Sumerian literature constitutes the earliest known corpus of
recorded literature, including the religious writings and other
traditional stories maintained by the Sumerian civilization and largely
preserved by the later Akkadian and Babylonian empires. These records
were written in the Sumerian language in the 3rd and 2nd millennia BC during the Middle Bronze Age.
The Sumerians invented one of the first writing systems, developing Sumerian cuneiform writing out of earlier proto-writing systems by about the 30th century BC.The Sumerian language remained in official and literary use in the Akkadian and Babylonian
empires, even after the spoken language disappeared from the
population; literacy was widespread, and the Sumerian texts that
students copied heavily influenced later Babylonian literature.
The basic genres of Sumerian literature were literary catalogues,
narrative/mythological compositions, historical compositions, letters
and legal documents, disputation poems, proverbs, and other texts which do not belong to these prior categories.
Poetry
Most Sumerian literature is written in left-justified lines, and could contain line-based organization such as the couplet or the stanza, but the Sumerian definition of poetry is unknown. It is not rhymed, although “comparable effects were sometimes exploited.”
Though rhymeless, the intricate patterns of similar and alternating
sounds of vowels and consonants and the similar and alternating verb and
noun endings give the language a musical resonance. It did not use syllabo-tonic versification, and the writing system precludes detection of rhythm, metre, rhyme, or alliteration.
Quantitative analysis of other possible poetic features seems to be
lacking, or has been intentionally hidden by the scribes who recorded
the writing.
Literary genres and topics
Genre
is often the first judgement made of ancient literature; types of
literature were not clearly defined, and all Sumerian literature
incorporated poetic aspects. Sumerian poems demonstrate basic elements
of poetry, including lines, imagery, and metaphor.
Humans, gods, talking animals, and inanimate objects were all
incorporated as characters. Suspense and humor were both incorporated
into Sumerian stories. These stories were primarily shared orally,
though they were also recorded by scribes. Some works were associated with specific musical instruments or contexts and may have been performed in specific settings. Sumerian literature did not use titles, instead being referred to by the work's first line.
Based on the categorization work of Miguel Civil, Modern assyriologists have divided the extant corpus of Sumerian literature into broad categories
including "Literary Catalogs", "Narratives and Mythological
Compositions", "Historical Compositions and Praise Poetry", "Letters,
Letter Prayers and Laws", "Hymns and Songs", "Heterogenous Compositions"
(including Wisdom literature), and "Proverbs".
Literary catalogs
Sumerian scribal education focused on a curriculum called the Decad. Manuscripts of these ten texts are some of the best preserved Sumerian literature.
Hymns to deities in the Sumerian pantheon, such as the Hymn to Enlil, as well as Hymns dedicated to specific temples, including The Sumerian Temple Hymns collection and the Kesh Temple Hymn
Apsides pertaining to orbits around the Sun have distinct names to differentiate themselves from other apsides; these names are aphelion for the farthest and perihelion for the nearest point in the solar orbit. The Moon's two apsides are the farthest point, apogee, and the nearest point, perigee, of its orbit around the host Earth. Earth's two apsides are the farthest point, aphelion, and the nearest point, perihelion, of its orbit around the host Sun. The terms aphelion and perihelion apply in the same way to the orbits of Jupiter and the other planets, the comets, and the asteroids of the Solar System.
General description
The two-body system of interacting elliptic orbits: The smaller, satellite body (blue) orbits the primary body (yellow); both are in elliptic orbits around their common center of mass (or barycenter), (red +). ∗Periapsis and apoapsis as distances: the smallest and largest distances between the orbiter and its host body.
There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ap-, apo- (from ἀπ(ό), (ap(o)-) 'away from') for the farthest or peri- (from περί (peri-) 'near') for the closest point to the primary body, with a suffix that describes the primary body. The suffix for Earth is -gee, so the apsides' names are apogee and perigee. For the Sun, the suffix is -helion, so the names are aphelion and perihelion.
According to Newton's laws of motion,
all periodic orbits are ellipses. The barycenter of the two bodies may
lie well within the bigger body—e.g., the Earth–Moon barycenter is about
75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., for satellites), then the orbital parameters are independent of the smaller mass.
When used as a suffix—that is, -apsis—the term can refer to the two distances from the primary body to the orbiting body when the latter is located: 1) at the periapsis point, or 2) at the apoapsis
point (compare both graphics, second figure). The line of apsides
denotes the distance of the line that joins the nearest and farthest
points across an orbit; it also refers simply to the extreme range of an
object orbiting a host body (see top figure; see third figure).
In orbital mechanics, the apsides technically refer to the distance measured between the center of mass of the central body and the center of mass of the orbiting body. However, in the case of a spacecraft, the terms are commonly used to refer to the orbital altitude of the spacecraft above the surface of the central body (assuming a constant, standard reference radius).
Keplerianorbital elements: point G, the nearest point of approach of an orbiting body, is the pericenter (also periapsis) of an orbit; point H,
the farthest point of the orbiting body, is the apocenter (also
apoapsis) of the orbit; and the red line between them is the line of
apsides.
Terminology
The words "pericenter" and "apocenter" are often seen, although periapsis/apoapsis are preferred in technical usage.
For generic situations where the primary is not specified, the terms pericenter and apocenter are used for naming the extreme points of orbits (see table, top figure); periapsis and apoapsis (or apapsis)
are equivalent alternatives, but these terms also frequently refer to
distances—that is, the smallest and largest distances between the
orbiter and its host body (see second figure).
For a body orbiting the Sun, the point of least distance is the perihelion (/ˌpɛrɪˈhiːliən/), and the point of greatest distance is the aphelion (/æpˈhiːliən/); when discussing orbits around other stars the terms become periastron and apastron.
When discussing a satellite of Earth, including the Moon, the point of least distance is the perigee (/ˈpɛrɪdʒiː/), and of greatest distance, the apogee (from Ancient Greek: Γῆ (Gē), "land" or "earth").
For objects in lunar orbit, the point of least distance are called the pericynthion (/ˌpɛrɪˈsɪnθiən/) and the greatest distance the apocynthion (/ˌæpəˈsɪnθiən/). The terms perilune and apolune, as well as periselene and aposelene are also used. Since the Moon has no natural satellites this only applies to man-made objects.
Etymology
The words perihelion and aphelion were coined by Johannes Kepler to describe the orbital motions of the planets around the Sun.
The words are formed from the prefixes peri- (Greek: περί, near) and apo- (Greek: ἀπό, away from), affixed to the Greek word for the Sun, (ἥλιος, or hēlíos).
Various related terms are used for other celestial objects. The suffixes -gee, -helion, -astron and -galacticon are frequently used in the astronomical literature when referring to the Earth, Sun, stars, and the Galactic Center respectively. The suffix -jove is occasionally used for Jupiter, but -saturnium has very rarely been used in the last 50 years for Saturn. The -gee form is also used as a generic closest-approach-to "any planet" term—instead of applying it only to Earth.
During the Apollo program, the terms pericynthion and apocynthion were used when referring to orbiting the Moon; they reference Cynthia, an alternative name for the Greek Moon goddess Artemis. More recently, during the Artemis program, the terms perilune and apolune have been used.
Regarding black holes, the term peribothron was first used in a 1976 paper by J. Frank and M. J. Rees, who credit W. R. Stoeger for suggesting creating a term using the greek word for pit: "bothron".
The terms perimelasma and apomelasma (from a Greek root) were used by physicist and science-fiction author Geoffrey A. Landis in a story published in 1998, thus appearing before perinigricon and aponigricon (from Latin) in the scientific literature in 2002.
Terminology summary
The suffixes shown below may be added to prefixes peri- or apo- to form unique names of apsides for the orbiting bodies of the indicated host/(primary) system. However, only for the Earth, Moon and Sun systems are the unique suffixes commonly used. Exoplanet studies commonly use -astron, but typically, for other host systems the generic suffix, -apsis, is used instead.
Host objects in the Solar System with named/nameable apsides
Diagram of a body's direct orbit around the Sun with its nearest (perihelion) and farthest (aphelion) points
The perihelion (q) and aphelion (Q) are the nearest and farthest points respectively of a body's direct orbit around the Sun.
Comparing osculating elements at a specific epoch
to effectively those at a different epoch will generate differences.
The time-of-perihelion-passage as one of six osculating elements is not
an exact prediction (other than for a generic two-body model) of the actual minimum distance to the Sun using the full dynamical model. Precise predictions of perihelion passage require numerical integration.
Inner planets and outer planets
The two images below show the orbits, orbital nodes, and positions of perihelion (q) and aphelion (Q) for the planets of the Solar System as seen from above the northern pole of Earth's ecliptic plane, which is coplanar with Earth's orbital plane.
The planets travel counterclockwise around the Sun and for each planet,
the blue part of their orbit travels north of the ecliptic plane, the
pink part travels south, and dots mark perihelion (green) and aphelion
(orange).
The first image (below-left) features the inner planets, situated outward from the Sun as Mercury, Venus, Earth, and Mars. The reference Earth-orbit is colored yellow and represents the orbital plane of reference. At the time of vernal equinox, the Earth is at the bottom of the figure. The second image (below-right) shows the outer planets, being Jupiter, Saturn, Uranus, and Neptune.
The orbital nodes are the two end points of the "line of nodes" where a planet's tilted orbit intersects the plane of reference; here they may be 'seen' as the points where the blue section of an orbit meets the pink.
The perihelion (green) and aphelion (orange) points of the inner planets of the Solar System
The perihelion (green) and aphelion (orange) points of the outer planets of the Solar System
Lines of apsides
The chart shows the extreme range—from the closest approach (perihelion) to farthest point (aphelion)—of several orbiting celestial bodies of the Solar System: the planets, the known dwarf planets, including Ceres, and Halley's Comet.
The length of the horizontal bars correspond to the extreme range of
the orbit of the indicated body around the Sun. These extreme distances
(between perihelion and aphelion) are the lines of apsides of the orbits of various objects around a host body.
Distances of selected bodies of the Solar System from the Sun. The left and right edges of each bar correspond to the perihelion and aphelion of the body, respectively, hence long bars denote high orbital eccentricity.
The radius of the Sun is 0.7 million km, and the radius of Jupiter (the
largest planet) is 0.07 million km, both too small to resolve on this
image.
Earth perihelion and aphelion
Currently, the Earth reaches perihelion in early January, approximately 14 days after the December solstice. At perihelion, the Earth's center is about 0.98329astronomical units
(AU) or 147,098,070 km (91,402,500 mi) from the Sun's center. In
contrast, the Earth reaches aphelion currently in early July,
approximately 14 days after the June solstice. The aphelion distance between the Earth's and Sun's centers is currently about 1.01671 AU or 152,097,700 km (94,509,100 mi).
The dates of perihelion and aphelion change over time due to
precession and other orbital factors, which follow cyclical patterns
known as Milankovitch cycles. In the short term, such dates can vary up to 2 days from one year to another. This significant variation is due to the presence of the Moon: while the Earth–Moon barycenter
is moving on a stable orbit around the Sun, the position of the Earth's
center which is on average about 4,700 kilometres (2,900 mi) from the
barycenter, could be shifted in any direction from it—and this affects
the timing of the actual closest approach between the Sun's and the
Earth's centers (which in turn defines the timing of perihelion in a
given year).
Because of the increased distance at aphelion, only 93.55% of the
radiation from the Sun falls on a given area of Earth's surface as does
at perihelion, but this does not account for the seasons, which result instead from the tilt of Earth's axis of 23.4° away from perpendicular to the plane of Earth's orbit. Indeed, at both perihelion and aphelion it is summer in one hemisphere while it is winter
in the other one. Winter falls on the hemisphere where sunlight strikes
least directly, and summer falls where sunlight strikes most directly,
regardless of the Earth's distance from the Sun.
In the northern hemisphere, summer occurs at the same time as
aphelion, when solar radiation is lowest. Despite this, summers in the
northern hemisphere are on average 2.3 °C (4 °F) warmer than in the
southern hemisphere, because the northern hemisphere contains larger
land masses, which are easier to heat than the seas.
Perihelion and aphelion do however have an indirect effect on the seasons: because Earth's orbital speed
is minimum at aphelion and maximum at perihelion, the planet takes
longer to orbit from June solstice to September equinox than it does
from December solstice to March equinox. Therefore, summer in the
northern hemisphere lasts slightly longer (93 days) than summer in the
southern hemisphere (89 days).
Astronomers commonly express the timing of perihelion relative to the First Point of Aries not in terms of days and hours, but rather as an angle of orbital displacement, the so-called longitude of the periapsis (also called longitude of the pericenter). For the orbit of the Earth, this is called the longitude of perihelion, and in 2000 it was about 282.895°; by 2010, this had advanced by a small fraction of a degree to about 283.067°, i.e. a mean increase of 62" per year.
For the orbit of the Earth around the Sun, the time of apsis is
often expressed in terms of a time relative to seasons, since this
determines the contribution of the elliptical orbit to seasonal
variations. The variation of the seasons is primarily controlled by the
annual cycle of the elevation angle of the Sun, which is a result of the
tilt of the axis of the Earth measured from the plane of the ecliptic. The Earth's eccentricity
and other orbital elements are not constant, but vary slowly due to the
perturbing effects of the planets and other objects in the solar system
(Milankovitch cycles).
On a very long time scale, the dates of the perihelion and of the
aphelion progress through the seasons, and they make one complete cycle
in 22,000 to 26,000 years. There is a corresponding movement of the
position of the stars as seen from Earth, called the apsidal precession. (This is closely related to the precession of the axes.) The dates and times of the perihelions and aphelions for several past and future years are listed in the following table:
Note that for conversion from heights above the surface to distances
between an orbit and its primary, the radius of the central body has to
be added, and conversely.
which is the speed of a body in a circular orbit whose radius is .
Time of perihelion
Orbital elements such as the time of perihelion passage are defined at the epoch chosen using an unperturbed two-body solution that does not account for the n-body problem.
To get an accurate time of perihelion passage you need to use an epoch
close to the perihelion passage. For example, using an epoch of 1996, Comet Hale–Bopp shows perihelion on 1 April 1997. Using an epoch of 2008 shows a less accurate perihelion date of 30 March 1997. Short-period comets can be even more sensitive to the epoch selected. Using an epoch of 2005 shows 101P/Chernykh coming to perihelion on 25 December 2005, but using an epoch of 2012 produces a less accurate unperturbed perihelion date of 20 January 2006.
Numerical integration shows dwarf planetEris will come to perihelion around December 2257. Using an epoch of 2021, which is 236 years early, less accurately shows Eris coming to perihelion in 2260.
4 Vesta came to perihelion on 26 December 2021, but using a two-body solution at an epoch of July 2021 less accurately shows Vesta came to perihelion on 25 December 2021.
Short arcs
Trans-Neptunian objects
discovered when 80+ AU from the Sun need dozens of observations over
multiple years to well constrain their orbits because they move very
slowly against the background stars. Due to statistics of small numbers,
trans-Neptunian objects such as 2015 TH367 when it had only 8 observations over an observation arc of 1 year that have not or will not come to perihelion for roughly 100 years can have a 1-sigma uncertainty of 77.3 years (28,220 days) in the perihelion date.
"The Deluge", frontispiece to Gustave Doré's illustrated edition of the Bible
A flood myth or a deluge myth is a myth in which a great flood, usually sent by a deity or deities, destroys civilization, often in an act of divine retribution. Parallels are often drawn between the flood waters of these myths and the primeval waters which appear in certain creation myths, as the flood waters are described as a measure for the cleansing of humanity, in preparation for rebirth. Most flood myths also contain a culture hero, who "represents the human craving for life".
One example of a flood myth is in the Epic of Gilgamesh. Many scholars believe that this account was copied from the AkkadianAtra-Hasis, which dates to the 18th century BCE. In the Gilgamesh flood myth, the highest god, Enlil, decides to destroy the world with a flood because humans have become too noisy. The god Ea, who had created humans out of clay and divine blood, secretly warns the hero Utnapishtim of the impending flood and gives him detailed instructions for building a boat so that life may survive.Both the Epic of Gilgamesh and Atra-Hasis are preceded by the similar Eridu Genesis (c. 1600 BCE)—the oldest surviving example of such a flood-myth narrative, known from tablets found in the ruins of Nippur in the late 1890s and translated by assyriologist Arno Poebel.
Academic Yi Samuel Chen analyzed various texts from the Early Dynastic III Period through to the Old Babylonian Period, and argues that the flood narrative was only added in texts written during the Old Babylonian Period. With regard to the Sumerian King List,
observations by experts have always indicated that the portion of the
Sumerian King List talking about before the flood differs stylistically
from the King List Proper. Essentially Old Babylonian copies tend to
represent a tradition of before the flood apart from the actual King
List, whereas the Ur III
copy of the King List and the duplicate from the Brockmon collection
indicate that the King List Proper once existed independent of mention
of the flood and the tradition of before the flood. Essentially, Chen
gives evidence to prove that the section of before the flood and
references to the flood in the Sumerian King List were all later
additions added in during the Old Babylonian Period, as the Sumerian
King List went through updates and edits. The flood as a watershed in
early history of the world was probably a new historiographical concept
emerging in the Mesopotamian literary traditions during the Old
Babylonian Period, as evident by the fact that the flood motif did not
show up in the Ur III copy and that earliest chronographical sources
related to the flood show up in the Old Babylonian Period. Chen also
concludes that the name of "Ziusudra" as a flood hero and the idea of the flood hinted at by that name in the Old Babylonian Version of "Instructions of Shuruppak"
are only developments during that Old Babylonian Period, when also the
didactic text was updated with information from the burgeoning
Antediluvian Tradition.
In the Hebrew Genesis, the god Yahweh, who had created man out of the dust of the ground, decides to flood the earth because of the corrupted state of mankind. Yahweh then gives the protagonist, Noah, instructions to build an ark
in order to preserve human and animal life. When the ark is completed,
Noah, his family, and representatives of all the animals of the earth
are called upon to enter the ark. When the destructive flood begins, all
life outside of the ark perishes. After the waters recede, all those
aboard the ark disembark and have Yahweh's promise that he will never
judge the earth with a flood again. Yahweh causes a rainbow to form as the sign of this promise.
In Hindu mythology, texts such as the Satapatha Brahmana (c. 6th century BCE) and the Puranas contain the story of a great flood, "manvantara-sandhya", wherein the MatsyaAvatar of the Vishnu warns the first man, Manu, of the impending flood, and also advises him to build a giant boat. In ZoroastrianMazdaism, Ahriman tries to destroy the world with a drought, which Mithra ends by shooting an arrow into a rock, from which a flood springs; one man survives in an ark with his cattle. Norbert Oettinger argues that the story of Yima and the Vara
was originally a flood myth, and the harsh winter was added in due to
the dry nature of Eastern Iran, as flood myths did not have as much of
an effect as harsh winters. He has argued that the mention of melted
water flowing in Videvdad
2.24 is a remnant of the flood myth, and mentions that the Indian flood
myths originally had their protagonist as Yama, but it was changed to
Manu later.
In Plato's Timaeus, written c. 360 BCE, Timaeus describes a flood myth similar to the earlier versions. In it, the Bronze race of humans angers the high god Zeus with their constant warring. Zeus decides to punish humanity with a flood. The TitanPrometheus, who had created humans from clay, tells the secret plan to Deucalion,
advising him to build an ark in order to be saved. After nine nights
and days, the water starts receding and the ark lands on a mountain.
Floods in the wake of the Last Glacial Period (c. 115,000 – c. 11,700 years ago) are speculated to have inspired myths that survive to this day. Plato's allegory of Atlantis is set over 9,000 years before his time, leading some scholars to suggest that a Stone Age society which lived close to the Mediterranean Sea could have been wiped out by the rising sea level, an event which could have served as the basis for the story.
Archaeologist Bruce Masse stated that some of the narratives of a
great flood discovered in many cultures around the world may be linked
to an oceanic asteroid impact that occurred between Africa and Antarctica, around the time of a solar eclipse, that caused a tsunami.
Among the 175 myths he analyzed were a Hindu myth speaking of an
alignment of the five planets at the time, and a Chinese story linking
the flood to the end of the reign of Empress Nu Wa. Fourteen flood myths refer to a full solar eclipse. According to Masse these indications point to the date May 10, 2807 BC. His hypothesis suggests that a meteor or comet crashed into the Indian Ocean around 3000–2800 BCE, and created the 18-mile (29 km) undersea Burckle Crater and Fenambosy Chevron, and generated a giant tsunami that flooded coastal lands.[29]
Mesopotamia
Mesopotamia, like other early sites of riverine civilisation, was flood-prone; and for those experiencing valley-wide inundations, flooding could destroy the whole of their known world. According to the excavation report of the 1930s excavation at Shuruppak (modern Tell Fara, Iraq), the Jemdet Nasr and Early Dynastic layers at the site were separated by a 60-cm yellow layer of alluvial sand and clay, indicating a flood, like that created by river avulsion, a process common in the Tigris–Euphrates river system.
Similar layers have been recorded at other sites as well, all dating to
different periods, which would be consistent with the nature of river
avulsions.
Shuruppak in Mesopotamian legend was the city of Uta-napishtim, the king who built a boat to survive the coming flood. The alluvial layer dates from around 2900 BC.
The geography of the Mesopotamian area changed considerably with the filling of the Persian Gulf after sea waters rose following the last glacial period. Global sea levels were about 120 m (390 ft) lower around 18,000 BP
and rose until 8,000 BP when they reached current levels, which are now
an average 40 m (130 ft) above the floor of the Gulf, which was a huge
(800 km × 200 km, 500 mi × 120 mi) low-lying and fertile region in
Mesopotamia, in which human habitation is thought to have been strong
around the Gulf Oasis for 100,000 years. A sudden increase in settlements above the present-day water level is recorded at around 7,500 BP.
Mediterranean Basin
The historian Adrienne Mayor
theorizes that global flood stories may have been inspired by ancient
observations of seashells and fish fossils in inland and mountain areas.
The ancient Greeks, Egyptians, and Romans all documented the discovery
of such remains in such locations; the Greeks hypothesized that Earth
had been covered by water on several occasions, citing the seashells and
fish fossils found on mountain tops as evidence of this idea.
Speculation regarding the Deucalion myth has postulated a large tsunami in the Mediterranean Sea, caused by the Thera eruption (with an approximate geological date of 1630–1600 BCE), as the myth's historical basis. Although the tsunami hit the South Aegean Sea and Crete, it did not affect cities in the mainland of Greece, such as Mycenae, Athens, and Thebes, which continued to prosper, indicating that it had a local rather than a region-wide effect.
Black Sea deluge hypothesis
The Black Sea deluge hypothesis
offers a controversial account of long-term flooding; the hypothesis
argues for a catastrophic irruption of water about 5600 BCE from the
Mediterranean Sea into the Black Sea basin. This has become the subject of considerable discussion.[38][39] The Younger Dryas impact hypothesis offered another proposed natural explanation for flood myths. However, this idea was similarly controversial and has been refuted.
The earliest known hypothesis about a comet that had a widespread effect on human populations can be attributed to Edmond Halley, who in 1694 suggested that a worldwide flood had been the result of a near-miss by a comet. The issue was taken up in more detail by William Whiston, a protégé of and popularizer of the theories of Isaac Newton, who argued in his book A New Theory of the Earth (1696) that a comet encounter was the probable cause of the Biblical Flood of Noah in 2342 BCE. Whiston also attributed the origins of the atmosphere and other significant changes in the Earth to the effects of comets.
In Pierre-Simon Laplace's book Exposition Du Systême Du Monde (The System of the World), first published in 1796, he stated:
[T]he greater part of men and
animals drowned in a universal deluge, or destroyed by the violence of
the shock given to the terrestrial globe; whole species destroyed; all
the monuments of human industry reversed: such are the disasters which a
shock of a comet would produce.
A similar hypothesis was popularized by Minnesota congressman and pseudoarchaeology writer Ignatius L. Donnelly in his book Ragnarok: The Age of Fire and Gravel (1883), which followed his better-known book Atlantis: The Antediluvian World (1882). In Ragnarok, Donnelly argued that an enormous comet struck the Earth around 6,000 BCE to 9,000 BCE, destroying an advanced civilization on the "lost continent" of Atlantis.
Donnelly, following others before him, attributed the Biblical Flood to
this event, which he hypothesized had also resulted in catastrophic
fires and climate change. Shortly after the publication of Ragnarok,
one commenter noted, "Whiston ascertained that the deluge of Noah came
from a comet's tail; but Donnelly has outdone Whiston, for he has shown
that our planet has suffered not only from a cometary flood, but from
cometary fire, and a cometary rain of stones."
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