Babylonian influence on Greek astronomy
Encyclopedia
According to Asger Aaboe
, the origins of Western
astronomy
can be found in Mesopotamia
, and all Western efforts in the exact sciences are descendants in direct line from the work of the late Babylonia
n astronomers. Our knowledge of Sumerian astronomy is indirect, via the earliest Babylonian star catalogues
dating from about 1200 BCE. The fact that many star names appear in Sumerian suggests a continuity reaching into the Early Bronze Age.
The history of astronomy
in Mesopotamia, and the world, begins with the Sumer
ians who developed the earliest writing system
—known as cuneiform
—around 3500–3200 BC. The Sumerians developed a form of astronomy that had an important influence on the sophisticated astronomy of the Babylonians. Astrolatry
, which gave planetary gods an important role in Mesopotamian mythology and religion
, began with the Sumerians. They also used a sexagesimal (base 60) place-value number system, which simplified the task of recording very great and very small numbers. The modern practice of dividing a circle into 360 degrees, of 60 minutes each, began with the Sumerians.
During the 8th and 7th centuries BCE, Babylonian astronomers developed a new empirical
approach to astronomy. They began studying philosophy
dealing with the ideal nature of the universe
and began employing an internal logic
within their predictive planetary systems. This was an important contribution to astronomy and the philosophy of science
, and some scholars have thus referred to this new approach as the first scientific revolution. This new approach to astronomy was adopted and further developed in Greek and Hellenistic astronomy. Classical Greek
and Latin
sources frequently use the term Chaldea
ns for the astronomers of Mesopotamia, who were, in reality, priest-scribes specializing in astrology
and other forms of divination
.
Only fragments of Babylonian astronomy have survived, consisting largely of contemporary clay tablets with ephemerides and procedure texts, hence current knowledge of Babylonian planetary theory is in a fragmentary state. Nevertheless, the surviving fragments show that, according to the historian A. Aaboe, Babylonian astronomy was "the first and highly successful attempt at giving a refined mathematical description of astronomical phenomena" and that "all subsequent varieties of scientific astronomy, in the Hellenistic world
, in India
, in Islam
, and in the West—if not indeed all subsequent endeavour in the exact sciences—depend upon Babylonian astronomy in decisive and fundamental ways."
(ca. 1830 BC) and before the Neo-Babylonian Empire
(ca. 626 BC).
The Babylonians were the first to recognize that astronomical phenomena are periodic and apply mathematics to their predictions. Tablets dating back to the Old Babylonian period
document the application of mathematics to the variation in the length of daylight over a solar year. Centuries of Babylonian observations of celestial phenomena are recorded in the series of cuneiform
tablets known as the Enûma Anu Enlil
—the oldest significant astronomical text that we possess is Tablet 63 of the Enûma Anu Enlil, the Venus tablet of Ammisaduqa
, which lists the first and last visible risings of Venus over a period of about 21 years. It is the earliest evidence that planetary phenomena were recognized as periodic.
The MUL.APIN
contains catalogues of stars and constellations
as well as schemes for predicting heliacal rising
s and settings of the planets, and lengths of daylight as measured by a water clock
, gnomon
, shadows, and intercalation
s. The Babylonian GU text arranges stars in 'strings' that lie along declination circles and thus measure right-ascensions or time intervals, and also employs the stars of the zenith, which are also separated by given right-ascensional differences. There are dozens of cuneiform Mesopotamian texts with real observations of eclipses, mainly from Babylonia.
, a 7th century BC copy of a list of observations of the motions of the planet Venus that probably dates as early as the second millennium BC. The Babylonian astrologers
also laid the foundations of what would eventually become Western astrology
. The Enuma anu enlil
, written during the Neo-Assyrian period in the 7th century BC, comprises a list of omen
s and their relationships with various celestial phenomena including the motions of the planets.
The Sumer
ians, predecessors of the Babylonians who are considered to be the first civilization
and are credited with the invention of writing
, had identified at least Venus
by 1500 BC. Shortly afterwards, the other inner planet Mercury
and the outer planets Mars
, Jupiter
, and Saturn
were all identified by Babylonian astronomers. These would remain the only known planets until the invention of the telescope
in early modern times.
presented in Mesopotamian and Assyro-Babylonian literature, particularly in Mesopotamian and Babylonian mythology, very little is known about the cosmology
and world view of the ancient Babylonian astrologers
and astronomers. This is largely due to the current fragmentary state of Babylonian planetary theory, and also due to Babylonian astronomy being independent from cosmology at the time. Nevertheless, traces of cosmology can be found in Babylonian literature and mythology.
In Babylonian cosmology, the Earth and the heavens were depicted as a "spatial whole, even one of round shape
" with references to "the circumference of heaven and earth" and "the totality of heaven and earth". Their worldview was not exactly geocentric
either. The idea of geocentrism, where the center of the Earth is the exact center of the universe
, did not yet exist in Babylonian cosmology, but was established later by the Greek philosopher
Aristotle
's On the Heavens
. In contrast, Babylonian cosmology suggested that the cosmos
revolved around the "cult-place of the deity
", who held ultimate authority as ruler of the cosmic polity. The Babylonians and their predecessors, the Sumerians, also believed in a plurality of heavens and earths. This idea dates back to Sumer
ian incantations of the 2nd millennium BC, which refers to there being seven heavens and seven earths.
n astronomers during the Neo-Babylonian
, Achaemenid
, Seleucid
, and Parthia
n periods of Mesopotamian history. A significant increase in the quality and frequency of Babylonian observations appeared during the reign of Nabonassar
(747–734 BC), who founded the Neo-Babylonian Empire
. The systematic records of ominous phenomena in astronomical diaries that began at this time allowed for the discovery of a repeating 18-year Saros cycle
of lunar eclipses, for example. The Egyptian
astronomer Ptolemy
later used Nabonassar's reign to fix the beginning of an era, since he felt that the earliest usable observations began at this time.
The last stages in the development of Babylonian astronomy took place during the time of the Seleucid Empire
(323–60 BC). In the 3rd century BC, astronomers began to use "goal-year texts" to predict the motions of the planets. These texts compiled records of past observations to find repeating occurrences of ominous phenomena for each planet. About the same time, or shortly afterwards, astronomers created mathematical models that allowed them to predict these phenomena directly, without consulting past records.
and not with theory. Most of the predictive Babylonian planetary models that have survived were usually strictly empirical
and arithmetic
al, and usually did not involve geometry
, cosmology
, or speculative philosophy
like that of the later Hellenistic models, though the Babylonian astronomers were concerned with the philosophy dealing with the ideal nature of the early universe
.
In contrast to Greek astronomy
which was dependent upon cosmology, Babylonian astronomy was independent from cosmology. Whereas Greek astronomers expressed "prejudice in favor of circles or spheres rotating with uniform motion", such a preference did not exist for Babylonian astronomers, for whom uniform circular motion
was never a requirement for planetary orbits. There is no evidence that the celestial bodies moved in uniform circular motion, or along celestial spheres
, in Babylonian astronomy.
Contributions made by the Chaldean astronomers during this period include the discovery of eclipse cycle
s and saros cycle
s, and many accurate astronomical observations. For example, they observed that the Sun
's motion along the ecliptic
was not uniform, though they were unaware of why this was; it is today known that this is due to the Earth moving in an elliptic orbit
around the Sun, with the Earth moving swifter when it is nearer to the Sun at perihelion and moving slower when it is farther away at aphelion.
Chaldean astronomers known to have followed this model include Naburimannu
(fl. 6th–3rd century BC), Kidinnu
(d. 330 BC), Berossus
(3rd century BCE), and Sudines
(fl.
240 BCE). They are known to have had a significant influence on the Greek astronomer
Hipparchus
and the Egyptian astronomer
Ptolemy
, as well as other Hellenistic
astronomers.
(b. 190 BC), who supported Aristarchus of Samos
' heliocentric
model. Seleucus is known from the writings of Plutarch
, Aetius
, Strabo
, and Muhammad ibn Zakariya al-Razi. Strabo lists Seleucus as one of the four most influential Chaldean/Babylonian astronomers, alongside Kidenas (Kidinnu), Naburianos
(Naburimannu), and Sudines
. Their works were originally written in the Akkadian language
and later translated into Greek
. Seleucus, however, was unique among them in that he was the only one known to have supported the heliocentric theory of planetary motion proposed by Aristarchus, where the Earth rotated around its own axis which in turn revolved around the Sun
. According to Plutarch, Seleucus even proved the heliocentric system through reasoning, though it is not known what arguments he used.
According to Lucio Russo
, his arguments were probably related to the phenomenon of tide
s. Seleucus correctly theorized that tides were caused by the Moon
, although he believed that the interaction was mediated by the Earth's atmosphere
. He noted that the tides varied in time and strength in different parts of the world. According to Strabo
(1.1.9), Seleucus was the first to state that the tide
s are due to the attraction of the Moon, and that the height of the tides depends on the Moon's position relative to the Sun.
According to Bartel Leendert van der Waerden
, Seleucus may have proved the heliocentric theory by determining the constants of a geometric
model for the heliocentric theory and by developing methods to compute planetary positions using this model. He may have used trigonometric
methods that were available in his time, as he was a contemporary of Hipparchus
.
None of his original writings or Greek translations have survived, though a fragment of his work has survived only in Arabic
translation, which was later referred to by the Persian philosopher
Muhammad ibn Zakariya al-Razi (865-925).
and Hellenistic
writers (including mathematicians
, astronomers
, and geographers) have been preserved up to the present time, or some aspects of their work and thought are still known through later references. However, achievements in these fields by earlier ancient Near East
ern civilizations, notably those in Babylonia
, were forgotten for a long time. Since the discovery of key archaeological sites in the 19th century, many cuneiform
writings on clay tablet
s have been found, some of them related to astronomy
. Most known astronomical tablets have been described by Abraham Sachs
and later published by Otto Neugebauer in the Astronomical Cuneiform Texts (ACT).
Since the rediscovery of the Babylonian civilization, it has become apparent that Hellenistic astronomy
was strongly influenced by the Chaldea
ns. The best documented borrowings are those of Hipparchus
(2nd century BCE) and Claudius Ptolemy
(2nd century CE).
is likely to have been learned by the Greeks from Babylonian scribes. Meton of Athens
, a Greek astronomer of the 5th century BCE, developed a lunisolar calendar
based on the fact that 19 solar years is about equal to 235 lunar months, a period relation already known to the Babylonians.
In the 4th century, Eudoxus of Cnidus
wrote a book on the fixed star
s. His descriptions of many constellations, especially the twelve signs of the zodiac
, are suspiciously similar to Babylonian originals. The following century Aristarchus of Samos
used an eclipse cycle of Babylonian origin called the Saros cycle
to determine the year length. However, all these examples of early influence must be inferred and the chain of transmission is not known.
IV.2 that Hipparchus improved the values for the Moon's periods known to him from "even more ancient astronomers" by comparing eclipse observations made earlier by "the Chaldeans", and by himself. However Kugler found that the periods that Ptolemy attributes to Hipparchus had already been used in Babylonian ephemerides, specifically the collection of texts nowadays called "System B" (sometimes attributed to Kidinnu
). Apparently Hipparchus only confirmed the validity of the periods he learned from the Chaldeans by his newer observations. Later Greek knowledge of this specific Babylonian theory is confirmed by 2nd-century papyrus, which contains 32 lines of a single column of calculations for the Moon using this same "System B", but written in Greek on papyrus rather than in cuneiform on clay tablets.
It is clear that Hipparchus (and Ptolemy after him) had an essentially complete list of eclipse observations covering many centuries. Most likely these had been compiled from the "diary" tablets: these are clay tablets recording all relevant observations that the Chaldeans routinely made. Preserved examples date from 652 BC to AD 130, but probably the records went back as far as the reign of the Babylonian king Nabonassar
: Ptolemy starts his chronology with the first day in the Egyptian calendar of the first year of Nabonassar; i.e., 26 February 747 BC.
This raw material by itself must have been tough to use, and no doubt the Chaldeans themselves compiled extracts of e.g., all observed eclipses (some tablets with a list of all eclipses in a period of time covering a saros
have been found). This allowed them to recognise periodic recurrences of events. Among others they used in System B (cf. Almagest IV.2):
The Babylonians expressed all periods in synodic month
s, probably because they used a lunisolar calendar
. Various relations with yearly phenomena led to different values for the length of the year.
Similarly various relations between the periods of the planet
s were known. The relations that Ptolemy attributes to Hipparchus in Almagest IX.3 had all already been used in predictions found on Babylonian clay tablets.
Other traces of Babylonian practice in Hipparchus' work are
probably shortly after the conquest by Alexander the Great (331 BC
). According to the late classical philosopher Simplicius
(early 6th century), Alexander ordered the translation of the historical astronomical records under supervision of his chronicler Callisthenes of Olynthus
, who sent it to his uncle Aristotle
. It is worth mentioning here that although Simplicius is a very late source, his account may be reliable. He spent some time in exile at the Sassanid (Persian) court, and may have accessed sources otherwise lost in the West. It is striking that he mentions the title tèresis (Greek: guard) which is an odd name for a historical work, but is in fact an adequate translation of the Babylonian title massartu meaning "guarding" but also "observing". Anyway, Aristotle's pupil Callippus of Cyzicus
introduced his 76-year cycle, which improved upon the 19-year Metonic cycle
, about that time. He had the first year of his first cycle start at the summer solstice of 28 June 330 BC (Julian
proleptic date), but later he seems to have counted lunar months from the first month after Alexander's decisive battle at Gaugamela in fall 331 BC
. So Callippus may have obtained his data from Babylonian sources and his calendar may have been anticipated by Kidinnu. Also it is known that the Babylonian priest known as Berossus
wrote around 281 BC
a book in Greek
on the (rather mythological) history of Babylonia, the Babyloniaca, for the new ruler Antiochus I; it is said that later he founded a school of astrology
on the Greek island of Kos
. Another candidate for teaching the Greeks about Babylonian astronomy
/astrology
was Sudines
who was at the court of Attalus I Soter
late in the 3rd century BC.
In any case, the translation of the astronomical records required profound knowledge of the cuneiform script
, the language, and the procedures, so it seems likely that it was done by some unidentified Chaldeans. Now, the Babylonians dated their observations in their lunisolar calendar, in which months and years have varying lengths (29 or 30 days; 12 or 13 months respectively). At the time they did not use a regular calendar (such as based on the Metonic cycle
like they did later), but started a new month based on observations of the New Moon
. This made it very tedious to compute the time interval between events.
What Hipparchus may have done is transform these records to the Egyptian calendar
, which uses a fixed year of always 365 days (consisting of 12 months of 30 days and 5 extra days): this makes computing time intervals much easier. Ptolemy dated all observations in this calendar. He also writes that "All that he (=Hipparchus) did was to make a compilation of the planetary observations arranged in a more useful way" (Almagest IX.2). Pliny states (Naturalis Historia II.IX(53)) on eclipse predictions: "After their time (=Thales
) the courses of both stars (=Sun and Moon) for 600 years were prophesied by Hipparchus, ...". This seems to imply that Hipparchus predicted eclipses for a period of 600 years, but considering the enormous amount of computation required, this is very unlikely. Rather, Hipparchus would have made a list of all eclipses from Nabonasser's time to his own.
, the city of Ctesiphon
, was founded in Mesopotamia. Astronomy was studied by Persians
and Babylonians in Ctesiphon and in the Academy of Gundishapur
in Persia. Most of the astronomical texts during the Sassanid period were written in the Middle Persian
language. The Zij al-Shah
, a collection of astronomical tables compiled in Persia and Mesopotamia over two centuries, was the most famous astronomical text from the Sassanid period, and was later translated into Arabic
.
, the province of Mesopotamia came to be known as Iraq in the Arabic language
. During the Abbasid
period of the region's history, Baghdad
was the capital of the Arab Empire, and for centuries, remained the centre of astronomical activity throughout the Islamic world
. Astronomy was also studied in Basra
and other Iraqi cities. During the Islamic period, Arabic was adopted as the language of scholarship, and Iraq continued to make numerous contributions to the field of astronomy, up until the 1258 sack of Baghdad
, when many libraries were destroyed and scientific activity in Iraq came to a halt. Despite this, the work that did survive had an impact on the subsequent development of astronomy, through the medieval Arabic-Latin translation movement in Europe and Maragheh observatory
in Persia.
Asger Aaboe
Asger Hartvig Aaboe was a historian of the exact sciences and mathematician who is known for his contributions to the history of ancient Babylonian astronomy...
, the origins of Western
Western world
The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...
astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
can be found in Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
, and all Western efforts in the exact sciences are descendants in direct line from the work of the late Babylonia
Babylonia
Babylonia was an ancient cultural region in central-southern Mesopotamia , with Babylon as its capital. Babylonia emerged as a major power when Hammurabi Babylonia was an ancient cultural region in central-southern Mesopotamia (present-day Iraq), with Babylon as its capital. Babylonia emerged as...
n astronomers. Our knowledge of Sumerian astronomy is indirect, via the earliest Babylonian star catalogues
Babylonian star catalogues
Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, individual stars, and planets...
dating from about 1200 BCE. The fact that many star names appear in Sumerian suggests a continuity reaching into the Early Bronze Age.
The history of astronomy
History of astronomy
Astronomy is the oldest of the natural sciences, dating back to antiquity, with its origins in the religious, mythological, and astrological practices of pre-history: vestiges of these are still found in astrology, a discipline long interwoven with public and governmental astronomy, and not...
in Mesopotamia, and the world, begins with the Sumer
Sumer
Sumer was a civilization and historical region in southern Mesopotamia, modern Iraq during the Chalcolithic and Early Bronze Age....
ians who developed the earliest writing system
History of writing
The history of writing records the development of expressing language by letters or other marks. In the history of how systems of representation of language through graphic means have evolved in different human civilizations, more complete writing systems were preceded by proto-writing, systems of...
—known as cuneiform
Cuneiform
Cuneiform can refer to:*Cuneiform script, an ancient writing system originating in Mesopotamia in the 4th millennium BC*Cuneiform , three bones in the human foot*Cuneiform Records, a music record label...
—around 3500–3200 BC. The Sumerians developed a form of astronomy that had an important influence on the sophisticated astronomy of the Babylonians. Astrolatry
Astrolatry
Astrolatry is the worship of stars and other heavenly bodies as deities, or the association of deities with heavenly bodies.The most common instances of this are sun gods and moon gods in polytheistic systems worldwide. Also notable is the association of the planets with deities in Babylonian, and...
, which gave planetary gods an important role in Mesopotamian mythology and religion
Mesopotamian religion
Mesopotamian religion refers to the religious beliefs and practices followed by the Sumerian and Akkadian peoples living in Mesopotamia that dominated the region for a period of 4200 years from the fourth millennium BC to approximately the 3rd century AD...
, began with the Sumerians. They also used a sexagesimal (base 60) place-value number system, which simplified the task of recording very great and very small numbers. The modern practice of dividing a circle into 360 degrees, of 60 minutes each, began with the Sumerians.
During the 8th and 7th centuries BCE, Babylonian astronomers developed a new empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
approach to astronomy. They began studying 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...
dealing with the ideal nature of the universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
and began employing an internal logic
Consistency proof
In logic, a consistent theory is one that does not contain a contradiction. The lack of contradiction can be defined in either semantic or syntactic terms. The semantic definition states that a theory is consistent if and only if it has a model, i.e. there exists an interpretation under which all...
within their predictive planetary systems. This was an important contribution to astronomy and the philosophy of science
Philosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...
, and some scholars have thus referred to this new approach as the first scientific revolution. This new approach to astronomy was adopted and further developed in Greek and Hellenistic astronomy. Classical Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
and Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
sources frequently use the term Chaldea
Chaldea
Chaldea or Chaldaea , from Greek , Chaldaia; Akkadian ; Hebrew כשדים, Kaśdim; Aramaic: ܟܐܠܕܘ, Kaldo) was a marshy land located in modern-day southern Iraq which came to briefly rule Babylon...
ns for the astronomers of Mesopotamia, who were, in reality, priest-scribes specializing in astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...
and other forms of divination
Divination
Divination is the attempt to gain insight into a question or situation by way of an occultic standardized process or ritual...
.
Only fragments of Babylonian astronomy have survived, consisting largely of contemporary clay tablets with ephemerides and procedure texts, hence current knowledge of Babylonian planetary theory is in a fragmentary state. Nevertheless, the surviving fragments show that, according to the historian A. Aaboe, Babylonian astronomy was "the first and highly successful attempt at giving a refined mathematical description of astronomical phenomena" and that "all subsequent varieties of scientific astronomy, in the Hellenistic world
Hellenistic civilization
Hellenistic civilization represents the zenith of Greek influence in the ancient world from 323 BCE to about 146 BCE...
, in India
History of India
The history of India begins with evidence of human activity of Homo sapiens as long as 75,000 years ago, or with earlier hominids including Homo erectus from about 500,000 years ago. The Indus Valley Civilization, which spread and flourished in the northwestern part of the Indian subcontinent from...
, in Islam
Islamic Golden Age
During the Islamic Golden Age philosophers, scientists and engineers of the Islamic world contributed enormously to technology and culture, both by preserving earlier traditions and by adding their own inventions and innovations...
, and in the West—if not indeed all subsequent endeavour in the exact sciences—depend upon Babylonian astronomy in decisive and fundamental ways."
Old Babylonian astronomy
Old Babylonian astronomy refers to the astronomy that was practiced during and after the First Babylonian DynastyFirst Babylonian Dynasty
The chronology of the first dynasty of Babylonia is debated as there is a Babylonian King List A and a Babylonian King List B. In this chronology, the regnal years of List A are used due to their wide usage...
(ca. 1830 BC) and before the Neo-Babylonian Empire
Neo-Babylonian Empire
The Neo-Babylonian Empire or Second Babylonian Empire was a period of Mesopotamian history which began in 626 BC and ended in 539 BC. During the preceding three centuries, Babylonia had been ruled by their fellow Akkadian speakers and northern neighbours, Assyria. Throughout that time Babylonia...
(ca. 626 BC).
The Babylonians were the first to recognize that astronomical phenomena are periodic and apply mathematics to their predictions. Tablets dating back to the Old Babylonian period
First Babylonian Dynasty
The chronology of the first dynasty of Babylonia is debated as there is a Babylonian King List A and a Babylonian King List B. In this chronology, the regnal years of List A are used due to their wide usage...
document the application of mathematics to the variation in the length of daylight over a solar year. Centuries of Babylonian observations of celestial phenomena are recorded in the series of cuneiform
Cuneiform
Cuneiform can refer to:*Cuneiform script, an ancient writing system originating in Mesopotamia in the 4th millennium BC*Cuneiform , three bones in the human foot*Cuneiform Records, a music record label...
tablets known as the Enûma Anu Enlil
Enuma anu enlil
Enuma Anu Enlil is a major series of 68 or 70 tablets dealing with Babylonian astrology...
—the oldest significant astronomical text that we possess is Tablet 63 of the Enûma Anu Enlil, the Venus tablet of Ammisaduqa
Venus tablet of Ammisaduqa
The Venus tablet of Ammisaduqa refers to the record of astronomical observations of Venus, as preserved in numerous cuneiform tablets dating from the first millennium BCE. It is believed that this astronomical record was first compiled during the reign of King Ammisaduqa , the fourth ruler after...
, which lists the first and last visible risings of Venus over a period of about 21 years. It is the earliest evidence that planetary phenomena were recognized as periodic.
The MUL.APIN
MUL.APIN
MUL.APIN is the conventional title given to a Babylonian compendium that deals with many diverse aspects of Babylonian astronomy and astrology....
contains catalogues of stars and constellations
Babylonian star catalogues
Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, individual stars, and planets...
as well as schemes for predicting heliacal rising
Heliacal rising
The heliacal rising of a star occurs when it first becomes visible above the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible....
s and settings of the planets, and lengths of daylight as measured by a water clock
Water clock
A water clock or clepsydra is any timepiece in which time is measured by the regulated flow of liquid into or out from a vessel where the amount is then measured.Water clocks, along with sundials, are likely to be the oldest time-measuring instruments, with the only exceptions...
, gnomon
Gnomon
The gnomon is the part of a sundial that casts the shadow. Gnomon is an ancient Greek word meaning "indicator", "one who discerns," or "that which reveals."It has come to be used for a variety of purposes in mathematics and other fields....
, shadows, and intercalation
Intercalation
Intercalation is the insertion of a leap day, week or month into some calendar years to make the calendar follow the seasons or moon phases. Lunisolar calendars may require intercalations of both days and months.- Solar calendars :...
s. The Babylonian GU text arranges stars in 'strings' that lie along declination circles and thus measure right-ascensions or time intervals, and also employs the stars of the zenith, which are also separated by given right-ascensional differences. There are dozens of cuneiform Mesopotamian texts with real observations of eclipses, mainly from Babylonia.
Planetary theory
The first civilisation known to possess a functional theory of the planets were the Babylonians. The oldest surviving planetary astronomical text is the Babylonian Venus tablet of AmmisaduqaVenus tablet of Ammisaduqa
The Venus tablet of Ammisaduqa refers to the record of astronomical observations of Venus, as preserved in numerous cuneiform tablets dating from the first millennium BCE. It is believed that this astronomical record was first compiled during the reign of King Ammisaduqa , the fourth ruler after...
, a 7th century BC copy of a list of observations of the motions of the planet Venus that probably dates as early as the second millennium BC. The Babylonian astrologers
Babylonian astrology
In Babylon as well as in Assyria as a direct offshoot of Babylonian culture, astrology takes its place in theofficial cult as one of the two chief means at the disposal of the priests for ascertaining the will and intention of the gods, the other being through the inspection of the liver of the...
also laid the foundations of what would eventually become Western astrology
Western astrology
Western astrology is the system of astrology most popular in Western countries. Western astrology is historically based on Ptolemy's Tetrabiblos , which in turn was a continuation of Hellenistic and ultimately Babylonian traditions....
. The Enuma anu enlil
Enuma anu enlil
Enuma Anu Enlil is a major series of 68 or 70 tablets dealing with Babylonian astrology...
, written during the Neo-Assyrian period in the 7th century BC, comprises a list of omen
Omen
An omen is a phenomenon that is believed to foretell the future, often signifying the advent of change...
s and their relationships with various celestial phenomena including the motions of the planets.
The Sumer
Sumer
Sumer was a civilization and historical region in southern Mesopotamia, modern Iraq during the Chalcolithic and Early Bronze Age....
ians, predecessors of the Babylonians who are considered to be the first civilization
Cradle of Civilization
The cradle of civilization is a term referring to any of the possible locations for the emergence of civilization.It is usually applied to the Ancient Near Eastern Chalcolithic , especially in the Fertile Crescent , but also extended to sites in Armenia, and the Persian Plateau, besides other Asian...
and are credited with the invention of writing
Writing
Writing is the representation of language in a textual medium through the use of a set of signs or symbols . It is distinguished from illustration, such as cave drawing and painting, and non-symbolic preservation of language via non-textual media, such as magnetic tape audio.Writing most likely...
, had identified at least Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
by 1500 BC. Shortly afterwards, the other inner planet Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
and the outer planets Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
, 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,...
were all identified by Babylonian astronomers. These would remain the only known planets until the invention of the telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
in early modern times.
Cosmology
In contrast to the world viewWorld view
A comprehensive world view is the fundamental cognitive orientation of an individual or society encompassing the entirety of the individual or society's knowledge and point-of-view, including natural philosophy; fundamental, existential, and normative postulates; or themes, values, emotions, and...
presented in Mesopotamian and Assyro-Babylonian literature, particularly in Mesopotamian and Babylonian mythology, very little is known about the cosmology
Cosmology
Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...
and world view of the ancient Babylonian astrologers
Babylonian astrology
In Babylon as well as in Assyria as a direct offshoot of Babylonian culture, astrology takes its place in theofficial cult as one of the two chief means at the disposal of the priests for ascertaining the will and intention of the gods, the other being through the inspection of the liver of the...
and astronomers. This is largely due to the current fragmentary state of Babylonian planetary theory, and also due to Babylonian astronomy being independent from cosmology at the time. Nevertheless, traces of cosmology can be found in Babylonian literature and mythology.
In Babylonian cosmology, the Earth and the heavens were depicted as a "spatial whole, even one of round shape
Spherical Earth
The concept of a spherical Earth dates back to ancient Greek philosophy from around the 6th century BC, but remained a matter of philosophical speculation until the 3rd century BC when Hellenistic astronomy established the spherical shape of the earth as a physical given...
" with references to "the circumference of heaven and earth" and "the totality of heaven and earth". Their worldview was not exactly geocentric
Geocentric model
In astronomy, the geocentric model , is the superseded theory that the Earth is the center of the universe, and that all other objects orbit around it. This geocentric model served as the predominant cosmological system in many ancient civilizations such as ancient Greece...
either. The idea of geocentrism, where the center of the Earth is the exact center of the universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
, did not yet exist in Babylonian cosmology, but was established later by the Greek philosopher
Greek philosophy
Ancient Greek philosophy arose in the 6th century BCE and continued through the Hellenistic period, at which point Ancient Greece was incorporated in the Roman Empire...
Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
's On the Heavens
On the Heavens
On the Heavens is Aristotle's chief cosmological treatise: it contains his astronomical theory and his ideas on the concrete workings of the terrestrial world...
. In contrast, Babylonian cosmology suggested that the cosmos
Cosmos
In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος , meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the word Universe . The word cosmos originates from the same root...
revolved around the "cult-place of the deity
Deity
A deity is a recognized preternatural or supernatural immortal being, who may be thought of as holy, divine, or sacred, held in high regard, and respected by believers....
", who held ultimate authority as ruler of the cosmic polity. The Babylonians and their predecessors, the Sumerians, also believed in a plurality of heavens and earths. This idea dates back to Sumer
Sumer
Sumer was a civilization and historical region in southern Mesopotamia, modern Iraq during the Chalcolithic and Early Bronze Age....
ian incantations of the 2nd millennium BC, which refers to there being seven heavens and seven earths.
Neo-Babylonian astronomy
Neo-Babylonian astronomy refers to the astronomy developed by ChaldeaChaldea
Chaldea or Chaldaea , from Greek , Chaldaia; Akkadian ; Hebrew כשדים, Kaśdim; Aramaic: ܟܐܠܕܘ, Kaldo) was a marshy land located in modern-day southern Iraq which came to briefly rule Babylon...
n astronomers during the Neo-Babylonian
Neo-Babylonian Empire
The Neo-Babylonian Empire or Second Babylonian Empire was a period of Mesopotamian history which began in 626 BC and ended in 539 BC. During the preceding three centuries, Babylonia had been ruled by their fellow Akkadian speakers and northern neighbours, Assyria. Throughout that time Babylonia...
, Achaemenid
Achaemenid Assyria
Athura was a geographical area within the Persian Achaemenid Empire during the period of 539 BC to 330 BC. Although sometimes regarded as a satrapy, Achaemenid royal inscriptions list it as a dahyu, a concept generally interpreted as meaning either a group of people or both a country and its...
, Seleucid
Seleucid Empire
The Seleucid Empire was a Greek-Macedonian state that was created out of the eastern conquests of Alexander the Great. At the height of its power, it included central Anatolia, the Levant, Mesopotamia, Persia, today's Turkmenistan, Pamir and parts of Pakistan.The Seleucid Empire was a major centre...
, and Parthia
Parthia
Parthia is a region of north-eastern Iran, best known for having been the political and cultural base of the Arsacid dynasty, rulers of the Parthian Empire....
n periods of Mesopotamian history. A significant increase in the quality and frequency of Babylonian observations appeared during the reign of Nabonassar
Nabonassar
Nabonassar founded a kingdom in Babylon in 747 BC. This is now considered as the start of the Neo-Babylonian Dynasty. At the time the Assyrian Empire was in disarray through civil war and the ascendancy of other kingdoms such as Urartu...
(747–734 BC), who founded the Neo-Babylonian Empire
Neo-Babylonian Empire
The Neo-Babylonian Empire or Second Babylonian Empire was a period of Mesopotamian history which began in 626 BC and ended in 539 BC. During the preceding three centuries, Babylonia had been ruled by their fellow Akkadian speakers and northern neighbours, Assyria. Throughout that time Babylonia...
. The systematic records of ominous phenomena in astronomical diaries that began at this time allowed for the discovery of a repeating 18-year Saros cycle
Saros cycle
The saros is a period of 223 synodic months , that can be used to predict eclipses of the Sun and Moon. One saros after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur, in what is referred to as an eclipse cycle...
of lunar eclipses, for example. The Egyptian
Egyptian astronomy
Egyptian astronomy begins in prehistoric times, in the Predynastic Period. In the 5th millennium BCE, the stone circles at Nabta Playa may have made use of astronomical alignments...
astronomer Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
later used Nabonassar's reign to fix the beginning of an era, since he felt that the earliest usable observations began at this time.
The last stages in the development of Babylonian astronomy took place during the time of the Seleucid Empire
Seleucid Empire
The Seleucid Empire was a Greek-Macedonian state that was created out of the eastern conquests of Alexander the Great. At the height of its power, it included central Anatolia, the Levant, Mesopotamia, Persia, today's Turkmenistan, Pamir and parts of Pakistan.The Seleucid Empire was a major centre...
(323–60 BC). In the 3rd century BC, astronomers began to use "goal-year texts" to predict the motions of the planets. These texts compiled records of past observations to find repeating occurrences of ominous phenomena for each planet. About the same time, or shortly afterwards, astronomers created mathematical models that allowed them to predict these phenomena directly, without consulting past records.
Empirical astronomy
Though there is a lack of surviving material on Babylonian planetary theory, it appears most of the Chaldean astronomers were concerned mainly with ephemeridesEphemeris
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...
and not with theory. Most of the predictive Babylonian planetary models that have survived were usually strictly empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
and arithmetic
Arithmetic
Arithmetic or arithmetics is the oldest and most elementary branch of mathematics, used by almost everyone, for tasks ranging from simple day-to-day counting to advanced science and business calculations. It involves the study of quantity, especially as the result of combining numbers...
al, and usually did not involve geometry
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
, cosmology
Cosmology
Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...
, or speculative 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...
like that of the later Hellenistic models, though the Babylonian astronomers were concerned with the philosophy dealing with the ideal nature of the early universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
.
In contrast to Greek astronomy
Greek astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the...
which was dependent upon cosmology, Babylonian astronomy was independent from cosmology. Whereas Greek astronomers expressed "prejudice in favor of circles or spheres rotating with uniform motion", such a preference did not exist for Babylonian astronomers, for whom uniform circular motion
Uniform circular motion
In physics, uniform circular motion describes the motion of a body traversing a circular path at constant speed. The distance of the body from the axis of rotation remains constant at all times. Though the body's speed is constant, its velocity is not constant: velocity, a vector quantity, depends...
was never a requirement for planetary orbits. There is no evidence that the celestial bodies moved in uniform circular motion, or along celestial spheres
Celestial spheres
The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others...
, in Babylonian astronomy.
Contributions made by the Chaldean astronomers during this period include the discovery of eclipse cycle
Eclipse cycle
Eclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles. The series of eclipses separated by a repeat of one of these intervals is called an eclipse series.- Eclipse conditions :...
s and saros cycle
Saros cycle
The saros is a period of 223 synodic months , that can be used to predict eclipses of the Sun and Moon. One saros after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur, in what is referred to as an eclipse cycle...
s, and many accurate astronomical observations. For example, they observed that the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
's motion along the ecliptic
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
was not uniform, though they were unaware of why this was; it is today known that this is due to the Earth moving in an elliptic orbit
Elliptic orbit
In astrodynamics or celestial mechanics an elliptic orbit is a Kepler orbit with the eccentricity less than 1; this includes the special case of a circular orbit, with eccentricity equal to zero. In a stricter sense, it is a Kepler orbit with the eccentricity greater than 0 and less than 1 . In a...
around the Sun, with the Earth moving swifter when it is nearer to the Sun at perihelion and moving slower when it is farther away at aphelion.
Chaldean astronomers known to have followed this model include Naburimannu
Naburimannu
Nabu-ri-man-nu was a Chaldean astronomer and mathematician.Classical and ancient cuneiform sources mention an astronomer with this name:...
(fl. 6th–3rd century BC), Kidinnu
Kidinnu
Kidinnu was a Chaldean astronomer and mathematician. Strabo of Amaseia called him Kidenas, Pliny the Elder Cidenas, and Vettius Valens Kidynas....
(d. 330 BC), Berossus
Berossus
Berossus was a Hellenistic-era Babylonian writer, a priest of Bel Marduk and astronomer writing in Greek, who was active at the beginning of the 3rd century BC...
(3rd century BCE), and Sudines
Sudines
Sudines : Babylonian sage. He is mentioned as one of the famous Chaldean mathematicians and astronomer-astrologers by later Roman writers like Strabo ....
(fl.
Floruit
Floruit , abbreviated fl. , is a Latin verb meaning "flourished", denoting the period of time during which something was active...
240 BCE). They are known to have had a significant influence on the Greek astronomer
Greek astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the...
Hipparchus
Hipparchus
Hipparchus, the common Latinization of the Greek Hipparkhos, can mean:* Hipparchus, the ancient Greek astronomer** Hipparchic cycle, an astronomical cycle he created** Hipparchus , a lunar crater named in his honour...
and the Egyptian astronomer
Egyptian astronomy
Egyptian astronomy begins in prehistoric times, in the Predynastic Period. In the 5th millennium BCE, the stone circles at Nabta Playa may have made use of astronomical alignments...
Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
, as well as other Hellenistic
Hellenistic civilization
Hellenistic civilization represents the zenith of Greek influence in the ancient world from 323 BCE to about 146 BCE...
astronomers.
Heliocentric astronomy
The only surviving planetary model from among the Chaldean astronomers is that of Seleucus of SeleuciaSeleucus of Seleucia
Seleucus of Seleucia was a Hellenistic astronomer and philosopher. Coming from Seleucia on the Tigris, the capital of the Seleucid empire, or, alternatively, Seleukia on the Red Sea, he is best known as a proponent of heliocentrism and for his theory of the origin of tides.- Heliocentric theory...
(b. 190 BC), who supported Aristarchus of Samos
Aristarchus of Samos
Aristarchus, or more correctly Aristarchos , was a Greek astronomer and mathematician, born on the island of Samos, in Greece. He presented the first known heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe...
' heliocentric
Heliocentrism
Heliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...
model. Seleucus is known from the writings of Plutarch
Plutarch
Plutarch then named, on his becoming a Roman citizen, Lucius Mestrius Plutarchus , c. 46 – 120 AD, was a Greek historian, biographer, essayist, and Middle Platonist known primarily for his Parallel Lives and Moralia...
, Aetius
Aetius (philosopher)
Aetius was a 1st or 2nd century doxographer and Eclectic philosopher.None of Aetius' works survive today, but he solves a mystery about two major compilations of philosophical quotes...
, Strabo
Strabo
Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...
, and Muhammad ibn Zakariya al-Razi. Strabo lists Seleucus as one of the four most influential Chaldean/Babylonian astronomers, alongside Kidenas (Kidinnu), Naburianos
Naburimannu
Nabu-ri-man-nu was a Chaldean astronomer and mathematician.Classical and ancient cuneiform sources mention an astronomer with this name:...
(Naburimannu), and Sudines
Sudines
Sudines : Babylonian sage. He is mentioned as one of the famous Chaldean mathematicians and astronomer-astrologers by later Roman writers like Strabo ....
. Their works were originally written in the Akkadian language
Akkadian language
Akkadian is an extinct Semitic language that was spoken in ancient Mesopotamia. The earliest attested Semitic language, it used the cuneiform writing system derived ultimately from ancient Sumerian, an unrelated language isolate...
and later translated into Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
. Seleucus, however, was unique among them in that he was the only one known to have supported the heliocentric theory of planetary motion proposed by Aristarchus, where the Earth rotated around its own axis which in turn revolved around the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. According to Plutarch, Seleucus even proved the heliocentric system through reasoning, though it is not known what arguments he used.
According to Lucio Russo
Lucio Russo
Lucio Russo is an Italian physicist, mathematician and historian of science. Born in Venice, he teaches at the Mathematics Department of the Science College in the University of Rome Tor Vergata....
, his arguments were probably related to the phenomenon of tide
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....
s. Seleucus correctly theorized that tides were caused by the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, although he believed that the interaction was mediated by the Earth's atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
. He noted that the tides varied in time and strength in different parts of the world. According to Strabo
Strabo
Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...
(1.1.9), Seleucus was the first to state that the tide
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....
s are due to the attraction of the Moon, and that the height of the tides depends on the Moon's position relative to the Sun.
According to Bartel Leendert van der Waerden
Bartel Leendert van der Waerden
Bartel Leendert van der Waerden was a Dutch mathematician and historian of mathematics....
, Seleucus may have proved the heliocentric theory by determining the constants of a geometric
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
model for the heliocentric theory and by developing methods to compute planetary positions using this model. He may have used trigonometric
Trigonometry
Trigonometry is a branch of mathematics that studies triangles and the relationships between their sides and the angles between these sides. Trigonometry defines the trigonometric functions, which describe those relationships and have applicability to cyclical phenomena, such as waves...
methods that were available in his time, as he was a contemporary of Hipparchus
Hipparchus
Hipparchus, the common Latinization of the Greek Hipparkhos, can mean:* Hipparchus, the ancient Greek astronomer** Hipparchic cycle, an astronomical cycle he created** Hipparchus , a lunar crater named in his honour...
.
None of his original writings or Greek translations have survived, though a fragment of his work has survived only in Arabic
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...
translation, which was later referred to by the Persian philosopher
Iranian philosophy
Iranian philosophy or Persian philosophy can be traced back as far as to Old Iranian philosophical traditions and thoughts which originated in ancient Indo-Iranian roots and were considerably influenced by Zarathustra's teachings...
Muhammad ibn Zakariya al-Razi (865-925).
Babylonian influence on Hellenistic astronomy
Many of the works of ancient GreekAncient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
and Hellenistic
Hellenistic civilization
Hellenistic civilization represents the zenith of Greek influence in the ancient world from 323 BCE to about 146 BCE...
writers (including mathematicians
Greek mathematics
Greek mathematics, as that term is used in this article, is the mathematics written in Greek, developed from the 7th century BC to the 4th century AD around the Eastern shores of the Mediterranean. Greek mathematicians lived in cities spread over the entire Eastern Mediterranean, from Italy to...
, astronomers
Greek astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the...
, and geographers) have been preserved up to the present time, or some aspects of their work and thought are still known through later references. However, achievements in these fields by earlier ancient Near East
Ancient Near East
The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia , ancient Egypt, ancient Iran The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia...
ern civilizations, notably those in Babylonia
Babylonia
Babylonia was an ancient cultural region in central-southern Mesopotamia , with Babylon as its capital. Babylonia emerged as a major power when Hammurabi Babylonia was an ancient cultural region in central-southern Mesopotamia (present-day Iraq), with Babylon as its capital. Babylonia emerged as...
, were forgotten for a long time. Since the discovery of key archaeological sites in the 19th century, many cuneiform
Cuneiform script
Cuneiform script )) is one of the earliest known forms of written expression. Emerging in Sumer around the 30th century BC, with predecessors reaching into the late 4th millennium , cuneiform writing began as a system of pictographs...
writings on clay tablet
Clay tablet
In the Ancient Near East, clay tablets were used as a writing medium, especially for writing in cuneiform, throughout the Bronze Age and well into the Iron Age....
s have been found, some of them related to astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
. Most known astronomical tablets have been described by Abraham Sachs
Abraham Sachs
Abraham Sachs was an American assyriologist. He earned his PhD in Assyriology in 1939 at Johns Hopkins University. He is known for his collaboration with Otto Neugebauer, whom he met in 1941 when the latter visited the Oriental Institute in Chicago; Neugebauer and Sachs joined on the publication...
and later published by Otto Neugebauer in the Astronomical Cuneiform Texts (ACT).
Since the rediscovery of the Babylonian civilization, it has become apparent that Hellenistic astronomy
Greek astronomy
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the...
was strongly influenced by the Chaldea
Chaldea
Chaldea or Chaldaea , from Greek , Chaldaia; Akkadian ; Hebrew כשדים, Kaśdim; Aramaic: ܟܐܠܕܘ, Kaldo) was a marshy land located in modern-day southern Iraq which came to briefly rule Babylon...
ns. The best documented borrowings are those of Hipparchus
Hipparchus
Hipparchus, the common Latinization of the Greek Hipparkhos, can mean:* Hipparchus, the ancient Greek astronomer** Hipparchic cycle, an astronomical cycle he created** Hipparchus , a lunar crater named in his honour...
(2nd century BCE) and Claudius Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
(2nd century CE).
Early influence
Many scholars agree that the Metonic cycleMetonic cycle
In astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...
is likely to have been learned by the Greeks from Babylonian scribes. Meton of Athens
Meton of Athens
Meton of Athens was a Greek mathematician, astronomer, geometer, and engineer who lived in Athens in the 5th century BC. He is best known for calculations involving the eponymous 19-year Metonic cycle which he introduced in 432 BC into the lunisolar Attic calendar.The metonic calendar assumes...
, a Greek astronomer of the 5th century BCE, developed a lunisolar calendar
Lunisolar calendar
A lunisolar calendar is a calendar in many cultures whose date indicates both the moon phase and the time of the solar year. If the solar year is defined as a tropical year then a lunisolar calendar will give an indication of the season; if it is taken as a sidereal year then the calendar will...
based on the fact that 19 solar years is about equal to 235 lunar months, a period relation already known to the Babylonians.
In the 4th century, Eudoxus of Cnidus
Eudoxus of Cnidus
Eudoxus of Cnidus was a Greek astronomer, mathematician, scholar and student of Plato. Since all his own works are lost, our knowledge of him is obtained from secondary sources, such as Aratus's poem on astronomy...
wrote a book on the fixed star
Fixed star
The fixed stars are celestial objects that do not seem to move in relation to the other stars of the night sky. Hence, a fixed star is any star except for the Sun. A nebula or other starlike object may also be called a fixed star. People in many cultures have imagined that the stars form pictures...
s. His descriptions of many constellations, especially the twelve signs of the zodiac
Zodiac
In astronomy, the zodiac is a circle of twelve 30° divisions of celestial longitude which are centred upon the ecliptic: the apparent path of the Sun across the celestial sphere over the course of the year...
, are suspiciously similar to Babylonian originals. The following century Aristarchus of Samos
Aristarchus of Samos
Aristarchus, or more correctly Aristarchos , was a Greek astronomer and mathematician, born on the island of Samos, in Greece. He presented the first known heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe...
used an eclipse cycle of Babylonian origin called the Saros cycle
Saros cycle
The saros is a period of 223 synodic months , that can be used to predict eclipses of the Sun and Moon. One saros after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur, in what is referred to as an eclipse cycle...
to determine the year length. However, all these examples of early influence must be inferred and the chain of transmission is not known.
Influence on Hipparchus and Ptolemy
In 1900, Franz Xaver Kugler demonstrated that Ptolemy had stated in his AlmagestAlmagest
The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...
IV.2 that Hipparchus improved the values for the Moon's periods known to him from "even more ancient astronomers" by comparing eclipse observations made earlier by "the Chaldeans", and by himself. However Kugler found that the periods that Ptolemy attributes to Hipparchus had already been used in Babylonian ephemerides, specifically the collection of texts nowadays called "System B" (sometimes attributed to Kidinnu
Kidinnu
Kidinnu was a Chaldean astronomer and mathematician. Strabo of Amaseia called him Kidenas, Pliny the Elder Cidenas, and Vettius Valens Kidynas....
). Apparently Hipparchus only confirmed the validity of the periods he learned from the Chaldeans by his newer observations. Later Greek knowledge of this specific Babylonian theory is confirmed by 2nd-century papyrus, which contains 32 lines of a single column of calculations for the Moon using this same "System B", but written in Greek on papyrus rather than in cuneiform on clay tablets.
It is clear that Hipparchus (and Ptolemy after him) had an essentially complete list of eclipse observations covering many centuries. Most likely these had been compiled from the "diary" tablets: these are clay tablets recording all relevant observations that the Chaldeans routinely made. Preserved examples date from 652 BC to AD 130, but probably the records went back as far as the reign of the Babylonian king Nabonassar
Nabonassar
Nabonassar founded a kingdom in Babylon in 747 BC. This is now considered as the start of the Neo-Babylonian Dynasty. At the time the Assyrian Empire was in disarray through civil war and the ascendancy of other kingdoms such as Urartu...
: Ptolemy starts his chronology with the first day in the Egyptian calendar of the first year of Nabonassar; i.e., 26 February 747 BC.
This raw material by itself must have been tough to use, and no doubt the Chaldeans themselves compiled extracts of e.g., all observed eclipses (some tablets with a list of all eclipses in a period of time covering a saros
Saros
Saros, Şaroş or Sáros may refer to:* Saros , an 18-year period, across which lunar and solar eclipses repeat* Saros , an American band* Saros , descendants of free slaves from Sierra Leone who migrated to Nigeria...
have been found). This allowed them to recognise periodic recurrences of events. Among others they used in System B (cf. Almagest IV.2):
- 223 (synodic) months = 239 returns in anomaly (anomalistic month) = 242 returns in latitude (draconic month). This is now known as the sarosSarosSaros, Şaroş or Sáros may refer to:* Saros , an 18-year period, across which lunar and solar eclipses repeat* Saros , an American band* Saros , descendants of free slaves from Sierra Leone who migrated to Nigeria...
period which is very useful for predicting eclipseEclipseAn eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer...
s. - 251 (synodic) months = 269 returns in anomaly
- 5458 (synodic) months = 5923 returns in latitude
- 1 synodic month = 29;31:50:08:20 days (sexagesimal; 29.53059413... days in decimals = 29 days 12 hours 44 min 3⅓ s)
The Babylonians expressed all periods in synodic month
Month
A month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept arose with the cycle of moon phases; such months are synodic months and last approximately...
s, probably because they used a lunisolar calendar
Lunisolar calendar
A lunisolar calendar is a calendar in many cultures whose date indicates both the moon phase and the time of the solar year. If the solar year is defined as a tropical year then a lunisolar calendar will give an indication of the season; if it is taken as a sidereal year then the calendar will...
. Various relations with yearly phenomena led to different values for the length of the year.
Similarly various relations between the periods of the planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s were known. The relations that Ptolemy attributes to Hipparchus in Almagest IX.3 had all already been used in predictions found on Babylonian clay tablets.
Other traces of Babylonian practice in Hipparchus' work are
- first Greek known to divide the circle in 360 degreesDegree (angle)A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
of 60 arc minutes. - first consistent use of the sexagesimal number system.
- the use of the unit pechus ("cubit") of about 2° or 2½°.
- use of a short period of 248 days = 9 anomalistic months.
Means of transmission
All this knowledge was transferred to the GreeksGreeks
The Greeks, also known as the Hellenes , are a nation and ethnic group native to Greece, Cyprus and neighboring regions. They also form a significant diaspora, with Greek communities established around the world....
probably shortly after the conquest by Alexander the Great (331 BC
331 BC
Year 331 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Potitus and Marcellus...
). According to the late classical philosopher Simplicius
Simplicius of Cilicia
Simplicius of Cilicia, was a disciple of Ammonius Hermiae and Damascius, and was one of the last of the Neoplatonists. He was among the pagan philosophers persecuted by Justinian in the early 6th century, and was forced for a time to seek refuge in the Persian court, before being allowed back into...
(early 6th century), Alexander ordered the translation of the historical astronomical records under supervision of his chronicler Callisthenes of Olynthus
Callisthenes
Callisthenes of Olynthus was a Greek historian. He was the son of Hero and Proxenus of Atarneus, which made him the great nephew of Aristotle by his sister Arimneste. They first met when Aristotle tutored Alexander the Great...
, who sent it to his uncle Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
. It is worth mentioning here that although Simplicius is a very late source, his account may be reliable. He spent some time in exile at the Sassanid (Persian) court, and may have accessed sources otherwise lost in the West. It is striking that he mentions the title tèresis (Greek: guard) which is an odd name for a historical work, but is in fact an adequate translation of the Babylonian title massartu meaning "guarding" but also "observing". Anyway, Aristotle's pupil Callippus of Cyzicus
Callippus
Callippus or Calippus was a Greek astronomer and mathematician.Callippus was born at Cyzicus, and studied under Eudoxus of Cnidus at the Academy of Plato. He also worked with Aristotle at the Lyceum, which means that he was active in Athens prior to Aristotle's death in 322...
introduced his 76-year cycle, which improved upon the 19-year Metonic cycle
Metonic cycle
In astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...
, about that time. He had the first year of his first cycle start at the summer solstice of 28 June 330 BC (Julian
Julian calendar
The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
proleptic date), but later he seems to have counted lunar months from the first month after Alexander's decisive battle at Gaugamela in fall 331 BC
331 BC
Year 331 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Potitus and Marcellus...
. So Callippus may have obtained his data from Babylonian sources and his calendar may have been anticipated by Kidinnu. Also it is known that the Babylonian priest known as Berossus
Berossus
Berossus was a Hellenistic-era Babylonian writer, a priest of Bel Marduk and astronomer writing in Greek, who was active at the beginning of the 3rd century BC...
wrote around 281 BC
281 BC
Year 281 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Barbula and Philippus...
a book in Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
on the (rather mythological) history of Babylonia, the Babyloniaca, for the new ruler Antiochus I; it is said that later he founded a school of astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...
on the Greek island of Kos
Kos
Kos or Cos is a Greek island in the south Sporades group of the Dodecanese, next to the Gulf of Gökova/Cos. It measures by , and is from the coast of Bodrum, Turkey and the ancient region of Caria. Administratively the island forms a separate municipality within the Kos peripheral unit, which is...
. Another candidate for teaching the Greeks about Babylonian astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
/astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...
was Sudines
Sudines
Sudines : Babylonian sage. He is mentioned as one of the famous Chaldean mathematicians and astronomer-astrologers by later Roman writers like Strabo ....
who was at the court of Attalus I Soter
Attalus I
Attalus I , surnamed Soter ruled Pergamon, an Ionian Greek polis , first as dynast, later as king, from 241 BC to 197 BC. He was the second cousin and the adoptive son of Eumenes I, whom he succeeded, and was the first of the Attalid dynasty to assume the title of king in 238 BC...
late in the 3rd century BC.
In any case, the translation of the astronomical records required profound knowledge of the cuneiform script
Cuneiform script
Cuneiform script )) is one of the earliest known forms of written expression. Emerging in Sumer around the 30th century BC, with predecessors reaching into the late 4th millennium , cuneiform writing began as a system of pictographs...
, the language, and the procedures, so it seems likely that it was done by some unidentified Chaldeans. Now, the Babylonians dated their observations in their lunisolar calendar, in which months and years have varying lengths (29 or 30 days; 12 or 13 months respectively). At the time they did not use a regular calendar (such as based on the Metonic cycle
Metonic cycle
In astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...
like they did later), but started a new month based on observations of the New Moon
New moon
In astronomical terminology, the new moon is the lunar phase that occurs when the Moon, in its monthly orbital motion around Earth, lies between Earth and the Sun, and is therefore in conjunction with the Sun as seen from Earth...
. This made it very tedious to compute the time interval between events.
What Hipparchus may have done is transform these records to the Egyptian calendar
Egyptian calendar
The ancient civil Egyptian calendar had a year that was 360 days long and was divided into 12 months of 30 days each, plus five extra days at the end of the year. The months were divided into three weeks of ten days each...
, which uses a fixed year of always 365 days (consisting of 12 months of 30 days and 5 extra days): this makes computing time intervals much easier. Ptolemy dated all observations in this calendar. He also writes that "All that he (=Hipparchus) did was to make a compilation of the planetary observations arranged in a more useful way" (Almagest IX.2). Pliny states (Naturalis Historia II.IX(53)) on eclipse predictions: "After their time (=Thales
Thales
Thales of Miletus was a pre-Socratic Greek philosopher from Miletus in Asia Minor, and one of the Seven Sages of Greece. Many, most notably Aristotle, regard him as the first philosopher in the Greek tradition...
) the courses of both stars (=Sun and Moon) for 600 years were prophesied by Hipparchus, ...". This seems to imply that Hipparchus predicted eclipses for a period of 600 years, but considering the enormous amount of computation required, this is very unlikely. Rather, Hipparchus would have made a list of all eclipses from Nabonasser's time to his own.
Sassanid astronomy
The capital of the Sassanid EmpireSassanid Empire
The Sassanid Empire , known to its inhabitants as Ērānshahr and Ērān in Middle Persian and resulting in the New Persian terms Iranshahr and Iran , was the last pre-Islamic Persian Empire, ruled by the Sasanian Dynasty from 224 to 651...
, the city of Ctesiphon
Ctesiphon
Ctesiphon, the imperial capital of the Parthian Arsacids and of the Persian Sassanids, was one of the great cities of ancient Mesopotamia.The ruins of the city are located on the east bank of the Tigris, across the river from the Hellenistic city of Seleucia...
, was founded in Mesopotamia. Astronomy was studied by Persians
Persian people
The Persian people are part of the Iranian peoples who speak the modern Persian language and closely akin Iranian dialects and languages. The origin of the ethnic Iranian/Persian peoples are traced to the Ancient Iranian peoples, who were part of the ancient Indo-Iranians and themselves part of...
and Babylonians in Ctesiphon and in the Academy of Gundishapur
Academy of Gundishapur
The Academy of Gondishapur , also Jondishapur , was a renowned academy of learning in the city of Gundeshapur during late antiquity, the intellectual center of the Sassanid empire. It offered training in medicine, philosophy, theology and science. The faculty were versed in the Zoroastrian and...
in Persia. Most of the astronomical texts during the Sassanid period were written in the Middle Persian
Middle Persian
Middle Persian , indigenously known as "Pârsig" sometimes referred to as Pahlavi or Pehlevi, is the Middle Iranian language/ethnolect of Southwestern Iran that during Sassanid times became a prestige dialect and so came to be spoken in other regions as well. Middle Persian is classified as a...
language. The Zij al-Shah
Zij
Zīj is the generic name applied to Islamic astronomical books that tabulate parameters used for astronomical calculations of the positions of the Sun, Moon, stars, and planets. The name is derived from the Middle Persian term zih or zīg, meaning cord...
, a collection of astronomical tables compiled in Persia and Mesopotamia over two centuries, was the most famous astronomical text from the Sassanid period, and was later translated into Arabic
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...
.
Islamic astronomy
After the Islamic conquest of PersiaIslamic conquest of Persia
The Muslim conquest of Persia led to the end of the Sassanid Empire in 644, the fall of Sassanid dynasty in 651 and the eventual decline of the Zoroastrian religion in Persia...
, the province of Mesopotamia came to be known as Iraq in the Arabic language
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...
. During the Abbasid
Abbasid
The Abbasid Caliphate or, more simply, the Abbasids , was the third of the Islamic caliphates. It was ruled by the Abbasid dynasty of caliphs, who built their capital in Baghdad after overthrowing the Umayyad caliphate from all but the al-Andalus region....
period of the region's history, Baghdad
Baghdad
Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...
was the capital of the Arab Empire, and for centuries, remained the centre of astronomical activity throughout the Islamic world
Islamic Golden Age
During the Islamic Golden Age philosophers, scientists and engineers of the Islamic world contributed enormously to technology and culture, both by preserving earlier traditions and by adding their own inventions and innovations...
. Astronomy was also studied in Basra
Basra
Basra is the capital of Basra Governorate, in southern Iraq near Kuwait and Iran. It had an estimated population of two million as of 2009...
and other Iraqi cities. During the Islamic period, Arabic was adopted as the language of scholarship, and Iraq continued to make numerous contributions to the field of astronomy, up until the 1258 sack of Baghdad
Battle of Baghdad (1258)
The Siege of Baghdad, which occurred in 1258, was an invasion, siege and sacking of the city of Baghdad, the capital of the Abbasid Caliphate at the time and the modern-day capital of Iraq, by the Ilkhanate Mongol forces along with other allied troops under Hulagu Khan.The invasion left Baghdad in...
, when many libraries were destroyed and scientific activity in Iraq came to a halt. Despite this, the work that did survive had an impact on the subsequent development of astronomy, through the medieval Arabic-Latin translation movement in Europe and Maragheh observatory
Maragheh observatory
Maragheh observatory is an astronomical observatory which was established in 1259 CE by Nasir al-Din al-Tusi, an Iranian scientist and astronomer...
in Persia.
See also
- Babylonian astrologyBabylonian astrologyIn Babylon as well as in Assyria as a direct offshoot of Babylonian culture, astrology takes its place in theofficial cult as one of the two chief means at the disposal of the priests for ascertaining the will and intention of the gods, the other being through the inspection of the liver of the...
- Babylonian calendarBabylonian calendarThe Babylonian calendar was a lunisolar calendar with years consisting of 12 lunar months, each beginning when a new crescent moon was first sighted low on the western horizon at sunset, plus an intercalary month inserted as needed by decree. The calendar is based on a Sumerian precedecessor...
- Babylonian mathematicsBabylonian mathematicsBabylonian mathematics refers to any mathematics of the people of Mesopotamia, from the days of the early Sumerians to the fall of Babylon in 539 BC. Babylonian mathematical texts are plentiful and well edited...
- Babylonian star cataloguesBabylonian star cataloguesBabylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, individual stars, and planets...
- History of astronomy (Section on Mesopotamia)