Sudines (or Soudines) (Greek, Modern (1453-);: Σουδίνες) was a Babylonian sage. He is mentioned as one of the famous Chaldean mathematicians and astronomer-astrologers by later Roman writers like Strabo (Geographia 16:1–6).
Like his predecessor Berossos, Sudines moved from Babylonia and established himself among the Greeks; he was an advisor to King Attalus I (Attalos Soter) of Pergamon. He is said (e.g., by Roman astronomer/astrologer Vettius Valens) to have published tables to compute the motion of the Moon; said to have been used by the Greeks, until superseded by the work of Hipparchus and later by Ptolemy (Claudius Ptolemaios). Sudines may have been important in transmitting the astronomical knowledge of the Babylonians to the Greeks, but little is known about his work and nothing about his life. He is also said to have been one of the first to assign astrological meaning to gemstones.
While other Chaldean astronomers have been tentatively identified in the cuneiform record, no Akkadian texts have yet been unearthed that reference Sudines. Stevens suggest that his name, however, looks Akkadian, with attestations of similar names like Šum(a)-iddin "He gave the name" or Šum(a)-iddina "He gave me a name" in the cuneiform record from the Neo-Assyrian and Hellenistic periods.
The 2nd century CE Greek author Polyaenus mentions an extispicer named Sudines, a job that this Sudines supposedly performed for King Attalus I of Pergamon, lending credence to the association between the astronomer Sudines and the attested diviner. However, while practitioners of astronomical science in Babylonia frequently also worked with astrological methods of celestial divination, the combination of astronomer and liver omen reader is rare, suggesting that Polyaenus' and King Attalus' Sudines is potentially different from the astronomer Sudines. Given the wide array of knowledge assigned to and associated with people named Sudines, it is unclear whether they all refer to the same person. The lack of biographical information about Sudines only adds to this difficulty.
Sudines is associated with computations for predicting lunar eclipses, with authors such as Vettius Valens claiming that he used Sudines to compute lunar eclipses. The "use" of Sudines in Valens' Anthologies suggests that he was perhaps the author of a table of data relating to lunar eclipses, recording the dates, times, or circumstances of previous ones that later authors could use to inform their theories. Such tables are attested in the cuneiform record, where observations of lunar eclipses were recorded for the greater part of the first millennium BCE and tables made of both observed and predicted eclipses. While no table authored by Sudines has been found or is mentioned in other sources, the abundance of Babylonian tables that have survived suggests that they were an integral component of astronomical practice in this Mesopotamian culture. As a Babylonian, it is not unlikely that Sudines collaborated in the construction of astronomical tables. Moreover, other astronomers listed alongside Sudines have astronomical tables attributed to them that are not extant. Hipparchus, a foundational figure in Greek astronomy whose work became the basis for Ptolemy's Almagest, is credited as authoring a solar table that has not survived and has been the topic of much speculation. Sudines is also credited with a particular value for the length of the solar year. Neugebauer lists Sudines' solar year length as 365 1/4 Greek, Ancient (to 1453);: γ' ε', which Rochberg interprets as 365 + 1/4 + 1/3 + 1/5, a value that she describes as making no astronomical sense. Valens references Sudines as a table author immediately after describing various values of year lengths, including two attributed separately to the Chaldeans and the Babylonians (Anthologies 9.12). Neither the Chaldean year length of 365 1/4 1/207 nor the Babylonian year length of 365 1/4 1/144 agrees with Sudines' value.
In a 3rd century CE papyrus fragment containing a summary of a commentary on Plato's Timaeus, the Stoic philosopher Posidonius is listed as crediting Sudines with describing the planet Venus as the destroyer of women. Identifying planets as "destroyers" fits in to a larger discussion of the influences and Aristotelian qualities of the five planets, the sun, and the moon. Sudines' alleged participation in astrological as well as astronomical work fits in with Babylonian standards that did not explicitly differentiate between the two fields.
Sudines is referenced in Greek and Latin texts as an expert on three topics: astrological knowledge, liver divination (hepatoscopy), and properties of stones and gems. Often he is listed alongside other known Babylonian astronomers. In addition to Sudines, Vettius Valens lists Kidenas, a Babylonian astronomer known from other references in Greek sources as well as the colophons of some Babylonian ephemerides. Valens also references Greek astronomers Hipparchus and Apollinarius who are both known to have iterated over Babylonian arithmetic methods and to have used Babylonian parameters and observations as integral parts of their astronomical theories.
In addition to the sources listed below, Stevens points to a reference to Greek, Ancient (to 1453);: Σωδίνων from a list of canonographers from a Vatican Aratea manuscript (Vat gr. 381).