Periodicity is the quality of occurring at regular intervals (e.g. of time) and can occur in different contexts: 8:17 am, August 6, 1945, Japanese time. ...

• A clock marks time at periodic intervals.
• A metronome ticks at periodic intervals.
• A publication published at periodic intervals can be called a "periodical", though it can also be called magazine.
• In mathematics, a function which recurs periodically is called periodic function.
• In chemistry, a table which classifies elements by means of periodicity is the periodic table.

The measure of periodicity is frequency. A clock (from the Latin cloca, bell) is an instrument for measuring time. ... A mechanical wind-up metronome in motion A metronome is a device that produces a strict rhythm. ... A collection of magazines A magazine is a periodical publication containing a variety of articles. ... Wikibooks Wikiversity has more about this subject: School of Mathematics Wikiquote has a collection of quotations by or about: Mathematics Look up Mathematics in Wiktionary, the free dictionary Wikimedia Commons has more media related to: Mathematics Bogomolny, Alexander: Interactive Mathematics Miscellany and Puzzles. ... In mathematics, a function is a relation, such that each element of a set (the domain) is associated with a unique element of another (possibly the same) set (the codomain, not to be confused with the range). ... In mathematics, a periodic function is a function that repeats its values, after adding some definite period to the variable. ... Chemistry (in Greek: χημεία) is the science of matter that deals with the composition, structure, and properties of substances and with the transformations that they undergo. ... The periodic table of the chemical elements, also called the Mendeleev periodic table, is a tabular display of the known chemical elements. ... Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...

See also: synchronicity, simultaneity. Synchronicity is a word created by the Swiss psychologist Carl Jung to describe the alignment of universal forces with the life experiences of an individual. ... Simultaneity is the property of two events happening at the same time. ...