The Canon of Kings was a dated list of kings used by ancient astronomers as a convenient means to date astronomical phenomena, such as eclipses. The Canon was preserved by the astronomer Claudius Ptolemy, and is thus known sometimes as Ptolemy's Canon. It is one of the most important bases for our knowledge of ancient chronology.
The Canon derives originally from Babylonian sources. Thus, it lists Kings of Babylon from 747 BC until the conquest of Babylon by the Persians in 539 BC, and then Persian kings from 538 to 332 BC. At this point, the Canon was continued by Greek astronomers in Alexandria, and lists the Macedonian kings from 331 to 305 BC, the Ptolemies from 304 BC to 30 BC, and the Roman and Byzantine Emperors, although they are not kings; in some manuscripts the list is continued down to the fall of Constantinople in 1453.
The Canon only increments by whole years, specifically the ancient Egyptian year of 365 days. This has two consequences. The first is that the dates for when monarchs began and ended their reigns are simplified to the beginning and the ending of the ancient Egyptian year, which moves one day every four years against the Julian calendar. The second is that this list of monarchs is oversimplified. Monarchs who reigned for less than one year are not listed, and only one monarch is listed in any year with multiple monarchs. Usually, the overlapping year is assigned to the monarch who died in that year, but not always. Note that the two periods in the Babylonian section where no king is listed the first represents two pretenders whose legitimacy the compiler did not recognize, and the second extends from the year Babylon was sacked by Sennacherib, King of Assyria to the restoration of Esarhaddon.
The Canon is generally considered by historians to be accurate, and forms part of the backbone of the commonly accepted chronology from 747 BC forward that all other datings are synchronized to. It is not, however, the ultimate source for this chronology; most of the names and lengths of reigns can be independently verified from archaeological material (coinage, annals, inscriptions in stone etc.) and extant works of history from the historical ages concerned.
Apepi (also Ipepi; Egyptian language ipp(i)) or Apophis (Greek: Ἄποφις; regnal names Neb-khepesh-Re, A-qenen-Re and A-user-Re) was a ruler of Lower Egypt during the fifteenth dynasty and the end of the Second Intermediate Period that was dominated by this foreign dynasty of rulers called the Hyksos. According to the Turin Canon of Kings, he ruled over the northern portion of Egypt for forty years. He ruled during the early half of the 16th century BC and outlived his southern rival, Kamose, but not Ahmose I. Although his reign only entailed northern Egypt, Apepi was dominant over most of Egypt during the early portion of his reign, and traded peacefully with the native Theban Seventeenth dynasty to the south.While he might have exerted suzerainty over Upper Egypt during the beginning of his reign, the seventeenth dynasty eventually assumed control over this region, and the Hyksos were driven out of Egypt no more than fifteen years after his death.Kamose, the last king of the Theban 17th Dynasty, refers to Apepi as a "Chieftain of Retjenu" in a stela that implies a Canaanite background for this Hyksos king.Before Present
Before Present (BP) years is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred in the past. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date of the age scale, reflecting the origin of practical radiocarbon dating in the 1950s. The abbreviation "BP" has alternatively been interpreted as "Before Physics"; that is, before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, making dating after that time likely to be unreliable.In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating.Calendar era
A calendar era is the year numbering system used by a calendar. For example, the Gregorian calendar numbers its years in the Western Christian era (the Coptic Orthodox and Ethiopian Orthodox churches have their own Christian eras). The instant, date, or year from which time is marked is called the epoch of the era. There are many different calendar eras such as Saka Era.
In antiquity, regnal years were counted from the accession of a monarch. This makes the Chronology of the ancient Near East very difficult to reconstruct, based on disparate and scattered king lists, such as the Sumerian King List and the Babylonian Canon of Kings. In East Asia, reckoning by era names chosen by ruling monarchs ceased in the 20th century except for Japan, where they are still used.Chronostratigraphy
Chronostratigraphy is the branch of stratigraphy that studies the age of rock strata in relation to time.
The ultimate aim of chronostratigraphy is to arrange the sequence of deposition and the time of deposition of all rocks within a geological region, and eventually, the entire geologic record of the Earth.
The standard stratigraphic nomenclature is a chronostratigraphic system based on palaeontological intervals of time defined by recognised fossil assemblages (biostratigraphy). The aim of chronostratigraphy is to give a meaningful age date to these fossil assemblage intervals and interfaces.Circa
Circa (from Latin, meaning 'around, about, roughly, approximately') – frequently abbreviated c., ca. or ca and less frequently circ. or cca. – signifies "approximately" in several European languages and as a loanword in English, usually in reference to a date. Circa is widely used in historical writing when the dates of events are not accurately known.
When used in date ranges, circa is applied before each approximate date, while dates without circa immediately preceding them are generally assumed to be known with certainty.
1732–1799: Both years are known precisely.
c. 1732 – 1799: The beginning year is approximate; the end year is known precisely.
1732 – c. 1799: The beginning year is known precisely ; the end year is approximate.
c. 1732 – c. 1799: Both years are approximate.Era (geology)
A geologic era is a subdivision of geologic time that divides an eon into smaller units of time. The Phanerozoic Eon is divided into three such time frames: the Paleozoic, Mesozoic, and Cenozoic (meaning "old life", "middle life" and "recent life") that represent the major stages in the macroscopic fossil record. These eras are separated by catastrophic extinction boundaries, the P-T boundary between the Paleozoic and the Mesozoic and the K-Pg boundary between the Mesozoic and the Cenozoic. There is evidence that catastrophic meteorite impacts played a role in demarcating the differences between the eras.
The Hadean, Archean and Proterozoic eons were as a whole formerly called the Precambrian. This covered the four billion years of Earth history prior to the appearance of hard-shelled animals. More recently, however, the Archean and Proterozoic eons have been subdivided into eras of their own.
Geologic eras are further subdivided into geologic periods, although the Archean eras have yet to be subdivided in this way.Floruit
Floruit (UK: , US: ), abbreviated fl. (or occasionally flor.), Latin for "he/she flourished", denotes a date or period during which a person was known to have been alive or active. In English, the word may also be used as a noun indicating the time when someone flourished.Fluorine absorption dating
Fluorine absorption dating is a method used to determine the amount of time an object has been underground.
Fluorine absorption dating can be carried out based on the fact that groundwater contains fluoride ions. Items such as bone that are in the soil will absorb fluoride from the groundwater over time. From the amount of absorbed fluoride in the item, the time that the item has been in the soil can be estimated.
Many instances of this dating method compare the amount of fluorine and uranium in the bones to nitrogen dating to create more accurate estimation of date. Older bones have more fluorine and uranium and less nitrogen. But because decomposition happens at different speeds in different places, it's not possible to compare bones from different sites.
As not all objects absorb fluorine at the same rate, this also undermines the accuracy of such a dating technique. Although this can be compensated for by accommodating for the rate of absorption in calculations, such an accommodation tends to have a rather large margin of error.
In 1953 this test was used to easily identify that the 'Piltdown Man' was forged, almost 50 years after it was originally 'unearthed'.Geologic Calendar
The Geologic Calendar is a scale in which the geological lifetime of the earth is mapped onto a calendrical year; that is to say, the day one of the earth took place on a geologic January 1 at precisely midnight, and today's date and time is December 31 at midnight. On this calendar, the inferred appearance of the first living single-celled organisms, prokaryotes, occurred on a geologic February 25 around 12:30pm to 1:07pm, dinosaurs first appeared on December 13, the first flower plants on December 22 and the first primates on December 28 at about 9:43pm. The first Anatomically modern humans did not arrive until around 11:48 p.m. on New Year's Eve, and all of human history since the end of the last ice-age occurred in the last 82.2 seconds before midnight of the new year.Geological period
A geological period is one of the several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place.
These periods form elements of a hierarchy of divisions into which geologists have split the Earth's history.
Eons and eras are larger subdivisions than periods while periods themselves may be divided into epochs and ages.
The rocks formed during a period belong to a stratigraphic unit called a system.Law of superposition
The law of superposition is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields dealing with geological stratigraphy. It is a form of relative dating. In its plainest form, it states that in undeformed stratigraphic sequences, the oldest strata will be at the bottom of the sequence. This is important to stratigraphic dating, which assumes that the law of superposition holds true and that an object cannot be older than the materials of which it is composed.Limmu
Limmu was an Assyrian eponym. At the beginning of the reign of an Assyrian king, the limmu, an appointed royal official, would preside over the New Year festival at the capital. Each year a new limmu would be chosen. Although picked by lot, there was most likely a limited group, such as the men of the most prominent families or perhaps members of the city assembly. The Assyrians used the name of the limmu for that year to designate the year on official documents. Lists of limmus have been found accounting for every year between 892 BC and 648 BC.
During the Old Assyrian period, the king himself was never the limmum, as it was called in their language. In the Middle Assyrian and Neo-Assyrian periods, however, the king could take this office.New Earth Time
New Earth Time (or NET) is an alternative naming system for measuring the time of day. In NET the day is split into 360 NET degrees, each NET degree is split into 60 NET minutes and each NET minute is split into 60 NET seconds. One NET degree is therefore equivalent to four standard minutes, and one standard hour is equivalent to 15 NET degrees.
NET is equivalent to the UTC read from a 24-hour analog clock as the clockwise angle past midnight of the hour hand. For example, noon is 180°0'0" NET and at that time the hour hand is pointing straight down forming a 180° angle when measured from the top, at midnight. A full circle is 360 degrees and one NET day.Nitrogen dating
Nitrogen dating is a form of relative dating which relies on the reliable breakdown and release of amino acids from bone samples to estimate the age of the object. For human bones, the assumption of about 5% nitrogen in the bone, mostly in the form of collogen, allows fairly consistent dating techniques.Compared to other dating techniques, Nitrogen dating can be unreliable because leaching from bone is dependent on temperature, soil pH, ground water, and the presence of microorganism that digest nitrogen rich elements, like collagen. Some studies compare nitrogen dating results with dating results from methods like fluorine absorption dating to create more accurate estimates. Though some situations, like thin porous bones might more rapidly change the dating created by multiple methods.Proleptic Gregorian calendar
The proleptic Gregorian calendar is produced by extending the Gregorian calendar backward to dates preceding its official introduction in 1582. In countries that adopted the Gregorian calendar later, dates occurring in the interim (between 1582 and the local adoption) are sometimes "Gregorianized" as well. For example, George Washington was born on February 11, 1731 (Old Style), as Great Britain and its possessions were using the Julian calendar with English years starting on March 25 until September 1752. After the switch, that day became February 22, 1732, which is the date commonly given as Washington's birthday.Regnal year
A regnal year is a year of the reign of a sovereign, from the Latin regnum meaning kingdom, rule.
The oldest dating systems were in regnal years, and considered the date as an ordinal, not a cardinal number. For example, a monarch could have a first year of rule, a second year of rule, a third year of rule, and so on, but not a zeroth year of rule.
Applying this ancient epoch system to modern calculations of time, which include zero, is what led to the debate over when the third millennium began.
Regnal years are "finite era names", contrary to "infinite era names" such as Christian era, Jimmu era, Juche era, and so on.Stratotype
A stratotype or type section is a geological term that names the physical location or outcrop of a particular reference exposure of a stratigraphic sequence or stratigraphic boundary. If the stratigraphic unit is layered, it is called a stratotype, whereas the standard of reference for unlayered rocks is the type locality.Turin King List
The Turin King List, also known as the Turin Royal Canon, is an ancient Egyptian hieratic papyrus thought to date from the reign of Pharaoh Ramesses II, now in the Museo Egizio (Egyptian Museum) in Turin. The papyrus is the most extensive list available of kings compiled by the ancient Egyptians, and is the basis for most chronology before the reign of Ramesses II.