The periodicity , rotation or recurrence generally denotes the property of a thing or a process that has a regularity with regard to the occurrence of a certain event. The regular series of events is a cycle. Meyers Großes Konversations-Lexikon from 1908 writes that periodicity is “the regular recurrence of certain phenomena after a certain period of time, as it is e.g. B. can be observed in the cycle of the seasons. ”The period of time between two identical phenomena of a repetitive process is called a period .
In the case of a temporal periodicity, the frequency makes a statement about how often the event is repeated in a certain period of time, or the period duration (often just: period ) about how long the time period between two events is. In the case of temporal periodicity, the term cycle is also used colloquially for period.
The opposite concept to periodicity is called aperiodicity . Processes that are not periodic are referred to as aperiodic.
- Mathematics : In mathematics, the occurrence of repetitive values is called periodicity and the corresponding functions are called periodic functions
- Chemistry : The chemical periodic table describes the regularities of the structures of atoms
- Physics and technology : The periodicity is shown by the fact that a period can be specified for regularly repeating physical phenomena, preferably for oscillations and waves
One speaks of temporal periodicity for:
- Seasons : spring, summer, autumn, winter
- Life cycle : birth, life, death
- Tides : ebb and flow
- Astronomy : Revolutionary period , Saros period (↔ Saros cycle), solar circles , lunar circles
- Tenure : The recurring in the same periods of office of organs or functionaries is in politics term called
- Calendar : meton period (↔ meton cycle)
- Journalism : The different publication rhythms of newspapers / magazines (e.g. weekly newspaper , Quarterlies)
- Zeno: Lexicon entry on "Periodicity". Meyers Großes Konversations-Lexikon, Volume 15. ... Accessed October 15, 2018 .
- period. Dudenverlag, accessed on May 24, 2020 .
- aperiodic. Dudenverlag, accessed on May 24, 2020 .