Dolmen of Sorginetxe, Basque Country, Álava, Spain
© David Herraez Calzada/plainpictur
Pi in the sky. Celebrating Pi Day
Calculating the ratio of a circle's circumference to its diameter is as easy as pi. Today is Pi Day, an event that celebrates this mathematical constant. This date was chosen because 3, 1, and 4 are the first three significant figures of pi (π) when it is written out. Pi is an irrational number, which means that it can't be written as a fraction. When written out, its decimal representation goes on infinitely without repeating. The oldest attempts to calculate pi date back to ancient Babylon and Egypt, around 1900 BCE.
Pi Day, however, has more recent origins. In the 1980s, physicist Larry Shaw organized the first celebration, where staff at a San Francisco science museum walked around in circles and then ate the number's delicious homophones: pies. Today's image takes us to Álava, northern Spain. The circular motion of the stars appears above the Dolmen of Sorginetxe, an ancient megalithic monument dating back to 3000 BCE. Pi has long played a key role in the study of the stars, and some of the most accurate early approximations of the number were calculated by Indian and Persian astronomers.
Related Images
Landmark Center clock tower and Winter Carnival Ice Palace, St. Paul, Minnesota
At the Arch of Septimius Severus in the Roman Forum for the ides of March
For Waitangi Day, the Pancake Rocks on New Zealand’s South Island
'El Problema del Caballo' by Claudia Fontes in Venice, Italy
Martin Luther King, Jr. Memorial in Washington, DC
At Casa Batlló for Sant Jordi’s Day in Barcelona, Spain
Meditation domes at the Beatles Ashram in Rishikesh, India
An old farm in the Shetland Islands, Scotland
Bing Today Images
