Month: August 2005

  • Presbyterian Justice

    News from today's New York Times:

    The Rev. Dr. Theodore Alexander Gill Sr., a Presbyterian theologian, a
    philosophy
    teacher, and an influential provost emeritus of John Jay College of
    Criminal Justice in
    Manhattan, died at 85 on June 10 in Princeton.  In retirement from
    John Jay, The Rev. Dr. Gill was theologian in residence at Nassau
    Presbyterian Church in Princeton.

    In memory of The Rev. Dr. Gill:

    Religious Symbolism at Princeton
        (on Nassau Presbyterian Church),
    Pro-Semitism
        (on number theory at Princeton),
    For the Mad Musicians of Princeton,
         (on Schroeder and Bernstein),
    Movie Date and its preceding entries
       (on Princeton's St. John von Neumann),
    Why Me?
       (for Princeton theologian Elaine Pagels),
    Notes on Literary and Philosophical Puzzles
       (Princeton's John Nash as Ya Ya Fontana), and
    Go Tigers!
       (for the Princeton Evangelical Fellowship).

    For a more conventional memorial, see

    The image “http://www.log24.com/log/pix05B/050807-SFTS-Logo.gif” cannot be displayed, because it contains errors.

    the obituary from

    San Francisco Theological Seminary.

  • The Fugue

       "True joy is a profound remembering, and true grief is the same.

        Thus it was, when the dust storm that had snatched
    Cal up finally died, and he opened his eyes to see the Fugue spread out
    before him, he felt as though the few fragile moments of epiphany he'd
    tasted in his twenty-six years-- tasted but always lost-- were here
    redeemed and wed. He'd grasped fragments of this delight before. Heard
    rumour of it in the womb-dream and the dream of love; known it in
    lullabies. But never, until now, the whole, the thing entire.

        It would be, he idly thought, a fine time to die.

        And a finer time still to live, with so much laid out before him."

    -- Clive Barker,
    Weaveworld,
     Book Two:
    The Fugue

    From Monday:

    Weaveworld,
    Book Three:
    Out of the
    Empty Quarter

    "The wheels of its body rolled,
    the
    visible mathematics

       
    of its essence turning on itself...."



    From Friday:

    The image “http://www.log24.com/log/pix05B/050806-Square.bmp” cannot be displayed, because it contains errors.

      For the meaning
    of this picture, see
    Geometry of the
    4x4 Square.

    For graphic designs
    based on this geometry,
    see Theme and Variations
    and Diamond Theory.

    For these designs in the
    context of a Bach fugue,
    see Timothy A. Smith's
    essay (pdf) on

    Fugue No. 21 in B-Flat Major
    from Book II of
    The Well-Tempered Clavier
    by Johann Sebastian Bach.

    Smith also offers a
    Shockwave movie
    that uses diamond theory
    to illustrate this fugue.

  • For André Weil on
    the seventh anniversary
    of his death:

     A Miniature

    Rosetta Stone

    The image “http://www.log24.com/log/pix05B/grid3x3med.bmp” cannot be displayed, because it contains errors.

    In a 1940 letter to his sister Simone,  André Weil discussed a sort of "Rosetta stone," or trilingual text of three analogous parts: classical analysis on the complex field, algebraic geometry over finite fields, and the theory of number fields.  

    John Baez discussed (Sept. 6, 2003) the analogies of Weil, and he himself furnished another such Rosetta stone on a much smaller scale:

    "... a 24-element group called the 'binary
    tetrahedral group,' a 24-element group called 'SL(2,Z/3),' and
    the vertices of a regular polytope in 4 dimensions called the
    '24-cell.' The most important fact is that these are all the
    same thing!"

    For further details, see Wikipedia on the 24-cell, on special linear groups, and on Hurwitz quaternions,

    The group SL(2,Z/3), also known as "SL(2,3)," is of course derived from
    the general linear group GL(2,3).  For the relationship of this
    group to the quaternions, see the Log24 entry for August 4 (the
    birthdate of the discoverer of quaternions, Sir William Rowan Hamilton).

    The 3x3 square shown above may, as my August 4 entry indicates, be
    used to picture the quaternions and, more generally, the 48-element
    group GL(2,3)
    .  It may therefore be regarded as the structure
    underlying the miniature Rosetta stone described by Baez.

    "The typical example of a finite group is GL(n,q), the
    general linear
    group of n dimensions over the field with q elements. The student who
    is introduced to the subject with other examples is being completely
    misled."

     -- J. L. Alperin, book review,

        Bulletin (New Series) of the American

        Mathematical Society 10
    (1984), 121

  • Music for the
    Feast of the
    Transfiguration

    "Jesus hits like

    an atom bomb."

    The image “http://www.log24.com/log/pix05/050312-AtomBomb.jpg” cannot be displayed, because it contains errors.
    Click on picture
    for a sound clip.

  • For Sir Alec

    From Elegance:

    "Philosophers ponder the
    idea of identity: what it is to give something a name on Monday and
    have it respond to that name on Friday...."

    -- Bernard Holland, page C12,
        The New York Times,
        Monday, May 20, 1996.

    Holland was pondering the identity of the Juilliard String Quartet,
    which had just given a series of concerts celebrating its fiftieth
    anniversary.

    "Elegant"

    -- Page one,
        The New York Times,
        Monday, August 7, 2000.
     
    The Times was describing the work of Sir Alec Guinness, who died on
    8/5/00.

    An example of the Holland name problem:

    Monday, August 1, 2005 -- Visible Mathematics:

        "Earlier,
    there had been mapping projects in Saudi Arabia's Rub' al-Khali, the
    Empty Quarter in the south and west of the country....
       '
    "Empty" is a misnomer...  the Rub' al-Khali contains many hidden riches.'"

    Friday, August 5, 2005 --

     
    The image “http://www.log24.com/log/pix05B/050805-Rag.jpg” cannot be displayed, because it contains errors.

    Related material:

    Geometry for Prince Harry

     

  • Abel's Birthday

    The image “http://www.log24.com/log/pix05B/050805-Lemniscate.jpg” cannot be displayed, because it contains errors.

    Click on picture
    for details.

  • Visible Mathematics, continued

    Today's mathematical birthdays:

    Saunders Mac Lane, John Venn,
    and Sir William Rowan Hamilton.

    It is well known that the quaternion group
    is a subgroup of GL(2,3), the general linear group on the 2-space over GF(3), the 3-element Galois field.

    The figures below illustrate this fact.

    The image “http://www.log24.com/theory/images/Quaternions2.jpg” cannot be displayed, because it contains errors.

    Related material: Visualizing GL(2,p)

    "The typical example of a finite group is GL(n,q), the
    general linear
    group of n dimensions over the field with q elements. The student who
    is introduced to the subject with other examples is being completely
    misled."

     -- J. L. Alperin, book review,
        Bulletin (New Series) of the American
        Mathematical Society 10
    (1984), 121

  • Epiphany Term

    "In Epiphany Term, 1942, C.S. Lewis delivered the Riddell
    Memorial Lectures... in.... 
    the University of Durham....  He
    delivered three lectures
    entitled 'Men without Chests,' 'The Way,' and 'The
    Abolition of Man.'  In them he set out to attack and
    confute what he saw as the errors of his age. He started by
    quoting some fashionable lunacy from an educationalists'
    textbook, from which he developed a general attack on moral
    subjectivism.  In his second lecture he argued against
    various contemporary isms, which purported to replace
    traditional objective morality.  His final lecture, 'The
    Abolition of Man,' which also provided the title of the
    book published the following year, was a sustained attack on
    hard-line scientific anti-humanism.

    The intervening fifty years have largely vindicated Lewis."

    -- J. R. Lucas, The Restoration of Man

    See also Log24,
    Epiphany 2003.
     
  • Austere

    The image “http://www.log24.com/log/pix05B/050802-Stone.gif” cannot be displayed, because it contains errors.

    Pictured:
    Modal Theology

    By SALAH NASRAWI

    The Associated Press

    Tuesday, August 2, 2005  9:50 AM EDT

    RIYADH,
    Saudi Arabia -- Muslim leaders and Saudi princes bade farewell to King
    Fahd on Tuesday, saying prayers in a packed Riyadh mosque and then
    burying him in an unmarked desert grave in keeping with the kingdom's
    austere version of Islam.

  • Today's birthday:


    Peter O'Toole

    "What is it, Major Lawrence,

     that attracts
    you personally

     to the desert?"

    "It's clean."

    Visible Mathematics,

    continued --

    From May 18:

    Lindbergh's Eden

    "The Garden of Eden is behind us
    and there is no road
    back to innocence;
    we can only go forward."

    -- Anne Morrow Lindbergh,
    Earth Shine, p. xii

    "Beauty is the proper conformity
    of the parts to one another
    and to the whole."

    -- Werner Heisenberg,
    "Die Bedeutung des Schönen
    in der exakten Naturwissenschaft,"
    address delivered to the
    Bavarian Academy of Fine Arts,
    Munich, 9 Oct. 1970, reprinted in
    Heisenberg's Across the Frontiers,
    translated by Peter Heath,
    Harper & Row, 1974

    Related material:

    The Eightfold Cube

    The Eightfold Cube

    (in Arabic, ka'b)

    and

    The image “http://www.log24.com/log/pix05B/050802-Geom.jpg” cannot be displayed, because it contains errors.