aurora bo·re·al·is /-ˌboriˈæləs, ˌbɔr-/
 北極光
 Light n.
 1. That agent, force, or action in nature by the operation of which upon the organs of sight, objects are rendered visible or luminous.
 Note: ☞ Light was regarded formerly as consisting of material particles, or corpuscules, sent off in all directions from luminous bodies, and traversing space, in right lines, with the known velocity of about 186,300 miles per second; but it is now generally understood to consist, not in any actual transmission of particles or substance, but in the propagation of vibrations or undulations in a subtile, elastic medium, or ether, assumed to pervade all space, and to be thus set in vibratory motion by the action of luminous bodies, as the atmosphere is by sonorous bodies. This view of the nature of light is known as the undulatory or wave theory; the other, advocated by Newton (but long since abandoned), as the corpuscular, emission, or Newtonian theory. A more recent theory makes light to consist in electrical oscillations, and is known as the electro-magnetic theory of light.
 2. That which furnishes, or is a source of, light, as the sun, a star, a candle, a lighthouse, etc.
    Then he called for a light, and sprang in.   --Acts xvi. 29.
    And God made two great lights; the greater light to rule the day, and the lesser light to rule the night.   --Gen. i. 16.
 3. The time during which the light of the sun is visible; day; especially, the dawn of day.
    The murderer, rising with the light, killeth the poor and needy.   --Job xxiv. 14.
 4. The brightness of the eye or eyes.
 He seemed to find his way without his eyes;
 For out o'door he went without their helps,
 And, to the last, bended their light on me.   --Shak.
 5. The medium through which light is admitted, as a window, or window pane; a skylight; in architecture, one of the compartments of a window made by a mullion or mullions.
    There were windows in three rows, and light was against light in three ranks.   --I Kings vii.4.
 6. Life; existence.
    O, spring to light, auspicious Babe, be born !   --Pope.
 7. Open view; a visible state or condition; public observation; publicity.
    The duke yet would have dark deeds darkly answered; he would never bring them to light.   --Shak.
 8. The power of perception by vision.
    My strength faileth me; as for the light of my eyes, it also is gone from me.   --Ps. xxxviii. 10.
 9. That which illumines or makes clear to the mind; mental or spiritual illumination; enlightenment; knowledge; information.
 He shall never know
 That I had any light of this from thee.   --Shak.
 10. Prosperity; happiness; joy; felicity.
    Then shall thy light break forth as the morning, and thy health shall spring forth speedily.   --Is. lviii. 8.
 11. Paint. The manner in which the light strikes upon a picture; that part of a picture which represents those objects upon which the light is supposed to fall; the more illuminated part of a landscape or other scene; -- opposed to shade.  Cf. Chiaroscuro.
 12. Appearance due to the particular facts and circumstances presented to view; point of view; as, to state things fairly and put them in the right light.
    Frequent consideration of a thing . . . shows it in its several lights and various ways of appearance.   --South.
 13. One who is conspicuous or noteworthy; a model or example; as, the lights of the age or of antiquity.
 Joan of Arc,
 A light of ancient France.   --Tennyson.
 14. Pyrotech. A firework made by filling a case with a substance which burns brilliantly with a white or colored flame; as, a Bengal light.
 Note: ☞ Light is used figuratively to denote that which resembles physical light in any respect, as illuminating, benefiting, enlightening, or enlivening mankind.
 Ancient lights Law, Calcium light, Flash light, etc. See under Ancient, Calcium, etc.
 Light ball Mil., a ball of combustible materials, used to afford light; -- sometimes made so as to be fired from a cannon or mortar, or to be carried up by a rocket.
 Light barrel Mil., an empty power barrel pierced with holes and filled with shavings soaked in pitch, used to light up a ditch or a breach. --
 Light dues Com., tolls levied on ships navigating certain waters, for the maintenance of lighthouses.
 Light iron, a candlestick. [Obs.]
 Light keeper, a person appointed to take care of a lighthouse or light-ship.
 Light money, charges laid by government on shipping entering a port, for the maintenance of lighthouses and light-ships.
 The light of the countenance, favor; kindness; smiles.
    Lord, lift thou up the light of thy countenance upon us.   --Ps. iv. 6.
 -- Northern lights. See Aurora borealis, under Aurora.
 To bring to light, to cause to be disclosed.
 To come to light, to be disclosed.
 To see the light, to come into the light; hence, to come into the world or into public notice; as, his book never saw the light.
 To stand in one's own light, to take a position which is injurious to one's own interest.
 North·ern a.
 1. Of or pertaining to the north; being in the north, or nearer to that point than to the east or west.
 2. In a direction toward the north; as, to steer a northern course; coming from the north; as, a northern wind.
 Northern diver. Zool. See Loon.
 Northern lights. See Aurora borealis, under Aurora.
 Northern spy Bot., an excellent American apple, of a yellowish color, marked with red.
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 Au·ro·ra n.; pl. E. Auroras L. (rarely used) Auroræ
 1. The rising light of the morning; the dawn of day; the redness of the sky just before the sun rises.
 2. The rise, dawn, or beginning.
 3. Class. Myth. The Roman personification of the dawn of day; the goddess of the morning. The poets represented her a rising out of the ocean, in a chariot, with rosy fingers dropping gentle dew.
 4. Bot. A species of crowfoot.
 5. The aurora borealis or aurora australis (northern or southern lights).
 Aurora borealis i. e., northern daybreak; popularly called northern lights. A luminous meteoric phenomenon, visible only at night, and supposed to be of electrical origin. This species of light usually appears in streams, ascending toward the zenith from a dusky line or bank, a few degrees above the northern horizon; when reaching south beyond the zenith, it forms what is called the corona, about a spot in the heavens toward which the dipping needle points. Occasionally the aurora appears as an arch of light across the heavens from east to west. Sometimes it assumes a wavy appearance, and the streams of light are then called merry dancers. They assume a variety of colors, from a pale red or yellow to a deep red or blood color. The Aurora australis is a corresponding phenomenon in the southern hemisphere, the streams of light ascending in the same manner from near the southern horizon.
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 Co·ro·na n.; pl. L.  Coronæ (-n░), E.  Coronas
 1. A crown or garland bestowed among the Romans as a reward for distinguished services.
 2. Arch. The projecting part of a Classic cornice, the under side of which is cut with a recess or channel so as to form a drip. See Illust. of Column.
 3. Anat. The upper surface of some part, as of a tooth or the skull; a crown.
 4. Zool. The shelly skeleton of a sea urchin.
 5. Astronomy A peculiar luminous appearance, or aureola, which surrounds the sun, and which is seen only when the sun is totally eclipsed by the moon.
 6. Bot. (a) An inner appendage to a petal or a corolla, often forming a special cup, as in the daffodil and jonquil. (b) Any crownlike appendage at the top of an organ.
 7. Meteorol. (a) A circle, usually colored, seen in peculiar states of the atmosphere around and close to a luminous body, as the sun or moon. (b) A peculiar phase of the aurora borealis, formed by the concentration or convergence of luminous beams around the point in the heavens indicated by the direction of the dipping needle.
 8. A crown or circlet suspended from the roof or vaulting of churches, to hold tapers lighted on solemn occasions. It is sometimes formed of double or triple circlets, arranged pyramidically. Called also corona lucis.
 9. Mus. A character [❚]  called the pause or hold.
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 Dan·cer n. One who dances or who practices dancing.
 The merry dancers, beams of the northern lights when they rise and fall alternately without any considerable change of length. See Aurora borealis, under Aurora.
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 aurora borealis
      n : the aurora of the northern hemisphere [syn: northern lights]