You mean the alarm clock system that Don uses at the hotel that has settings ranging from "Gentle Reminder" to "Earthquake"? That'd be fun. :)
Interesting you bring up Between Planets, because that shows a prediction Heinlein made that isn't covered in this article. Read the description of the "crazy wagon," and, specifically, the conical metal cover it has that reflects away all incoming radar beams. Heinlein was basically describing stealth technology in 1951, six years before Pyotr Ufimtsev's paper on the subject...and it wasn't until 1976 that development started on the F-117, a real implementation of his idea.
Interesting you bring up Between Planets, because that shows a prediction Heinlein made that isn't covered in this article. Read the description of the "crazy wagon," and, specifically, the conical metal cover it has that reflects away all incoming radar beams. Heinlein was basically describing stealth technology in 1951, six years before Pyotr Ufimtsev's paper on the subject...and it wasn't until 1976 that development started on the F-117, a real implementation of his idea.