Monday, March 14, 2016

Why is PI so important? 2016 Edition

It's one of my favorite days of the year!  A day when geeks of all ages can show off their PI stuff and skills at recitation.  I have PI memorized to 75 digits. Chicks dig it. My wife digs it...so she says. Your kids might have PI day activities planned at school today (Tuesday). I gave my son my PI shirt to wear. Reluctantly, he's going to do it.

I'm sure back in 1737 when Leonard Euler first used the symbol π, he never envisioned the fascination with π that developed since.  There are t-shirts, π plates (yes, I have two), π mugs...and on and on. Novelty websites have just about every π trinket you can think of!

What is PI " π"?

PI is the number that represents the ration of a circle's circumference to its diameter.

As we entered the computer age, the calculation for more digits became a test for computer system efficiency and accuracy. In 2014, scientist Ed Karrel calculated more than 10 QUADRILLION bits (unfortunately not in base 10 units) decimals of PI.  Here is his blog.

The interesting part is that PI is non-repeating and never ending so its very nature is an approximation. Mathematicians have tried to find patterns within π since ancient times. Archaeologists believe that the ancient Egyptians constructed the Great Pyramid of Giza with knowledge of π.  Greek mathematician Archimedes was the first to calculate a range for π  using polygons.

Throughout it's history, π has become a fascination among mathematicians and more recently computer programmers. Welsh mathematician William Jones was the first to use the symbol π to represent the ratio of a circle's circumference to it's diameter in the early 1700s. In the 1940s, a little over 1000 digits of π were known.

As we entered the computer age, the calculation for more digits became a test of computer system efficiency, power and accuracy. In 2014, scientist Ed Karrel calculated more than 10 QUADRILLION hexadecimal digit of PI.  Using hexadecimals make it faster to calculate. Converting hex to base 10 numbers which we all is very difficult when you have these many digits according to Ed.  Here is his blog.

To put the number of digits in Ed Karrel's calculation into perspective, you only need 39 digits of PI to calculate the circumference of the observable universe (assuming it's a sphere) to the accuracy of a width of the inside of an atom!

To put it another way, if you were to recite EVERY digit, it would take you 317,000,000 years to complete. You'd need to start before the dinosaurs were alive in order to finish today!

All of this great if you are a math or computer geek. But why should the rest of us care?

PI is present in every aspect of our lives. PI is used in most calculation in the development of all the world's infrastructure. All communications, CAT scans, MRI machines, genetic research, propulsion systems (space and military aircraft), quantum physics....the list goes on.

Famous scientific discoveries and the math that describes them incorporate PI:

* The calculation for determining the horsepower of your car has PI in it.

* Einstein's famous equations that describe relativity which is now directly applied in
satellite calibration has PI in it. Here it is in very simple form:

* The math that determines electric force (electricity) includes PI.

*  How about the speed and volume of blood flow inside the first artificial heart? You bet.
PI is included in that calculation too.

* Want to figure out the position of two planets nearest to the earth? You need PI.

* Radio communications, cellphones, GPS satellites (see Einstein's equation above) computer hard drive/processor technology were both developed using mathematics that incorporates the number "PI".

* Airlines use PI to calculate flying distance around the earth

* Manufacturing uses PI to figure out how much of a substance will fit into a volume
of circular or cylindrical space

You might not like math. You might not get PI.  Just remember that PI (3.14159...) is integrated into our everyday life unlike any other number. Without it, your daily life would be totally different.