Director James Cameron’s acclaimed sci-fi movie Aliens turns 40 in August. It’s a sequel to Ridley Scott’s claustrophobic breakout hit Alien, made in 1979. Where the original featured one terrifying creature, Cameron’s movie features hundreds – and pits them against a squad of space marines. A host of intriguing technologies make an appearance, including interstellar travel, hypersleep (where humans are preserved in stasis for long space journey…