zero pointn.
/ˈzɪərəʊ pɔɪnt/, U.S. /ˈzɪroʊ ˌpɔɪnt/, /ˈziroʊ ˌpɔɪnt/ The lowest point on a scale, order, or ranking; a value from which a positive or negative quantity is reckoned. Also: a point respresented by a 0 on an instrument or device, used as the basis for taking measurements. Cf. zero n. 4a, zero n. 4b.
ΘΚΠ
the world > matter > physics > quantum theory > [adjective] > of system, etc.: at absolute zero
zero point1789
1789 2nd Rep. Philanthropic Soc. 15 It's plan is to begin it's operations upon lives, which in their present state are below the Zero point, in the scale of estimation.
1810 T. Thomson Syst. Chem. (ed. 4) I. 565 A thermometer, the zero point of which indicates absolute cold.
1826 Mem. Astron. Soc. II. 469 Every star observed in the course of the sweep which can be identified with a star in any catalogue, and whose place is determined with certainty, is taken as a zero point.
1895 Physical Rev. 2 326 The balls were placed horizontally in their neutral position, and the reading of the zero-point of the scale taken.
1920 Metal Industry 18 412/2 To avoid errors in weighing, one must know how to determine the Zero Point of the balance.
1993 H. Thurston Early Astron. i. 32 The zero point for measuring celestial longitude is the spring equinox.
2014 Daily News (Sri Lanka) (Nexis) 8 Jan. The octane rating was developed..in 1926. The selection of n-heptane as the zero point of the scale was due to its availability in high purity.
Compounds
C1. attributive. Physics. In quantum mechanics: designating properties of and phenomena exhibited by physical systems when possessing the minimum possible amount of energy.See also zero-point energy n. at Compounds 2.
ΚΠ
1929 Physical Rev. 34 280 Experiments which have been made to determine the intensity of the x-ray diffraction pattern as a function of the temperature seem to point rather clearly to the existence of zero point energy and a zero point motion of the system.
1955 H. B. G. Casimir in W. Pauli Niels Bohr & Devel. Physics 130 The interaction with the zero point vibrations of the crystal lattice leads to an interaction between electrons.
1973 Sci. Amer. Jan. 91/1 In quantum physics the ground state is not a state of absolute rest or motionlessness but only a singular ‘zero point’ form of motion in which there are no quasiparticles.
1999 V. F. Petrenko & R. W. Whitworth Physics of Ice (2003) ii. 25 Pauling's model was devised in part to account for the known zero-point entropy of ice.
2005 New Scientist 13 Aug. 16/4 The object would also warp the zero-point field such that a particle in its vicinity would encounter more photons on the side away from the object than on the nearer side.
C2.
zero-point energy n. Physics (in quantum mechanics) the minimum energy possessed by a physical system at a temperature of absolute zero.
ΚΠ
1913 Proc. 3rd Internat. Congr. Refrigeration 2 126 (note) Planek's [sic] theory of radiation.., in which the vibrators have a zero-point energy, received firm support from an unexpected source.
1935 J. Dougall tr. M. Born Atomic Physics 339 According to the classical theory, the state of least energy of an oscillator is that of zero energy. According to wave mechanics, however, the ground state has a finite energy E = ½hv0... This zero-point energy can be explained by Heisenberg's uncertainty principle.
1952 C. A. Coulson Valence i. 11 Even in the lowest allowed vibrational state there still remains the zero-point energy of vibration.
2007 F. Close Nothing: Very Short Introd. (2009) vii. 100 Quantum mechanics implies that there is a minimum sum of kinetic and potential energies that can be achieved: both cannot simultaneously be zero. This minimum amount is the zero point energy of the atomic assembly.
This entry has been updated (OED Third Edition, June 2018; most recently modified version published online March 2022).
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n.1789