observableadj.n.

1589 G. Puttenham Arte Eng. Poesie iii. xv. 142 More obseruable to the Greekes and Latines for the brauenesse of their language, ouer that our is.

1614 T. Ravenscroft Briefe Disc. Musicke Pref. sig. A2^v Such are the Times, Numbers, and Measures, obseruable, not in Man alone that vses the Pastime [sc. hunting or hawking], but euen in the Creatures also, that either make the game, or pursue it.

1646 Sir T. Browne Pseudodoxia Epidemica 101 As the head may be disturbed by the skin, it may the same way be relieved; as is observable in balneations. View more context for this quotation

1690 J. Locke Ess. Humane Understanding ii. xxiii. 136 'Tis the ordinary Qualities, observable in Iron, or a Diamond, put together, that make the true complex Idea of those Substances.

1711 J. Addison Spectator No. 256. ¶3 Any little Slip is more conspicuous and observable in his Conduct than in another's.

1788 J. Madison in Federalist Papers lv. 142 A very considerable difference is observable among states nearly equal in population.

1823 H. J. Brooke Familiar Introd. Crystallogr. 33 The regularity and symmetry observable in the forms of crystallized bodies.

1874 J. R. Green Short Hist. Eng. People viii. §1. 455 A marked change in public sentiment became at once observable.

1910 Encycl. Brit. I. 945/2 There are gentler and more beneficial aspects observable to-day in China and Japan.

1963 T. Morris & P. Morris Pentonville x. 212 The effects of this are likely to become increasingly observable with the development of in-service promotion.

2001 Isis 92 242/2 She countered Freud by insisting on the psychic importance of woman's readily observable role in reproduction.

1932 Science 9 Sept. 222 Hubble estimates that about 30 million nebulae are contained within a sphere of this radius, and that so far as the observations go..they are uniformly distributed..throughout the observable universe.

1982 F. H. Shu Physical Universe xv. 376/2 The distinction between the universe and the observable universe is important because astronomers have not yet settled the question of whether the universe is open or closed.

1991 D. Overbye Lonely Hearts of Cosmos xiii. 241 At the time of the breakdown of grand unified symmetry the region that we today call the observable universe—a sphere roughly 10 billion light-years in radius—was about the size of a grapefruit and sizzling at 10²⁷ degrees K.

1995 New Scientist 16 Sept. 20/1 Paul Francis of the University of Melbourne..discovered the newborn giant elliptical [galaxy] near the edge of the observable Universe.

1660 H. More Explan. Grand Myst. Godliness iii. vi. 70 Apparent as well from what they write of his birth and amours, as from other observables in his Image.

1954 A. J. Ayer Philos. Ess. i. 9 It may be left open what situations are to count as being observable; whether, for example, we are to treat such objects as electrons as being directly accessible to observation, or only such common-sense objects as chairs and tables, or only sense-data. Whatever decision may be taken..we are..likely to be left with some descriptive expressions which do not signify observables.

1968 J. J. C. Smart Between Sci. & Philos. v. 143 The instrumentalist..would agree with the operationist in holding that in science no statements are made about entities other than macroscopic observables.

a1990 W. Percy Signposts in Strange Land (1991) 122 We are dealing, not with thoughts or subjective states, but with behavior and observables, with people, words and things, and what people do with words and things.

1930 P. A. M. Dirac Princ. Quantum Mech. ii. 25 In quantum mechanics it is more convenient to deal with something that refers to one particular time instead of to all times, analogous to the value of a classical variable at a particular instant of time. We shall call such a quantity an observable.

1966 C. G. Hempel Philos. Nat. Sci. vi. 74 These wavelengths are not observables in the ordinary sense of the word.

1974 H. Clark First Course Quantum Mech. iii. 54 In quantum mechanics..not all the observables of a system can be measured simultaneously. If some observable is measured, this act of measurement may disturb the system and change the value of some other observable.

1999 Proc. National Acad. Sci. U.S.A. 96 11309 There are two sets of experimental observables that can be used to test the sequential binary collision model: protein folding rates and ϕ-values.