*Re-posted for obvious reasons. Happy 142nd Birthday, Dr. Einstein ~ TMC*

π (Pi), how could we live without it. So let’s celebrate π on it’s day 3.14, which now celebrated around the world.

As you remember from grammar school math, π is the mathematical constant consisting of the main numbers 3, 1 and 4. According to the Wikipedia of π, “it is the the ratio of a circle’s circumference to its diameter, and is approximately equal to 3.14159.”

It has been represented by the Greek letter “π” since the mid-18th century, though it is also sometimes written as pi. π is an irrational number, which means that it cannot be expressed exactly as a ratio of two integers (such as 22/7 or other fractions that are commonly used to approximate π); consequently, its decimal representation never ends and never settles into a permanent repeating pattern. The digits appear to be randomly distributed, although no proof of this has yet been discovered. π is a transcendental number – a number that is not the root of any nonzero polynomial having rational coefficients. The transcendence of π implies that it is impossible to solve the ancient challenge of squaring the circle with a compass and straight-edge.

NASA’s Jet Propulsion lab only uses 15 digits to calculate interplanetary travel, while mathematician James Grime argues that just 39 digits of pi is enough to calculate the circumference of the known universe.

OK, enough of that. Let’s get on to the fun stuff.

It’s earliest known celebration was in California where in 1988 at the San Francisco Exploratorium physicist Larry Shaw along with the staff and the public marched around one of its circular spaces eating fruit pies. In 2009. The US House of Representatives passed a non-binding resolution declaring 3.14 π (Pi) Day. And in 2010, a French computer scientist claimed to have calculated pi to almost 2.7 trillion digits. This year is no different. The party starts at 10 AM PT and all are invited and it’s FREE!!

Coincidentally, it is also the birthday of theoretical physicist Albert Einstein. So at Princeton University in New Jersey there are numerous celebrations around both events that also include an Albert Einstein look alike contest.

Besides the partying at Princeton, here’s what is going on elsewhere to celebrate this mathematical necessity that drives mathematicians nuts.

The Massachusetts Institute of Technology releases its undergraduate admissions decisions on Pi Day, and starting in 2012, it began sending the verdicts at 6:28 pm, or “Tau time,” for the mathematical equation 2π.

Today is the 33rd anniversary of Pi Day. In its honor of the 30th anniversary, Google created this doodle, although not as cool as the one at the top of this post but it may taste better. The doodle is based on a pi-inspired dish, salted caramel apple pie, courtesy of Cronut creator and pastry pioneer Dominique Ansel.

Check your local news and on line for specials on everything from pizza to deserts to geeky tee shirts, gadgets and memorabilia.

In 2010’s “Moment of Geek”, Rachel Maddow, host of MSNBC’s “The Rachel Maddow Show,” featured a math student teacher, Teresa Miller, from the University of New Mexico with a hula hoop and a Rubic’s Cube that was quite amazing.