The plane slows down after it lands. Heading to passport control, one of the passengers stops at a vending machine to buy a bottle of soda — but the device is absolutely indifferent to all of their credit cards, cash, coins and everything else. All of that is part of a foreign economy as far as the machine is concerned, and as such, they can’t buy even a droplet of Coke.

The machine would be happy to accept a Mastercard (NYSE 🙂 or Visa (NYSE 🙂 in the real world. The airport cash exchange would also have been happy to help (with a substantial markup). However, in blockchain, this scenario works well for some observers, provided we can swap travelling abroad and move assets from one chain.