John Oliver: So, roughly speaking, what are the chances that the world is going to be destroyed? One-in-a-million? One-in-a-billion?Walter Wagner: Well, the best we can say right now is a one-in-two chance.John: 50-50?Walter: Yeah, 50-50... It's a chance, it's a 50-50 chance.John: You come back to this 50-50 thing, what is it Walter?