Tuesday, April 28, 2015

The Simulation Hypothesis: a Story

Here's the short story, "Copernican Principle," that I wrote after encountering Nick Bostrom's treatment of the simulation hypothesis. It appeared in the March, 2005, issue of Analog.The title comes from my own interpretation of Bostrom's argument -- I think of it as a version of the Copernican Principle, since it relies on the idea that we do not occupy a special place in the universe. And you'll see in the story how that idea gets taken to its logical conclusion...


Robert Scherrer

Professor John Rapaport paced back and forth at the front of his Astronomy 111 class, waving a sheaf of papers in the air.  “Class,” he said, “your performance on the midterm exam was abysmal.  Let me correct a few of your misconceptions: Venus is not a star.  The Sun is a star.  And Pluto is not, repeat not ‘Mickey’s dog.’”
John dropped the exams on the lectern and surveyed the faces of his yawning students.  Mike McNamara snored in the last row, his enormous forearms folded on the desk, his crew-cut head resting on his arms.  Mike had been the football team's star linebacker until that unfortunate incident involving the Chevy dealer.
“Mike, wake up!”
Mike's head shot up.  “Yes, Professor Rapaport?”
“Mike, today we’re going to discuss the Copernican Principle.”  John picked up a green marker and wrote “COPERNICAN PRINCIPLE” on the whiteboard. “What is the Copernican Principle?”
Mike stared, his eyes wide and his mouth gaping – a moose caught in the headlights.  “Uh, I don't remember.”
“Did anyone do the assigned reading?” asked John.  “Paul, please tell me that you did the reading.”
Paul Kresge put down his newspaper, revealing a face covered with metal studs – pierced ears, pierced nose, pierced lips. Did the man set off airport metal detectors?  But at least Paul thought for himself – he was the only one in class who ever challenged anything John said.
“No,” said Paul.  “I thought this week's reading was boring.  I read Chapter 17 instead.”
“Not too smart, Paul,” said John. “Okay, class, I'll just tell you what the Copernican Principle says.  Copernicus showed that the earth is not the center of the universe. The Copernican Principle says that we don't occupy any special place in the universe.”  John sketched a green spiral on the whiteboard and marked an X near the edge.  “For example, the sun is not located at the center of the Galaxy.  It occupies an unremarkable location about two-thirds of the way out from the center.”
“Wait a minute,” said Paul.  “Last week you told us that our galaxy is larger than average.  Doesn't the Copernican Principle mean we should live in an average-sized galaxy?”
John smiled.  “Now you're thinking, Paul.  The Copernican Principle says that the earth should orbit an average star.  We're just as likely to orbit one star as any other –”
“– and the bigger galaxies have more stars,” interrupted Paul, “so we're more likely to find ourselves living in a big galaxy.”
“Exactly!”  said John. “Can anyone think of another application of the Copernican principle?”
An awkward silence filled the room, broken only by the faint ticking of the wall clock above the whiteboard.  Paul raised his hand.  “I've got one for you,” he said.  “I just read about this guy in England who claims that any advanced civilization will make computer simulations that are just like real life.  So if every civilization made a million of these simulations, then the Copernican Principle says that we're more likely to be living inside a computer than in the real world.”
“Well, Paul, you shouldn't push these arguments too far.”
“And what's wrong with my argument?” asked Paul.
“Well, it's just that. . .”  John scratched his head.  “Let me think about it – I'll tell you tomorrow.”

Walt Gustafson slurped a strand of egg noodles in the Chinese dive on High Street where he always met John for lunch on Wednesdays.  “That’s the problem with theoretical types like you,” said Walt, pointing a chopstick at John. “An engineer like me is never going to start believing this kind of nonsense.”
“But how can you prove it?” asked John.
Walt tried to pry open a plastic pouch of hot Chinese mustard with his fingers, gave up, and slit it with a knife.  “Well, for one thing,” said Walt, “if we lived in a computer simulation, these mustard pouches would be a lot easier to open.”
“Be serious,” said John.  “I think the kid's argument is basically right – the Copernican Principle says we’re more likely to be living in a computer simulation than not.”
Walt shrugged.  “Theories should follow reality, not the other way around.”  He cracked open his fortune cookie and pulled out the slip of paper from inside.  “Hey, look at this,” he said.  “It says, ‘The system will be shutting down in five minutes.  Please save your work.’”
“What!” said John.  He lunged across the table and tried to grab the fortune, but Walt pulled it away from his grasp.
“Sheesh,” said Walt.  “I’m just kidding.”  He popped the fortune cookie into his mouth.  “You’re really wound up about this.”
“Well, what if they did shut us down?”
“Let me put your mind at ease,” said Walt.  He slapped the table, rattling the dishes and knocking over a plastic cup.  “There, does that sound like a computer simulation to you?  Ouch, it hurt, too.  That's reality.”
“Or it could just be a very convincing simulation of reality,” said John.
               “Oh, it's going to be hard to convince you, isn't it?  I'll tell you what – suppose I can come up with an argument from the Copernican Principle that's so completely absurd that it shows that the whole idea is preposterous.  Will you give up and stop worrying then?”
“Like what?” asked John.
Walt leaned back in his chair.  “Try this one,” he said.  “Any advanced civilization is going to produce an enormous number of works of fiction.  So the Copernican Principle says that we're actually more likely to be fictional characters than real people.  Now you have to admit that that’s ridiculous.”
John was silent for a moment and then chuckled.  “That’s a good one, Walt.”
Walt laughed.  “And the funniest thing is that when the story ended, we would just disappear – poof!  Now stop worrying and please pass the – ”

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