abheirrant: (Default)
[personal profile] abheirrant
—pposed to know when to start speaking? That wasn't a very thorough explanation on what I'm to do this, now was it? Hello? Hello? Are you listening to me? Are you even still ther—

[beep]
Thread Depth: 2

Date: 2020-05-05 02:02 am (UTC)
superposition: ((see i told you it would work))
From: [personal profile] superposition
Close! Very close. [ So he's familiar with something like Cartesian coordinates, that's a good start. ] Of course they won't be squares, since the surface is curved, but -

[ Qubit taps a couple of keys on his watch, and the globe redraws itself more abstractly, a plain blue sphere with the continents outlined in green, and a few more elements that get drawn in as he mentions them, sometimes poking the globe and sometimes his watch. ]

Rotational axis, north pole to south. Equator - an orthogonal plane bisecting the axis. They intersect at the center of the planet, we'll make that the origin. [ Represented by another orange dot. ] Lines of latitude - indicating the angle of deflection north or south of the equator. So here's thirty degrees, sixty, and the poles at ninety. Lines of longitude - the angle east or west of an arbitrary Prime Meridian, here. Thirty, sixty, ninety, and they meet at one-eighty. And I should clarify, these are just the conventions in use on my world, yours may be different.

[ Which is a long and excessively pedantic way of saying "yeah, you divide it into segments." They've got a very nice wire-frame Earth now. Good job. ]

However - [ he holds up two fingers. ] - that still only gives us two-dimensional coordinates. What about elevation?
Thread Depth: 4

Date: 2020-05-05 08:57 pm (UTC)
superposition: (Through hell and high tide)
From: [personal profile] superposition
[ Baby steps! The image, of course, does not bite. Or respond in any way. See, not all technology is out to get you! ]

Hm. "Dead reckoning" in more ways than one. [ Cause... cause if you get it wrong, you're dead. It's mildly amusing, okay. ]

Not quite the level of precision I'm looking for, though. You'd need a proper survey - manual, or via satellite, or a barometric altimeter, properly calibrated, of course. But let's say that's been done, you have that data. Now you can express any position on the planet as a vector in a spherical coordinate system.

[ With his finger, he draws a line connecting the center with the dot on the surface. The surface end has an arrow. ]

The components being, of course, latitude, longitude, and magnitude - your absolute distance from the center of the Earth. Which is preferable to mean sea level, since technically the planet is an oblate spheroid, not a perfect sphere.

[ Still following? Good, cause he's moving right along. ]

So now, let's say you want to be somewhere else. [ He looks up the target coordinates on his watch, and does the math in his head while he's talking. ] All you need to solve for is the transform between this vector and the new one, and that's basic linear algebra.

[ Plugs in his answer, and voila - the vector swings over to a point in central Europe. Qubit smiles, self-satisifed. ]

Child's play.
Thread Depth: 6

Date: 2020-05-06 07:49 am (UTC)
superposition: ((i told you so))
From: [personal profile] superposition
[ ... Okay, yeah, maybe he did get bogged down in the details a bit there. Whatever, it's fine, we'll fix it in post. He was making his way toward the point, though: ]

Oh, he teleported himself to Germany.
Thread Depth: 8

Date: 2020-05-10 04:58 am (UTC)
superposition: (Because I've only got two hands)
From: [personal profile] superposition
[ A short laugh. ] Not quite. He actually ended up further south, in Garmisch-Partenkirchen. His hometown.

[ Or Earth-β's version, anyway. But homesickness does not make such distinctions. ]

He was still figuring out his power at the time. I believe at this point he'd only worked out teleportation in theory - it was the first time he'd actually done it, and he hadn't meant to. And then he didn't have enough energy to make the return trip, so he asked me to come pick him up.