Today is Pi Day – a celebration of all things Ï€. It also happens to be Albert Einstein’s birthday.

To celebrate, here’s a few Pi facts:

- Pi occurs in hundreds of equations in many sciences including those describing the DNA double helix, a rainbow, ripples spreading from where a raindrop fell into water, superstrings, general relativity, normal distribution, distribution of primes, geometry problems, waves, navigation.
- If one were to find the circumference of a circle the size of the known universe, requiring that the circumference be accurate to within the radius of one proton only 39 decimal places of Pi would be necessary.
- Write the letters of the English alphabet, in capitals, clockwise around a circle, and cross-out the letters that have right-left symmetry, A, H, I, M, etc. The letters that remain group themselves in sets of 3, 1, 4, 1, 6.
- Pi has its own domain name – http://14159265358979323846264338327950288419716939937510582097.org
- Today I’m 9.93 Pi years old – my tenth Pi birthday will be on the 6th June this year – a cause for celebration if there ever was one!

Happy Pi Day!