Did Neolithic humans build this structure to celebrate Pi Day? Not likely. Pi Day is a relatively recent phenomenon—invented by a physicist in 1988 and designated by Congress a national holiday in 2009. But it"s already almost certainly the most popular holiday celebrating a mathematical constant. While Pi Day is a young tradition, the number π (pi) itself has been a fascination since antiquity, when it was first calculated as the ratio of a circle"s circumference to its diameter.
Pi Day
Today in History
More Desktop Wallpapers:
-
Frost-covered dunes on Mars
-
Lionfish off the coast of Indonesia
-
Arrr, it be Talk Like a Pirate Day
-
I ll call for pen and ink
-
National Park Week: Everglades National Park
-
Tall, taller, tallest
-
Does this shark have an Irish accent?
-
International Museum Day
-
Al-Khazneh in Petra, Jordan
-
Berlin Festival of Lights
-
Mexican giant cardon cactus
-
Spring comes to Glacier National Park
-
A Welsh wonder turns 70
-
A view from the top
-
Shark Awareness Day
-
Earthrise on Moon Day
-
World Space Week begins
-
Bringing the moon to Earth
-
American bison
-
Okefenokee Swamp
-
Russell lupines, Lake Tekapo, New Zealand
-
Reflecting on Black History Month
-
With leaves this tasty, who cares about a view?
-
Swimming with the sea cows
-
World Rainforest Day
-
Great hornbill, Thailand
-
Here comes summer
-
Indigo bunting
-
International Surfing Day
-
Red skies at Ruby Beach