I've been meaning to post this for a while now, so...

I read Dorothy and the Wizard in Oz via Daily Lit a couple months back, and found the following passage pretty fascinating:

And Ozma has an enchanted picture hanging in her room that shows her the exact scene where any of her friends may be, at any time she chooses. All she has to do is to say: 'I wonder what So-and-so is doing,' and at once the picture shows where her friend is and what the friend is doing. That's REAL magic, Mr. Wizard; isn't it?

Could you conceive of such incredible technology?