Lu picks up the top half of the apple off her lap. "So they will cut things if they go fast enough, but they're not really sharp..." She holds down the bottom apple half, guides the shine at it to see what speed it needs to bite into the peel when the apple won't nudge easily.

It doesn't need speed as such. If the apple won't nudge then continuing to press into it will result in the apple yielding.

She turns the shine and pushes with the flat side.

This will squash it a little and push it out of her hand if she applies enough pressure.

"Okay. So these would be hazardous to use as ground-level vehicles unless I can program them sufficiently well and they can see things they aren't touching..." She writes down her results and starts experimenting with running them into each other at various angles and speeds.

If they run into each other they will mostly bounce off. They don't suffer damage from the collisions.

She can, if she's very alert to timing, make them just stop when they hit instead of bouncing back, but she cannot make them damage, intersect, break, or pass through each other.

That's correct, she can't. It's not that difficult to make them just stop, but it does require some degree of attention so long as she is manually piloting them.

Helen will pay attention to this part, since ultimately 3D syntax is going to be more useful to her than the regular kind.

Lu shows her the notes she's got on how she needs to revise the standard syntax. (It's all in natural language, to a point, just standardized for easy error-checking; it is not necessary to write a new shine operating system.) Shines normally have directions designated with an array of symbols, conventionally shortening "north south east west" even though they will retain the mapping of directions to sides after turning - at least that's what the book says; it turns out Lu prefers abbreviations for "bow stern starboard port" (as translated by Milliways. She has added "mast" and "keel" for, loosely, up and down. There is no way to draw the new directions into a flat instruction sheet, so Lu has written a short program introduction describing "mast" as the direction away from the side of the shine reading the instructions and "keel" as towards the instructions. Likewise, she has to describe pitch and roll. (Yaw is handled just fine with conventional shine instructions; it's just called turning.) "It's possible that after I've been working with these long enough they'll embed into the natural language without further explanation and I'll be able to use them plain. Which will be important if I want to give them long complicated instructions."

"This is a lot like computer science. I wonder if studying that will help. There's no way I'm going to learn all of this in the time we spend here, and Bar says the book won't be comprehensible once I leave the premises."

"I don't know. What's computer science?"

"Computer science is, relevantly, the instructions we use to program our communications devices for the network that keeps coming up."

"Oh. Well, if those things are programmed then it's entirely possible that it's similar. Will your own notes be legible when you take them out? You could copy the index of shine commands and my inventions."

"Yeah, I've been copying some stuff down." She brandishes some more paper she had solicited from Bar. "I'm just well aware that there's a difference between that and the years of study people in your world who work with these things get."

"I mean, I'm only seventeen, don't remember most of my first two rounds of servantmaking education, and had to learn the other four servant kinds too, two of which don't require programming at all and the other two of which are different in general limitations and applications, so I don't want you to think this is more complicated than it is. For the flat kind, anyway."

Worlds with histories resembling yours that have advanced farther into the field of study exist. However, their results are contradictory and I have no obvious way to distinguish between the underlying models they found in your particular case.

"Dang. It briefly occurred to me that maybe Bar had some way to duplicate my S-Factor into you, but apparently that's a bust."

"I'm sure I would have thought of that sooner rather than later, but copying mine was the first thought I had," she shrugs.

"I appreciate the thought."

"Oh well, it was worth a shot. I expect whatever it is that lets people in her universe do the servant thing is likewise non-transmissible."

To the best of my understanding, yes.