Planes write out pi over the skies of San Francisco Bay Area

Planes write out pi over the skies of San Francisco Bay Area | Crave - CNET: "Many denizens of the San Francisco Bay Area and Silicon Valley noticed a long series of cloudy numbers in the skies around noon on Wednesday, September 12. No, their coffee wasn't spiked with hallucinogens. The ephemeral event, known as Pi in the Sky, utilized five aircraft with dot-matrix skywriting technology to write out a thousand numbers of the beloved mathematical constant pi (3.14159..) at a 10,000-foot altitude. If that wasn't impressive enough, the numerals of pi written in the sky each stood nearly a quarter-mile tall, stretched for a 100-mile loop, and undoubtedly caused mass inspiration and confusion all at once."