LOS ANGELES (AP) – There’s no defying “Gravity.” The Sandra Bullock-George Clooney space drama “Gravity” has the best October opening ever — with more than $55 million. It’s also best opening for both of the stars. “Cloudy With a Chance of Meatballs 2” drops to second this weekend. “Runner Runner,” starring Ben Affleck and Justin Timberlake, opens in third. “Prisoners” and “Rush” round out the weekend’s top five.