"Yes, if we are told the geometry of spacetime, we can completely work out a geodesic if we know a point it goes through and its tangent vector (velocity) at that point. It satisfies a second-order differential equation, which I have avoided writing down, and you just solve that."
Excited, Oz replies: "Honestly, a red flag to a bull, "which I have avoided writing down"! Any chance of seeing the form of this? "
"WHAT?!?!" The wizard's eyebrows bristle and daggers of light shoot out from them.
"You want to see THAT?? NO!!! I keep that equation in the room back there, behind that curtain, where I do my work. That's where I keep all my heavy-duty equipment. I can't let you go back there, because you don't know how to use that machinery and it's VERY DANGEROUS. There's really no telling what trouble you might get into if I let you back there! So, just remember this: never, NEVER go back there, especially when I'm not around."
"Now get out of here! The impudence!!"
Sheepishly, Oz skulks off, not without a peek to see what's back behind the curtain.
But later...
[Quiet, doleful music plays in the background.]
[From Ducas "The Sorcerer's Apprentice" of course: what else?] "
The aged retainer shuffles back to his hole in the wall, dragging his broom behind him over the solid milk quartz floor. From time to time he peers wistfully over his shoulder at the Great Wizard who ignores him and is busy curving space with a wave of his arms and producing black holes with a flick of his fingers. He arrives at his cramped, cold and damp cave in the corner, pulls the tattered curtain across the doorway and sits on his straw filled bunk. It's ichy. He is not so sure that getting sorcery lessons and food (food: ha!) for keeping the Great Wizards cave tidy is such a good deal as it seemed originally, but determines to soldier on.
The Great Wizard watches his aged retainer close the curtain. "At last," he thinks, "he has gone, time for some proper work. Time to cut this simple child's stuff. Got to get up the wizard rankings.".
[Music changes to Borodin: Night on a Bare Mountain: fortissimo.]
The yelps from the Great Wizard and occasional fireballs wake the aged retainer from his reverie. He peers cautiously through one of the many holes in his curtain. The Great Wizard seems to be working on something terribly small that keeps slipping from his fingers. He just can't hold it in one place, every time he does it zooms away painfully taking a chunk of wizard with it. Fireballs erupt from the clear shielding the Great Wizard has thrown up around himself. "Oh well." thinks the aged retainer "It's not always that much fun being a Great Wizard, either.".
[Music changes to Brahms lullaby]
The aged retainer falls asleep on his itchy bunk. He dreams of creating black holes with a flick of his finger, but always ends up being dragged in and painfully turned into sorcerer's spaghetti. He dreams that he goes behind the curtain and is immediately filled with knowledge without any effort at all. If only he could remember it all in the morning.
[Music fades]
Dream on.