| 释义 |
gravity|ˈgrævɪtɪ|
Also 6 gravite(e, -yte, -etie, -ytye.
[ad. F. gravité (12–13th c. in Hatz.-Darm.) or L. gravitāt-em, gravitās, n. of quality f. gravis heavy, weighty: see grave a.1 (n.1) The word was first introduced in figurative senses, corresponding generally to the Eng. senses of the adj. The primary physical sense of the Lat. word came into Eng. first in the 17th c.]
I. The quality of being grave.
1.
†a. Weight, influence, authority. Obs.
1534Whitinton Tullyes Offices i. (1540) 2 Plato if he wolde have practysed this maner of persuadynge, he might have persuaded with singular gṙavytie. 1535St. Papers Hen. VIII (1849) VII. 614 So in all their procedinges..they shew themselffes to be men of gravyte and wisedom. 1620Brent tr. Sarpi's Counc. Trent i. (1676) 95 To send Ambassadours, men of gravity and authority. 1728Morgan Algiers II. iv. 290 Why should these Circumstances be mentioned by a Historiographer of such gravity. 1741Middleton Cicero II. x. 406, I would not have you think, that any Letters were ever read in the Senate of greater weight than yours, both for the eminent merit of your services, and the gravity of your words and sentiments.
†b. As a title of honour or respect. Obs.
1618Barnevelt's Apol. Ded. A ij, I offer it to you with all singular affection, and bending submission to your grauitie. 1629Prynne New Antith. Pref. 2 It cannot be unknown to your gravities, that [etc.]. 1781Gibbon Decl. & F. xvii. II. 24 Your Gravity, your Excellency, your Eminence [etc.].
c. Of a ceremony, proceedings, etc.: Solemnity.
1647Clarendon Hist. Reb. iii. §10 The earl was, with more clamour than was suitable to the gravity of that supreme court, called upon to withdraw. 1689Evelyn Corr. 12 Aug. (1879) III. 445 There was at least something of more grauity and forme kept up. 1716Lady M. W. Montagu Let. to C'tess Mar 14 Sept., The whole [drawing-room] passes with a gravity and air of ceremony that has something very formal in it. 1849Macaulay Hist. Eng. vi. II. 40 The gravity and pomp of the whole proceeding made a deep impression even on the Nuncio. 1855Prescott Philip II, v. 83 The process went on with suitable gravity.
d. Something grave; a grave or serious subject, speech, or remark. Obs. or arch.
1609Shakspere's Tr. & Cr. (Qo. 1) Epist. ⁋ij, You should see all those grand censors, that now stile them [Playes] such vanities, flock to them for the maine grace of their grauities. 1850L. Hunt Autobiog. II. x. 18 He seldom ventured on a gravity, but in echo of another's remark. 1871Geo. Eliot in J. W. Cross Life (1885) III. 131, I read aloud..books of German science, and other gravities. Ibid. III. 325 We are deep among the gravities.
2. Grave, weighty, or serious character or nature; importance, seriousness:
†a. of literary productions, style, etc. (obs.);
b. of events, facts, conditions.
1519Interl. Four Elem. (Percy Soc.) 3 They myght, yf they wolde, in our Englyshe tonge Wryte workys of gravyte. 1533Sir T. More Debell. Salem Wks. 964/2 The iudges parte is to see that the punishemente passe not the grauitie of the offence. 1594Hooker Eccl. Pol. i. x. §9 To punish the injury committed according to the gravity of the fact. 1649Milton Eikon. viii. Wks. (1847) 295/2 Empty sentences that have the sound of gravity, but the significance of nothing pertinent. 1659Pearson Creed (1839) 203 The gravity of every offence must needs increase proportionably to the dignity of the party offended. 1790Burke Fr. Rev. Wks. V. 74 The wise will determine from the gravity of the case. 1878R. B. Smith Carthage 213 He was himself alive to the gravity of the occasion. 1883J. Parker Tyne Ch. 274 Great questions should be considered in a spirit worthy of their gravity.
3. Weighty dignity; reverend seriousness; serious or solemn conduct or demeanour befitting a ceremony, an office, etc.; staidness. In later use with wider application: Seriousness or sobriety (of conduct, bearing, speech, temperament, etc.); opp. to levity and gaiety.
1509Barclay Shyp of Folys (1570) 233 Let these fooles auoyde this mad misuse, And folowe the right way of vertuous grauitie. 1549Compl. Scot. vii. 70 Sittand in ane chair..kepand grite grauite, heffand ane beuk in his hand. 1585T. Washington tr. Nicholay's Voy. ii. xxv. 66 Marching with great gravitie. 1597Morley Introd. Mus. 166 Those songs which are made for the high key be made for more life, the other in the low key with more grauetie and staidnesse. 1598Shakes. Merry W. iii. i. 57, I neuer heard a man of his place, grauity, and learning, so wide of his owne respect. 1642Fuller Holy & Prof. St. iii. xxi. 209 Gravity in the ballast of the soul. 1647Clarendon Hist. Reb. i. §185 He was a man of very morose manners and a very sour aspect, which in that time was called gravity. 1689–90Temple Ess. Pop. Discontent Wks. 1731 I. 259 Gravity often passes for Wisdom, Wit for Ability. 1698Fryer Acc. E. India & P. 70 Our Entertainment was truly Noble, and becoming the Gravity of the Society [Jesuits]. 1703Maundrell Journ. Jerus. (1732) 145 Let. 2 Their Religion is fram'd to keep up great outward Gravity. 1771Mackenzie Man Feel. xl. (1803) 77 The natural gravity of her temper..was such as not easily to be discomposed. 1823Lamb Elia Ser. ii. Poor Relations, His deportment was of the essence of gravity. 1837W. Irving Capt. Bonneville III. 39 Captain Bonneville sat..listening to them with Indian silence and gravity. 1868Stanley Westm. Abb. i. (ed. 2) 13 His manners presented a singular mixture of gravity and levity. 1894Hall Caine Manxman iii. vii. 142 She grew uneasy at the settled gravity of his face.
II. In physical senses.
4.
†a. The quality of having weight, ponderability; the tendency to downward motion, regarded in ancient physics as a property inherent in certain bodies (opposed to levity, or the upward tendency ascribed, e.g., to the element of fire). Obs.
1622Malynes Anc. Law-Merch. 62 But Aristotle his reasons are generally approued, to proue the earths stabilitie in the middle or lower part of the world, because of grauitie and leuitie. 1625N. Carpenter Geog. Del. i. iv. (1635) 85 Grauity or heauinesse is nothing els but an inclination of the parts of the Earth, returning to their naturall place. 1626Bacon Sylva §704 Similitude of Substance will cause Attraction, where the Body is wholly freed from the Motion of Grauity. 1646Sir T. Browne Pseud. Ep. ii. iii. 72 To overcome the resistance of its gravity and to lift it up from the earth. 1656Stanley Hist. Philos. vi. (1701) 250/2 Heaven hath neither gravity nor levity: this is manifest from its motion which is circular, not from the center which is proper to light things, nor to the center, as is proper to heavie, but about the center. 1665Glanvill Scepsis Sci. xi. 63 Gravity, which makes great bodies hard of Remove. 1678Hobbes Decam. viii. 84 Gravity is an Intrinsecal Quality by which a Body so qualified descendeth perpendicularly towards the Superficies of the Earth.
b. Weight, heaviness; chiefly = specific gravity (see c), but occasionally the weight of an individual portion of matter, a definite amount of weight. Not now in scientific use, exc. in centre of gravity (see centre n. 16).
1641Wilkins Math. Magick i. iii. (1648) 15 With this kinde of Ballance, it is usuall by the help onely of one weight, to measure sundry different gravities. 1650Bulwer Anthropomet. 122 Their gravity and weight may also offend the upper Lip. 1664Power Exp. Philos. ii. 105 The reason why the Quicksilver descends at all in the first Experiment, is from its exceeding gravity. 1722Wollaston Relig. Nat. ix. 213 Inanimate bodies, which have different gravities. 1750Johnson Rambler No. 69 ⁋8 Liquors of different gravity and texture which never can unite. 1805–17R. Jameson Char. Min. (ed. 3) 265 The degrees of gravity of minerals. 1807Hutton Course Math. II. 149 The weights, or gravities, of bodies near the surface of the earth, are proportional to the quantities of matter contained in them. c1860Faraday Forces Nat. i. 21 Let us examine it with regard to the amount of its heaviness, or its gravity.
c. specific gravity. The degree of relative heaviness characteristic of any kind or portion of matter; commonly expressed by the ratio of the weight of a given volume to that of an equal volume of some substance taken as a standard (viz. usually water for liquids and solids, and air for gases). Abbreviated sp. gr.
Since the weights of bodies are proportional to their masses, their specific gravities are in the same ratio as their densities; and in some scientific books the term density has displaced specific gravity.
1666Boyle in Phil. Trans. I. No. 14. 234 In case its (specifick) gravity were considerably alter'd. 1685Phil. Trans. XV. 1004 As if they were different fluids, of different specifick gravities (as the word is now a-days) or (as it was wont to be called, and I think, better) Intensive gravity, one from the other. 1696Whiston Theory Earth i. (1722) 61 Fluids are..as capable of all degrees of Density and specifick Gravity, as Solids. 1758Reid tr. Macquer's Chym. I. 234 As the fire carries off the most aqueous part, the other which remains in the retort increases in specific gravity. 1822J. Imison Sci. & Art I. 120 The Hydrometer is the most eligible instrument for finding the specific gravity of fluids. 1831Lardner Hydrost. viii. 135 By the weights of equal bulks bodies may be separated and arranged in species. Hence the term specific weight or specific gravity. 1868Lockyer Elem. Astron. ix. §50 (1879) 311 The mean density, or specific gravity, of its materials. 1870Atkinson Ganot's Physics (ed. 4) §24 The relative density of a substance is generally called its specific gravity.
fig.1841–4Emerson Ess., Spir. Laws Wks. (Bohn) I. 66 The permanence of all books is fixed by..their own specific gravity, or the intrinsic importance of their contents.
d. specific gravity beads or bulbs: small hollow glass spheres used in determining the specific gravity of a liquid (see quot. 1884). specific gravity bottle or flask: an instrument for determining the specific gravity of a liquid by a comparison of the weight of a given volume of it with that of an equal volume of a standard liquid under the same conditions of temperature and pressure; a pycnometer.
1863Atkinson Ganot's Physics §99 Specific gravity flask. 1881Ibid. (ed. 10) §122 The pyknometer or specific gravity bottle. 1884A. Daniell Princ. Physics 198 Specific-gravity bulbs. Bulbs are sold which are known to float without rising or sinking in liquids of the sp. gr. marked in numbers upon them. A number of them are thrown into the liquid; those which bear too high a number sink, those which are too light rise; the one exactly corresponding, if there be one, is at rest anywhere in the fluid.
5. The attractive force by which all bodies tend to move towards the centre of the earth; the degree of intensity with which a body in any given position is affected by this force, measured by the amount of acceleration produced. Also often in wider sense, the degree of intensity with which one body is affected by the attraction of gravitation exercised by another body. absol. A force equal to the accelerating force of gravity; abbrev. g.
Some writers who restrict the word to terrestrial attraction apply it to the resultant of the earth's attraction of gravitation and the centrifugal force due to the earth's rotation, while others apply it to the gravitational component only.
1692Bentley Boyle Lect. iv. (1724) 126 Without Gravity, the whole Universe..would have been a confused Chaos. a1721J. Keill Maupertuis' Diss. (1734) 53 The Gravity in A towards γ being = π. 1756Burke Subl. & B. iv. i, If I were to explain the motion of a body falling to the ground, I would say it was caused by gravity. 1812Woodhouse Astron. xxxiv. 329 A mean force tending to diminish the Moon's gravity to the Earth. 1816Kirby & Sp. Entomol. (1843) II. 219 These ubiquitaries—some flying about—others pacing against gravity up the walls or upon the ceiling. 1837Brewster Magnet. 246 A pendulum, oscillating by the action of gravity. 1854― More Worlds iv. 70 An accurate calculation of the force of gravity upon Jupiter. 1867Herschel Fam. Lect. Sci. 90 note, A force directed to the sun differing by a mere infinitesimal from its direct gravity. 1879Thomson & Tait Nat. Phil. i. 230 Thus, approximately, the poundal is equal to the gravity of about half an ounce. 1945Jrnl. Exper. Zool. C. 398 A sample of lobster⁓serum was..subjected to ultracentrifugation in a small air-turbine..machine at approximately 120,000 gravities. 1949W. Ley Conquest of Space (1950) 44 If we assume the average acceleration of a moonship amounts to 4 g (gravities), which is something we are sure the pilot can stand.
†6. Heaviness, sluggishness (of bodily condition). Obs.—1 (a Latinism).
1610Healey St. Aug. Citie of God xxii. xv. (1620) 838 About thirty yeares man is in his full state and from that time he declineth to an age of more grauity and decay.
7. Of sounds: Lowness of pitch.
1669Holder Elem. Sp. 18 There may be other ways of discriminating the voice, e.g. by Acuteness and Gravity. 1721A. Malcolm Treat. Mus. 539 All this seems plainly to put the Difference of the Tones only in the Acuteness or Gravity of the Whole. 1828Busby Mus. Man., Gravity, a word used in contradistinction to acute: depth of sound. 1889H. C. Banister Music (ed. 14) §2 The pitch—acuteness or gravity—of a musical sound depends upon the rapidity of the vibrations which produce it.
III. 8. attrib. and Comb. a. simple attrib.
1882Rep. to Ho. Repr. Prec. Met. U.S. 650 The mill itself is put up on the terrace or ‘gravity’ plan, the movement of ore in process of treatment being always down. 1894Outing (U.S.) XXIV. 173/2 The house was..held together nominally by a little mud and mortar, in reality by virtue of being laid in the gravity line.
b. Special comb.: gravity anomaly, the difference between the observed acceleration due to gravity at a point on the surface of the earth (or another planet) and a value derived either from calculations of the geoid or from observations at some reference point; gravity balance, a type of torsion balance formerly used to measure the variation in the force of gravity from one place to another; gravity battery, cell, a galvanic battery or cell in which the liquids are kept apart by the force of gravity alone; gravity-collapse structure (see quot. 1961); gravity conveyor, a conveyor in which material slides, rolls, or falls under its own weight, the rate of descent being determined by friction; also, a conveyor in which the material is contained in freely suspended buckets kept upright by gravity; gravity dam, a dam that resists the pressure of the water by its weight; gravity die-casting, die-casting in which the metal is poured into the mould rather than forced in under pressure; a casting so made; gravity escapement (see quot. 1884); gravity meter = gravimeter 2; gravity-railroad, ‘a railroad in which the cars move down an inclined plane, or a series of inclined planes, under the action of gravity alone’ (Cent. Dict.); gravity stamp, a machine for crushing ore in which a heavy weight is repeatedly raised by a revolving cam and allowed to drop on the ore; gravity survey (see quot. 1923); gravity tank, a fuel container from which the petrol is fed by gravity to the engine; gravity water system (see quot. 1940); gravity wave, a wave on the surface of a liquid in which the dominant force is gravity rather than surface tension; also, a wave in the atmosphere propagated because of gravity; gravity-wedge, a wedge that falls into position, when released, by the force of gravity alone; gravity wind (see quot. 1959).
1912Hayford & Bowie Effect of Topography & Isostatic Compensation upon Intensity of Gravity 112 A study was made to see if a possible relation could be discovered between the *gravity anomalies..and the geoid contours. 1924H. Jeffreys Earth ix. 121 It is seen from an examination of the formula for the gravity anomaly that only the second term arises from the attraction of the mountain itself. 1959B. F. Howell Introd. Geophysics xxi. 326 Positive rather than negative gravity anomalies would be expected in the regions into which more mass is sliding. 1969Z. Kopal Moon xiii. 202 Local concentration of denser material would accelerate overflying spacecraft; and, conversely, negative gravity anomalies would slow the motion down.
1899Threlfall & Pollock in Phil. Trans. R. Soc. A. CXCIII. 215 (title) On a quartz thread *gravity balance. Ibid. 216 Our..attempts to construct a gravity balance began in September, 1889. 1923Glazebrook Dict. Appl. Physics III. 403/1 In Threlfall and Pollock's gravity balance a quartz thread is mounted horizontally and is attached, at one end to a spring which takes up variations of tension, and at the other end to an axle which can be rotated, in line with the thread.
1870Atkinson Ganot's Physics (ed. 4) §704 A kind of battery has been devised in which the porous vessel is entirely dispensed with, and the separation of the liquids is effected by the difference of density. Such batteries are called *gravity batteries. 1876Preece & Sivewright Telegraphy 31 The so called ‘Gravity’ batteries.
1936Harrison & Falcon in Q. Jrnl. Geol. Soc. XCII. 91 (title) *Gravity collapse structures and mountain ranges, as exemplified in south-western Iran. 1961J. Challinor Dict. Geol. 95/2 Gravity-collapse structures, structures, in stratified rocks, produced on the limbs of (simple) folds as a result of collapse under the force of gravity.
1910Encycl. Brit. VII. 56/1 The *gravity or tilting bucket conveyor can be used as a combined elevator and conveyor. 1966McGraw-Hill Encycl. Sci. & Technol. III. 447/2 The most economical means for lowering articles and materials is by gravity conveyors.
1940Chambers's Techn. Dict. 388/1 *Gravity dam. 1957Encycl. Brit. VII. (caption, facing p. 8), Solid masonry gravity dams. 1971N. Smith Hist. Dams ii. 33 A gravity dam is in general a straight wall of masonry or earth which resists the applied water⁓pressure because of its sheer weight.
1940Chambers's Techn. Dict. 388/1 *Gravity diecasting, a process by means of which castings of various alloys are made in steel or cast-iron moulds, the molten metal being poured by hand. 1960Metallurgia LXI. 65/2 Although there are many methods of producing castings in aluminium alloys, only three are of major importance, namely sand casting, gravity die casting, and pressure die casting. 1964S. Crawford Basic Engin. Processes (1969) xi. 246 Gravity die castings are generally superior in structure and strength to both sand castings and pressure die castings.
1850Denison Clock & Watch Making 71 The most simple..form of the *gravity escapement is this. 1884F. J. Britten Watch & Clockm. 115 Gravity Escapement, an escapement in which impulse is given to the pendulum by a weight falling through a constant distance.
1941J. M. Bruckshaw in Proc. Physical Soc. LIII. 449 The present interest in *gravity meters arises from two..considerations. Ibid. 452 It is by no means an easy matter to produce a gravity meter..which..is robust and sufficiently transportable to be employed in the field. 1955Sci. Amer. Sept. 164/1 The only way we can trace its girth and plot its distances accurately is to travel over its surface with a gravity meter, measuring the tiny differences in gravity from point to point as a guide to the ups and downs of the globe's undulating shape. 1957Encycl. Brit. X. 677/1 The gravity meter or gravimeter is simply a spring balance comprising a constant mass supported by a spring system, the changes in elongation of which may be read with precision.
1903R. H. Richards Ore Dressing I. v. 144 *Gravity stamps are lifted by cams and drop by their own weight. 1965E. J. Pryor Mineral Processing (ed. 3) iv. 60 The gravity stamp..is a fixed-path machine. It is obsolescent, its place being taken by the rod mill.
1913Q. Jrnl. Geol. Soc. LXIX. p. lxxxii, A *Gravity Survey seems clearly to be called for. 1923Glazebrook Dict. Appl. Physics III. 398/1 The primary object of a gravity survey is to obtain values of the force and direction of gravity at various points of the sea-level surface. 1959New Scientist 5 Feb. 274/2 The Americans are now planning an airborne seismic and gravity survey of the central section of the supposed graben, in Marie Byrd Land.
1917‘Contact’ Airman's Outings 225 A small *gravity tank for his machine, to be used when the pressure tank is ventilated by a bullet. 1934V. M. Yeates Winged Victory 48 A small reserve supply [of fuel] in the gravity tank. 1940Chambers's Techn. Dict. 388/1 *Gravity water system, a system in which flow occurs under the natural pressure due to gravity. 1960R. Davies Voice from Attic 99 The same unpleasing charts of the sexual organs (the male, like plans for a gravity water system; the female like the skull of an elk, with vastly branching antlers).
1877Proc. Lond. Math. Soc. IX. 22 The following particular cases..are here tabulated for convenience:—V ∝ λ, U = o, Reynold's disconnected pendulums. V ∝ λ½, U = ½V, Deep-water *gravity waves. V ∝ λ0, U = V, Aërial waves, &c. V = λ-½, U = 3/2V, Capillary water waves. V ∝ λ-1, U = 2V, Flexural waves. 1930N. Shaw Man. Meteorol. III. i. 30 The genesis of gravity-waves in air is not generally understood. 1957Jrnl. Marine Res. XVI. 107 At wind velocities between 16 and 20 knots it is common for capillary waves having the same velocity as the gravity waves to ride just at the beginning of the crest of the gravity waves. 1971Nature: Physical Sci. 29 Mar. 99/2 The excitation of atmospheric gravity waves by a nuclear test in the atmosphere.
1888Pall Mall G. 23 Oct. 2/2 A very simple but effective *gravity-wedge safety apparatus.
1928N. Shaw Man. Meteorol. II. 255 Katabatic winds... Such winds are *gravity-winds which pay no attention to isobars until they get into the open where they have time to adjust themselves to the requirements of the earth's rotation. 1959R. E. Huschke Gloss. Meteorol. 259 Gravity wind, a wind..directed down the slope of an incline and caused by greater air density near the slope than at the same levels some distance horizontally from the slope.
Hence ˈgravityship, used as a mock title.
1772Nugent tr. Hist. Friar Gerund I. 370 God forgive his Gravityship the very Reverend Father Provincial. |