penumbraとは 意味・読み方・使い方

別の表記

• pænumbra (obsolete, rare)

語源

From New Latin pēnumbra, from Latin paene (“almost”) + umbra (“shadow”).

発音

• IPA: /pəˈnʌm.bɹə/, enPR: pĭ-nŭm'brə
• ハイフネーション: pen‧um‧bra or pe‧num‧bra

名詞

penumbra (plural penumbras or penumbrae or (obsolete) penumbræ)

1. A partially shaded area around the edges of a shadow, especially an eclipse.
   • 1875 October, E. Neison [pseudonym; Edmund Neville Nevill], “On the Condition of the Atmospheres of the Planets”, in William Crookes, editor, The Quarterly Journal of Science, […], volume V (New Series; XII, Old Series), London: Offices of the Quarterly Journal of Science, […], →OCLC, page 460:

     [A]ny penumbral fringe that may be detected cannot be well distinguished from the effects of the true penumbræ; […]

   • 2011, Galen C. Duree, Jr., Optics for Dummies, Wiley Publishing, Inc., published 2011, →ISBN, page 61:

     The other places see the penumbra of the moon's shadow fall on the earth, so the eclipse is partial, and part of the sun's disc is still visible.

   • 2011, Frank McLynn, Captain Cook: Master of the Seas, Yale University Press, published 2011, →ISBN, page 112:

     In the boiling temperature of 119 ° F – the hottest they had experienced so far – they watched as the penumbra of Venus blurred its outline at the precise moment the disc crossed the sun.

   • 2012, Michael A. Seeds, Dana E. Backman, Horizons: Exploring the Universe, Brooks/Cole, published 2012, →ISBN, page 37:

     The part of the moon that remains in the penumbra receives some direct sunlight, and the glare is usually great enough to prevent your seeing the faint coppery glow of the part of the moon in the umbra.

2. (astronomy) A region around the edge of a sunspot, darker than the sun's surface but lighter than the middle of the sunspot.
   • 1868 December 8, Henry Pratt, “The Transit of Mercury”, in The Astronomical Register: […], volume VII, number 73 (January 1869), London: J. D. Potter, […], →OCLC, “Correspondence” section, page 20:

     The atmosphere was very clear, evidenced by the steadiness with which the mottling of the sun’s surface and the penumbræ of several spots were visible.

   • 1921, Kodaikanal Observatory Bulletin, volume III, New Delhi: Manager of Publications, →OCLC, page 173:

     The velocities found in the penumbræ of spots generally increase with the distance from the centre of radiation, the motion being zero at some point in the umbra, and accelerating outwards.

3. (figuratively) An area of uncertainty or intermediacy between two mutually exclusive states or categories.
   • 1998, Debraj Ray, Development Economics, Princeton University Press, →ISBN, pages 346–347:

     These firms or businesses are not illegal in the strict sense, but there is a shadowy penumbra within which they live, and it is often convenient for the government to look the other way.

   • 2010, Denis Farkasfalvy, Inspiration and Interpretation: A Theological Introduction to Sacred Scripture, The Catholic University of America Press, published 2010, →ISBN, page 188:

     […] God chose to descend into the realm of human imperfection, where the light of truth is spare and must exist in the penumbra of partial knowledge mixed with partial ignorance.

   • 2011, Bill Schwartz, The White Man's World, Oxford University Press, published 2011, →ISBN, page 136:

     Unlike some of his contemporaries Parkes never implied that the Irish were close, in the racial hierarchy, to black, condemned to some racial penumbra, between black and white; but nor, given Catholic exclusion from the given traditions of his native radicalism, were the Irish white in the same way that he was.

4. (figuratively) An area that lies on the edge of something; a fringe.
   • 1842, [George B. Loring], England Opposed to Slavery, or Some Remarks upon “An Examination into the Real Causes of the War Against the United States, and an Appeal to the Other Powers of Europe Against the Purposes of England.”, Boston: Benjamin H. Greene, pages 48–49:

     Thank God we are not all cowards, we have not all a low ambition, which would make men shades, pœnumbræ of their fellows.

   • 1975, Bryan R. Wilson, The Noble Savages: The Primitive Origins of Charisma and Its Contemporary Survival, Quantum Books, published 1975, →ISBN, page 116:

     Whilst the orthodox, de-charismatized churches steadily lose influence and support and the new cults develop, in the religious penumbra there have persisted, during the last century, echoes of charisma.

   • 1986, John McCormick, “Chicago Bounces Back”, in Newsweek, volume 108, page 42:

     But for all the expansionist energy of a metro area that sprawls from Wisconsin to Indiana (total population: 7.2 million), downtown Chicago and its penumbra also stand rejuvenated.

   • 2000, Steve Jones, The Language of Genes‎, Flamingo, →ISBN, page xv:

     Some are accounts of the latest advances, but too many are in that weary penumbra of science inhabited by sociologists, who wander like children in a toyshop, playing with devices they scarcely understand.

5. Something related to, connected to, and implied by, the existence of something else that is necessary for the second thing to be full and complete in its essential aspects.
   • 1965, William O. Douglas, Griswold v. Connecticut, United States Reports, 381 U.S. 479

     The foregoing [United States Supreme Court] cases suggest that specific guarantees in the Bill of Rights have penumbras, formed by emanations from those guarantees that help give them life and substance.

6. (medicine, preceded by "ischaemic", after a stroke) A region of the brain that has lost only some of its blood supply, and retains structural integrity but has lost function.

同意語

• (area of uncertainty or intermediacy): grey area
• (area that lies on the edge of something): periphery, outskirt

派生語

参照

名詞

pēnumbra f (genitive pēnumbrae); first declension

1. (New Latin) alternative form of paenumbra

語形変化

First-declension noun.