| 释义 |
symmetry|ˈsɪmɪtrɪ|
Also 6 symmetrye, simetrie, 6–7 simetry, sym(m)etrie, 7 simmetry, -ie, symetry.
[a. F. † symmetrie (1529), mod. symétrie (= It. simm-, Sp. sim-, Pg. symetria), or ad. late L. symmetria, a. Gr. συµµετρία, f. σύµµετρος, f. σύν sym- + µέτρον measure (see metre).]
†1. Mutual relation of the parts of something in respect of magnitude and position; relative measurement and arrangement of parts; proportion.
With qualifying adj. such as just, right, true, coinciding with sense 2.
1563Shute Archit. A iij b, Concerning y⊇ proportion and simetry to vse the accustomed terme of the arte of the fornamed columbes. Ibid. B j b, They not knowing any measure of pillours considered howe to make a iust Symetrie,..after that they deuised to make a temple to the goddesse Diana, wherein they dyd deuise an other Symetrie, for that temple. 1570Dee Math. Pref. a iv, The exhibiting to our eye,..the plat of a Citie,..or Pallace, in true Symmetry. Ibid. c iij b, Now, may you, of any Gunne,..make an other, with the same Symmetrie..as great, and as little, as you will. 1624Wotton Archit. in Reliq. (1672) 23 Man..is..as it were the Prototype of all exact Symmetrie. 1650Bulwer Anthropomet. 241 True and native beauty consists in the just composure and symetrie of the parts of the body. 1730A. Gordon Maffei's Amphith. 313 He marks out a Stair..which agrees not with the Symmetry of the Building.
2. Due or just proportion; harmony of parts with each other and the whole; fitting, regular, or balanced arrangement and relation of parts or elements; the condition or quality of being well-proportioned or well-balanced. In stricter use (approaching or passing into 3 b): Exact correspondence in size and position of opposite parts; equable distribution of parts about a dividing line or centre. (As an attribute either of the whole, or of the parts composing it.)
a. (a) of natural objects or structures, esp. the human or animal body: often (esp. in early use) = regularity and beauty of form, fair or fine appearance, comeliness.
1599B. Jonson Cynthia's Rev. i. iii, If I had thought a creature of her symmetry, could have dar'd so improportionable, and abrupt a digression. 1633G. Herbert Temple, Ch. Porch lxx, Who marks in church-time others symmetrie, Makes all their beautie his deformitie. 1635A. Stafford Fem. Glory (1869) 5 Whether her Beauty chiefly consisted in colour, in symmetry of parts, or both. 1778H. More Bleeding Rock 224 Hers every charm of symmetry and grace. 1820W. Irving Sketch Bk. I. 185 The small Italian hound of exquisite symmetry. 1853C. Brontë Villette xxiv, Her pale, small features, her fairy symmetry, her varying expression. 1858O. W. Holmes Aut. Breakf.-t. xii. 113 One of the finest trees in symmetry and beauty I had ever seen.
† (b) in semi-concr. sense: (Well-proportioned) figure or form (of a person or animal). Obs.
1602Marston Ant. & Mel. ii. Wks. 1856 I. 25 Ladie, erect your gratious simmetry. 1633Ford Love's Sacr. ii. E j, She cannot..more really, behold her owne Symmetry in her glasse. 1794W. Blake Songs Exper., Tiger 4 What immortal hand or eye Could frame thy fearful symmetry?
b. of artificial things or structures, esp. buildings.
1601Holland Pliny xxxiv. viii. II. 499 The Symmetrie, which..he observed most precisely in all his workes, is a tearme that cannot properly be expressed by a Latine word. Ibid. xxxv. x. 543 Asclepiodorus, whome for his singular skill in observing symetries and just proportions, Apelles himselfe was woont to admire. 1702W. J. Bruyn's Voy. Levant ix. 31 There is no regularity of Architecture nor any Symmetry observ'd in it. 1723Chambers tr. Le Clerc's Archit. I. 97 This Column..must have a Pilaster by its side, to make a Symmetry with that on the other side the Window. 1820Lamb Elia Ser. i. Two Races of Men, Spoilers of the symmetry of shelves. 1849Longfellow Building Ship 179 Till, framed with perfect symmetry, A skeleton ship rose up to view! 1907Verney Mem. I. 15 The utter disregard of symmetry evinced by our ancestors which is one secret of the picturesqueness of their groups of buildings.
c. (a) in general sense, or of immaterial or abstract things, as action, thought, discourse, literary composition, etc.
1603Holland Plutarch's Mor. 60 Beautie and fauour is composed..of many numbers meeting and concurring in one..and that by a certaine symmetrie, consonance and harmonie. 1609Bp. Andrewes Serm., Resurrection iv. (1631) 420 The way, to peace, is the mid way: neither..too much; nor..too little. In a word; all analogie, symmetrie, harmony, in the world, goeth by it. 1643Sir T. Browne Relig. Med. ii. §9 Whatsoever is harmonically composed, delights in harmony; which makes me much distrust the symmetry of those heads which declaime against all Church musicke. 1711Shaftesbury Charac. iv. ii. (1737) I. 139 The ordering of Walks, Plantations, Avenues; and a thousand other Symmetrys, will succeed in the room of that happier and higher Symmetry and Order of a Mind. 1742West Let. in Gray's Poems (1775) 142 The connection and symmetry of such little parts with one another must naturally escape me, as not having the plan of the whole in my head. 1860Pusey Min. Proph. 291 This book, Micah, has remarkable symmetry. Each of its three divisions is a whole, beginning with upbraiding for sin, threatening Gods judgments, and ending with promises of future mercy. a1862Buckle Civiliz. (1864) II. vi. 445 Into that dense and disorderly mass, did Adam Smith introduce symmetry, method, and law. 1904H. Black Practice of Self-Culture v. 132 Culture..aims at symmetry of life.
(b) Agreement, consistency, consonance, congruity, keeping (with something). rare or Obs.
1654H. L'Estrange Chas. I (1655) 9 You furnished my Father with..supply's, but they held no symmetry or proportion with the charge of so great an enterprise. 1659Evelyn Let. to R. Boyle 3 Sept., I will..shew what symmetry it [sc. the building] holds with this description. 1878Stubbs Lect. Med. & Mod. Hist. viii. (1900) 192 It is in exact symmetry with Western usage, that this great compilation was not received as a code until the year 1369.
3. Various specific and technical uses.
†a. Physiol. Harmonious working of the bodily functions, producing a healthy temperament or condition. Obs. rare.
1541Copland Galyen's Terap. 2 E j b, In Symmetrye, that is to say..in competent [? competence] and commoderacyon of smal conduites lyeth and consisteth the helth. And in Ametrie, that is to saye, in vncompetence and immoderacyon in them the dysease.
b. (a) Sci. Exact correspondence in position of the several points or parts of a figure or body with reference to a dividing line, plane, or point (or a number of lines or planes); arrangement of all the points of a figure or system in pairs (or sets) so that those of each pair (or set) are at equal distances on opposite sides of such line, plane, or point. More widely, a property by virtue of which something is effectively unchanged by a particular operation; an operation or set of operations that leaves something effectively unchanged; in Physics, a property that is conserved (cf. symmetry operation, sense 4 below).
Symmetry, e.g. in crystals, may be of various grades, according to the number of radiating or non-parallel lines or planes about which the figure or body is symmetrical.
axis of symmetry, centre of s., plane of s., the line, point, or plane about which a figure or body is symmetrical, i.e. which bisects every straight line joining a pair of corresponding points of such figure or body.
1823H. J. Brooke Introd. Crystallogr. 13 From the perfect symmetry of its form, the cube has a similar axis in four directions. 1837Brewster Magnet 39 A horse-shoe magnet..was made to revolve..about its axis of symmetry. 1850McCosh Div. Govt. ii. i. (1874) 119 The oblong, or two-and-two-membered symmetry, may be traced..among crystals and flowers, as may also the three-membered symmetry. 1877Huxley Physiogr. (1878) 56 The best example of this hexagonal symmetry..is furnished by crystals of snow. 1878Gurney Crystallogr. 29 A plane..through the centre of a model of a crystal will be a plane of symmetry, if the perpendiculars drawn to it from every point of the model, on being produced to equal distances on the other side..will terminate in points of the model similar to those from which they are drawn. 1908H. Hilton Theory of Groups of Finite Order iv. 42 If a movement (other than identity) brings every point of a figure F into the position previously occupied either by itself or by some other point of F, F is said to possess symmetry. 1941Birkhoff & MacLane Survey Mod. Algebra vi. 122 The algebra of symmetries has its genesis in the fact that we can multiply two motions by performing them in succession. 1965R. P. Feynman et al. Feynman Lect. Physics III. xvii. 8 Symmetry with respect to displacements in time implies the conservation of energy; symmetry with respect to position in x, y, or z implies the conservation of momentum. 1967Physical Rev. Lett. XIX. 1264/2 As far as we know, two of these symmetries are entirely unbroken: the charge Q..and the electron number N. 1968M. S. Livingston Particle Physics xii. 201 One consequence of the translational symmetry of space is the invariance of physical laws under translation from one location to another. 1974Frauenfelder & Henley Subatomic Physics vi. 154 Some of the symmetries are perfect even under closest scrutiny, and no breakdown in the corresponding conservation law has ever been found. Rotational symmetry and conservation of angular momentum are one example.
(b) Alg., Higher Math., and Logic. The fact of being symmetrical, as an expression or function: see symmetrical a. 2 b.
1888Amer. Jrnl. Math. X. 173 Notes on Geometric Inferences from Algebraic Symmetry. 1950[see reflexivity]. 1967S. C. Kleene Math. Logic iii. 158 Sometimes ‘equality’ is used in a different sense, so that it possesses only the first three properties (reflexivity, symmetry and transitivity).
c. (a) Anat. and Zool. Arrangement of parts or organs in pairs or sets on opposite sides of a dividing plane, or around an axis or centre; repetition of similar corresponding parts in the two halves, or other number of divisions, of the body. (Nearly coinciding with 3 b or the stricter use in 2, except that corresponding parts are not necessarily equal, nor do all the parts necessarily correspond.) (b) Path. Affection of such corresponding parts simultaneously by the same disease.
1849–52Todd's Cycl. Anat. IV. 845 Symmetry is a word used to express..the fact, that one half of an animal is usually an exact reversed copy of the other... To this there are numerous exceptions. a1883Fagge Princ. Pract. Med. (1886) II. 619 Symmetrical distribution means that exactly the corresponding parts on the right and left side are simultaneously affected... This is bilateral symmetry, but we also see examples of serial symmetry in pathology where the same condition is seen on the elbow and the knee, the wrist and the ankle.
d. Bot. Equality of the number of parts in the several whorls of the flower: see symmetrical 3 a.
1845–50A. H. Lincoln Lect. Bot. 138 The symmetry of structure observable in [Enchanter's Night-shade] is seen in many flowers. 1849Balfour Man. Bot. §643 When the number of parts is two, the flower is dimerous..and the symmetry two-membered. When the number of parts is three, the flower is trimerous, and when the parts are arranged in an alternating manner, the symmetry is trigonal or triangular [etc.]. 1908Henslow How to Study Wild Fl. 113 The flowers [of Lythrum Salicaria] vary in symmetry; for sometimes the central flower will differ from the lateral ones in the number of parts.
4. attrib. and Comb., as symmetry principle, symmetry property; symmetry-breaking ppl. a. and vbl. n. Physics, (causing) the absence of manifest symmetry in a situation despite its presence in the laws of nature underlying it; symmetry group, a group (group n. 5 a) whose elements are all the symmetry operations of a particular entity; symmetry operation Physics, an operation or transformation that leaves something effectively unchanged.
1961M. Gell-Mann in Gell-Mann & Ne'eman Eightfold Way (1964) We attempt..to treat the eight known baryons as a supermultiplet, degenerate in the limit of a certain symmetry but split into isotopic spin multiplets by a symmetry-breaking term. 1977Dædalus Summer 29 As a result of this symmetry-breaking, the quanta of the weak interactions are predicted to acquire a mass approximately forty or more times heavier than that of a proton. 1981Nature 10 Dec. 522/1 The usual analogy used for spontaneous symmetry breaking is ferromagnetism. Maxwell's equations are rotationally invariant; however, below the Curie temperature the rotational invariance of a ferromagnet is spontaneously broken when the magnetization chooses a specific direction.
1956Ibid. 10 Mar. 458/1 To-day the instinctive reaction of every theoretical physicist, confronted with an unexplained regularity in the behaviour of elementary particles, is to postulate an underlying symmetry-group. 1975I. Stewart Concepts Mod. Math. vii. 97 Every shape has a symmetry group. 1981Sci. Amer. Apr. 50/2 The SU(2) × U(1) theory is only a partial unification because it still includes two distinct forces, each with its own symmetry group and its own coupling constant.
1952H. Weyl Symmetry 27 For forms fixed to the bottom of the ocean the direction of gravity is an important factor, narrowing the set of symmetry operations from all rotations around the center P to all rotations about an axis. 1973B. H. Bransden et al. Fundamental Particles iv. 56 The symmetry operations with which we are concerned are transformations of the dynamical variable that leave the Hamiltonian operator unaltered.
1968M. S. Livingston Particle Physics xii. 201 It is possible that the number of such symmetry principles is limited and that they are interrelated. Ibid., One of the most basic symmetry principles is that of the homogeneity of space and the associated symmetry of time. 1977Dædalus Fall 31 Some theorists turned to the study of symmetry principles and conservation laws, which can be applied to physical phenomena without detailed dynamical calculations.
1935Pauling & Wilson Introd. Quantum Mech. xiv. 388 The symmetry properties of molecular wave functions. 1968M. S. Livingston Particle Physics iii. 58 The type of quantum statistics which applies to a system of particles (all of one kind) is related to the symmetry properties of the wave function describing this system of particles. |