catflap.org Online Dictionary Query

  Magnitude \Mag"ni*tude\, n. [L. magnitudo, from magnus great.
     See Master, and cf. Maxim.]
     1. Extent of dimensions; size; -- applied to things that have
        length, breadth, and thickness.
        [1913 Webster]
  
              Conceive those particles of bodies to be so disposed
              amongst themselves, that the intervals of empty
              spaces between them may be equal in magnitude to
              them all.                             --Sir I.
                                                    Newton.
        [1913 Webster]
  
     2. (Geom.) That which has one or more of the three
        dimensions, length, breadth, and thickness.
        [1913 Webster]
  
     3. Anything of which greater or less can be predicated, as
        time, weight, force, and the like.
        [1913 Webster]
  
     4. Greatness; grandeur. ``With plain, heroic magnitude of
        mind.'' --Milton.
        [1913 Webster]
  
     5. Greatness, in reference to influence or effect;
        importance; as, an affair of magnitude.
        [1913 Webster]
  
              The magnitude of his designs.         --Bp. Horsley.
        [1913 Webster]
  
     6. (Astron.) See magnitude of a star, below.
        [PJC]
  
     Apparent magnitude
  
     1. (Opt.), the angular breadth of an object viewed as
        measured by the angle which it subtends at the eye of the
        observer; -- called also apparent diameter.
  
     2. (Astron.) Same as magnitude of a star, below.
  
     Magnitude of a star (Astron.), the rank of a star with
        respect to brightness. About twenty very bright stars are
        said to be of first magnitude, the stars of the sixth
        magnitude being just visible to the naked eye; called also
        visual magnitude, apparent magnitude, and simply
        magnitude. Stars observable only in the telescope are
        classified down to below the twelfth magnitude. The
        difference in actual brightness between magnitudes is now
        specified as a factor of 2.512, i.e. the difference in
        brightness is 100 for stars differing by five magnitudes.
        [1913 Webster +PJC]

  
  
     4. Greatness; grandeur. ``With plain, heroic magnitude of
        mind.'' --Milton.
  
     5. Greatness, in reference to influence or effect;
        importance; as, an affair of magnitude.
  
              The magnitude of his designs.         --Bp. Horsley.
  
     Apparent magnitude (Opt.), the angular breadth of an object
        viewed as measured by the angle which it subtends at the
        eye of the observer; -- called also apparent diameter.
        
  
     Magnitude of a star (Astron.), the rank of a star with
        respect to brightness. About twenty very bright stars are
        said to be of first magnitude, the stars of the sixth
        magnitude being just visible to the naked eye. Telescopic
        stars are classified down to the twelfth magnitude or
        lower. The scale of the magnitudes is quite arbitrary, but
        by means of photometers, the classification has been made
        to tenths of a magnitude.