What are black holes?

Famous quotes containing the words black and/or holes:

    And my eyes are blue;
    So ferry me across the water,
    Do, boatman, do!”

    “Step into my ferry-boat,
    Be they black or blue,
    Christina Georgina Rossetti (1830–1894)

    But Father John went up,
    And Father John went down;
    And he wore small holes in his shoes,
    And he wore large holes in his gown.
    William Butler Yeats (1865–1939)