### Pi Day

Today, March 14 (3.14) is Pi Day, where we honour what is arguably the most important mathematical constant we know of. Pi was originally defined as the ratio of the circumference of a circle to it’s diameter, but it has a habit of popping up in a variety of unrelated places, for example when calculating particle lifetimes or interaction cross sections. To celebrate today I thought I’d post the number here, up to the end of the Feynman Point, along with a nice animation from Wikipedia that illustrates where the number comes from by unrolling a circle's circumference. Enjoy.

3.1415926535897932384626433832795028841

971693993751058209749445923078164062862

089986280348253421170679821480865132823

066470938446095505822317253594081284811

174502841027019385211055596446229489549

303819644288109756659334461284756482337

867831652712019091456485669234603486104

543266482133936072602491412737245870066

063155881748815209209628292540917153643

678925903600113305305488204665213841469

519415116094330572703657595919530921861

173819326117931051185480744623799627495

673518857527248912279381830119491298336

733624406566430860213949463952247371907

021798609437027705392171762931767523846

748184676694051320005681271452635608277

857713427577896091736371787214684409012

249534301465495853710507922796892589235

420199561121290219608640344181598136297

7477130996051870721134999999 and so on