Urn
From Freepedia
- For the computing term, see URN.
An urn is a vase, ordinarily covered and without handles that usually has a narrowed neck above a footed pedestal. Knife urns on pedestals flanking a dining-room sideboard were an English innovation of the late 1760s that went out of fashion as sideboards with deep cupboard drawers were introduced at the end of the following decade.
Funerary urns were used by many civilizations. After death, a body would be cremated and the ashes were typically collected in an urn (for example, the Greek lekythos). John Keats' "Ode on a Grecian Urn" (1820) is not thought to have been inspired by any single Greek vase.
Romans placed the urns in a niche in a collective tomb called a "columbarium" (literally, "dovecote": the interior of a dovecote is usually covered in rows of niches to house doves).
The discovery of a Bronze Age urn burial in Norfolk prompted Sir Thomas Browne to deliver a careful description of the antiquties found, and then expand to give a survey of most of the burial and funerary customs, ancient and current, of which his era was aware, in Hydriotaphia or Urn Burial (1658).
The Ashes, the prize in the biennial Test cricket competition between England and Australia, are contained in a miniature urn.
Urns are a common form of architectural detail and garden ornament. Well-known ornamental urns include the Waterloo Vase.
An urn problem is a thought experiment in which some objects of interest are represented as colored balls in an urn, such as the Ellsberg paradox. One imagines removiing one or more balls from the urn, with the goal of determining the probability of drawing one color or another, or some other properties. Another is (Polya's urn: an urn initially contains r red and b blue marbles. One is chosen randomly. Then it is put back together with another one of the same colour. Let Xn be the number of red marbles in the urn after n iterations of this procedure, and let Yn=Xn/(n+r+b). Then the sequence { Yn : n = 1, 2, 3, ... } is a martingale.
