A group, in mathematics, is a set together with an operation that combines any two of its elements to form a third element, in such a way that the operation is associative, an identity element exists, and every element has an inverse. These three conditions, called group axioms, are familiar from number systems. The ubiquity of groups in numerous areas—both within and outside mathematics—makes them a central organizational tool in contemporary mathematics. The concept of a group arose from the study of polynomial equations, starting with Évariste Galois in the 1830s. After contributions from other fields such as number theory and geometry, the group notion was generalized and firmly established around 1870. Today, group theory is a very active mathematical discipline that studies groups in their own right. Symmetry groups are widely applied in molecular chemistry and various physical disciplines.

Read more: https://en.wikipedia.org/wiki/Group_%28mathematics%29

_______________________________ Today's selected anniversaries:

1489:

Catherine Cornaro, Queen of Cyprus, was forced to abdicate and sell the administration of the island to the Republic of Venice. https://en.wikipedia.org/wiki/Catherine_Cornaro

1885:

The Mikado, Gilbert and Sullivan's most frequently performed Savoy opera, debuted at the Savoy Theatre in London. https://en.wikipedia.org/wiki/The_Mikado

1969:

Edward M. Burke, the longest-serving alderman in the history of the Chicago City Council, was sworn into office. https://en.wikipedia.org/wiki/Edward_M._Burke

1984:

Gerry Adams, leader of Sinn Féin, was seriously wounded in an assassination attempt by Ulster Freedom Fighters in central Belfast, Northern Ireland. https://en.wikipedia.org/wiki/Gerry_Adams

_____________________________ Wiktionary's word of the day:

Pi Day: March 14th, an annual celebration of the mathematical constant π (pi). https://en.wiktionary.org/wiki/Pi_Day

___________________________ Wikiquote quote of the day:

With an aching heart I add my voice to that of the common people, who implore the end of the war. In the name of God, listen to the cry of those who suffer, and put an end to the bombings and the attacks! The city that bears the name of the Virgin Mary, Mariupol, has become a city martyred by the ruinous war that is devastating Ukraine. Before the barbarism of killing children and innocent and defenceless citizens, no strategic reasons hold: the only thing to be done is to cease the unacceptable armed aggression before cities are reduced to cemeteries.   --Pope Francis https://en.wikiquote.org/wiki/Pope_Francis