Hearing The Shape of A Drum

Hearing The Shape Of A Drum

To hear the shape of a drum is to infer information about the shape of the drumhead from the sound it makes, i.e., from the list of overtones, via the use of mathematical theory. "Can One Hear the Shape of a Drum?" was the witty title of an article by Mark Kac in the American Mathematical Monthly 1966 (see the references below), but these questions can be traced back all the way to Hermann Weyl.

The frequencies at which a drumhead can vibrate depend on its shape. The Helmholtz equation tells us the frequencies if we know the shape. These frequencies are the eigenvalues of the Laplacian in the region. A central question is: can they tell us the shape if we know the frequencies? No other shape than a square vibrates at the same frequencies as a square. Is it possible for two different shapes to yield the same set of frequencies? Kac did not know the answer to that question.

Read more about Hearing The Shape Of A Drum:  Formal Statement, The Answer, Weyl's Formula, The Weyl–Berry Conjecture

Famous quotes containing the words hearing the, hearing, shape and/or drum:

    “That myth—that image of the madonna-mother—has disabled us from knowing that, just as men are more than fathers, women are more than mothers. It has kept us from hearing their voices when they try to tell us their aspirations . . . kept us from believing that they share with men the desire for achievement, mastery, competence—the desire to do something for themselves.”
    —Lillian Breslow Rubin (20th century)

    “Orpheus with his Lute made Trees,
    And the Mountaine tops that freeze,
    Bow themselves when he did sing.
    To his Musicke, Plants and Flowers
    Ever spring; as Sunne and Showres,
    There had been a lasting Spring.
    Every thing that heard him play,
    Even the Billowes of the Sea,
    Hung their heads, and then lay by.
    In sweet Musicke is such Art,
    Killing care, and griefe of heart,
    Fall asleepe, or hearing dye.”
    —John Fletcher (1579–1625)

    “We shape our buildings: thereafter they shape us.”
    —Winston Churchill (1874–1965)

    “We call ourselves a free nation, and yet we let ourselves be told what cabs we can and can’t take by a man at a hotel door, simply because he has a drum major’s uniform on.”
    —Robert Benchley (1889–1945)