When the Atlanta Falcons decided to move into a new stadium, they wanted the architecture to be so dynamic that it would “provide a game-day spectacle that can’t be experienced at home or in a bar,” lead architect Bill Johnson told Co.Design in 2016 when the project was an Innovation by Design Awards finalist. The signature detail turned out to be a kinetic roof that opens and closes in a motion reminiscent of a camera’s aperture.
The retractable roof is composed of eight petals with 200-foot-long cantilevers. They’re covered with an architectural fabric called ETFE, which is highly durable, lightweight, and lets light shine through. While the petals look like they rotate to shut, it’s actually an optical illusion: They travel in a straight line.
The entire process in the time-lapse video took about 48 hours since the roof isn’t fully mechanized. Once it’s complete–most likely sometime during the 2017 season, though there’s no firm timeline–the full closing process should take about 15 minutes. For now, the roof will stay closed, or as Deadspin‘s Tom Ley put it: “Megatron’s butthole to remain clenched.”