syzygy

plural syzygies

1. countableuncountableastrologyAn alignment of three celestial bodies (for example, the Sun, Earth, and Moon) such that one body is directly between the other two, such as occurs at an eclipse.

   The duration of an eclipse depends on the relative positions of the sun, moon, and earth in their syzygy.

   1991, Phyllis M. Lugger (editor), Asteroids to Quasars: A Symposium Honoring William Liller, Cambridge University Press, →ISBN, page 67

2. countableuncountableJungian psychologyAn archetypal pairing of contrasexual opposites, symbolizing the communication of the conscious and unconscious minds.

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   In 1936 Jung defends his concept of animus and anima by reference to the idea of the syzygy, concluding from the evidence in many different mythologies of the divine couple, united by a sacred marriage, that this motif is as universal as the existence of men and women. He postulates that in the syzygy the archetypal union of the parents is expressed, the mother corresponding to the anima.

   2006, Renos K. Papadopoulos, The Handbook of Jungian Psychology: Theory, Practice and Applications, Psychology Press, →ISBN, page 117

3. countableuncountablelinear algebraA relation between generators of a module.

   A finitely presented module is an A-module M given by a finite number of generators and relations. Therefore it is a module with a finite generator set having a finitely generated syzygy module.

   2015, Henri Lombardi, Claude Quitté, Commutative Algebra: Constructive Methods: Finite Projective Modules, Springer, →ISBN, page 173

4. countableuncountablemedicineThe fusion of some or all of the organs.
5. countableuncountablebiologyThe association of two protozoa end-to-end or laterally for the purpose of asexual exchange of genetic material.

   When two or more arm-joints meet transversely by a rigid suture, and only the upper one is pinnule-bearing, those joints form a syzygy, whether their apposed faces are striated, dotted, or smooth.

   1900, Karl Alfred von Zittel, Text-book of Paleontology: Protozoa. Coelentrata (zoophytes). Echinodermata. Vermes (Worms). Molluscoidea. Mollusca. Arthropoda (articulates)

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   These include syzygy, fusion of larvae or adults of flatworms, fusion of buds of some Tunicata, somatic fertilization (fusion of spermatozoa with somatic cells), composite zygotes of some Cestoda and Insecta, and fusion of cells in various tissues.

   2018, Richard E. Blackwelder, The Diversity of Animal Reproduction, CRC Press, →ISBN

6. countableuncountablebiologyThe pairing of chromosomes in meiosis.
7. countableuncountableGnosticismComplementary female–male pairings of the emanations known as Aeons.