Transparent Aluminum from Star Trek – yeah we’ve had that since 1981

The material, called aluminum oxynitride (AlON), or transparent aluminum is used to make bulletproof windows in armored cars. Here’s the story: The scene, as written, seems to imply that Scotty is talking about some fancy way of making metallic aluminum into a transparent form. Which ain’t happening. What has happened, however, (and in fact what …