"I don't know about those specific medical applications but it seems likely to me that there are still medical applications, or medical research ones."

"Cool. When I have a less embarrassing command of Radchaai I can start looking into that. - Oh, also, I don't know if this is useful but the clothes thing lets me permanently vanish small objects. If I put something in a pocket and then don't have a pocket it's just gone."

"Huh! That seems potentially useful, though nothing springs to mind."

"It's not very much used at home either but some people find it reassuring that we can destroy as well as create matter rather than it being a one-way ratchet."

"Something that may be less salient in a world that's always had magic is that we expect to run out of the ability to do work someday, and have the whole universe die."

"Run out of ability to do work? - oh, uh, negentropy. The opposite of - inevitable breakdown of systems, the thing where there are systems left to break down."

"Yes, that's it. Without magic, you're out of everything eventually."

"I mean, I suppose it's possible that magical girls are actually eating stars in another galaxy and we never noticed."

"It is worth looking into, but on the face of it you're cause for optimism."

"I can't generate universe-entropy-nudging quantities of matter, but sure, in principle."

"I mean, it'd require some technologies we don't have yet, but in principle you could run trillions of lives off the spontaneous generation of fairly small amounts of matter."

"Organic matter. If I remove something inorganic -" She takes off a ring and drops it and it disintegrates into nothing as soon as it leaves her hand. She remakes it.

"If you're dropping it into black holes that doesn't matter very much, but point taken."

"- no, I mean, it's gone, it's not dust, they've checked, if I stepped into a sealed environment you were weighing and took off jewelry the sealed environment would get lighter."

"Sorry, I mean that the black hole won't mind that its diet is all pearls."

"Oh. Yes, that's true, they're omnivorous."

"Anyway, that's probably the thing that makes magic so exciting even if most of what it can do can also be done technologically."

"How would you run a civilization on a black hole powered by one magical girl's worth of pearls?"

"There's some dangerous technology that seems like it could potentially be safe if done sufficiently carefully, which we haven't pursued because the advantages it'd present are not enormous and the risks are. If it seemed like we needed to transition - eventually - to powering our civilization off the energy released when objects pass into a black hole, I'd start a fifty-thousand-year-plan to do it sufficiently carefully."

"It must be neat to be able to make fifty thousand year plans. Are there any in progress?"

"Only in the broadest sense. I want to arrange a more stable peace with the aliens and figure out what human civilizations can do if they aren't constantly knocked back into the bronze age."

"What usually motivates people who are like - I don't know what it usually is, whatever the equivalent of 'I could ignite the atmosphere like they used to think nukes would do from the comfort of my garage'? I guess they may not usually live to explain..."

"They're very rare, really, it's just that they aren't quite rare enough - sometimes it's religious and sometimes it's philosophically principled and sometimes it's very grandiose suicidality and sometimes it's warring polities."

"Mm. Is the computer use monitoring so no one... releases catastrophic viruses, or are there, like, memetic, information hazards..."

"There's nothing I know of that's dangerous to know if you're not going to use it, at least not to a stable grounded person with some practice at entertaining horrible ideas. 'releases viruses' is closer."