Moment (unit)

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Moment (time)
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St. Emmeram Abbey
. The day is divided into 24 hours, and each hour into 4 puncta, 10 minuta, or 40 momenta. Similarly, the week is divided into seven days, and each day into 96 puncta, 240 minuta, or 960 momenta.

A moment (momentum) is a

solar hour, a twelfth of the period between sunrise and sunset. The length of a solar hour depended on the length of the day, which, in turn, varied with the season.[1] Although the length of a moment in modern seconds was therefore not fixed, on average, a medieval moment corresponded to 90 seconds. A solar day can be divided into 24 hours of either equal or unequal lengths,[2][3] the former being called natural or equinoctial, and the latter artificial. The hour was divided into four puncta (quarter-hours), 10 minuta, or 40 momenta.[4]

The unit was used by medieval

computists before the introduction of the mechanical clock and the base 60 system in the late 13th century. The unit would not have been used in everyday life. For medieval commoners the main marker of the passage of time was the call to prayer
at intervals throughout the day.

The earliest reference found to the moment is from the 8th century writings of the

Bartholomeus Anglicus in his early encyclopedia De Proprietatibus Rerum (On the Properties of Things),[8] as well as Roger Bacon,[7] by which time the moment was further subdivided into 12 ounces of 47 atoms
each, although no such divisions could ever have been used in observation with equipment in use at the time.

References

  1. ^ North, John David (1988). Chaucer's Universe. University of Michigan Press.
  2. . Retrieved 23 January 2017.
  3. ^ Bacon, Roger. Opera quaedam hactenus inedita. Oxford University Press. p. 45. Retrieved 5 July 2014.
  4. . Retrieved 23 January 2017.
  5. . Retrieved 23 January 2017.
  6. . Retrieved 23 January 2017.
  7. ^ a b Bacon, Roger. Opera quaedam hactenus inedita. Oxford University Press. p. 48. Retrieved 5 July 2014. Note the distinction between minucia and minuta, as well as the introduction of the ostenta, the precursor to the modern minute.
  8. . Retrieved 5 July 2014.