missing massn.

Brit.

/ˌmɪsɪŋ ˈmas/, U.S.

/ˌmɪsɪŋ ˈmæs/

Origin: Formed within English, by compounding. Etymons: missing adj., mass n.²

Etymology: < missing adj. + mass n.²

Chiefly Astronomy and Physics.

The amount by which a measured or calculated mass falls short of an expected or inferred mass; (Astronomy) the discrepancy between the mass of a galactic cluster calculated from the velocities of its component galaxies and the mass of the visible (luminous) stars and gas within it, usually attributed to the presence of dark matter; (also) the difference between the mass there must be in the universe if it is closed and the total mass accounted for by direct observation.The existence of missing mass and dark matter is at present hypothetical.

ΘΚΠ

the world > the universe > [noun] > missing mass

missing mass1889

dark matter1932

the world > the universe > constellation > galaxy > [noun] > missing mass

missing mass1889

1889 Amer. Naturalist 23 497 Captain Wharton estimates that a fiftieth part of the missing mass of Krakatoa, which was estimated to be at least 200,000,000,000 cubic feet, would..form a wave circle of 100 miles in circumference.

1933 Proc. Royal Soc. A. 140 271 The deficit gravitational field of the missing mass in r₀ has repulsive effect and is responsible for the expansion.

1967 Astrophysical Jrnl. 148 713 It has been known for some time that the mass in ordinary galaxies is inadequate by a factor of about 40 to close the Universe... Apparently the missing mass necessary for a closed Universe could not be uniformly distributed hydrogen.

1968 M. S. Livingston Particle Physics v. 93 The magnitude of the excitation of such a heavier particle is given by the ‘missing mass’ calculated from the Q-equation when the mass of the normal particle is assumed.

1970 New Scientist 9 Apr. 57/1 Information about the incoming pi meson, the target proton and the recoil proton is sufficient to calculate the ‘missing mass’.

1976 G. B. Field in E. H. Avrett Frontiers Astrophysics xii. 529 The missing mass in the Coma cluster or other clusters.

1982 Nature 24 June 623/1 Such holes might today provide the ‘missing mass’ known to reside in clusters of galaxies and galactic haloes.

1990 R. Morris Edges of Sci. ii. vi. 96 Astronomers no longer speak of missing mass. Nowadays, they prefer the term dark matter instead, and indeed the latter term is more accurate, because there really isn't anything ‘missing’.

1993 Ecol. Appl. 3 264/1 The missing mass [of chow and sucrose] was presumed to be loss of sucrose to the rat tub surface.

2001 Guardian 23 Mar. i. 13/4 Astrophysicists have been struggling for 50 years to explain what they call the ‘dark matter’ that makes up the missing mass of the universe.

This entry has been updated (OED Third Edition, June 2002; most recently modified version published online March 2022).

单词	missing mass
释义	missing massn. Brit. /ˌmɪsɪŋ ˈmas/, U.S. /ˌmɪsɪŋ ˈmæs/ Origin: Formed within English, by compounding. Etymons: missing adj., mass n.² Etymology: < missing adj. + mass n.² Chiefly Astronomy and Physics. The amount by which a measured or calculated mass falls short of an expected or inferred mass; (Astronomy) the discrepancy between the mass of a galactic cluster calculated from the velocities of its component galaxies and the mass of the visible (luminous) stars and gas within it, usually attributed to the presence of dark matter; (also) the difference between the mass there must be in the universe if it is closed and the total mass accounted for by direct observation.The existence of missing mass and dark matter is at present hypothetical. ΘΚΠ the world > the universe > [noun] > missing mass missing mass1889 dark matter1932 the world > the universe > constellation > galaxy > [noun] > missing mass missing mass1889 1889 Amer. Naturalist 23 497 Captain Wharton estimates that a fiftieth part of the missing mass of Krakatoa, which was estimated to be at least 200,000,000,000 cubic feet, would..form a wave circle of 100 miles in circumference. 1933 Proc. Royal Soc. A. 140 271 The deficit gravitational field of the missing mass in r₀ has repulsive effect and is responsible for the expansion. 1967 Astrophysical Jrnl. 148 713 It has been known for some time that the mass in ordinary galaxies is inadequate by a factor of about 40 to close the Universe... Apparently the missing mass necessary for a closed Universe could not be uniformly distributed hydrogen. 1968 M. S. Livingston Particle Physics v. 93 The magnitude of the excitation of such a heavier particle is given by the ‘missing mass’ calculated from the Q-equation when the mass of the normal particle is assumed. 1970 New Scientist 9 Apr. 57/1 Information about the incoming pi meson, the target proton and the recoil proton is sufficient to calculate the ‘missing mass’. 1976 G. B. Field in E. H. Avrett Frontiers Astrophysics xii. 529 The missing mass in the Coma cluster or other clusters. 1982 Nature 24 June 623/1 Such holes might today provide the ‘missing mass’ known to reside in clusters of galaxies and galactic haloes. 1990 R. Morris Edges of Sci. ii. vi. 96 Astronomers no longer speak of missing mass. Nowadays, they prefer the term dark matter instead, and indeed the latter term is more accurate, because there really isn't anything ‘missing’. 1993 Ecol. Appl. 3 264/1 The missing mass [of chow and sucrose] was presumed to be loss of sucrose to the rat tub surface. 2001 Guardian 23 Mar. i. 13/4 Astrophysicists have been struggling for 50 years to explain what they call the ‘dark matter’ that makes up the missing mass of the universe. This entry has been updated (OED Third Edition, June 2002; most recently modified version published online March 2022). < n.1889
随便看	to be gloamed to be go to stud to be going a person's way to be going in to be going on to be going on another age to be going on with to be going strong to be going upon to be gold-weight to be golden to be goldweight to be gone to be gone up to be good bad money to be good enough to to be good enough to eat to be good etc money to be good etc on one's feet to be good fast on one's feet to be good friends to be good fun to be good kokum to bear evidence to bear faith