"You'd be surprised, Clarissa hasn't decided what she wants to do with you yet but she might decide she wants to show off her pet roleless alien."

That produces a series of utterly ridiculous mental images that look like a cross between an adults-only Halloween party and a gaming convention; he snickers. "Well, fair enough. What else should I know? Or, no, I should just get an etiquette book instead of taking up your time explaining."

"Eh, that's enough etiquette," Eli decides. "We should talk about natural philosophy! You have vaccines, what other discoveries do you have?"

Awwww yes, it's infodump time! Antibiotics and antivirals and what prions are and airplanes and the internal combustion engine and rocketry and we landed! On! The Moon!

"You landed on the moon!?"

"We super did! It was really hard but we managed it! And we've got machines that can send us images of places and drill into rocks to see what they're made of and stuff, and we put some of those on Mars."

"Your natural philosophers must be so excited!"

"Yup! Though we've actually split natural philosophy up into a lot of different disciplines; there are a lot of people and there's a lot of stuff to learn in any one field, so people tend to specialize."

"I mean, so do we in practice, a lot of people only dissect monkeys or play around with lenses."

He tries to keep his distaste for the phrase "dissecting monkeys" out of his expression. People have to do medical research somehow. Still, he should definitely invent the IRB at some point. "That makes sense. Specialization is important, even though if I was going to live forever I would definitely want to study everything."

"What did you do before? I'm a political economist."

"I was studying biology! Our lab worked on immune systems; we were studying why old mice are worse than younger nice at fighting off infections. Political economist is, what, seeing how government policy affects the economy?"

"Sort of? It's like studying economy but instead of talking about the household you're talking about countries." 

"Oh neat, that sounds similar to what we call macroeconomics. Unfortunately in my world different macroeconomics theories have gotten attached to political factions, so it's hard to tell whether someone is telling you what the evidence says or just what they wish was true because they like the implications for government policy."

"It would be nice if they listened to us," Eli says mournfully. "The Senate thinks the more gold your country has the wealthier you are and they won't pay any attention when we explain that political economy is not at all like household economy."

"Oh dear. Most countries in my world have switched to fiat currency--paper money that isn't backed by anything, it's just valuable because people will sell you stuff for it."

"...what happens if everyone decides to stop accepting it at once?"

"Nothing good! But that pretty much only happens when a government decides to try to give itself infinite money by printing a huge pile of it, and governments know that, so they only do it when they're already desperate for other reasons. The advantage is that it lets the amount of money flowing around change to match the amount of actual wealth available, so if you do it properly prices only change slowly."

"...I wonder if your world has anything about my work. I study the creation of wealth through trade."

"That's definitely a thing people study! I don't know much about it, but I know that international trade lets countries specialize in different industries and end up with more of every kind of good. There's mathematical models of how much benefit you can get from that but I only know how to draw the tiny two-variable version."

"...oh. Um. That's what I'm working on. That thing."

"Oh cool, I get to meet the guy who discovered gains from trade! I bet you're going to get famous for it if you haven't already."

"Well, I think you're probably going to be the one who invents it now."

(He sounds remarkably cheerful about this.)

"It'll probably take both of us to get it to a publishable level of detail; we can both invent it. Which raises the question of whether I should get a legal identity at some point."

"We could always say you're a talented nondynamic of the lower classes that Clare decided to sponsor."