March 14th, or π-day, this year takes on additional numerical significance. Only once in a hundred years we are able to celebrate π to its billionth decimal place.
3.141592653
3/14/15 9:26:53
I wonder if Galileo Galilei geeked out on 3/14/1592 6:53:59.
In other mathematically geeky news, while doing several calculations on my Mac I was longing for my old HP scientific calculator with reverse polish notation. Looking through the Mac app store at all the emulators, I decided to see if the built-in calculator app had this feature. And guess what it does.
In the View menu, you can select “RPN mode” and now you get a calculator with a stack visible 2 deep. I don’t know if this was possible in previous versions of OS X, but I love the geeks at Apple that made this happen.
Happy π-day. Now we wait for May the Fourth.
my peripheral brain 
π day & RPN Calculator.app http://t.co/k9WDGsTVoN