ENCYCLOPEDIA GALACTICA Edition 428193 - Earth English Definition: 'The Twenty-Four Hour Convention' A Language English1 expression pertaining to the fact that thirty-seven (37) civilizations of the Community2 parse their primary day-night cycle into twenty-four (24) segments of equal period. This is seventy-seven percent (77%) of all confirmed civilizations. Humans refer to these segments as “hours” or by equivalent translations. In all cases, the establishment of the convention dates into 'antiquity'.3 The accepted hypothesis for the convention is mathematical. There are twenty-four (24) fifteen (15) degrees of arc in a circle.4 A circle being representative of a birth world's full rotation – a 'day'. Fifteen (15) degrees is significant for being the smallest angle that can be drawn or measured to high accuracy using simple technical implements. These implements being a straight edge and a compass. Fifteen (15) degrees of arc is obtained through application of Euclidean5 geometric principles. By scribing two circles of identical radius where the second circle is centred on the limb of the first, the resulting two intersection points form a one hundred and twenty (120) degree angle through the centre of either circle. This obtuse angle can be subsequently bisected thrice through similar Euclidean techniques to obtain fifteen (15) degrees of arc. Of coarse, further bisecting of angles is possible but the tools necessary for accuracy are often beyond the capacity of an early civilization to mass produce. Accuracy is crucial for the collective needs of an early civilization. Simple standards, independent of cultural norms, language or history makes commerce and exchange of knowledge easier to engage. Successful societies do develop the means to mass produce more accurate tools for geometric measure but by that stage the fifteen (15) degree unit is an accepted standard. Unless there is a necessity for adopting a new standard, civilizations will resort to separate subdivision of their pre-existing unit of temporal measure. Such as “minutes” and then “seconds” or by equivalent translations. The standard number of 'hours' is retained well into a civilization's space age and rarely altogether abandoned.6 The standard maintains a convenience and cultural acceptance for planetary bound municipalities and members within a space faring civilization. There are exceptions. If a birth world's day-night cycle exceeds the maximum period members can self sustain without energy, an 'hourly' standard never establishes. Called the 'Kusuma limit'7 it occurs on planets which rotate slowly or are rotationally captured by their central star(s). Members of Civilization Aquila have no concept of a 'day' and measure that time scale through an overlay of non-uniform personal and seasonal events.8 The aluluei influenced avian cultures of Civilization Sagittarius Orange established a ninety-six (96) hour day. They further bisected the Euclidean model twice. 'The Graceful', as they call themselves have an instinctive devotion to mathematical and navigational discipline.9 Other known avian civilizations establish at least a forty-eight (48) hour day for similar reasons. Instead of elongating their standard 'hour' as their birth world's rotation slowed, the membership of Civilization Taurus added additional hours to there standard clock. They now maintain a twenty-six (26) hour day. See references: 1Civilization Humanity: Linguistic Types 2Definition: 'The Community' 3Prior to verifiable recorded history. 4Civilization Humanity: Scientific Standards 5Civilization Humanity: Euclid of Alexandria, Members of Note 6Civilization Lacerta: History, Temporal Measurement 7Definition: 'Kusuma Limit' 8Civilization Aquila: Planetary Dynamics, Temporal Measurement 9Civilization Sagittarius Orange: Social Order, Temporal Measurement