Gabriella Penuela

In the summer of 2012, the 1,592-pound space probe Voyager 1 became the first man-made object to exit our solar system. NASA had launched the probe in 1977; the multi-billion-mile trek to the edge of our solar system took 35 years. (Good thing we weren't waiting for it to bring sugar back.)

There were no humans aboard the spacecraft, only machines. But imagine if there had been: How would NASA pay them? How would they shop, manage their bank accounts, pay taxes, and communicate with people back on Earth? What if they wanted to set up the first Interstellar (Free) Trade Agreement? How would this new economy work?


Just a year after the Voyager took flight, Paul Krugman — the voicey, often funny, economist and New York Times columnist — came up with The Theory of Interstellar Trade to iron out the financial intricacies of settling space. It was "a serious analysis of a ridiculous subject, which is of course the opposite of what is usual in economics," he wrote. It's also what's so great about it.

Let's quickly fast-forward to 2015. Voyager is still our only venture beyond our home system to date, but we have made some considerable advances since Krugman first theorized an interstellar economy. We landed on a comet. We're inching closer to Jupiter and Pluto. We landed on Mars, multiple times. Yes, these missions were unmanned, but Elon Musk is hard set on colonizing Mars, and others agree that it isn't some hair-brained idea.

"Certainly, within the solar system, one of the big things that will happen within this century is that people will start living off the Earth," Seth Shostak, the director of the Search for Extraterrestrial Intelligence Research program, told me. "Even if they're just living in a rotating aluminum can, they still need to earn a living, so they're going to have to trade."

In other words, Krugman's "ridiculous" theory is looking less bonkers now.

He imagined a future where our space vehicles moved close to or at the speed of light — a Hyperloop for space, if you will. At such mind-bending speeds, space travelers would experience time differently than stationary Earthlings, Martians or Tranton-ites, the inhabitants of the imaginary planet Krugman describes in his paper. As a result of this time shift, interest rates — and the value of goods — wouldn't be the same for the senders and receivers. The elapsed time would feel shorter to the persons in motion. (Thanks, Relativity!) But even at light speed, the travel time would still be considerable, so the goods would need to be worth the wait. You wouldn't want to order the iPhone 82 when everyone on Earth was using the iPhone 3000 by the time it arrived.


The big question is how you would price your interstellar purchase and the costs of delivery. How do you compute the cost of a Galactic Lyft ride or an Amazon StarPrime delivery? The value will hinge partly on interest rates (or rates of depreciation), and time is an important variable here. And to recap, time isn't equal for the sender, receiver, and courier. For the courier, who's in motion, time is shorter, so if the value of the goods is depreciating, the messenger would have a bit of an advantage. So Krugman concludes, it's best to use stationary clocks on planets, since that's where the goods come from and are ultimately headed.

So, what if you had assets in two different galaxies? How would the space-haves figure out the worth of their Earthly home compared to the one in the galactic suburbs? "Competition will equalize the interest rates on the two planets," Krugman wrote, so it will be possible to fairly assess their values.

Krugman had some of the economics pretty well figured out by 1978. "From this point," he wrote, "the picture of the world — or, rather, of the universe — which emerges is not a lunatic vision; stellar, maybe, but not lunatic. Is space the Final Frontier of economics? Certainly this is only the first probe of the subject, but the possibilities are surely endless."

And he was right. Even with a Nobel Prize-winning economist on the case, gaps in the workings of our future interstellar economy remained. His work inspired others to take on things like interstellar finance and taxation. But these are the issues we haven't figured out yet:

Amazon StarPrime. 2-light-year delivery for only $70,000,000 USD per month. Image: NASA.

Energy and time

It's going to take a lot of fuel to transport goods from one planet to the next. "I think the biggest problem is the energy cost of sending something back. The transportation costs will dwarf the value of the goods," said Shostak. Even with digital goods whizzing through space at the speed of light, the time you'd have to wait to get them would be astronomical. Given those two constraints, Shostak predicts that the "local" fad we have today will become a necessity in most space economies of the future. Truly interstellar societies can only exist when we crack the energy problem. Another incentive to invest in green technologies.

A message just came in. I have no idea what it says. Image: NASA.

Language and culture

Once we make contact with other alien communities how will we communicate with them? Will we be able to understand their social cues? These questions apparently bothered Berry College's John Hickman, according to the Australian website Chartered Accountants:

“Absence of a common language and all of the shared meaning that goes with it would be the largest problem,” he says. “We have scant chance of solving the other problems of exchange until we overcome the language barrier. We don’t know how different intelligence produced by a distinct process of development would think, but the difficulty we face in understanding the minds of non-human animals, with which we share a biological evolution, suggests that it will be daunting.”

And what happens when linguistic and cultural differences naturally evolve between communities separated by such vast distances? After all, if communication only happens once every 10 years, the process of learning and relearning each other's slang and cultural norms could be endless. Constant contact — even if it's only on the interstellar internet — is imperative. Otherwise we're always going to be dependent on Microsoft's Interstellar Skype Translator, equipped with state-of-the-art AI that can learn and translate spoken and body language on the fly.

Virus! Image: CDC.

Interstellar Contagions

Communication issues aside, what will save us from this?: "Such [interstellar] exchange also threatens the release of new and dangerous memes," Hickman wrote in a paper. Without having read the entire thing (everything but the abstract is behind a paywall), I'm going to go out on a limb here and say that he probably means some kind of super viral virus, and not annoying-yet-super-shareable photos of Grumpy AlienCat.


Evolution might be our strongest ally here. When we initially make contact, it's probable that the space contagions we'd encounter wouldn't know what to do with us. This kind of thing happens on Earth too. That's why a lot of animal diseases don't affect us. It's only when we're in close proximity that our viruses and theirs start to adapt to their potential new hosts. And when they do, boom! You've got an outbreak because we have no immunity to these new maladies. So, it might take a while for Hickman's predictions to come through, which gives us time to start doing research into what alien viruses are most likely to make that leap. The we can start creating the vaccines we'd need. Oh! And an Intergalactic Centers for Disease Control and Prevention would probably be a good idea. I just hope anti-vaxxers aren't a thing in space.

Can you believe it!? They ripped me off again. Humans always overcharge. Image: NASA.


Hickman also worried about having a common currency. How could we trade if we used dollars and aliens used SpaceCoin? We'd have to set up an exchange capable of taking into account fluctuations over time. After all, remittances and payments wouldn't just happen instantly. They could take months or even years to reach their final destination… yes, even with Bitcoin.

Hello, HAL. Please don't kill me. Image: NASA/Wikimedia.

Alien Super AIs

Here on earth, moviemakers constantly bring us superintelligent robots eradicating the human race. But the Terminator might look like Rosie the Robot compared to what we encounter in the great beyond. Scientists like Shostak think that outside our blue planet, the dominant life forms are superintelligent robots. With the ones we cook up, we at least stand the chance of being able to pull the plug. After all, we built them, so we know how they work and how to break them. (Throw some water on the transistors that make up a 'bot brain, and it short-circuits.) Humans 1. Robots 0.


But what about these super-alien robots that Shostak talks about? What's their biology? We'd really have no clue about how they function or what they're capable of. So, the real robo-apocalypse might await us once we venture out of own solar system.

The solution might be kind of meta. Once we collect enough data on these super space AIs (hopefully from afar), we can create a super-big-data AI model to predict how we should interact with them and how best to defeat them. Take that, robots!

Futures Past is a weekly look at the technologies and science that imagined the future, wrong or right. If you've got a tip, email me at Brownie points if you're from the future.


Daniela Hernandez is a senior writer at Fusion. She likes science, robots, pugs, and coffee.