. . "As you might know, a \"dilating door\" is science fiction Fan-Speak for the trope that we call \"Cool but Inefficient\". This trope refers exclusively to Cool But Inefficient doors and hatches - doors that slide up into the ceiling, doors that dilate like an iris, doors that dissolve and rematerialise... Apparently, plain old hinges are extinct in the future. It's probably a reference to Heinlein's advice that you could make a futuristic air by casually throwing out details like \"the door dilated\", as if such things were nothing to really notice, like your use of a globally interlinked computer network for information and entertainment. Subtrope of Our Doors Are Different. Examples of Dilating Door include:"@en . . . . . . . "Dilating Door"@en . . . . . . . . . . . . . "As you might know, a \"dilating door\" is science fiction Fan-Speak for the trope that we call \"Cool but Inefficient\". This trope refers exclusively to Cool But Inefficient doors and hatches - doors that slide up into the ceiling, doors that dilate like an iris, doors that dissolve and rematerialise... Apparently, plain old hinges are extinct in the future. Subtrope of Our Doors Are Different. Examples of Dilating Door include:"@en . . .