English

Deutsch

Español

Français

Hrvatski

Italiano

Polski

Türkçe

Русский

中文

日本語

한국어

powered by CADENAS

Go to Article

Licensed under Creative Commons Attribution-Share Alike 3.0 (English Wikipedia user Ronhip).

Day celebrating the mathematical value π (3.141...) on 14 March

For National Pie Day, see American Pie Council § National Pie Day.

Pi Day | |
---|---|

Significance | 3, 1, and 4 are the three most significant figures of π in its decimal representation. |

Celebrations | Pie eating, discussions about π^{[1]} |

Date | March 14 |

Next time | March 14, 2020 (2020-03) |

Frequency | Annual |

First time | 1988 |

Related to | Pi Approximation Day |

Part of a series of articles on the |

mathematical constant π |
---|

3.1415926535897932384626433... |

Uses |

Properties |

Value |

People |

History |

In culture |

Related topics |

**Pi Day** is an annual celebration of the mathematical constant π (pi). Pi Day is observed on March 14 (3/14 in the *month/day* format) since 3, 1, and 4 are the first three significant digits of π.^{[2]}^{[3]} In 2009, the United States House of Representatives supported the designation of Pi Day.^{[4]}

**Pi Approximation Day** is observed on July 22 (22/7 in the *day/month* format), since the fraction ^{22}⁄_{7} is a common approximation of π, which is accurate to two decimal places and dates from Archimedes.^{[5]}

**Two Pi Day**, also known as **Tau Day**, is lightly observed on June 28 (6/28 in the *month/day* format).^{[6]}

In 1988, the earliest known official or large-scale celebration of Pi Day was organized by Larry Shaw at the San Francisco Exploratorium,^{[7]} where Shaw worked as a physicist,^{[8]} with staff and public marching around one of its circular spaces, then consuming fruit pies.^{[9]} The Exploratorium continues to hold Pi Day celebrations.^{[10]}

On March 12, 2009, the U.S. House of Representatives passed a non-binding resolution (111 H. Res. 224),^{[4]} recognizing March 14, 2009 as National Pi Day.^{[11]} For Pi Day 2010, Google presented a Google Doodle celebrating the holiday, with the word Google laid over images of circles and pi symbols;^{[12]} and for the 30th anniversary in 2018, it was a Dominique Ansel [fr] pie with the circumference divided by its diameter.^{[13]}

The entire month of March 2014 (3/14) was observed by some as "Pi Month".^{[14]}^{[15]} In the year 2015, March 14 was celebrated as "Super Pi Day".^{[16]} It had special significance, as the date is written as 3/14/15 in month/day/year format. At 9:26:53, the date and time together represented the first 10 digits of π.^{[17]}

Pi Day has been observed in many ways, including eating pie, throwing pies and discussing the significance of the number π, due to a pun based on the words "pi" and "pie" being homophones in English ( /paɪ/), and the coincidental circular nature of a pie.^{[1]}^{[18]}

Massachusetts Institute of Technology has often mailed its application decision letters to prospective students for delivery on Pi Day.^{[19]} Starting in 2012, MIT has announced it will post those decisions (privately) online on Pi Day at exactly 6:28 pm, which they have called "Tau Time", to honor the rival numbers pi and tau equally.^{[20]}^{[21]} In 2015, the regular decisions were put online at 9:26 am, following that year's "pi minute".^{[22]} June 28 is "Two Pi Day", also known as "Tau Day". 2π, also known by the Greek letter tau (τ) is a common multiple in mathematical formulae. Some have argued that τ is the more fundamental constant, and that Tau Day should be celebrated instead.^{[23]}^{[24]} Celebrations of this date jokingly suggest eating "twice the pie".^{[25]}^{[26]}^{[27]}

Princeton, New Jersey, hosts numerous events in a combined celebration of Pi Day and Albert Einstein's birthday, which is also March 14.^{[28]} Einstein lived in Princeton for more than twenty years while working at the Institute for Advanced Study. In addition to pie eating and recitation contests, there is an annual Einstein look-alike contest.^{[28]}

Pi Pie at Delft University

ArithmeticConstructive solid geometryFibonacciFibonacci numberGeometric Description LanguageGeometric dimensioning and tolerancingGeometric shapeGeometryHoneycomb (geometry)International Article NumberMathematicsMathematics and artMatrix (mathematics)Advent wreathAmerican Morse codeCarnivalChristmasChristmas and holiday seasonChristmas carolChristmas cookieChristmas decorationChristmas giftChristmas gift-bringerChristmas lightsChristmas musicChristmas stockingChristmas traditionsClara ZetkinDiwaliEasterFestivalFestival of Lights (Berlin)HalloweenHalloween costumeHaunted attraction (simulated)Haunted houseHuman Rights DayInternational Coffee DayInternational Women's DayJack-o'-lanternMrs. ClausParadeRio CarnivalRosa LuxemburgRudolph the Red-Nosed ReindeerSaint Patrick's DaySanta Claus's reindeerStar Wars DayTrick-or-treatingValentine's DayPiMathematical constantIrrational numberNumberGreek mathematicsInternational Day of HappinessUniversal Day of CultureInternational Day For Monuments and SitesEarth DayInternational Mother Earth DayInternational Dance DayInternational Jazz DayMay DayCinco de MayoRamadanWorld Red Cross and Red Crescent DayEurope DayWorld Oceans DayWorld Blood Donor DayGlobal Wind DayIndependence Day (United States)World Emoji DayMandela DayInternational Tiger DayFriendship DayInternational Youth DayWorld Elephant DayInternational Lefthanders DayWorld Mosquito Day

This article uses material from the Wikipedia article "Pi Day", which is released under the Creative Commons Attribution-Share-Alike License 3.0. There is a list of all authors in Wikipedia

Day Of, celebration,holiday

Share