An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Topological irregularities in the → space-time  → continuum, caused by the abrupt cooling of the → early Universe shortly after the → Big Bang, as predicted by some → cosmological models. These regions of immensely high density might have been the seeds of → structure formation through → gravity. Same as → topological defect.

→ cosmic; → defect.

General: Something or a lack of something that results in incompleteness, inadequacy, or imperfection.
Crystals: A discontinuity in the arrangement of atoms, ions, or electrons.
Cosmology: → cosmic defect.

From L. defectus "failure," from p.p. of deficere "to fail, desert," from → de- "down, away" + facere "to do," (cf. Fr. faire, Sp. hacer), from PIE base *dhe- "to put, to do" (cf. Av. dadaiti "he puts," Skt. dadhati "puts, places," Hitt. dai- "to place," Gk. tithenai "to put."

Âk "defect, blemish;" Mid.Pers. ak, âk "evil, harm;" Av. aka- "bad, wicked;" cf. Skt. aka- "pain , trouble."
Kâst "loss," from kâstan, kâhidan "to decrease, lessen, diminish," from Mid.Pers. kâhitan, kâstan, kâhênitan "to decrease, diminish, lessen;" keh "small, little, slender;" Av. kasu- "small, little;" Proto-Iranian *kas- "to be small, diminish, lessen."

The difference between the rest mass of an atomic nucleus (made up of protons and neutrons) and the sum of the masses of its individual protons and neutrons. The mass difference is equal to the released binding energy. Also called mass deficiency

→ mass; → defect.

Of an atomic energy level, the difference between the principal quantum number and the effective quantum number.

→ quantum; → defect.

An unoccupied position in a crystal lattice which forms when oppositely charged ions leave their lattice sites, creating vacancies.

Named after Walter Hans Schottky (1886-1976), German physicist; → defect.

In → cosmological models, a stable configuration of → matter formed when the → early Universe underwent → phase transitions during which fundamental symmetries were broken. There are a number of possible types of defects, such as domain walls, → cosmic strings, → magnetic monopoles, and → texture s. Same as → cosmic defect.

→ topological; → defect.