Over the past couple of years many puzzled people have been witness to a mysterious series of numbers appearing in the skies before their very eyes. With no visible craft to explain the slowly growing stream of digits many have stared upward and wondered why is Pi appearing in the sky?

Watching the many videos that have captured the mysteries numbers floating upon high you will quickly notice that they seem to continue on for an eternity, stretching to the horizon. The display is actually always the same, Pi expressed to 1000 digits (3.14…etc) which probably does require a canvas the size of the sky to complete, makes my wrists hurt and Pacer pencil cringe just thinking about it.

The amazing display of digits is the work of sky writing company AirSign using a new system designed to capture people’s attention. Instead of the traditional sky writing that uses 1 plane to do all of the work AirSign use 5 planes in formation to write each of the numbers. Printing Pi over 100 miles of the sky in a sense as the 5 planes act much like an inkjet print head.

The highly observant may have also noticed that Pi seems to appear in the sky at the same time each year, Mach 13(ish). The day that just happens to be International Pi day, a day set aside to help us to understand Pi just a little better. I’d have eating far more pie in the last few years if I’d known there was a whole day for it.

Reference: LiveScience – Pi Day Sky Writing
Reference: Berkeley – Pi in the sky
Reference: Pi Day
Reference: AirSign