[I'm not sure we have... anything like that at all... but we do have food and I am absolutely stopping to eat once we're off the subway, do you want pasta-and-tomatoes or rice-and-fish?]

[Whichever seems more likely to be an exotic delight to a stranger from another world!]

[Sushi it is.]

They get off at Isabella's subway stop and she shows Thellim to a sushi place, where they can sit at the bar and behold raw fish. The guy behind the counter seems to know Isabella, asks her "the usual?" and gets a "yeah, plus a sampler for her". Thellim gets an assortment of slices of fish on pats of rice and also an avocado cucumber roll. Isabella gets a giant bowl of rice covered in raw fish and drizzled with mayo and sprinkled with fish eggs, plus a side of edamame and a few shrimps tempura.

Nom!  It's not the tastiest thing she's ever eaten but it seems noticeably outside the space of supposedly-wildly-creative dath ilani food variations in some way that's hard to describe!  Now this is a proper interdimensional adventure.

Isabella puts away her food very efficiently, pays by card, gets a complimentary matcha ice cream mochi for both of them to munch as they walk back to Isabella's apartment. "It's freezing out!" she tells the guy. "The better to appreciate your warm home!" he replies cheerfully. He has an accent. She eats her dessert.

"The food actually is different from anything on Earth - no, do not translate that, brain.  It is subtly different from anything in dath ilan.  And tasty!  I will chalk that up as minor evidence for your worries about insufficient internal variance in dath ilan.  We do have debates about that, you know, and different people have different opinions and everything!"

"Many cultures have internal debates and are still the same culture."

"Of course!  Civilization has a culture, it's just not a monoculture."

"Yeah, this is why I was switching to the phrase meta-culture." Here is Isabella's apartment building. It has a doorperson. Isabella nods to her and she nods back and peers at Thellim. "Who's this?"

"Thellim, you can let her in if she's by herself too," Isabella says.

"Yes ma'am," says the doorperson.

"Thanks for taking care of me!" Thellim says to the doorperson.  Hopefully she didn't give off any wrong or just misleading social cues by saying that?  Then Thellim follows slightly behind Isabella, a natural optimization for following somebody else when you're not sure of the forward path you're taking.  Along the way, she absentmindedly brushes her long hair back over her shoulder.

"Sorry," Thellim continues the previous conversation, "I must have missed it when you first said meta-culture instead of monoculture - I don't think it's a standard word in the vocabulary I was given.  But I think I rather like it?  Meta-culture is exactly what we try to have.  Different ideas, one language; people buy what they want, in one currency and transaction system; experimental regions try different things and argue about the meanings of the outcomes, but they report their likelihood functions with respect to the same hypothesis spaces for ease of multiplication."

"How do you stop the language from fracturing into dialects?"

"No... idea?  I've never heard of that being necessary?  I don't think the interaction graph between language-users clusters enough for that?  I could see how you'd have to coordinate against that before radio had been invented, but we're well past radio."

"I guess that's what I would have expected too if I lived before substantial communications technology but it turns out not to work that way. Like, Americans can understand Brits and vice-versa but there are definite differences."

"Huh!  I don't think we've run into that problem - maybe because our population was barely approaching one billion, we were going to celebrate the milestone soon - but I expect that if it started happening, we'd have a big debate about whether dialects are glorious diversity or dangerous meta-protocol corruption.  I'd probably vote on the first side if the dialects still had a very easy time understanding each other, and there were no famous catastrophes being caused by 'yes' in one language meaning 'no' in the other.  If the concerned side won the vote by a supermajority, we'd probably try... finding people with very central dialects and favoring their careers in radio and television?  That's just me thinking very briefly, we'd actually run a big prediction market about what the results would be if we tried the top twenty-four strategies under consideration."

"As far as you're aware nobody's had to vote on this in the history you're allowed to know about?"

"Not that I recall!  To be clear, I wouldn't be surprised at all if there was a debate before I was born, or if there's a bunch of Very Serious People in the background half of whom are yelling about the importance of hiring more people from the linguistic centroid of Civilization to prevent drift, and the other half of whom are saying that we should underweight the Great City in hiring journalists because the Great City contains too little interesting variance relative to its population.  Any time you strike a balance right it shouldn't be surprising if half the Very Serious People end up arguing on either side of it." 

"Is... Very Serious Person... I assume you have some less silly sounding name for them and it's just translating that way... is that, like, a job, or what."

"It's what happens when you go around being terribly worried about all the things Civilization is doing not optimally, and somehow build up enough credibility that enough other people pay attention to you that you can make a living at it.  Like, imagine the conversations we've been having, but now imagine that either of us was actually good at that."

"...'somehow'? You don't know how the credibility part happens?"

"Well, the central trust fountains come from people with ridiculous, clearly non-chance outperformance at some task very demanding of mental acuity, where it's easier to judge later who got it right than it was to solve the problem earlier on.  One classic example of a trust fountain would be Warren Buffett what no would be Nemamel, who beat the prediction markets for roughly her entire life, to the point where she could only trade anonymously and the name got retired for future children.  Now say you have a good trading record, were first to short an experimental paper you later helped overturn in detail, initially staked a prediction market that later turned out important, wrote a lot of essays that seem well-argued, and then somebody like Nemamel says she thinks your essays are making a useful contribution to Civilization.  Somebody like that is liable to be taken seriously, in the sense that other Very Serious People take the time to respond to their essays?"

It's like Harrison Bergeron and The Giver had a baby and the baby was fed nothing but liquefied game theory and economics textbooks. "I see. I'm going to tell the Swede she needs to fix how her name pointers work in her English installations."

"I wouldn't blame her if she said that would be impossible, or way too expensive in detailed effort.  Some people are themselves concepts, and if you're doing concept-mappings it's not surprising if you end up mapping those people."

"Einstein is a legitimate idiom. Warren Buffet is not." The elevator has finally arrived and taken them to Isabella's floor. Here's her apartment. It's very compact but it's sleek and fancy and tidy.

"Maybe the person who gave me English had a different taste in idioms.  Anybody worthy of mapping onto Nemamel should be an idiom!"

Thellim gazes around in appreciation at the elegant minimalism of the forechambers.  She looks forward to seeing the rest of this moderately wealthy person's house!

"You can help yourself to anything in the kitchen if you get hungry, I keep stuff on hand for midnight snacks but I mostly eat out or at work - that's the bathroom there - I'll get you the spare sheets for the couch, it folds out." She demonstrates this and fetches sheets and a blanket and pillow.