Why the laws of physics mean Will Smith’s birthday stunt probably won’t kill him

For his 50th birthday next month, Will Smith will bungee-jump from a helicopter over the Grand Canyon. It’s a dramatic stunt that strikes fear into the hearts of fans (or at least some Verge staffers; you know who you are) who wonder whether it’s possible he’ll spring directly up into the helicopter’s blades.That’s not going to happen. Will Smith isn’t the first one to bungee-jump from a helicopter, and no one — not Smith, not the non-famous adrenaline