As I’m working on this fic, I’ve been thinking about Jack’s wrist strap. We all know what the dash of the thing looks like:
Not a single visual display in sight. So how does Jack know what he’s doing or read information from it, since it clearly has so many different functions?
I wonder if there’s a mental component with vortex manipulators. Maybe a synced user can get information uploaded directly to their brain. Users who aren’t synced (Clara, Martha, etc.) can only use it for base functions.
Or maybe that glowing blue square light is a HUD, beaming visual information onto Jack’s eyeballs like Google Glass.
I’ve wondered that myself. And hell for that matter it’s only got 3 buttons. How does it do all the things? And if it is a mental + physical link, how does Gray hack John’s? I’ve got a headanon that Jack would have had at least some pyschic training, 51st century and all that. I think that’s why Tosh can’t read his mind in Greeks bearing Gifts and why he knows what she’s up to.
Obviously John and Jack were part of the Time Agency and went through probably some rigorous training. We know nothing about that organization aside from it was shut down and Jack’s missing a year of his life or so. Judging off Jack and John’s personalities I doubt it was an agency dedicated to goodness and light.
Clearly they wouldn’t hand a device that allows time travel to any idiot off the street (the Doctor had to steal his). So no matter how much the doctor may disparage the manipulator as a crappy way to travel, at least Jack earned his.