When the SU-15 flew so close to Gagarin's plane, the passage caused the MiG to go into an uncontrollable spin, similar to that scene in Top Gun I bet at least half of you are picturing right now. Leonov explains to Russia Times:

Personally, I'm the most excited to hear about this supposed overhaul to iOS. It's been pretty boring for a while, so if it's a total change—and not just a cosmetic one (although shying away from the skeuomorphism sounds great)—I'll be happy. I'd also love to see things like the ability to set default apps, delete…