.